Natural Truth

Wetlands Fen and Raised Bog Characteristics. Threats and Management

2007-09-07T01:22:00.000-07:00

Fen

Formation and Characteristics
Fens are an integral stage of ecological succession, the initial development of a fen occurs when freshwater fills a depression in the land surface, soon after a pond or lake has developed, vegetation begins to colonise, this is often a reed swamp. The last ice age created vast changes to the landscape, which majorly influenced the formation of new water bodies and flows, by changing land depressions, forming valleys and transporting base minerals.

The water is fed by mineral rich alkaline groundwater; this provides conditions for typical plant species. As the plants build up and die they create layers of dead organic matter. New vegetation grows on top of the older, slightly decaying matter.
Over time the bed of the lake rises with partially decayed plants. The saturated soils reduce aerobic respiration by bacteria and fungi in the soil, reducing decomposition rates and eventually leading to layers of peat with low mineral content.

At this point the fen is regulated and prevented from turning into a bog by the presence of alkaline ground water passing into the fen. If the water source were to change to rainwater instead of groundwater, the fen would soon convert into a bog and a raised bog can grow on. Once the surface of the peat reaches the water surface it becomes a fen.
Too little rain or seasonal dryness allows air to get into the peat, spurring sudden decomposition, alternatively too much water can wash out hydroxide ions and rainwater acidifies the peat, converting the fen to bog.
Fen development is fragile and can be brief once created as succession continues to Carr and eventually woodland, fen can be maintained where removal of willow and alder by grazing occurs and can often merge into marsh in these areas.

Characteristic Plant Species:

Flat sedge
Great fen sedge
Davall's sedge
Dioecious sedge; Brown sedge
Slender sedge
Flea sedge
Common spike rush
Few-flowered spike rush
Slender spike rush
Broad-leaved cotton sedge
Brown bog rush
Meadow thistle

Rare species:

Fen Orchid
Crested buckler

The UK supports a large proportion of fen-land found in Europe, unfortunately fens have declined dramatically over the past century, this is due to several influence factors:

Neglect.
Fens are a stage of ecological succession, without human intervention this habitat would naturally progress to scrub and eventually woodland, drying out in the process.

Loss of habitat from drainage.
Conversion to agriculture and excessive abstraction from aquifers have resulted in a lower water table, subsequently springs and groundwater have a reduced flow and fens do not receive the high water quantities they demand.

Change in water quality.
Abstraction affects the balance of water quality between ground and surface waters, resulting in unstable volumes of chemicals entering the ecosystem and changing the plant community types. This can also occur s from agricultural runoff, (valley fens are increasingly vulnerable to this)

Fragmentation. Continually smaller and more fragmented areas become incredibly vulnerable when several key species are reliant on the habitat.

Fen-lands are dynamic, semi-natural habitats, which require a low level of management (mainly scrub clearance and water level control) to preserve their natural characteristics and to retain an open fen. Fens can support up to 550 different species of plant and in some cases more, they are also an ideal habitat for over half of Britain’s dragonflies, several thousand insects and birds such as bittern, Bearded tit and marsh harrier.

Unsurprisingly most fens have some protective designation, from SSSI/ASSI to the Ramsar Convention and SPA protection from the Birds Directive. Some larger sites are designated NNR and are management with influence from Natural England. Several fen types are listed as priority habitats in the Habitats Directive (transitional mire, poor/rich fen)

Management generally focuses on:

Restoration of fen to favourable condition
Reedbed management – prevent over encroachment of reeds that could lead to succession, this often involves “in water” work and aquatic plant removal with hand tools.
Removal of woody growth can be implemented through mowing and grazing regimes, this prevents invasion of scrub and tree species.
Management of water levels controls how much water enters and leaves the site, ditches, drains and storage sites allow managers of fens to remove excess water or allow more water in when necessary. The careful balance of water levels keeps the habitat in favourable condition.
Fen creation is beginning to occur on former abandoned peat workings, this could allow a slow development of new fens to areas where they have ceased to exist in recent years.
Connection of fragmented fens can occur with the purchase and removal of arable land or forest plantations between two fen sites, these often have extensive drains which could divert water away from the site
Monitoring and surveys continually provide a deeper understanding of fens and their ecosystems, bird surveys, plant/invertebrate transect counts, water quality testing etc.
Species recovery for damaged populations with the fen ecology.

Raised Bog

Formation and Characteristics
These bogs form from vegetation which can survive merely on what is provided by rainwater, the raised bogs develop on already existing fens or reed swamps where the peat built up has become deep to the point where vegetations is no longer influenced by alkaline groundwater and develops a more acidic tolerant layer of vegetation: predominantly species of sphagnum moss.

Layers of the sponge like sphagnum moss can hold up to twenty times its own cellular weight in water, providing water for the next generation of moss. As with other waterlogged soils decomposition is reduced and the layers build up increasing the height of the bog over thousands of years. The older sphagnum directly above the fen is well humified and often present with bog cotton, newer layers of peat are relatively un-humified and quite well intact, fresh vegetation continues to grow on the surface.

Raised bogs do not follow the natural contours of the landscape, instead they can be raised, several metres above the local landscape and seem to be domed across its span. The actual surface of the raised bog is an even pattern of hummocks, hollows and pools that harbour microhabitats.

Typical raised bog characteristics

Water content; Undrained
Solids: Undrained
PH: 3.8 – 6.5
Organic content: 97%
Inorganic content: 3%
Peat depth: average of 7.5m (up to 13 metres)
Annual rainfall: 700-1000mm

Raised bog have declined greatly in recent years with up 94% of natural raised bogs in the UK lost or irreversibly damaged due to the effects of modern life; peat extraction, landfill development, forestry, drainage, pollution, dereliction after previous disruption poor livestock management, built development, atmospheric nitrogen deposition and climate change all contribute to bog destruction and continue to do so.

The mosaic of pools, hummocks and lawns provides habitat a for a variety of flora occurring in micro-habitats, though mostly dominated by sphagnum moss’, undisturbed raised bog surfaces can support species of cross leaved heath, ling, cotton-grass, deer-grass, and sun dews. These tolerant species in waterlogged soils provide a habitat ideal for waders or wildfowl such as Curlew, Hen harrier, Meadow pipit, Skylark and Snipe, invertebrates and other species. The unique wildlife value of raised bogs raises their conservational importance and this has been internationally recognised, as this habitat is now a priority in the UKBAP.

Most bogs are designated or are the process of being designated (SSSI, SAC, SPA, NNR etc) this works to prevent further decline of the habitat. The active management on raised bogs is limited as even slight disturbance, can permanently damage this fragile ecosystem.

Natural Primary Bogs are defined as being sites, which have only received natural disturbance and have reached a natural climatic phase of raised bog. The layered make up of raised bogs has developed over thousands of years to reach this stage, peat removed for whatever use, is irreplaceable.

Raised bogs are affected by three main factors:

Increasing rate of water loss.
A loss of water will result in drying of the bog, accelerated decomposition and shrinking. Managers of bogs need to work towards providing a stable water table and prevent land drainage where it will affect bogs.

Increases in nutrient status.
Nutrient drift or runoff can effect competition between bog species; increased nutrients unbalance the ecosystem, favouring other species over the developed acidic loving plants of a bog. Nutrients can come from fertiliser, pesticide/herbicide, pollutants etc and get into the bogs hydrological cycle.

Loss of vegetation as a natural regulator of water retention.
Raised bogs depend on the layers of living sphagnum to hold water and keep the site continually wet. This is how raised bogs can regularly be higher than the local water table. A loss of this vegetation means water will not be held and the site will eventually dry out, as vegetation becomes less.

Degraded raised bog habitats, occur when active peat formation ceases, this is when no more layers of vegetation are being put down and growth of peat forming vegetation has disappeared. Despite the cease in formation, these sites have an opportunity for restoration with some very careful, long-term management.

If degradation occurs as a result of local forestry and the installation of drains diverting water away from the local hydrological cycle, then removal of trees and blocking of drains could re-wet the site and sphagnum growth may resume. The slow growth of sphagnum makes it very difficult to monitor the success of a rewetting program.

Some species associated with raised bog:

Dragonflies
Emerald Damselfly
Large Red Damselfly
Blue-tailed Damselfly
Common Blue Damselfly
Variable Damselfly
Azure Damselfly
Irish Damselfly
Common Hawker
Four-spotted Chaser
Common Darter
Black Darter

Moths
Beautiful Yellow Underwing
Bordered Grey
Common Heath
Drinker
Emperor moth
Fox moth
Grass wave
Northern Eggar
Puss moth
Scallop shell
Wood tiger

References:
http://www.ukbap.org.uk/UKPlans.aspx?ID=18
http://www.raisedbogrestoration.ie/about/default.asp
http://www.peatlandsni.gov.uk
http://en.wikipedia.org/wiki/Fen
http://www.bnm.ie/files/20061124040538_raised_bogs.pdf.
http://www.greatfen.org.uk/about-management.php

Wetland: Types and General Management Considerations

2007-09-07T01:01:00.000-07:00

A wetland is defined as being an area of land where the water table never, drops below 15cm from the surface or exceeds 6 metres depth above the surface of the land. The British climate is suitable for sustaining wetland habitats though climate change could lead to a reduction in habitat size. There are several wetland types and habitats vary even within the habitat. There are six main wetland habitats.

Wetland Types

Marsh
Marshes are often dominated by grasses rushes and sedges, they occur near lakes and rivers where the water table is predominantly high and close to, but rarely above, the surface. Marshes do not contain a layer of peat and are composed on mineral soils. Marshes can be fresh or salt water.

Reed Swamp
Reedbeds/swamps are wetlands dominated by stands of the Common Reed (Phragmites australis), it occurs on mineral soils where the water table is at, or above ground level for most of the year Reed swamps are amongst the most important habitats for birds in the UK, despite this they are largely fragmented.

Wet Meadow
Wet meadows are similar to marshes but receive seasonal flooding rather than continual, this often results is more dominant grasses. They often occur in poorly drained areas such as shallow lake basins, low-lying farmland, and the land between shallow marshes and upland areas.

Fen
Fens develop on alkaline, mineral rich soils, vegetation builds (sedges, grasses and rushes) up and when the plants die, they become caught in amongst the other vegetation, forming layer after layer of dead organic matter, the built up DOA and water saturated soils prevent/ delay the decaying process and eventually peat forms.

Carr
A Carr is a transition to woodland, it is part of the process of ecological succession occurring when the area has developed to being dominated by alder or willows, this succession will continue until the area becomes dry and a new succession will occur.

Bog
A bog is characterised as being an acid mire, vegetation accumulated in waterlogged soils due to a lack of oxygen required for aerobic decomposition. As a result peat accumulates, bogs can accumulate metres and metres of peat in one site, though this forms over thousands of years.
Bogs can be split into different types:

Ombrogenous Mires
These are created by extensive rainfall and rely on a reasonably wet climate to survive as all water replenishment comes from the atmosphere.

There are two forms of ombrogenous mire: blanket bog and raised bog. Blanket bog is so called because its development is mostly independent of basins or topographical features where water collects; it simply covers the landscape like a blanket. Raised bogs develop from a basin or dip in the land where rainwater collects into and builds up layers until the peat sits above the surrounding land.

Topogenous Mires
These are dependant on the formation of the land for existence they are influenced by topography and receive relief water from drainage and seepage. Water rarely comes above the surface or falls far below. Valley bogs receive a flow of water wick keeps the bog continually wet. Basin bogs have no flow of water and water seeps out slowly or evaporates in the basin.

Soligenous Mires
Here the wetness of the ground is maintained by slow lateral gravitational seepage of water through the substrate or the peat. Topography is still the main determining factor but the high water table results not from the concentration of water as in a topogenous mire, but by a sustained, slow flow through the site; usually along some definable drainage or seepage line. As the moving water flowing through the substrate is more oxygenated and hence decomposition is more effective in soligenous mire sites, the depth of peat accumulation is usually less than in topogenous mires, although there are considerable similarities in peat types

Factors Important to the Management of Wetlands
Wetlands are a varied set of habitats with waterlogged soils for some part of the year, the extent of the water-logging varies from habitat to habits and often they overlap and appear in close proximity of each other. Wetlands provide habitat, food, cover for a huge range of invertebrates, wildfowl and waders and so many wetlands are subsequently identified and protected under designation of Ramsar or SPA to prevent decline and work towards improving the quality of the habitat. These important species co-exist with (and often rely upon) specific vegetation present within the community typical to waterlogged soils.

The species found on the wetland should influence the management of the site for example; if wildfowl are present manage for the benefit of waders, who are dependant on winter flooding for feeding opportunities. If waders are present manage for waders etc. In the interest of diversifying a wetland, a mosaic of flooded and non-flooded provides benefits to a wider variety of species.

We have already established that wetlands rely on regular water logging to sustain the habitat; centuries of land drainage have contributed to the loss of wetland sites and their current conservational importance. Any alterations to the habitat will effective the competitive balance between plant species and sudden change could lead to a change of habitat rather rapidly.
The water table should not be altered by draining, or diversion of water into the site from the surrounding area.

Most wetlands rely upon the low nutrient availability that accompanies waterlogged soils; enrichment from agriculture could lead to domination of fewer more competitive species rather than a diverse, rich community that can thrive on low nutrients. This means that no fertilisers, slurry or manure should be used where it can drain into wetlands and pesticide spray must occur away from wetland and surface surrounding it.

Scrub needs to be managed to prevent encroachment and succession towards a climax community, grazing in certain seasons provide vegetation management as well as the removal of nutrients.

Trees and hedges planted near wetlands consume much larger amounts of water and also increase transpiration rates, reducing water and leading to dryer, more successive areas. The seeding of trees and hedges encroaches in to the wet areas and lays down deep layers of litter annually.

Reference:
http://www.envf.port.ac.uk/geog/teaching/ecol/b6notes.htm
http://www.sac.ac.uk/mainrep/pdfs/tn519wetlandswildlife.pdf.

Water. Management, Supply and Demand

2007-09-07T00:49:00.000-07:00

Water
Water is an essential component of nearly all life on earth, plants require it for essential functions as do birds, insects, fish, mammals, fungi, bacteria etc.

70% of the earth is covered in water, however only a mere 2.5% of this if freshwater the rest is saltwater in seas and oceans: only 1% of freshwater is actually accessible for direct human use and demand often exceeds sustainable volumes.

There are increasing concerns regarding the sustainability of water across the globe, especially with prolonged reduced levels of precipitation causing droughts in many areas.

Supply
Water is supplied to homes and businesses through water companies; they are responsible for abstraction, distribution and treatment some also deal with sewage treatment as well as returning water to the environment. There are over 20 water companies supplying water to England and Wales but only one company for Scotland and one for Northern Island. The water supplies come from two sources, surface water and ground water and are greatly effected by the levels of rainfall in a particular area, in areas with low annual rainfall rates, stronger measures must be taken to make sure water is available through, water resources plans, drought plans and water efficiency plans.

Surface water is channeled off from fallen rainwater, instead of running into rivers and streams and back into the hydrological cycle it is directed onto storage reservoirs. The reservoirs can hold vast volumes of water for long periods of time, this means that water can be collected during the winter in times of high precipitation and stored until needed during dryer summer weather conditions.

Groundwater comes from underground natural reservoirs known as aquifers, this is where water has managed to penetrate through fractures and pores in geological formations. Naturally the water is released out from the aquifer in the form of springs or rise to the surface creating wetlands. Groundwater is abstracted through the use of wells, which are put in place to actively pump the water up and out. Groundwater is naturally replenished by rainwater but water companies have taken to the habit of artificially re-filling aquifers as a means of storage.

Before water is distributed out to the public it goes through a series of treatments, these are designed to provide users with clean healthy water suitable for a range of needs. Firstly the water is put through a range of processes to remove suspended solids such as clay silts, soils and metal oxides as well as and micro-organisms, this is done by passing the water through fine meshes or the addition coagulants which bind the particles making them easier to remove.

To make water suitable for drinking it needs to possesses some particular chemical properties, oxygen needs to be present some groundwater may be very low in dissolved oxygen and would subsequently be passed through a cascading structure which allows for oxygen to get trapped and dissolve into the water. The pH is also checked and adjusted if too acidic or alkaline as either extreme can cause problems to plumbing and pipes, it can also have an adverse effect on human health. The original pH of the water before treatment will be dependent on its source and the level of adjustment dependent on its intended use.

Finally before water can leaves the treatment center it must be disinfected, this final process removes the last traces of pathogens and means that water is clean through its journey until its use. There are several products used to do this though it is treatment with chlorine tends to be the most popular and effective.

Water consumption is an ever-increasing problem for water providers, the growth of industry and agriculture in the last century demands massive volumes of water each day and so do the millions of washing machines, dishwashers, baths, toilets and hosepipe found in most households today.

Demand
Population size is the main contributing factor to increased demand for water people across the globe already account for the use of 54% of all accessible fresh water on the planet. This is estimated to increase to 70% by 2025 based on population growth alone. The effects of this will be drastic to other species depriving them of access to water, which is as important to their survival as it is to ours.

Water consumption is divided into three main categories, agriculture, industry and domestic use, with agriculture having by far the largest water requirements globally.

Global water consumption distribution:

69% - Agriculture
23% - Industry
8% - Domestic

However distribution varies in different regions and large difference occur between developed and lesser-developed countries, for example:

Africa

88% - Agriculture
7% - Domestic
5% - Industry

Europe

54% - Industry
33% - Agriculture
13% - Domestic

Agriculture causes several problems when it comes to water consumption, large quantities of water are needed for the regular irrigation of crops, the crops are needed to meet demand from the public and pressure on successful production of crops is high. Competition for business in the agricultural sector is high due to strong competition from cheap over-seas exporters; this encourages producers to use excessive amounts of water to increase productivity.

Water used for agriculture is not only removed from the natural water cycle but can create potential pollution problems with the introduction of chemicals back into the water cycle from surface water runoff and groundwater leaching. Nitrates, phosphates and sulphates are all produced naturally by grazing livestock urine and faeces and are commonly found in fertilisers and pest/herbicides; these can easily build up in local waterways and wetlands.

These compounds are essential to supporting plant and aquatic life but high levels can be dangerous, nitrogen encourages dramatic growth of algae species, which then starve other species of light and oxygen. The result of this process known as dentrification is a decline in habitat quality and subsequently a reduction in population and community size as well as the dominance of aggressive invasive plant species.

The use of water in industry has a strong impact on the environment, when we speak of industry we are referring to the production of goods for economic gain. The term industry covers many sectors of production including food and drink production, chemical production, fuel production, paper production and household waste incineration etc. increases in population size and the growth of consumerism attitudes by developed society have lead to an increased demand for millions of products.

The production of products in industry uses large amounts of water daily, nearly every product in the world will use water at some stage, this could be through fabricating, processing, washing, diluting, cooling, or transporting a product; incorporating water into a product; or for sanitation needs within the manufacturing facility.

Industry not only consumes vast quantities of water daily but the bi-products produced in many of these processes can cause severe harm to the environment. Industrial facilities are most commonly recognised by plumes of dark smoke billowing from tall chimneys, this smoke contains many hazardous chemicals such as Sulphur Dioxide (SO2), Carbon Monoxide (CO),
and Nitrogen Dioxide (NO2) as well as many hydrocarbons, heavy metals and toxic organic micro-pollutants. These substances are absorbed by water molecules in the atmosphere and enter water systems through precipitation making, the water is then either cycled through waterways and wetlands or abstracted for human consumption; the polluted water requires heavier treatment and damages natural habitats.

Although domestic consumption of water by volume is far less than agriculture and industry on a global scale, it accounts for high levels of wasted water in local communities. The availability of fresh, clean and hot water on demand has reduced societies appreciation for this essential, life sustaining resource. In areas of high levels of rainfall or areas low on the water table this is not so much of a problem as water is constantly renewed and replenished and there is plenty to meet demand. However in dryer areas, water wastage can be a big problem leading to hose pipe bans and drought situations; normally when there is most need of water.

Wastewater produced by households creates problems of its own, sewage treatments are responsible for treating wastewater to a state where it can be released back into the water cycle. Wastewater is categorised as being either “sullage” (baths, basins, washing machines etc) or “foul waste” (sewage) for water from toilets.

Sewage treatment involves separating water from organic and inorganic material that has been flushed down a toilet, as with livestock earlier human urine and faeces contain high concentrations of ammonium, nitrate and phosphorous, which are damaging to the environment if exposed in the quantities that are produced daily. To be able make the water acceptable for release into rivers, streams and wetlands or for use in groundwater replenishment it must go through a long process of intensive filtrations, chemical treatments and biological treatments; treated water is finally released back into the water cycle.

Main effects of water abstraction from freshwater habitats
The Problems associated with abstraction of water are broad and effect all walks of life, habitats, environments and local and national communities are all affected by possible results of regularly removing large volumes of water from a single source. Over thousands of years the flow and cycle of water has established its own courses and has been a major influence in the success of many habitats heavily influenced by the water flowing through the land. Freshwater in rivers and streams is an important habitat for many species of plant, insect, amphibian, mammal and bird and if its primary requirement for existence (freshwater) is reduced or lost because of abstraction there are going to be significant consequences.

Reduction in habitat size and loss of habitat severely reduces the population density of a species; many species require a certain amount of space or territory to survive. If that space is reduced species will either migrate to another site or if they cannot will probably suffer decline due to over competition for food and a reduction in resources. A reduction in habitat also removes essential cover for predated species making them easier to target, predator species would soon take advantage of the prey’s vulnerable situation and ultimately species could suffer heavy losses.

A reduction of freshwater to a site reduces the waterways effectiveness for self-cleansing and this allows chemicals to build up changing the chemical composition of the water and reducing the suitability of the habitat for a range of species. This change will either result in migration of species or for those who are unable to migrate, most probably death from over contamination. Each species has its own tolerance levels to pollution but even the loss of one species from pollution can have resonating effects throughout this unstable environment.

Groundwater abstraction from aquifers poses some new problems for humans and the environment. Removal of large volumes of water from underground has effects on the local water table and other wells may not be deep enough to reach the lower table and a drop in supply. This reduction in water can also have harsh effects on wetlands that are used to high saturation levels, which become dryer and attract less species of insect and bird, the loss of wetland habitat leads to reduced conservation interest and eventually the land could be completely lost to housing or industry development.

The pumping of groundwater exerts downward pressure onto the surface layers of rock and sediment causing them to compress and lower. Lowering of land can lead to regions sinking to below the water table, increasing the likelihood of flood in the future. The effects to the environment in such a situation would be harsh, areas previously dry are subject to high levels of water saturation, many plant species would be unable to cope with the sudden change in environment and their decline would be felt through the food chain.

The water found in aquifers sits in the pores of rocks helping to stabilise the structure and supports some of the weight from overlying rock, the removal of water and its support can lead to subsidence and sinkholes when the upper rock layers collapse under increased pressure.
In some cases, identified aquifers may have taken thousands of years to reach their currant state with water flowing in to the area slowly or unreliably, the abstraction off water from these sites is a non sustainable resources with very limited supply.

Main effects of pollution to freshwater habitats
Pollution occurs when water is released back into a waterway after abstraction, use and treatment, even though the water has been treated three are still traces of pollutants or higher levels of nutrients than would naturally be present in the water.

Water treatment facilities are monitored by the Environment Agency and have to abide by strict regulations on the quality of water they emit, despite this there is always going to be traces of some substances in water that are higher than they should be and even a slight change in chemical composition or pH can lead to changes within a habitat. General water quality and waterway management has improved in certain areas in recent years especially when water companies make efforts to create and action Biodiversity Action Plans. (BAP)

Anglian Water is one of the largest water providers and treatment facilities in England, providing water to over 4 million people and managing thousands of kilometres of rivers, this company is making efforts towards improving the quality of freshwater habitats both for the environment and recreation in several ways. Anglian Water is currently delivering a 10-year BAP as well of introduction of two new species as part of Water for Wildlife (a project with the Environment Agency and the Wildlife Trusts focused on wetland habitat and species action on the ground). Surveys carried out by the Environment Agency show improvements in the water quality managed by Anglian Water.

Another source of pollution is from the use of water in agriculture and industry. Surface runoff and ground water leaching transport chemicals on and in the soil and into freshwater sites. As discussed earlier the chemicals from livestock waste and fertiliser can damage freshwater habitats by allowing nutrient build up. Runoff and leaching also transport pesticides and herbicides used in modern agriculture directly into the water. These chemicals are designed to kill and impair, they are essentially a poison and can cause the death of flora and fauna in and around the site.

References
http://en.wikipedia.org/wiki/Groundwater
http://www.aeat.co.uk/netcen/airqual/kinetics/#hc
http://www.water-guide.org.uk/companies.html
http://www.anglianwater.co.uk
http://www.globalchange.umich.edu

Heathland Development and Ecology

2007-09-05T04:04:00.000-07:00

The lowland heath that is present today across Britain and Europe has evolved as a result of climate change and historical human management, the development of agriculture and land use has effected the vegetation and habitat of lowland heath throughout the ages, affecting both establishment and decline.

Influence of Humans
The first signs of heathland came with the retraction of ice sheets at the end of the last ice age, approximately 14,000 years ago tundra type of vegetation began to establish as ice melted and moved, over the next 4,000 years these species developed and spread over Britain and Europe. Tundra vegetation is typically low and slow growing having adapted to survive the harshest and most hostile of conditions, these characteristics can still be seen today in some heathland plants although adaptations to new climates and soils has changed the vegetation significantly.

As the climate continued to warm new species emerged and the landscape of Britain quickly changed, from 10,000 – 6,000 BP the domination and succession of vegetation to forest over-competed with heath vegetation and soon most of Britain was covered in dense forest; lower growing species were shaded out and only existed in open glades and woodland margins.

The birth of heathlands came during Neolithic times (6,000 – 4,000 BP), Neolithic man turned away from hunter-gatherer survival and began the domestication of plants and animals which lead to management of land and the beginnings of agriculture. During this time large areas of forest and woodland were cleared, most probably by the use of fire, as technology had not yet developed tools suitable for large-scale tree clearance.

The cleared land was used for growing crops for food, in the early days of agriculture man did not have the knowledge to be able to sustain crop growth and so every 20-25 years the soil would be depleted of nutrients and farmers were forced to move to another area and begin the process anew.

The land now became open to succession with the desertion of agriculture and trees began to re-establish, if the area were totally neglected succession would continue to permanent woodland cover. In other cases the land was used to graze livestock such as cattle, sheep and pigs; this prevented the dominance of tree species and allowed for heathland species to establish. Grazing by livestock is a key contributor to the development of heathlands, as we know them today.

By the start of the Bronze Age heathlands had become well established, the growth of population and immigration of people from Europe changed the way that people were living. Human settlements started to appear on more nutrient rich grounds and the development of agriculture there showed a higher productivity and yield of crops than on the previously farmed nutrient poor soils of the Neolithic times. The abandonment of heathland allowed for further domination by heath species.

Despite their reduced popularity, heathlands were still utilised by local people for the resources they could provide and the small scale, low impact management continued to encourage specialised species to develop.

Heathland management continued with little change until the start of the 17th century, by this time much technological advancement allowed for agricultural improvement to take place on barren lands. The enclosure of common lands by the authority of Acts of Parliament in the 17th and 18th Centuries allowed farmers to further develop fields systems and improve agricultural management,

This meant that “waste areas” such as heathlands could now be used for development and reclamation. This lead to a national decline as land is reclaimed for agriculture or abandoned as it became easier to transport and purchase goods rather than self produce, in which case succession to woodland began.

The industrial revolution saw dramatic decline to heathland, as thousands of hectares were lost to other forms of management and industrial growth. Increased agriculture and forestry as well as large-scale extraction of sand and gravel only added to the reduction of lowland heath habitats.

Of all the heathland habitats present in Britain in1800, only 18% still exists today.

The heathland landscape was considered of little importance or interest to the growing economic society that thrived after the industrial revolution, however it was an ideal setting for military manoeuvres and army camps took up residence on heathlands from the late 18th century. Evidence of this can still be seen of this all over lowland Britain today as many of the military stations have continued to exist and grow on heathland sites.

Today heathland is of significant conservational importance due to its decline and continued threat from human activities. Most are now designated SSSI or SAC with some also coming under SPA designation if certain birds are present at the site.

Heathland sites are now more fragmented than ever with small-localised habitats, 82% of all sites designated are considered as being in unfavourable condition. Heathland is a key issue in conservation today and its future hangs in the balance, and it may already be too late as only 58,000 ha exist today in the UK and most of these are in very poor condition. However the Biodiversity Action Plan (BAP) aims to improve existing sites and establish a further 6,000 ha of heathland in lowland Britain.

The Physical Environment
Lowland heath has developed as result of human interference; its survival has also depended on several physical factors that have contributed to its current status. Heathland is restricted by climate, despite it frequenting well drained soils it cannot thrive on continental climates with dry summers and cold winters as water availability is just too low, preferring a more moist “oceanic” climate, of which Britain is ideal. The high precipitation levels in the UK allow heathland to continue and strengthen.

Lowland heath predominantly occurs on acidic, free-draining, sandy soils with poor nutrient availability. The underlying geology varies but in the south and east, heathland soils sit upon sands and gravels and sometimes clays: E.g. heathland found in the Thames Basin is made up of tertiary sands over London clay. The presence of clay can help to trap water, creating microhabitats within the heath and increased moisture spurs an increase in species diversity especially with regard to invertebrates. Although heathland may seem uniform and similar in appearance, variation in geology and soils produces different habitats and communities.

There are three types of heathland, wet, dry and humid; wet heath occurs in areas where the water table is predominantly high throughout the site and water is readily available, dry heath occurs on very well drained soils and underlying rock formations and thus the water table remains consistently low. Humid heath is an intermediate of the two, experiencing both wet and dry conditions throughout the year.

Topography varies from one heathland to another, though predominantly rolling hills and varied mounds and valleys seem to provide the most opportune structure for varied wildlife. The hilly landscape creates high and low points with continual erosion of unstable loose sand deposits on the slope; this helps new species to develop and provides ideal conditions for some specialised species that require base open ground.

Hills and valleys also allow minerals to be washed down from higher ground, possibly creating podzols and iron pans: areas capable of containing water, increasing the diversity of the habitat. Another factor that arises from varied slopes is the amount of light and shade varies depending on which face faces south, this allows for very different types of vegetation to occur in close proximity to one another. Although there is often a lot of slope on lowland heath it can also experience areas of very flat terrain, and even in the hillier areas there it does not compare to the heathland of highland Britain that occurs at high altitudes and on much larger, steeper slopes.

Plants and Animals
Vegetation
Lowland heaths are dominated by the presence of ling heather (Calluna vulgaris); this is the most common heathland plant and is the sole species of its Genus. Ling is a small perennial shrub growing 20-50cm tall. Small scale like leaves have adapted to conserve moisture and reduce transpiration rates. The roots spread radially to absorb moisture quickly and the evergreen leaves allow the plant to produce food all year round. Ling heather also benefits from a symbiotic relationship with mycorrhiza in which the plant is aided with nutrient absorption and the fungi receive sugars.

Ling has developed and adapted to withstand fire, a popular historical form of management and one still practiced today, its ability to withstand controlled fire conditions and show positive regeneration afterwards has contributed to its success on heathlands. The seeds can lay dormant for many years in the soil and fire open up the area to light allowing new growth to commence.

Ling heather is a valuable food resource for a wide range of species including sheep, deer, grouse, heather beetle and the larvae of numerous species of Lepidoptera.

Ling is also accompanied often by Bell Heather (Erica cinerea) a low growing shrub with needle like leaves. It is less woody and more slender than Ling and often uses other heathers and gorse for support and grow tall in close proximity with higher vegetation. Bell Heather forms dense uniformed swards and accompanies other heathers in providing food and protection for heathland animals.

Common Gorse (Ulex europaeus) is a spiny evergreen shrub that can reach up to 2 meters, the stem is hairy and leaves have adapted to low water availability by tuning to spines, which reduce water loss rates. Common Gorse is also a fire climax plant; it burns easily but regenerates well from the roots after a fire.

The bright yellow flowers bloom in mid summer attracting hundreds of invertebrates to feed on the sweet nectar; the plant emits a sweet coconut-like fragrance to attract insects. Stonechats (Saxicola torquata) use the higher branches to sing and Dartford Warblers (Sylvia undata) are attracted by the abundance of insects and will nest when gorse occurs in dense growth with heather. In the south of England you will also find Dwarf Gorse (Ulex minor), which as its name suggests is much smaller than Common Gorse, reaching up to a metre tall.

Invertebrates
5,000 species of invertebrate occur on heathland in the UK, with a variety of butterflies, wasps, bees, beetles, spiders and ants. Digger wasps and solitary bees are common to heathland because of the patches of open sandy ground that occurs throughout.

Sand wasps (Bembix spp) construct tunnels in bare patches of ground in which they lay their eggs, the tunnels are then sealed stocked with food (normally spiders or caterpillars but dependant on prey species choice) which is eaten when the eggs hatch.

Potter Wasps (of which there are over 200 Genera but are most often considered to be of the Subfamily: Eumeninae), construct pots from the soil which they stick to heather branches. The pots are filled with eggs and paralysed prey and then sealed.

The Silver Studded Blue Butterfly (Plebeius argus) is a common inhabitant of heathlands, feeding on ling, Bell Heather and Gorses. Males display bright silvery-blue wings, whilst the females are a dimmer brownish hue, both sexes display the characteristic metallic spots on the hind wing that the species is known for. The butterflies rely on short, sparse vegetation and prefer the open canopy of recently burnt heath.

Birds
Heathland provides food and shelter for both migratory and native birds; there are several species of particular association with heathland over other habitats. Nightjars (Caprimulgus europaeus), are African migratory birds that arrive in spring to nest, they inhabit lowland heaths as well as open woodland and young conifer plantations: theses birds prefer open patches of heath and the small clearings that occur there.

Both sexes are well camouflaged for ground nesting, displaying mottled grey to brown hues, the body is sleek and pointed and well adapted to hunting prey on the wing. Nightjars feed at dusk, dining on the abundant invertebrates that arrive on heathlands over the warmer months.

A popular bird of lowland heath is the Dartford warbler (Sylvia undata), it has suffered decline in past years but populations are slowly begging to rise again with the milder winters that Britain has been experiencing and designative protection from the government (however still confined to southern heaths).

Dartford warblers are small birds with long tails, the coats are brown above with pink below and the both sexes have similar coats with the male exhibiting brighter shades. Most warblers fly to Africa in the autumn, Dartfords survive from the protection provided by dense stands of evergreen heather and gorse, the vegetation provides a barrier from snow, rain and cold winds and the canopy is inhabited by enough insects to make survival possible.

These birds benefit from managed heath with varied ages of stands providing continual protection.

Stonechats (Saxicola torquata) though not restricted to heathland, are frequent inhabitants nesting in dense patches of gorse and heather. The males also require higher local vegetation on which to sit and call this is normally an upper gorse or scrub branch. This species benefits from some scrub present and feeds on fruits as well as insects.

Reptiles
Heathlands can be home to all six native species of reptile, four of them can be found in other habitats around the country, but two species are restricted to heathland and its surrounding boarders.

The Smooth Snake (Coronala austriaca) is a pretty rare species found only in the lowland heath of Dorset, Hampshire and Surrey. The skin is a camouflaged grey-brown colour with two rows of small, dark markings don the length of the body. Smooth snakes grow to 60-70cm long and feed on other heathland reptiles such as common lizards (Lacerta (zootoca) vivipara) and slow worms (Anguis fragilis), as well as small mammals. These snakes will bite to protect themselves but have no venom: they predate through constriction. Smooth snakes rely utterly upon well-managed, mature heathland with plenty of hiding places in which to sun itself.

Sand Lizards (Lacerta agilis) are another heathland dependant and are scarce in the UK occupying small areas in Dorset, Hampshire, Surrey and Lancashire. Their survival is closely linked to managed heathland especially where bare patches of sand are created, on which they can dig tunnels for their eggs. The eggs remain buried for several months and the open sand helps to keep the eggs warm. Sand lizards are distinctively stockier than the common lizard with a deep short head and bulkier frame. Both sexes are marked with a mix of black, brown and cream spots running down the back, in spring males are bright green whilst females remain a pale brown, sandy colour.

References:
http://www.butterfly-conservation.org/species/bdata/butterfly.php?code=sib
http://www.dorsetforyou.com/index.jsp?articleid=336264
http://www.surreycc.gov.uk
http://home.freeuk.com/offwell/whatis.htm
http://www.ukbap.org.uk/ukplans.aspx?ID=15
http://www.surreyheath.gov.uk/tourism/AboutSurreyHeath/heritage.htm#camberley
http://www.wildlifetrust.org.uk/cheshire/heathland.html
http://www.countrysideinfo.co.uk/historic.htm

River Pollution

2007-09-05T03:49:00.000-07:00

Rivers are an important part of our landscape; they distribute water all over the country and provide a habitat for wildlife. Over history they have been an essential factor in the survival and growth of man, providing water, food, transport, power and more recently for disposing of waste! Without the presence of rivers our country would be a very different place.

Today they are highly valued for their beauty and attract much tourism. Pollution threatens to spoil and damage the rivers and streams that have been such a large resource to us. Pollution can occur in rivers from various sources. It could come about from direct disposal, surface run off, groundwater drainage, side streams, other water sources and acid rain. All these fall into two general types of pollution direct and indirect. Direct comes from pollution being directly deposited into the water and indirect entering the water from soils and rain runoff from land.

Agriculture has a large role to play in river pollution and as it covers a large part of the country has a lot of influence on how clean rivers can be kept. Farmers will often keep livestock on fields near rivers, of which cattle are most relevant regarding water pollution. The manure passed from these animals washes of the surface of the soil and into the river, as the manure breaks down nutrients leach into the river through ground water. This manure or “silage” is a strong pollutant that can have a massive effect on the quality of the surrounding water and give rise to environmental issues.

Manure produces certain chemicals, some of which are essential to life in a river. The quantities of these chemicals need to be a certain level to sustain a healthy ecosystem; the excessive amounts of these nutrients that manure provides are far too much for a river to cope with.

Nitrates, phosphates and sulphates are all released from manure, they are essential plant nutrients and once in the water will soon cause an abundance of growth in aquatic plants. This excessive growth causes problems for wildlife species that use the river for food, shelter etc. The flow of the river is reduced and as organic matter dies the bed becomes shallower increasing the chances of flood.

In these situations biodiversity is reduced but the overall biomass of the water can be increased this is because only a few species dominate but they are extremely abundant and numerous.

The chemicals not on only increase vegetation but effect species of fish, invertebrates and aquatic mammals that live in or around the river. Each species has its own tolerance levels of nutrients in water, but the numbers of species that can survive in a polluted river decreases as these nutrient levels continue to increase.

Chemical pesticides can have a more direct relationship with pollution simply from the fact that they have direct killing power, this means that certain species who absorb or consume the pesticide will die. This is different to chemicals altering the properties of water, which results in a change of habitat and life in the river. The sudden death of any organisms within the river ecosystem will have a direct impact on other species in the community, through loss of shelter or food. The use of these pesticides also increases the nutrient levels in the water with the same effect as with manure.

Disposal of domestic waste combines both these pollutants with human excrement and grey water from washing machines, baths, sinks etc. Although these waste products are treated there is still high levels of pollutants in the water that is released into rivers by sewage companies. Industry waste dumps massive amounts of chemicals and poisons into rivers regularly which poison and destroy aquatic life.

When fossil fuels are burnt they release sulphur dioxide into the atmosphere, which are absorbed by clouds and falls to the earth as rain. The rain enters the river directly and through soil run off and leaching. The sudden decrease in pH can kill fish and invertebrates and cause the water to be unsuitable for many species. There are few species that tolerate water with a pH lower than 5.

Once the pollution has entered the river it is hard to control, it quickly spreads with the movement of the water to other rivers, streams lakes and ponds. This movement, despite spreading the pollution to other areas is what helps rivers to cleanse themselves. Because of the constant distribution of fresh water the pollution gets diluted and dispersed, lessening its impact on particular areas. Rivers with water falls get a lot more oxygen into the water supply, the oxygen is used by aerobic bacteria to break down dead organic matter, this helps the river to disperse nutrients and clutter on the bed.

If the same levels of pollution were deposited into a still body of water the nutrient levels would rise continuously and provide a habitat suitable only for the most hardy of creatures, such as rat tailed maggots and sludge worms if any life at all.

Ponds and rivers have very different reactions to the same pollutants, pond require a much higher degree of management in relation to pollution due to their ‘closed’ nature, pollution can only be diluted by rainfall or from directed ditches and channels. It cannot cleanse itself through water flow.

Pond and lakes are a much more stable environment because of the lack of flow, plants and animal life can establish and develop easily. In a fast flowing river aquatic life can be reduced to bottom dwelling creatures living in the silt and stones because the force on anything higher is too much for many plants to take root. For this reason changes in nutrient level from pollution can be far more devastating in ponds than in rivers and streams.

In polluted pond water the vegetation ‘blooms’ chocking off oxygen to other species in the water, this unbalances the ecosystem and reduces the ability for diversity, algae blooms dominate shutting out light and consuming lots of oxygen, the growth gets to a point where the water can no longer sustain it and the algae production collapses, this damages the ecosystem even more by sinking to the bottom and building up a layer of organic matter. The reduced oxygen in the water means bacteria and fungi cannot break down the matter and the depth of the pond decreases. Constant pollution accelerates eutrophication resulting in the succession to land with no aquatic life left.

Algae blooms cannot build up in rivers due to the flow, but can in slower parts of the river or small pool off the river, when the matter dies it is more likely to be washed away and distributed more evenly over a wider scale. Lessening the impact of silt build up.

Ponds and rivers can also be affected by oil runoff from roads; the oil creates a film over the surface of the water. In a pond this layer will sit and spread evenly over the surface preventing oxygen dependant species from surfacing to breath resulting in death and reduced diversity. Larva living in the water will not be able to emerge reducing populations for the season; this will affect other species that feed on them by reducing a resource. This causes whole population to dip and without water cleansing disappear from the site all together. In rivers the oil would flow down the course and be deposited in pools and ponds attached creating problems in unique habitats that survive along side the river. The main body of flowing water often recovers well from pollution but at the cost of other habitats.

Another area where flow helps to cleanse pollution is where suspended soils hang in the water, in ponds where water remains generally still, organic matter and clays from surface runoff sit in the water reducing light to vegetation and damaging animals by clogging and chocking breathing and feeding mechanisms. In rivers these soils cannot be suspended but move with the flow and are deposited along the bed and banks when the water slows.

Generally the water in a river can cope well with pollution but the vegetation and land around the river suffers as pollutants are deposited there. These bank sides are vital habitats for many birds, insects and aquatic mammals. When the soil around the water is rich in nutrients, it tends to be dominated by only a few invasive species such as Himalayan balsam, which quickly spreads along the watercourse, out competing species more valuable to wildlife.

The presence of waterfalls and increased gradients along river help with the cleansing process through increased oxygen. I measured the cleanliness of water in three areas along a water course, at one point a water treatment facility deposited treated water back into the river. Even though the water had been treated there are still visible traces of increased nutrients in the water. Several test were done, measuring the cleanliness by chemical tests and species of invertebrates found. The results showed that the water quality decreased immediately after the input of treated water, with higher nutrient values and decreased diversity of invertebrates.

Further down the river after a small waterfall, the water had become cleaner and more abundant. This shows the rivers ability to recover from the effect of pollution through self-cleansing. The oxygen gained from waterfalls and changing gradients helps to defend the river from the effects of plant growth and oxygen reduction that occurs with it. These features also help to increase the speed of the flow dispersing pollutants faster.

Lentic Habitats

2007-09-05T03:31:00.000-07:00

Lentic habitats are still water habitats. This means they have no distinct flowing water through them, some examples of lentic habitats are:

Ponds
Canals
Reservoirs
Ditches
Dew Ponds
Moats

As lentic habitats are all land locked they renew their water supplies mainly from rainfall, this can be directly into the water or through draining from the ground; without this the habitat would eventually dry up through evaporation.

Some lentic waters have drains built to draw water from nearby lotic habitats to keep them replenished. The water renewal also plays apart in the level of permanence to the habitat, for example puddles can be classed as lentic habitats but are temporary as they only occur when rain has fallen and evaporate pretty quickly.

Lentic habitats can be classed in three levels of permanence; temporary, semi-permanent and permanent. It all depends on the structure of the habitat and ecological influences such as duration of rainfall and climate.

Areas such as lakes and big ponds will be permanent fixtures in places that have plenty of rainfall and cool temperatures, where as in hot dry climates they would probably be a semi permanent body of water because of the lack of rain and increased levels of evaporation at certain times of year. The depth of the habitat also will affect its level of permanence: the deeper it is the more water it can afford to lose and still be a quality habitat. These permanent habitats are home to creatures all year round.

Semi permanent habitats are often seasonal, places such as ditches will come into this category, they fill up over the wetter seasons and spend the rest of the year drier. Semi permanent habitats are not a constant water habitat and during its dry season will be home to non-water dependant animals. The potential habitat is always there but water renewal rate controls the frequency of it being a water habitat.

Temporary habitats are unreliable habitats for creatures dependent on living in water, they can come and go on a day to day basis, the animals that live in these habitats must be highly adapted or be able to migrate when the need arises. Temporary water habitats can appear in any divot or dip in the landscape and are not constrained by defined margins.

Lentic habitats will vary in their nutritional status; this will affect the diversity of species that inhabit the water. The nutritional status is generally put into four groups

Oligotrophic - Areas of water will very few nutrients and offers little in which to sustain life.
Most of what is found here are bacteria; a creature would have to be very
Specialised to survive in this environment.

Mesotrophic - This is used to describe areas of water with beds of submerged vegetation and medium levels of nutrients. Places like this are more suited to assisting
life than oligotrophic waters.

Eutrophic - Relates to areas of water with rich mineral and nutrient properties, habitats
with these levels of nutrients are often covered with excessive amounts of
algae which can be detrimental to other species inhabiting the water.

Dystrophic - The water has a very acid content and poor in other nutrients, this limits the
vegetation and creatures that can survive in these waters. Often very ‘boggy’
areas.

Zones
Lentic habitats are divided into three zones, littoral, limnetic and profundal. These zones are the layers that support different organisms; each zone has its own special characteristics that certain species will favor over others.

Littoral zones are closest to the shore, they tend to be shallower and hold a lot of vegetation as light can reach all the way to the floor. This zone tends to be abundant with life due to its food source and plenty of shelter. This is where you will tend to find emerging plants, which will increase the diversity of species living here.

The next zone is the limnetic, this is a layer of open water away from the shore, this is the area where most photosynthesis occurs as thw water gets a lot of light and doesn’t run to deep. Floating micro-organisms and swimming creatures dominate this area.

The profundal zone is the deeper level of a body of water more common in lakes than ponds, as this is a deep area with little light. This zone relies on dead organic matter dropping down from the other zones: which is then recycled into nutrients by bacteria and fungi decomposing it. There is less life down in the profundal zone due to its lack of light and cooler temperatures.

Thermocline formation
A thermocline is a layer within a body of water that acts as a barrier between the higher and lower levels. It is formed when sunlight hits the surface layer of the water (epilimnion) and heats the water. Most of the heat is absorbed in the epilimnion and is circulated to warm the rest of the water, however the lower level of water (hypolimnion) is to deep and dark to get heated by the sun, here the temperature is much lower. The area between these two layers where the temperature begins to change rapidly is known as a thermocline. The hypolimnion continues to drop in temp but at a more gradual rate.

The thermocline then acts as a barrier, preventing the two layers from mixing: this means that we end up with two different habitats within the same are of water. The epilimnion is warm with higher levels of oxygen and the longer the thermocline continues the more stable this layer becomes. However the thermocline prevents nutrients from rising to the surface from DOM, which reduces the resources available to this layer.

The hypolimnion at this time is affected by various factors including lack of light and heat and oxygen: which prevents plants from growing, restricting food for organisms living in this layer. The bacteria in this layer will also consume most of the oxygen creating a difficult environment for non-specialised creatures to live in.

References: www.broadwaters.fsnet.co.uk
http://home.comcast.net
http://en.wikipedia.org
www.answers.com

Physical and Chemical Properties of Water

2007-09-05T03:01:00.000-07:00

Physical Properties

Lack of Desiccation. All organisms need water to survive; this applies especially to creatures living in water that would die if removed. In water these organisms are kept constantly wet and only survive because of it.

Support. Water has the ability to physically support the weight of life forms, lifting smaller more fragile life forms higher where they can receive light, heat and nutrients. These organisms are often at the base of the food chain and are extremely important for sustaining life in and around the water.

The support provided by water also makes swimming and paddling much easier due to its density. Creatures can push water away to move where as in air they could not. This support also allows plants to float on the surface, this can be in the form of free floating plants or plants rooted to the bottom with the upper most part extending out of the water. These plants provide food and shelter for animals.

Surface Tension. Water has a high surface tension; this means that there is a strong cohesion between water molecules. This allows some life forms to stand and move over the surface of the water because the force of cohesion is stronger than the force put upon it by the life form. This level of tension works in a similar way when trapping small creatures that fall in, because they put such a small force on the water they do not sink, in these cases they will provide food for surface dwelling animals. This tension also helps creatures to hang from the surface to breath, as the molecules force together and hold the creature in place.

Temperature. Water has a reasonably constant water temperature, the change in water temp is a gradual rather than rapid process, and this is because it can absorb large amounts of heat energy before it actually starts to get hot. This provides a consistent environment for life, rather than the swinging temperatures of air. Oxygen dissolves naturally when it comes into contact with air; lower temps of water dissolve greater amounts of oxygen, which is used to sustain life. The lower temps also dissolve more CO2 causing them to have lower pH levels: which tend to provide a greater biodiversity compared to more alkaline waters.

Temperature is also the instigator for thermocline formations (if deep enough), creating separated areas with very different temperatures and this variation in temp causes the habitat to almost become two separate habitats.

Ice. The surface layers of water are affected most dramatically by temperatures dropping, at these times this layer will freeze and become ice, because water is less dense at freezing point it will float and stay at the surface leaving warmer waters deeper down. The water will have no contact with air and wind for fresh circulation of oxygen, which will cause death in organisms that breathe oxygen. Ice will also cause damage to plants putting extra pressure on roots and decreasing its nutrient supply. The total coverage of ice is dependant on how still the water is, (some lakes are large enough to have wave action and this movement can prevent the ice from forming).

Waves. Water can be moved by wind, with strong enough directional force a wave can occur. In areas with regular wind made waves there will be erosion of banks and plants from the continual stress of the heavy water. Waves can also circulate the water spreading oxygen and nutrients.

Transparency. Water is naturally clear, (it is discoloured by chemicals, organisms and sediments). This transparency is what allows photosynthesis and growth to occur in plants beneath the water. Light penetration can be impaired by organisms (algae, water lilies etc), sediments (soils, pollution) and shadow (from boats, trees, walls). Some natural staining can occur from peat, which turns water brown and also iron, turning water red. All this turbidity can have a negative affect on the aquatic plants ability to produce oxygen. There gets to a certain depth and turbidity where plants can only just survive as their oxygen out equals their intake per day. Any lower than this and the plant cannot survive.

Chemical Properties

Dissolved minerals. The level of minerals in a body of water will essentially determine what will live there, as they are essential plant nutrients. These minerals can come from several sources:when manure is put on soil to fertilise bacteria and fungi break it down, this process produces Nitrates. These minerals get in to the soil and when it rains, leach through the soils into the body of water. The plants then use the Nitrate for growth. Phosphates will work in a similar way.

They can also be produced by dead organic matter (DOM) breakdown in the water and from detergents and wastewater being washed in. Sulphates and chlorides are naturally present in water but can also be washed in too. Minerals such as calcium carbonate and magnesium carbonate are also essential to aquatic life and determine water hardness; the more present the harder the water. Water hardness is closely linked with pH levels and so is important for sustaining life. Calcium and magnesium in water will affect alkalinity, certain species will not be able to tolerate alkaline waters and others will thrive, so levels are relevant to biodiversity and the types of species found in the habitat.

These minerals are all dissolved when they come in contact with water, this chemical process make minerals far easier to absorb and for use by plants, this will then benefit the growth and health of the vegetation in and around the water.

With a lot of minerals coming from surface water run off and leached groundwater you tend to find ponds and lakes on lowlands to be very high in these nutrients (eutrophic) and the abundance of algae is usually an indication of this. Ponds or lakes situated on higher ground will often have lower levels of nutrients in varying levels.

Dissolved gases. Oxygen is the most important gas to sustain life in waters, when air and water come in contact oxygen is dissolved into the water. This allows the species living in the water to breath. Oxygen is also produced by plant life in the water from photosynthesis. The temperature of the water greatly affects how much oxygen can be absorbed, the cooler the water the greater the amount of oxygen that can be dissolved. Oxygen is lost at night when plants respire, absorbing oxygen and producing CO2, it can also be lost through an abundance of algae sitting on the surface of the water blocking the light, which then restricts photosynthesis.

There are also varying amounts of CO2 present in water, produced by respiration from plants and animals, too much CO2 in water can be very detrimental to pond life.

Acidity. The pH of water is dependant on various factors; the geology of the area will provide certain types and levels of minerals, which can influence the pH level along with their presence in the surrounding soils. The pH level is directly linked to species found in a pond or lake, high levels of acidity can kill fish or cause so much stress that weight, size, ability to hunt or flee may become impaired and ultimately the species may no longer survive on the site. reducing biodiversity and upsetting the balance of the ecosystem.

Small fluctuations can occur to the pH level at night when plants are producing CO2 but the fluctuations are minimal and the levels are generally quite stable.

Organic matter. The bulk of organic matter found in the water sits at the bottom, it comes from the death of macrophytes (algae) and leaves that have fallen from trees and been blown into the water. All this DOM sinks and eventually gets broken down by bacteria and fungi.

During this process CO2 is given off and oxygen used up and so links directly to the oxygen supply and nutrient values.

Shallower bodies of water will have a rich substrate because of the presence of vegetation at the bottom, compared to this deeper bodies like lakes will have less of this richness because plants cant survive at that depth because of the lack of light. You have to be careful with the shallower pond because this level of organic matter can build up substantially and reduce the water depth over a few years. Organic matter also comes from the breakdown of reedy plants, their structure allows for slower decomposition and produces detritus: which is an essential food for many smaller species living in the water.

Exploitation of the Rainforest

2007-09-03T09:03:00.000-07:00

Rainforests now only account for less than 6% of the lands surface; despite this they are home to nearly half the populations of species found in the world. A rich and diverse habitat provides some exceptionally interesting and unique species of flora and fauna. The dangerous and inhospitable environment has meant that plant and animal species have been able to thrive for thousands of years without human intervention of influence, hundreds, even thousands of years the rainforests were home only to small indigenous communities, living only with the resources provided to them by their natural environment.

In recent centuries many events have occurred that have lead to the destruction and exploitation of the world’s rainforests and its people, the cause of the damage is directly linked to human population growth and the knock on effects that come with this. Over-population in local communities, though often blamed was never really the problem, it has been the ever hungry over consumption of rich, developed countries that has lead to mass deforestation and changes in land use, changes which often cripple the land and rob it of a chance at regeneration.

Human Population growth
Population figures for humans have increased rapidly over just a few hundred years, 2000 years ago human populations stood at approximately 300 million, this figure rose very slowly over a thousand years by just 10 million, the next 800 years populations grew steadily to a milestone1 billion. From the beginning of the 18th centaury the industrial revolution and improvements in health care, sanitation, agriculture, housing and energy supply have allowed populations to soar all over the world: and in just 127 years the population doubled to 2 billion. The time frame for each billion has been getting smaller and smaller since then, it took just 33 years to reach 3 billion and then 13 years to reach 5. The population now sits in the 6 billion mark and is expected to continue to grow.

The rapid growth of human populations has seen a massive reduction in available local resources, despite this human consumption in rich countries continues to grow. Approximately half the human population live in poverty, in places where there is barley enough resources to survive and as a result the mortality rate is high. Despite the huge numbers of people living in these areas, they have had little impact on the tropical forests of the world; an individual person in a rich country is expected to use sixty times more resources than a single person in an undeveloped country.

Rapid growth of industry and economy over the last 50 years has caused companies and governments to exploit resources from other areas, as they can no longer sustain their own. Colonialists discovered the vast resources of the rainforest and have since exploited its use to the detriment of indigenous individuals. Indigenous people once had their own sustainable methods for managing their environment with low impact farming and utilisation of abundant foods and resources; these have now been displaced by areas of mass agriculture, plantations and logging. Each of these topics have their own effects and impacts on the rainforest and all contribute to the destruction of a very special habitat.

Colonialists also took it upon themselves to start moving indigenous populations around; they believed they could help over-population problems by moving people to uninhabited areas of the rainforest. This soon became a problem as the soils could not sustain the new numbers of people, meaning that areas were drained of nutrients and people had to move on to new places leaving a trail of destruction behind.

Increased levels of tourism have been made possible by continual reductions in the cost of travel, interest in the rainforest has led to resorts and developments being built to accommodate ever growing numbers of people. Tourism is seen as a quick financial solution as it brings in economy that can be used to fund conservation projects, but damage usually occurs before management of the area is put in place leading to further damage.

Animal Utilisation
The rainforests have long been home to many interesting and beautiful species of animal; many of these have been hunted to near extinction for the purpose of man. Though most reduction in species populations is closely linked to habitat loss rather than hunting, it has still however played a large part in the endangerment of certain species.

Fur is a massive trade and although there are many legislations in place to prevent the decline of species for fur, there are still large numbers of species being poached and sold on the black market to be made into coats, bags, hats belts etc. large cats and giant otters are particularly at threat as reduced habitat is making them easier to find.

Ivory has been used throughout history for a range of human items due to its hardness, workability and attractive surface. It has been the basis of many ornamental objects and art works for hundreds of years, the demand for ivory objects became so popular that elephants all over the world were driven to near-extinction; it became illegal to trade in ivory in 1989.
The illegal pet trade is the second biggest threat to rainforest animals after habitat loss; it is actually the third biggest trade in the world and in a multi-million pound industry. There is a keen interest within richer countries to own unusual pets, the vast sums of money available for producing these creatures drives population reductions.

The National Network to Fight Wild Animal Trafficking in Brazil estimates that approximately 38 million animals are trapped and smuggled out of the country on a yearly basis. The process is inhumane and traumatic, most of the animals don’t even make the journey, they die from dehydration, starvation and injuries sustained during the trapping and transport; which just funds the cycle more.

Many tropical animals have close links with ancient medicines and some were used for a range of treatments, aphrodisiacs, and poisons. This interest still exists today at the expense of endangered species. They suffer the same treatment as animals killed for fur, ivory, and most animals trapped for pets.

Plant Utilisation
Plants have suffered similar disregard from companies and governments in richer countries with so many species found in the rainforest being drained of resources for use in medicines and food consumed in developed countries.

Many of the foods we eat today originated in rainforests:
Avocado, banana, black pepper, Brazilian nuts, cayenne pepper, cassava/manioc, cashews, chocolate/cocoa, cinnamon, cloves, coconut, coffee, cola, corn/maize, eggplant, fig, ginger, guava, herbal tea ingredients (hibiscus flowers, orange flowers and peel, lemon grass), jalapeño, lemon, orange, papaya, paprika, peanut, pineapple, rice, winter squash, sweet pepper, sugar, tomato, turmeric, vanilla, and Mexican yam. The wild strains still in the rainforests of many of these plants provide genetic materials essential to fortify our existing agricultural stock. Many other rainforest plants have great promise to become other staple foods.
(Caufield, Catherine, In the Rainforest)*

Plants are also a basis for many drugs and medicines used everyday in developed countries to treat cancers, leukaemia, Hodgkin’s disease, arthritis, heart conditions, hypertension and birth control to name but a few. Scientist have discovered some very useful chemicals and components in rainforest plants for treating cancer and infact 70% of recognised cancer drugs are derived from plants that are only found in the rainforests.

Pollution
Pollution is a concern that effects all of the worlds biomes, it is growing issue especially in developed countries where they is more education and media leading to a better understanding of the issue. Pollution has and still is occurring in all areas of the rainforest, the rainforest is know to be a massive carbon storage unit extracting tonnes of co2 and releasing fresh oxygen into the atmosphere and the large areas of forest help to regulate the temperature and climate. Despite all this one of the worlds most delicate biomes is severely threatened by the effects of pollution. Several factors have contributed to the pollution of the rainforests.

Oil
The reduction in available fossil fuels has caused oil companies to look further a field for resources, extracting oil from third world and poor countries means that companies can maximise profits through exploitation of resources and people. The effect that oil extraction has on the rainforest and local communities is disastrous leading to sickness and death in people, animals and plants.

The most well known example of the damaging effects of oil extraction in rainforests is in the Amazon. For twenty years the international petroleum and fuel giant Texaco worked alongside the Ecuadorian state Oil Company to extract billions of gallons of oil from the Amazon rainforest. During this time the company did not use the now standard practice of returning waste to the earth where it was extracted, instead they dumped heavy sludge in unlined open pits and flushed 20 billion gallons of waste into near-by streams, rivers and wetlands.

The waste from the pits leached into the surrounding soils and waters, the waterways carried waste out to larger areas spreading contamination over a much larger area. The toxic materials found in oil and oil waste products is extremely dangerous to the health of plants and animals and the constant presence of it in local water sources and soils is passed onto plants and animals through the food chain. The cumulative impact of this is that plants, animals and people are slowly poisoned by continual ingestion of toxic material and because of their circumstances they have no choice but to drink the polluted water and eat the contaminated food they produce.

The soils of the rainforest are already very delicate, being generally nutrient poor means that they suffer dramatically from the effects of heavy chemicals in the soil. Native vegetation suffers as well as the agricultural crops grown for local and mass market, very little will grow on the poisoned soils and soon the land becomes dry, barren and uninhabited.

Despite this oil companies are still pushing to open up new areas all over the rainforest to search for and extract oil. From the extraction, to the burning of fuels for products, to the mass felling of trees to build extraction sites, to the industrial waste that is produced during the from machinery and vehicles, the whole process of oil extraction is highly pollutive and damaging to the rainforests delicate ecology.

Industry, Tourism and Urbanisation
The growing industry, tourism and urbanisation that is occurring in developing countries (where most rainforests are found), contributes to the pollution that is absorbed by vegetation and soils in the rainforest. More and more people are being forced to move out from overcrowded urban areas, they are often relocated closer and closer to forest and as the forest shrink populations of people move further and further in. the land around the forest gets built up as houses are built, industry is created and vehicles appear.

Industry, vehicles and the burning of fossil fuels creates toxic gases in the form of sulphur dioxide, nitrogen oxide and hydrocarbons. When released into the atmosphere they react with water and light to form dilute sulphuric acid, nitric acid and ammonium salts. These wash into soils and are absorbed by plants, subsequently many plants cannot tolerate they highly acidic soils and die. Much of the diversity that is lost on a daily basis in the rainforest is due to the increased acid content present in the soils.

Intensified Agriculture
Intensified agriculture is a growing concern for the future of the worlds rainforests, as populations grow all over the world a greater demand for food arises, with less space in developed urban areas many countries are importing the majority of their goods. Due to the demand, larger and larger areas of forest are being cleared for growing crops and grazing cattle. A vast amount of the agriculture is owned and controlled by large corporate companies who exploit the local people by paying them barely enough to survive on after robbing them of their own natural resources.

One of the main problems with intensified agriculture is that the soils found in the rainforest are not sustainable for a mass production of crop. The poor soils are low in nutrients, what is there is soon depleted and the crops will no longer grow. The process of harvesting leaves soils exposed to erosion and nutrient leaching from rainwater and drying out in the sun.

The heavy farming is usually accompanied by heavy pesticide and herbicide use, the chemicals leach into the soil and surrounding waters, causing nitrification and depletion of diversity further into the forest, away from the farms and industries.

The burning of rainforests to make way for agriculture and industry produces a range of toxic fumes that are released into the atmosphere, carbon dioxide, nitrous oxides and methane are all released and subsequently enter plants and soils through the water cycle as well as during photosynthesis.

Mineral Exploitation
There are large deposits of minerals hidden in the rainforests of the world and through out history mineral and metal extraction has been the cause of many environmental and social problems. It is here in the third world rainforests that it seems to have made the greatest impact and still continues to do so.

The Amazon basin in Brazil is a store of deposited minerals; it has been heavily mined for gold, bauxite, iron ore, tin ore and diamonds. Large areas of the forest are cleared to build extraction sites and then subsequently drained of resources, polluted and abandoned.
The mineral mining industry is driven by money, with all profits being made by foreign companies and no contribution to the enrichment of local populations. Many of the people have no choice but to be dependant on handouts from mining companies that have taken over their homes and land. The companies actively encourage this behaviour as it means they have more control over the indigenous people and can behave as they please.

Mineral extraction sites are often very violent and constantly he focus of civil wars and violations of human rights, the governments are generally powerless to stop the will of massive industrial companies and the lure of corrupt financial deals attracts officials to turn a blind eye.

The process of mineral extraction is very damaging to the local and wider environments as unwanted by-products (known as tailings) are dumped into local waterways as a means of disposal. The tailings are made up of heavy metals and acids that erode and are released destroying entire ecosystems in certain areas. The mines are left as gapping craters in the landscape void of vegetation and abandoned by the companies, the indigenous people are left to fend for themselves and suffer greatly from the loss of handouts.

As mineral deposits become sparser, the value increases; mines become very hostile and competitive places with opposing mineral companies waging war to gain control of mineral sites. The conflict comes at the expense of local indigenous people who suffer injuries, sickness and death as a consequence.

Timber Extraction
Timber extraction and logging regimes in rainforests is one of the biggest issues circulating debate at the moment. In recent years it has become apparent that the largest damage to rainforests come from intensive logging and deforestation. The 1980s and 90s saw foreign companies make movements into rainforests after depletion of their own natural timber resources. The issue has become highly documented and protective legislation has come into force to try to prevent further degeneration of the world’s rainforests. Despite this illegal unsustainable logging continues in a massive industry that sees mass felling that is unplanned and poorly managed with no environmental consideration.

The disposable attitude of modern developed countries requires a high amount of resources this obviously apparent as nearly all timber felled in rainforests is exported to rich countries to be used for furniture, flooring, ornamental objects and paper. The vast quantities of trees felled during extraction projects takes it toll on the environment not only locally but inter-nationally through changes in climate and loss of species diversity.

Timber extraction offers a limited non-sustainable product, many trees that are felled have taken hundreds of years to reach maturity and regeneration of resources can only occur over a very long period, secondary forests that appear in the after math of heavy logging are considerably different to the original primary forests and do not produce the same timber value as before logging took place.

In many places timber extraction is based on selective logging, in these circumstances specific high yield species are selected for timber sale. The species considered high value for timber are more often than not large well-established species that provide food and shelter to communities of insect, bird and animal. Selective logging is not considered to be as detrimental to wildlife as clear felling of large areas, however it does still have a very dramatic effect on microenvironments within the forest.

A single tree felled in a forest damages surrounding vegetation by pulling out connected root systems and large canopies crash down taking other trees with them that are connected by vines. This leads to a gap in the canopy with increased light availability, which is more vulnerable to wind damage and erosion. The abundance of light damages and kills soil organisms, disabling decomposition and nutrient fixing cycles.

Much of the rainforest is destroyed in transporting and managing cut timber, large areas of unwanted timber is felled to make way for large machinery and vehicles. Roads are built through the forest to make transportation easier whilst numerous skid trails are made from forest to road. The heavy machinery and timber being moves takes it toll on the sallow nutrient poor soils of the rainforest. Constant erosion takes place as tyres pick up nutrients and compact the soil. This makes regeneration even more difficult once logging is abandoned in the area.

Once the logging regime ceases and moves on the disturbed forest is subject to many changes. Rainforests characteristically are places of heavy and frequent rainfall, most of this is self sustained through evaporation from the canopy, the majority of rainfall is absorbed in the canopy and does not ever see the ground, the precipitation that drips from leaves and branches to the floor is soon absorbed into the soil and taken in by plants, which is then evaporated to continue the unique water cycle of the rainforest.

Gaps in the canopy mean that less water is absorbed by trees and subsequently not evaporated as it reaches the ground and is washed away to steams and rivers. The higher levels of disturbance compact soils so mush that no rainwater can leach in to the ground to supply new seeds with moisture. In these areas surface run off is greatest and large amounts of water are removed from the water cycle leading to dryer forests near logged areas.

Most rainforest trees have evolved to store nutrients in their systems, this is because the soil nutrient levels are poor, when trees are logged and removed they not only remove timber but also a store of nutrients that would have eventually been re-invested into the soils when the tree decomposed. The new exposure of the soil allows for more nutrient depletion from surface runoff and wind erosion. The soils are already very shallow, being bound mainly by the root structures of trees; removal of trees allows topsoil to blow away leaving nutrient scarce subsoil. It can take decades for soils to recover from the effects of nutrient removal in which time regeneration will be dominated by a few adaptable species, severely reducing species diversity.

Rainforest trees absorb 11% more light radiation than pasture, the absorbed radiation is emitted as heat, gaps in the canopy reduce the amount of light absorbed and thus the levels of heat, reducing temperatures. The reduction in temperature results in a reduced capacity for evaporation in the forest environment, disturbing the finely balanced ecosystems that exist within it. The overall long-term effects of persistent heavy logging could have a dramatic effect on rainforest climate, which will not be experienced for many years.

Timber extraction has a massive impact on the rainforest as a wildlife habitat; the disturbance then has a range of chain reactions that occur through out the rest of the forest. The rainforests are home to thousands of species of insect, bird, reptile and mammal, all with individual reactions to the effects of commercial logging.

The noisy machinery used to fell and transport timber can be heard for miles, this initially scares and stresses local animals. Primates are particularly susceptible to the effects off logging, the noise drives them away from their own territory into the territory of other communities, this leads to aggression and violence from competition for spaces and food, ultimately one community will suffer, numbers will dwindle and genetic diversity is reduced. Gorillas and orang-utans deal better in these situations as territories usually overlap and species are not so territorial.

Infant mortality rates among primates increase in logged areas as they fall out of trees, are abandoned when community flees an area and have difficulty moving about in open spaces. The open ground makes it easier for predators to target prey, which is why most rainforest species live high up in the canopy as a rule.

The mass felling of trees leads to a sudden reduction in food sources for native fauna, which can have instant impact on population figures. Some species of primate have adapted to eat foods from a select range of tree species that is suddenly removed leading to starvation and increased inter-specific competition for food. Removal of important resources can have huge effects on animal populations that even low level selective felling can have catastrophic consequences. For example strangler figs (as fore-mentioned in 5.3P) are an important source of annual food for many rainforest species, they tend to be found growing around large, high value timber trees, when the trees are removed the unwanted fig dies and a valuable food source is destroyed.

Rainforests are abundant with insect species, many of which have evolved to rely on specific host species of tree and are unable to revert to other food sources and subsequently die out, leading to a reduction of diversity and biomass that reverberates through the food chain.

The regeneration of vegetation from timber extracted sites is known as secondary forest, the increased light levels coming through large gaps in the canopy lead to extensive growth of pioneer light loving species such as vines and climbers, at the expense of tree seedlings used to growing slowly in the shade of mature trees. The level of regeneration is directly related to the level of disturbance and less disturbed sites stand a better chance of similar vegetative regeneration.

The level of damage overall is dependant on the ability of native plant and animal species to adapt to the vast change in environment, some species, such as forest elephant have been able to utilise the canopy gaps by browsing the new growth springing up from the exposed floor. In timber extraction regimes the most specialised species suffer greatest, unable to make the changes necessary to survive in the new changing environment.

The aftermath of large scale timber extraction attract people to inhabit and start to farm the cleared ground which is made easier by all the roads now in place, as communities move further in and spread out into rainforests the effects of agriculture, industry and urbanisation increase the damage and prevent regeneration from naturally occurring.

Loss of Species Through Exploitation
With 58 million square miles of rainforest being cleared every year it is inevitable that plant and animal species will be directly affected by a loss of habitat. It is estimated that a typical four square mile patch of rainforest contains as many as 1,500 flowering plants, 750 species of trees, 400 species of birds and 150 species of butterflies. If the current trend of destruction continues approximately 5-10% of species will become extinct every decade.

The development of the rainforest over a long period has evolved very specific relationships between plants and animals. The loss of one species can have a massive chain effect through the ecosystem resulting in unstable populations in species in surrounding areas. The inability of so many species in rainforests to adapt is a key factor in their decline and extinction.

Tank bromeliads are from the Family (Bromeliaceae) these plants are native to rainforests across the world and are characterised as being able to store water within they’re bodies. Tank bromeliads are utilised by many rainforest species who use them as a water source, over 250 species of insect have been identified as occupying tank bromeliads for food, water and hunting of other species, certain species of mosquito and frog use them as breeding grounds and for rearing young. The loss of these plants through deforestation for whatever reason have a major impact on insect populations and subsequently species that fed on those insects.

On the other side of this coin many tree rely on insects, birds and mammals for reproduction and decline of species will have a knock on effect to areas outside the damage zone. A past example of this occurred with the calvaria tree on the island of Madagascar, the trees hadn’t reproduced in hundreds of years which lead to a scientific investigation that showed that the seeds needed to pass through the digestive tract of the now extinct Dodo in order to germinate; luckily the species was saved by the introduction of turkeys which took up the role. This same effect could easily occur with the exploitation of rainforest resources and animal extinction but without human awareness.

Loss of habitat is the main cause for concern with a reduction of rainforest from 6 million square miles to just 2.1 million square miles over a very short period in history. With rainforests already being densely inhabited by plants and animals, this immense reduction in habitat only serves to increase competition between species for resources essential to their survival.

North-South Resource Consumption Differential
The North-South divide is an economic and political division between rich developed countries and poor developing “third world countries”. Wealth developed countries are classed as north and poor countries south. Although most of the north division do occur in the northern hemisphere the divide is not based on geological position but economic value.
There is an unbelievable difference in consumption between the two, with the north being mainly responsible for the vast majority of rainforest destruction. In wealthy developed countries, society strives for improved comforts and quality of living, this normally occurs at the expense of poor underdeveloped societies.

A large contributor to the problem of rainforest destruction arises through the debt burden of countries on the south of the divide. The areas highlighted in yellow on the map indicate a mid level of development and the red areas show very poorly developed countries.

During the 70s and 80s poor countries borrowed large sums of money from developed countries to fund developments and growth of a self-sustaining industry. These countries are still having to repay the debt with high interest rates, an effort that is becoming increasingly difficult when developed countries come in and exploit those countries natural resources.

Developing countries have to pay more money back in debts than they receive in aid every year, this itself drives communities to exploit their own resources and encourage outside developments for small-scale benefit. The pressure of debt means that governments focus more on financial gain by maximising exports rather than addressing important social and economic issues.

Developed counties abuse the situation in under-developed countries to exploit is resources and people through continued large-scale agriculture and timber extraction, of which very little is given to the country. The USA have been accused of manipulating prices for agricultural goods produced by small local communities for export to wealthy countries at the expense of the people producing their product. This activity occurs all over developed countries with multi-national companies making massive profits and their employees are barely provided with enough to survive.

References:
http://www.rainforestinfo.org.au/background/causes.htm
http://www.nature.org/rainforests/explore/facts.html
http://www.saverfn.org/lessonssymb.html
http://www.globalchange.umich.edu
http://www.archipelago.gr
*http://www.ijms-wildlife.co.uk/forest.html
http://www.commondreams.org/headlines05/0427-03.htm
http://library.thinkquest.org/26993/amazon.htm
http://www.twnside.org.sg/title/mine-cn.htm
www.rainforestfoundationuk.org/files/LOGGING.pdf

Plant Adaptations

2007-09-03T06:24:00.000-07:00

The earth is subject to various climates and changes, precipitation and water availability can range from extremely high to moderate to low and temperatures can range from well below zero up to 49∞C and yet vegetation manages to survive in all areas of the planet, plants can be found in even the most hostile and seemingly uninhabitable places. The success of plant survival is the diversity of adaptations that plant species have evolved and the ingenious methods used to optimise chances of survival in any given surroundings.

All photosynthetic plants need to open stomata’s on leaves to allow carbon dioxide and oxygen in and out but this process allows for evaporation to occur. To retain optimum levels of moisture many plants have more stomata’s on their lower side away from direct sunlight.

The plant needs to be able to balance effective photosynthesis with reduced transpiration rates. One way most plants do this is by having a large surface area for absorbing light and a thin layer of photosynthetic cells so that the process can occur quickly with minimal energy use. This is a common adaptation and you can see this in a vast range of vegetation by looking at the thickness of the leaves compared to its surface area.

Plants in water deficient areas have developed a range of adaptations to help them cope with reduced water availability and increased temperatures. Vegetation found in desserts and tundra are a good examples of areas with reduced water availability but both have very different temperature and weather patterns, which will also influence adaptations. Plant species adapted to be able to withstand reduced water availability are known as xerophytes.

Adaptations can occur on three levels, firstly there are morphical features, which relate to the structure of the plant, physiological features, which relate to biological function and behavioural features which relates to plants choosing suitable places to inhabit.

Morphical features
These adaptations are obvious characteristics of plants and are often used as identification features, easily visible they can be seen in many dessert and water deficient areas, with most species present displaying at least one if not more of the following features.

Fuzzy leaf surface – the hair on the leaf acts as a buffer for winds that contribute to increased transpiration levels
Shiny reflective leaves reduce the amount of solar energy absorbed by the plant this means that less water is evaporated and the less energy required to perform actions that result in temperature reduction.
Waxy leaves help to reduce water loss from transpiration
Small leaves – reduced surface area means that less solar energy is absorbed preventing the plant drying out and over heating.
Thicker leaves can hold more water allowing plants to store some water within their bodies rather than having to rely on moisture in the soil.
Spines instead of leaves on many plants help to reduce impact of solar radiation reducing absorption and evaporation rates.
Extensive shallow roots not only bind dry loose soil, which is vulnerable to erosion, but also allows plants to absorb as much rainfall as possible before it drains away or evaporates.
Deep taproots allow some plants to absorb moisture from deeper soils where other plants cannot reach giving them a competitive advantage.
Self-shading plants protect the majority of the plant from the effects of the sun by growing leaves, which shade out the rest of the plant.

Physiological features cannot always be seen without dissection and examination of the cellular structure and chemical composition of the plant. Water accumulation as seen in succulents is a visible feature and a common adaptation to extremely arid conditions, as is self pruning, in which a plant shuts off its circulation to particular leaves or branches to conserve water for the rest of the plant; the cut off parts wither and die eventually dropping off but the plant is able to survive.

Behavioural features can be observed in the areas in which the plant is found, certain plants will make use of microclimates that have more available water such as cracks in the landscape where water can accumulate

There are several ways of grouping plants with similar adaptation features.

Drought escapers make use of favourable conditions where they exist, more often than not they are short-lived annuals (Ephemerals) that complete their life cycle in a matter of weeks or even days when the right conditions arise. These plants put all their energy into reproduction and seed production and keep none for continued existence, their survival relies on the plants ability to ‘not exist’ for most of the year with seeds lying dormant in the soil through most of the year especially in places with predominantly unfavourable conditions.

Drought resistors are often perennial species that show adaptations that allow the plants to survive and grow throughout the year and onto the next. These species put a lot of energy into their adaptations and so generally do not initially flower for several years having finally established enough to put energy into reproduction.

The nature of the adaptation varies greatly over the spectrum of drought resisting plants and particular adaptations are favoured by plants depending on whether they are woody, herbaceous or succulent.

Typical adaptations on woody plants are small spiny leaves which reduce the impact of solar radiation, a waxy coating on the leaves help to keep moisture trapped and stomata’s are often sunken on the leaf to protect from evaporation from winds. The woody stems and trunks are often smooth and green contributing towards food production and preventing moisture loss. Hair can often be found over the trunk and stem this helps to protect from transpiration and hold onto moisture around stomata’s.

Trees and shrubs in areas with reduced water availability do not grow very tall, the lack of water means that growth is slow and production reduced. Many plants go into a state of dormancy for a large part of the year, conserving enough energy to survive until the next growth season begins with the arrival of precipitation.

Plants in dry areas often have thorns on stems and trunks; this adaptation helps to create self shade, which protects the plant from intense heat and thus reducing the rate of transpiration.

Some of the more dominant woody and shrub plants have developed deep tap roots that reach far down into the soil to draw water up that is unavailable to the other local species, plants that do this are known as Phreatophytes.

Succulents are the most well adapted Families to arid conditions showing adaptations that allow long-term plant survival. There are hundreds of species of succulent most notable of these is the Family Cactaceae, this is a relatively young group who have adapted rapidly into extremely specialised plants. Trunks and stems have evolved into green succulent structures containing chlorophyll and leaves have become the characteristic spines found on many species of cactus. While size and shape can vary greatly the function and internal make up is very similar.

Cacti stems have become swollen and enlarged with moisture storing tissue; this allows the plant to store its own supply of water in areas with uncertain future precipitation.

Many cacti have adapted to a spherical shape as this combines highest possible volume with lowest possible surface area. The spines shade the plant from high temperatures and protect from animals trying to gain water from plants.

Cactus roots are shallow but radiate out around the plant to maximise absorption of water when it finally rains, some species can begin to grow within hours of rainfall thanks to their shallow but widely radiated root structure. The stem of the cactus is also adapted to absorbing water, moisture in the air is just as important as in the soil and the presence of chlorophyll and spines

Cactus keep their stomata closed during the day when temperatures are highest, instead they store carbon dioxide within their bodies until night when temperatures are cooler, CO2 is then released and the stomata’s open, this means that transpiration rate are greatly reduced.

A long period of dormancy and short growing season help cactus to survive anything from 25 - 300 years. During this time initial growth can be very slow and it can be many years before a cactus reaches maturity and the ability to reproduce. Reproduction is also favoured at night and flowers will open to allow nocturnal animals, which frequent hot arid areas to transport and fertilise seeds.

Drought evaders manage to survive in areas of reduced available water by making use of micro-climates within an area grow in places where more moisture is constantly available such as desert caves and crevices, taking advantage of cool, moist conditions. These species show less morphical and Physiological adaptations in favour of behavioural adaptations because they are able to survive as they are in favourable conditions without the need for adaptation.

Plants in extreme high and low temperatures often show similar adaptations to vegetation in areas of reduced water availability, this is because in areas of extreme temperature water becomes less available to plants.

Plants of the tundra exhibit characteristics such low growing plants and hairs on leaves, this keeps the plant warm as well as preventing evaporation which is as important in the tundra as it is in the desert.

When temperatures drop as low as they do in the arctic circle a layer of permafrost covers the ground preventing plants from absorbing water, although surrounded by water they are in fact in drought conditions. One adaptation seen in plants of reduced temperatures is dark or red leaves; the dark pigmentation improves the plants light absorbing capabilities.

In areas with high levels of rainfall plants need to adapt to survive in waterlogged soils, in water oxygen is difficult for a plant to absorb, mainly because there are very few air spaces in the wet soil. Often what little air there is becomes utilised by decomposers and so plants need to develop sufficient adaptations to survive; these species are known as hydrophytes.

Aquatic plants have evolved in a very different habitat to terrestrial vegetation so much so that these plant types differ greatly in structure and behaviour.

Common Adaptations of Aquatic Plants:

Less rigid stems as supported by the water
Flexible stems/leaves that allow the plant to move with force of water currents
Reduced external protective tissue, this would normally limit water loss on a plant but as water is abundant all around there is no need for cuticle formation
Reduced or absent transportation system, water, nutrients and gases are taken directly from surrounding water and not from soils.
Reduced or absent roots and root hairs, as materials are absorbed else where and water already supports the plant, roots are often used as anchorage but some species have adapted to free-float, increasing light absorption
Air filled sacs/cavities in stem and leaves that work to hold the plant up and gain a competitive edge with increased light absorption
Highly dissected/divided submerged leaves, this maximises surface area for absorption of light, water, nutrients and dissolved gases, minimises damage from resistance in water
Chlorophyll restricted to surface leaves, this maximises absorption of light where it is most intense
Waxy coating on surface leaves to repel water that would otherwise reflect light energy
Floating seeds allow plants to spread across vast expanses of water broadening the gene pool and preventing local over-competition

References:
http://en.wikipedia.org/wiki/Cactaceae
http://www.desertusa.com/du_plantsurv.html
http://www.huntington.org/Education/lessons/BG-RP-leaf-adapt.pdf.
http://www.microscopy-uk.org.uk
http://www.4corners.net/ccyc/pl3.htm

Temperature and Precipitation in the UK

2007-09-03T06:18:00.000-07:00

The UK has one of the most variable weather patterns in the world, in one day you may experience rain, snow, thunder and lightning, hail and warm sunshine. There are several influences that give Britain such variable weather, a Northern latitude, close proximity to the Atlantic Ocean and the directional flow of the Gulf Stream all have a massive influence on the climate (temperature/precipitation) that the UK experiences during a year.

Temperature
The UK is a temperate region with average temperatures of 7-11º C, the temperature varies throughout the year but the range is small (approximately 12º C) compared to temp variations in other places.

Largely its latitude influences the temperature of the UK; it lies in the Northern Hemisphere 50-60 degrees north of the equator and it subject to constant changes in solar radiation levels. When the Northern Hemisphere is facing towards sun, the UK experiences summer, the winter occurs when the Northern Hemisphere is facing away from the sun.

During winter in the UK the sun sits low in the sky because the earths tilt causes it to be farther away from the direct energy being radiated towards the equatorial regions. This tilt also means that the hours of daylight are reduced from those of the summer months and so its effects are weaker still.

The winter season is experienced differently throughout the UK with varying degrees of temperature change, the average temperatures in England and Wales are about 4,4º C, Scotland being further north has lower winter temperatures with averages of 3º C.

The reduced hours of daylight that come with the Britain’s winter position also contribute to lower temperatures, the land does not have as long to absorb heat during the day leading to cold nights and mornings, the further north you travel lesser hours of light are experienced, this contributes to Scotland’s cooler winter temperatures.

The UK experiences a temperature ‘lag’ due to it being a small island and surrounded by water, as water stores energy for longer than land the water surrounding the UK keeps the temperature up in winter, the overall temperature of the UK is generally higher than other inland European countries on similar latitudes.

Variations in temperature occur because of the effects of warming ocean and air currents that have travelled through the Atlantic Ocean having originated in the Gulf of Mexico. These warm waters raise the temperature around north and Western Europe. The UK receives warm air and water from the North Atlantic drift from the west, warming the UK by 5-8º C; this gives the west and southwest coasts warmer winter temperatures than would be expected at this latitude. The east coasts of Britain during winter is a good few degrees colder on average than the west, the eastern temperature is more reflective of temperatures experienced in inland Europe.

January on average is the coldest month, the ocean has time to cool down during the previous autumn/winter months and has very little warming influence; temperatures drop to an average of 2-3º C.

As the earth continues on its obit the northern hemisphere starts to turn towards the sun, this increases day length and brings the UK into a more direct path of the suns rays. The sun gets higher in the sky and days get gradually longer so the land has a longer time to heat and is absorbing/radiating more heat.

Summer in the UK can be variable and quite unpredictable a lot of the time. Everything that occurs during the winter months is flipped for the summer, the tilt of the earth means that the UK is getting plenty of solar energy and the waters are gradually warming up, average temperatures are about 15.6º C but can sometimes reach heights of 32º C.

The tilt also gives different areas of Britain different amounts of solar energy, The southeast gets more intense heat for longer periods and so the average temperature is much higher than that of northwest, which is receiving less energy per day. Temperatures in the southwest average at 17º C compared to 14º C for Northwest Britain.

The summer months bring strong solar rays, these rays have the dominant effect on temperature in Britain but the Atlantic Ocean still contributes to the overall temperature by bring cooler water and air to the waters surrounding Britain. The cooler waters bring the land temperature down and create weather patterns along the coast. Inland Britain remains higher in temp and is only very mildly influenced by the cooling effects of the ocean.

The ocean has a regulating and cooling effect on annual coastal temperatures compared to inland temperatures, this is especially so for areas directly influenced by the effects of the Gulf Stream. Temperatures in the west and southwest have a smaller temperature range and don’t experience the highest and lowest temperatures.

Precipitation
Precipitation in Britain is closely linked with temperature and temperature changes from season to season. It is also influenced by geography and altitude. The whole of Britain experiences regular rainfall with dry areas experiencing 150 days of rain and wet areas 200 days, the difference between the wet and dry areas is the quantity and across the UK there is a wide range of rainfall volumes.

During winter the precipitation across Britain varies, the land is cool but water in the ocean still stores some heat. Areas closer to abundant water will experience more precipitation than inland areas. The warmer waters brought in by ocean currents causes evaporation to occur when it meets with cooler waters immediately round the island.

The warm waters reach Britain on the west and so the most noticeable changes occur here, air is forced to rise when confronted by a coastal mountain barrier and then reaches the colder higher landforms. Once the evaporated water reaches cooler land its temp drops and the water condenses and forms precipitation. The precipitation falls more on coastal areas in the west and northwest where temp change is largest.

Much of the precipitation in Britain is caused by depressions where cold and warm air meet, these start out in the ocean and move northeast across the Atlantic, these depressions pass over west Britain with the warmer fronts travelling north. These frontal depression cause increased levels of rainfall across the west and northwest coast.

The highlands of Britain are subject to higher levels of rainfall because of the altitude, as warm air is blown in and hits he colder airs surrounding landforms at higher altitude the temperature change is rapid and large causing large quantities of precipitation to be deposited over these areas. The western highlands of Scotland can experience over 3000mm of rain annually, where as the Scottish east coat can have just 800mm. The lowlands of Britain have much less rainfall, with some southeast inland areas having as little as 500mm of rain a year, this is often because the cold temperatures and high altitudes of the western highlands have caused most of the moisture to be lost before the air passes over the east.

The air coming into lowland South and southeast Britain has travelled over land in Europe and much less water so the air is cold and dry, the colder dryer air coming in form more stable weather pattern and reduced amounts of precipitation. Most of this area is in a rain-shadow from highland Britain and so this reduces the amounts of precipitation more so.

During summer the overall precipitation of the UK is reduced but is still subject to varying amounts of rainfall. The increased temperatures over the land mean that cool air brought in from the surrounding air and water currents is more stable with less cloud formation. However, British precipitation can be very unpredictable and there are periods of heavy rain often with thunderstorms during the summer months.

The land gets incredibly warm during the summer especially in areas of lowland Britain that are not so influenced by the cooling presence of the ocean currents. The heat of the land forces the air up, through air that is cooler; this convection heating causes unstable air movement and eventually it cools forming large cumulo-nimbus clouds which are notorious rain and thunder clouds.

Reference:
http://www.metoffice.gov.uk/education/secondary/students/bi_climate.html

Climate and Seasons

2007-09-03T06:12:00.000-07:00

Seasons
Seasons are caused because of the 23.5-degree tilt of the earth. The spherical shape of the earth means that the same amount of solar radiation hits constantly, if the earth had no tilt the seasons would not change. The tilt of the earth means that both north and south poles will face towards and away from the sun at specific points during its orbit.

When the North Pole is inclined towards the sun the Northern Hemisphere experiences summer, this is the time where areas in the north are facing towards the sun and so receive more direct light for longer periods of time. During this time the sun rises high in the sky providing a more direct force of energy for up to 15 hours. The more direct energy has fewer atmospheres to travel through so less energy is absorbed before it reaches the surface.

The energy provided to the Northern Hemisphere during the summer months causes changes to occur on the surface and in the atmosphere, energy absorbed by the sun is often emitted from sources as heat, the raised temperature drives the process of evaporation as well as most weather patterns. The Northern Hemisphere summers are times of reduced precipitation and dryer airs as well as increased temperatures.

When the Northern Hemisphere is in summer the Southern is in its period of winter because at is facing away from the sun. As the earth orbits the solar energy is reduced in both intensity and length, as the tilt of the north turns further away from the sun the seasons change through to autumn and then winter.

Winter is the time when the pole receives the least amount of the energy emitted from the sun. In the Northern Hemisphere during winter the sun is most direct over the tropic of Capricorn giving more energy to the south. The north is farther away from the sun directional radiation and so the sun is low in the sky with its energies spread thinner on the surface and having to go through a larger density of atmosphere before it reaches the surface, meaning more radiation could be absorbed by particles in the atmosphere and clouds.

The cooler temperatures means that the air gets more saturated with moisture during winter allowing for more movement of moisture. The cold temperatures mean heavier cold air forces underneath the warmer air creating high pressures and plenty of “mixing”, resulting in more cloud and precipitation.

During this time the Southern Hemisphere is experiencing its summer.

The climate of different areas is dependant on the variations of sunlight it receives during the earths orbit. Areas closest to the equator receive more constant levels of radiation and so their seasons are not divided into spring, summer, autumn, winter as they are in temperate zones but are classified as wet and dry seasons as the temperature is pretty much consistent throughout the year. Theses seasons are more influenced by the direction of moisture, extreme heat leads to rapid evaporation, which is deposited either north or south at different times of the year.

Climate Influence by Oceans
Oceans account for 75% of the earth’s surface, and has had a direct influence on climate throughout history. Long-term continental changes have helped to direct ocean movement, resulting in the ocean currents that we now experience.

Temperature changes during different seasons are experienced faster over land than oceans this is because water stores heat for longer periods of time. It means that the ocean will take longer to heat and to cool than the land. Land and water in close vicinity experience the same variations in energy as the earth tilts towards and away from the sun but have different rates of temperature increase and decrease.

The suns energy is absorbed by the ocean and as a result the temperature rises, it takes a long time for the massive body of water to heat up after the cold winter, which is why the hottest temperatures are not recorded until the late summer months when land temperature is actually reducing.

The heated water is moved over great distances through water currents and circulation caused by wind, rotation of the earth and the presence of continents. The currents and streams carry warm water to cooler areas. The change in air temperature causes evaporation of water molecules with their retained heat energy; the warmed air is transported overland warming the temperature. After the summer season has gone, the land is cool, but warm air is still carried in from the warm ocean until late in the winter.

The ocean also carries cooler temperatures inland through wind; this is after the winter has passed and the land is getting warmer. The land is heating rapidly with increased sun energy, but the ocean is taking much longer to heat, so cool breezes keep the temperature low until the water heats up.

The slow change of temperature in water is the reason why in Britain summers are not as hot as they could be and winters are milder than expected.
The effects of warming or cooling by oceans are experienced most in areas close to or surrounded by the water, further inland the air that has heated/cooled over the sea has already mixed with the air over the land and so temperature changes by oceans are not such an influence.

Reference:
www,niwascience.co.nz
www.gdre.org/oceans/fsheet-01.html
www.astronomy.org/programs/seasons/index.html
www.earthguide.ucsd.edu
www.wikipedia.com

Transfer of Energy

2007-09-03T05:58:00.000-07:00

Laws Of Thermodynamics

First Law: Energy cannot be created or destroyed and is transformed to another form. The total amount of energy stays constant, constantly changing form.

Second law: The transformation of energy from one state to another is never 100% efficient, some is always lost to another state, in most cases it is lost to heat.

Forms of Energy

Kinetic Energy
This type of energy refers to motion; any object that moves possesses kinetic energy.

Radiant energy comes under the kinetic heading; it is electromagnetic energy, which travels in waves. The length of the wave varies massively, from one end of the scale to the other; these waves also vary greatly in the level of energy they provide.

The sun provides a range of these waves; they are listed below in order of wavelength, starting with the shortest. Shorter wavelengths provide higher amounts of energy than the longer waves and are potentially dangerous because of their high amounts of energy.

Gamma rays
X-rays
Ultraviolet rays
Visible light
Infra-red
Microwaves
Radio waves

Only a small portion of radiant energy is visible to the naked eye, it is only visible light which can be naturally seen, waves on either side of the scale become invisible without the aid of specialist tools. Light rays provide the planet with the energy for a number of essential functions (mainly photosynthesis and vision).

Thermal energy is another form of kinetic energy, which relates to heat, heat is present where ever molecules and atoms vibrate or move about. The level of energy depends on the amount of movement going on inside the object or body, (higher temperatures contain more energy than lower ones).

Thermal energy can be transferred from one body to another in three ways, thermal conduction, convection and radiation. Heat is the result of many energy conversions and can be got from light, electrical, mechanical, chemical, nuclear and sound. For this reason heat is usually the cause for the second rule of thermodynamics.

Potential Energy
This types of energy relates to any object that has stored energy, this stored energy has the potential to change other objects; it is waiting to become kinetic.

Gravitational energy comes from an object that has a position or place; it is the effects of a gravitational force pulling on the object. When an object is raised its gravitational potential energy is increased, it is increased to an amount equal to the force used to lift it. The object will hold or store this energy until it is released and can fall to the ground. At this point the energy is converted into kinetic energy and when it hits the floor the energy is transformed to heat and sound. Gravitational potential energy is relative to its distance from the ground and mass.

This type of energy is what holds the solar system together; the gravitational force of the sun keeps the planets in its orbit.

Chemical energy is energy that is stored in an object due to its arrangement of atoms and molecules, the energy comes from the chemical bonds that hold the atoms and molecules together. Chemical energy is transformed into many other forms by chemical reactions be they natural or man-made.

Petrol – Burnt to release energy (mainly heat)
Food – Digested to release energy
Plants – photosynthesis is a natural chemical reaction resulting from plant exposure to solar energy.

Earths Atmosphere
The atmosphere is the general name given to the layers of gas that envelop the earth. The atmosphere exists because of events that have happened in space and on the planet for billions of years and are still undergoing change with the aid of life on earth. Different amounts of gases are being consumed and emitted continually; the changes normally occur slowly giving the atmosphere time to stabilise but sometimes sudden large amounts of particular gasses are released, unbalancing the composition of the atmosphere.

The gases remain in the atmosphere rather than disappearing into space because they are attracted to the gravitational pull of the Earth, different gases have different weights and so the gas composition can be divided into two sections; homosphere, where the composition is generally mixed, this extends to about 80km vertically from the surface and the heterosphere which consists mainly of the lighter elements of helium and hydrogen above.

Atmosphere can also be divided into layer according to the temperature and pressure variations that occur throughout the atmosphere.

Troposphere
This is the layer closest to the surface and is heated from the surface as well as the above atmospheric layer. Temperature decreases with height in this layer, as the layer above increases with height this makes troposphere well mixed and thus quite turbulent. The turbulence means that this layer experiences nearly all the weather on the planet and is regarded as the “zone of weather”.

The troposphere extends to approximately 11-16km above the earths surface depending on where it is geographically. For example the troposphere extends higher in the tropics than it does over the poles, the higher temperatures from the surface create more turbulent mixing; pushing the boundary of the layer higher.

The boundary between the troposphere and the next layer is called the tropopause, this is the area where the temperature stabilises and remains constant with increased height. When the temperature begins to change with height you enter into the next layer.
The pressure within the troposphere decreases with height this is because pressure is the weight and force of the atmosphere upon the earth, so as the height rises the mass of atmosphere is reduced and thus the pressure.

Stratosphere
This layer lies above the tropopause and reaches heights of approximately 50km. This is a stable layer of atmosphere with little mixing and because of this pollutants that enter can reside in the stratosphere for many years.

Temperature increases with height in this layer this is because of the layer of ozone that is present, the ozone absorbs ultraviolet radiation emitted from the sun and when this happens heat is released warming the layer. The reaction occurs at the higher level of the stratosphere making the lower heights cooler because there is less UV radiation to absorb.

The absorption of UV rays in the ozone helps to protect the surface from harm; UV in large concentrations is very damaging to many forms of life. The pressure throughout this layer again reduces with height.

The stratopause is the area between the stratosphere and the layer above, where temperature remains constant with height before going into another stage of change.

99.9% of the atmosphere is contained within these two layers, which means that this is where the pressure is most exerted. Above these layers the atmosphere is filled with lighter particles that exert a minute force on the earths surface.

Gaseous composition of the lower atmosphere

Nitrogen 78.1%
Oxygen 20.9%
Argon 0.9%
Carbon dioxide, methane, rare (inert) gases 0.1%

The composition varies from place to place due to the presence of water vapour and aerosols.

Mesosphere
The mesosphere lies above the stratopause and extends to an altitude of approximately 85km. Temperature decreases with height in this layer, this is because there is no ozone present to absorb UV radiation and heat the layer. The lowest temperatures are experienced in the mesosphere, with temp dropping to a low of approx -100 degrees Celsius /173 degrees Kelvin.

It is in this layer that most meteors that have entered the atmosphere are burnt up, we can see this in what is commonly know as shooting stars. There is still a small trace of moisture at this height and noctilucent clouds can be seen sometimes when the conditions are right.

The ionosphere begins within the mesospheric layer at an altitude of about 60km. The ionosphere is not an atmospheric layer but occupies the same space and is a layer of ionised air. In this area and upwards the energy from the sun is so strong that it forces apart molecules and atoms leaving ions and free floating electrons. The ionosphere continues up through the upper atmosphere to heights of about 600km.

The mesopause is the boundary between the mesosphere and the layer above where temperature remains constant with height until it changes on the other side.Pressure reduces with height and in the mesosphere pressure reaches zero and continues to decrease.

Thermosphere
This is the layer above the mesopause and has a strong increase in temperature with height. Molecules are heated by the sun to temperatures up to 1727 degrees Celsius/ 2000 degrees Kelvin. The total air temperature is not high though, this is because air temp is measured by its kinetic energy and the air here is very thin with few particles so the stored energy is not noticeable.

The ionosphere extends through the thermosphere and out into the exosphere.

Exosphere
This is the upper most layer of atmosphere and extends to approximately 10,000km above the earths surface. At this point the atmosphere merges into space and molecules can be lost out of the atmosphere. This area is composed of hydrogen and helium at extremely low densities and is where most satellites will orbit the earth.

Global Radiation Budget
The global radiation budget is the balance between energy from the sun coming in and out of the earth’s atmosphere and its surface. The energy input and output are equal, if they were not the earth would either heat up or cool down, the balance and energy transfer means that the earth has a constant temperature. Once the solar energy enters the atmosphere it does a range of things before leaving, the things it does fuel nearly all life on the planet.

Energy In
Energy from the sun travels 93 million miles in just 8 minutes (speed of light) to reach the earth; once it enters the atmosphere it can be absorbed or reflected. Reflected energy returns to space, while absorbed energy becomes trapped in the earth’s cycles, transferring and changing form before leaving the earth’s atmosphere.

Some energy is reflected straight back into space, firstly in the atmosphere, then by clouds and finally by the surface of the earth (land and oceans). The lighter in colour the higher the amount of energy reflected, hence clouds reflecting more light than anything else. This reflected energy does not interact with the particles and so does not have any warming effects.

Of all the solar energy that enters the atmosphere, 30% is reflected back out.

Atmosphere 6%
Clouds 20%
Land/Oceans 4%

The other 70% is absorbed.

Certain particles in the atmosphere absorb solar radiation, these are mainly, water vapour, dust and carbon dioxide, and the water molecules in clouds also absorb radiation. Land and oceans absorb visible light energy. Different surfaces will absorb solar energy at different rates.

Atmosphere 16%
Clouds 3%
Land/Oceans 51%

Energy Out
All energy that is absorbed must eventually be released and will leave the earth’s atmosphere.

Radiation absorbed by water can be released as latent heat; this means that the water molecule holding the absorbed energy is moved into the atmosphere by the process of evaporation. With latent heat no temperature change is detected.

Sensible heat can be detected as a change in temperature and is an energy transfer; the heated water molecules release the energy back into the atmosphere.

The energy absorbed by the earth and oceans transfer this energy into infra red energy (heat), on sunnier days when higher levels of solar radiation are absorbed by the earths surface you can feel the heat emitting, darker surfaces absorb more radiation and so give off more heat. Some of the energy that is released is then absorbed by the atmosphere.
Energy absorbed by the atmosphere and clouds eventually has to be released and radiates out into space.

Atmosphere 38%
Clouds 26%
Land/Oceans 21% (of which 15% is re-absorbed by atmosphere)
Latent heat 23%
Sensible heat 7%

Reference:
www.eia.doe.gov/kids/energyfacts/science/formsofenergy.html
http://vortex.plymouth.edu/atmosphere
www.ace.mmu.ac.uk

Basic Principles of Ecological Science

2007-09-03T05:40:00.000-07:00

Evolution

Darwin’s Theory is a scientific theory laying out a reasoning for evolution, not only that it does occur but also why. The theory itself says basically, that through natural process certain species and individuals within a species will survive over others due to their ability to adapt or to be more suited to their environment.

If a genetic characteristic within a species allows it to survive and produce more offspring, that characteristic will then be carried on to a grater number of the species. The members of the species who do not have the characteristic will not survive to reproduce so well, and over time tend to be eliminated. This is known as Natural selection.

Classification
The scientific system of classification is a means of organisation for plants and animals so that you can identify and understand how they relate to other plants and animals. It allows you to see the relationships between species and what common attributes the may have. There are seven main levels to this and some sub-divisions occur. The classification is arranged from the largest to smallest groups, with smaller groups becoming closer in relation to each other.

The classes are as follows,
Kingdom, Phylum, Class, Order, Family, Genus and Species.

Habitat
Habitat is an area/environment that supports an organism or an ecosystem. There are plenty of different types of habitats but these can often fall under the four major habitat types.

Terrestrial – Relating to the earth and generally composed on land/ ground.

Freshwater – Aquias habitat, relating to water that is not salty or contains minimal salts.

Estuarine – A habitat where the seas salt water meets and mixes with freshwater.

Saltwater – Habitat occurring in sea or saltwater.

Population Ecology
This is the study of populations, their patterns, influences, effects and interactions. It also works to use these statistics to try to predict survival and reproduction in management of natural populations.

Populations are limited by numerous factors, space, food supply, disease, competition, predation. For a species to survive it must have adequate room to live, in a certain areas their may be limited nesting spaces, a lack of space can also lead to a lack of food and species numbers would be effected. Competition between species for food and space will affect population levels. A disease within a species could kill off and limit survival rates.

Behaviour between individuals within a species (intra-specific) has a direct effect on their population rates. All species need to survive and reproduce, and to do so successfully will result in population growth. How a species interact affect its survival and reproduction. Their mating habits, feeding habits and how territorial they might be are all factors to consider, along with social behaviour and family units. Some species can be fiercely territorial and will attack and kill each other, some eat their own young, some can have complicated and difficult mating habits. This will all have a direct effect on population rates.

Behaviour between different species (inter-specific) can have a massive influence on individual species populations. If two different species are competing for the same space and food one will generally be more dominant or aggressive than the other, resulting in a growth in the dominant species and decline in the other. When a new species is introduced into an environment it can upset the already existing balance of that ecosystem. Competition then grows for food and space and other species may loose out, these introduced species can lead to a loss of native species, e.g. Grey vs. Red squirrels, it all depends on the individual species involved and their ability to adapt.

Ecosystem ecology
Ecosystem is the word used to describe a community of organisms in an environment and how they all functions as a unit. There are two components to this unit, abiotic, which is everything that is ‘non living’ such as soil, climate, water, atmosphere. The second component is the biotic, which refers to the ‘living’ organisms; plants, animals, insects, fungi and bacteria are all part of this.

The abiotic factors will produce the initial environment and cannot be controlled, however the biotic part of the ecosystem will influence their non-living habitat in how they populate, feed and interact with other species as well as their environment.

All components of an ecosystem rely on each other for future survival and must exist as a whole.

Community
A community is the term given to a group of species living in an area under similar environmental conditions that interact with each other in various ways. These include competition (for food, space), predation and the different types of symbiosis. All the organisms living in the community are dependant on each other for survival, be it directly or indirectly.

Communities have an organised system or structure, through which energy flows and nutrients and water are cycled. Because species in community have similar reactions to the environment, you tend to find a characteristic set of species in that area. For example on heathland you will find heather, bilberry, lichen and birch scrub, this is because they all require very similar conditions and react in similar ways to the properties of the environment they are found in. This helps you to recognise communities with relative ease.

Ecological Succession
This is the term applied to a predictable sequence of changes that occur in a community over time if left unmanaged. If an area is left to it’s own devices it will go through various stages, each stage making more suitable conditions for the next. Succession takes place because the impact that organisms have on an environment changes its structure. Changes in environment (soils, moisture, nutrients, light) means that species will adapt, these adaptations will affect the environment and thus the cycle begins again. This means that no area ever stays the same and will be continually changing.

Ecological succession occurs in two ways. Primary succession takes place where no soils were present before, new substrate can be deposited (e.g. from lava flow or glacial melts), pioneer plants such as mosses and lichen (known as primary colonisers) start to create more suitable conditions for plant growth. Plants are found at specific stages of succession, firstly grasses then shrubs followed by trees. The species of animals found depends on the vegetation present. The final stage is known as the climax and in many cases this final stage is dominated by mixed deciduous woodland.

Secondary succession occurs in areas that already support life but have been unable to develop to the climax stage through damage/destruction either by natural disaster or human intervention. In many cases secondary succession occurs much faster than primary, this is because there is already an existing seed bank in the soil and roots that may have been undisturbed. The reduced competition would mean than more competitive or adapted species would dominate quickly. The final result is the same though and all although it may have taken a different route the climatic stage will still eventually occur if left to do so.

Once the climax stage has occurred the area still continues to develop through the regeneration cycle. If a tree falls, it leaves an open space in the canopy; eventually this space will be filled by another tree. In the beginning many plants will attempt to succeed this space, but a mini succession will occur with similar stages but on a much smaller scale. This will be continually occurring as the vegetation in the community is of various ages and stages.

Nutrient cycles

Carbon Cycle
Carbon dioxide is taken in by plants and used to produce carbohydrates for growth. Some is put back into the atmosphere through respiration. When animals eat plants they take on the carbon, which is then passed up the food chain. When the organism dies, the carbon in the tissue is broken down by bacteria and fungi (with the aid of oxygen) and converted into carbon dioxide. This is then released back into the atmosphere.

In areas of water, cooler temperatures allow for more carbon dioxide to be dissolved, the water circulates and warmer waters allow the carbon to be released back into the atmosphere.

Nitrogen cycle
Nitrogen in the atmosphere becomes fixed in the soil by nitrifying bacteria, which convert it into nitrogen compounds (nitrite, nitrate, ammonium), which allows plants to absorb and utilise the nitrogen. It is then stored in the plant, when animals eat the plants they take on the nitrogen and again it is released back into the cycle via decomposition by bacteria and fungi, this process is known as mineralization.

Phosphorous cycle
This cycle differs from many, as the cycle doesn’t have a gaseous stage, the largest source of phosphorous is found in sedimentary rock.
Rain causes weathering of rock, exposing and distributing of the phosphates throughout soils and water. Plants take up the phosphate ions and they are stored in organic tissue. The phosphate is passed on through the food chain, it is returned through excretion of urine and faeces and by decomposition of dead organic matter.

Phosphates that runoff into water, settle on the bed and can take along time to return to the cycle if not circulated in the water to be taken in by aquatic plants and passed through the food chain.

Energy Flow
Energy is what allows everything to survive; it cannot be created only transferred. This applies to all life on the planet, everything needs energy and as it cannot be made it must be obtained from outer sources. Nearly all life on the planet is dependant on the energy from the sun.

Solar energy radiates down onto the earths surface, photosynthesis transfers this light energy into chemical energy, which is then passed on through the food chain to sustain other organisms. These are known as trophic levels.

Only a minute percentage of all the sun’s energy reaches the earth’s surface, most of the light and heat energy is lost on passage through the atmosphere. From this energy only1-5% is used in photosynthesis. These organisms are the first trophic level or primary producers. The energy is stored in the plant until it is consumed by another organism; this energy is then passed into the consumer. These are usually herbivores also known as the primary consumers. The energy is passed on to creatures that prey on the herbivore and thus continue through the food chain.

During this process of energy transfer, losses occur along the way, this is because of energy used for heat, respiration, growth, movement etc. This means that at each trophic level the total amount of energy declines from one transfer to another, limiting the total number of trophic levels (usually to about 5). This is known as transfer efficiency. Transfer efficiency varies from one organism to another and also in different types of food chain. Because carnivores use more energy than herbivores when obtaining new energy, the total energy gain is less; it reduces the further up the chain you go. Energy is also transferred to bacteria and fungi when an organic organism decomposes.

Because of this flow of energy, it is unrealistic to think in terms of food chains, very few species rely on one species for food (it would be highly inefficient) and if changes were to occur to one species in a chain, it would directly effect all the other organisms in that chain. This is why food webs give a better understanding of the way that organisms transfer and gain their energy needs. Secondary consumers (carnivores) tend to have a varied diet, creating more complex webs. These webs are more stable then simple ones, allowing for a bigger range of energy sources.

World Biomes

2007-09-03T03:15:00.000-07:00

Biomes are large areas of characteristic and distinctive groups of flora and fauna, they are the highest grouping of life and all other groupings of environments, ecosystems, habitats etc exist within the Biome.

Biomes are classified according to the climate and geography as well as being heavily influenced by oceans and ocean systems. Latitude has a strong influence on a biome. Areas closer to the equator receive stronger solar radiation for longer periods of time, further north or south from the equator receives far less energy for reduced lengths of time; the varying amounts of sunlight create different seasons and weather patterns. The presence of oceans and currents also contribute to temperature changes and moisture levels, the two influences constantly react with each other creating unique climates and weather patterns to the area.

The influences create specific environments for life to grow in; the rates and abundance of growth depend of the characteristics of the biome and will vary immensely from one biome to another.

There are 7 major world biomes:

Tropical forest
Desert
Temperate broadleaved forests
Coniferous forests
Grassland
Tundra
Ocean

Tropical Forests
Found in:

Central America
South America (Amazon)
East Africa (Madagascar)
Africa (Congo River basin)
South East Asia
Australia (Queensland)

Tropical forests occur along the equator (up to15-25 degrees north or south) and so receive very direct sunlight all year round. Due to the central position, these areas of land constant levels of sun with 12 hours days constantly throughout the earths orbit. Temperatures average at 77 degrees Fahrenheit

The incredible heat evaporates large amounts of water and once they have risen and cooled, condense to form clouds. 50% of the rain that falls in rainforests comes from its own evaporation and not carried in or out by winds. North and South equatorial currents circulate warm water away from the equator and bring in cooler waters, as the water gets closer to the equator it rapidly heats, creating masses of evaporation. Rainy seasons are dependent on whether the northern or southern hemisphere is facing the sun. Rainforest experience about 2.5 meters of precipitation a year, this coupled with large amounts of solar energy creates an environment for rapid and large growth.

Rainforests make up 6% of land surface and are home to over half the population of all plant and animal life on earth (over 15 million species). The most abundant group found in rainforests are trees making up 70% of all species in the rain forest.

The soils are often nutrient poor in rainforests because nutrients are leached away by periodic precipitation and the abundant life here means they are highly competed for. The lack of light that penetrates the canopy means little life survives on the forest floor, all the activity goes on high in the tree canopy. These conditions are ideal for bacteria and fungi making the decomposition process rapid, this also adds to the reduced nutrient availability in the soil.

Vegetation
Strangler Fig (Ficus ssp)
This is the name given to species of figs that exert the following characteristics. Figs are an important part of the food chain in the rainforests and a constant source of food as they fruit several times a year. Strangler figs are tall canopy trees (up to 148 ft) with light bark and waxy ovate leaves that protect the tree from too much sun evaporation from sun and wind.

Strangler figs start out as epiphytes attached to a host tree; they rely on the tree for stability but not for nutrients. The fruits are eaten by animals and birds and are deposited higher up in the trees. The figs use water that has collected on the tree and catch more sunlight, as it grows further up. From its height the fig sends out roots that suspend from branches, once they reach the ground they take root and start draining nutrients from the soil and are very direct competition with the original host tree. The fig then starts to send out a network of shoots that envelop the host and fuse together. Gradually the roots encompass more of the tree and squeeze tight around it cutting of its circulatory system. Once the fig reaches the canopy it branches out across the canopy in an umbrella shape with lots of small leaves. The host tree, now internally damaged and out-competed for nutrients and light, dies.

Strangler figs have a very unique symbiotic relationship with a species of wasp (Aggaoninae ssp), the reproductive process is complex and very specific and without it the strangler figs would cease to exist.

Fig trees in the rainforest are at threat due to excessive logging regimes and fires, further loss of populations could have dire consequences for the many species of bird and animal that feed from its fruit all year round.

Mangrove Forests
Mangrove forests have specially adapted to live on the edge of rainforests where the forest meets with the ocean. They protect species further inland by slowing the flow of water and collecting sediment and salt. Mangroves account for 39.3 million acres of coastline across rainforests, 27% of these are in Southeast Asia where they are thought to originate.

Specialised aerial root systems hold the trunk of the tree over the water; support roots are buried into the mud for stability. The trees can survive in waters of high salinity because their aerial and tap roots filter out salt, salt taken in by the tree is stored in the leaves and is shed periodically.

Seeds of the mangrove germinate and grow into seedlings on the parent tree, eventually they are dropped and will either take root in the mud or will be swept out with the tide and take root somewhere else. The seeds are hardy and can travel vast distances from the parent tree before taking root

These forests support a wide variety of life and have their own environments and ecosystems within the biome. They are breeding grounds for an assortment of marine animals such as fish, shrimp, prawns, shellfish and snails. They provide nesting nesting sites for many shore birds and are home to crab eating monkey and proboscis moneys as well as fishing cats, lizards, sea turtles and fruit bats.

All these species rely heavily on the mangrove forests and yet they are under threat from human activity. Mangrove forests act as sinks for pollutants, crude oil, sewage and toxic materials build up in the waters around the trees, the presence of all these products put to much stress on the trees and they die. Mangroves also make good charcoal and so are at threat from logging to feed a growing industry. The loss of mangroves not only means a major loss of bio-diversity, but also leaves inland forest and land open to damage from salinity and coastal weather patterns that they are not adapted to deal with.

Animals
Howler Monkeys (Alouatta spp)
Howler moneys are primates that are native to Central and Southern America, there are 9 species recognised. Howler monkeys are the loudest land animal, they are second in volume only to the blue whale and can be heard up to three miles away.
Howler Monkeys are found in:

Southern Brazil
North Argentina
Paraguay
Bolivia

The males are black-brown and females and young are much lighter, adults weigh from 3.5 – 10kg and are between 56-92cm long.

The species have specially adapted to life in the rainforest, spending pretty much all there time in the trees howler monkeys have developed long prehensile tails that act as another limb when moving around the canopy. The hands are specially adapted with the first two fingers being separate and opposite from the other three; this helps with gripping and moving on branches. The monkeys diet consists mainly of canopy leaves with some ingestion of fruit, flowers, buds and maggots to supplement their diet.

Howler monkeys live in the canopy in small social groups of about 15 to 20 animals, they communicate through vocals and can make the forest vibrate with their calls. These monkeys are very gentle despite their loud manner and can live to 20 years. They do not survive well in captivity and are very much a monkey of the rainforest canopy.

Howler monkeys are in decline and are under threat from habitat loss due to excessive logging for timber, which is shipped across the world and sold by many popular retailers.

Slender Loris (Tardigradus malabaricus)
This small primate is native to the tropical rainforests of South India and Sri Lanka and tends to live along the edge of the forest in wet or dry conditions. They prefer the cover of thick thorny vegetation, which provides them with protection from predators.

Slender Loris are small weighing about 275-348g, they have light red to brown fur on their backs and pale fur on their fronts. The arms and legs are long and very slender with the hair becoming very thin around the forearms, hands and feet. The lack of hair helps them when hunting; they stretch their arms through the twisted thorny vegetation to gram unsuspecting insects. The Loris has a short vestigial tail, which offers little balance, and so all movement is slow and calculated. The second finger is short on both hand and foot and works alongside the thumb, this helps with holding onto branches in the high unstable canopy.

Slender Loris are insectivorous which means their diet mainly consists of insects but they are also know to eat slugs, leaves, flowers, shoots and occasionally eggs. They hunt alone or in pairs but will share food and live in small social communities in tree hollows. They rarely leave the safety of the canopy and are seldom known to use the rainforest floor.

Interestingly the slender Loris have a taste for toxic insects and will regularly eat insects with poisons that could numb a mans arm.

As with so many rainforest creatures the slender loris are under threat from habitat loss due to excessive logging.

Dessert
There are two types of desert biome ‘hot and dry’ and ‘cold’, both types characteristically have very little or no vegetation and highly specialised animal species.

Hot and Dry Deserts
Found in:

North America
South Asia
Africa
Australia

Hot and dry desserts are found near the equator and are generally found along the tropics of Capricorn and Cancer. These deserts cover a fifth of the lands surface but are home to few species of flora and fauna. Temperatures in the hot and dry dessert are somewhere between 20-25 degree centigrade, maximum extreme temperatures occur up 45 degrees and the temperature fluctuates little over the year because of its latitude. The spring and autumn is warm and summers are very hot, the temp cools little over the winter months, there is very little rainfall in the area in general, even winters bring little or no rain.

Vegetation in hot, dry deserts is rare, any vegetation that does survive needs to be able to store its own water and nutrients and be able to withstand the suns radiation. Any vegetation that manages to grow in this hostile environment are usually ground hugging shrubs and small woody trees.

Animals that live in this barren hot environment need to have the ability to burrow into the sand, this helps them to keep cool during the hot days and they will then venture out at night when it is cooler. The creatures most likely to be found in this biome are nocturnal carnivores, insect, arachnids, reptiles and birds.

Cold Deserts
Found in:

Antarctic
Greenland
Nearctic realm
Atacama (Coasts of Peru and Chile)
Gobi (Northern China and Southern Mongolia)
Great Basin (Western United States)

Cold deserts are found near the arctic, temperatures are so low that no vegetation can grow with the exception of a few mosses, lichen and grasses. Temperatures at this latitude vary greatly with summers reaching up to 20 degrees centigrade and winters averaging from –2 to 4 degrees. Spring and summer never get warm enough for plants to establish and winters bring long months where the ground is covered in snow, this makes difficult conditions for life.

As with hot deserts, cold deserts have little vegetation, the plants that are present are scattered and ground coverage varies from 10% - 85%, once established the brush can reach 15-122cm high, these are mainly deciduous and many have spiny leaves

Some animals found here also have to burrow as do those species in hot, dry deserts, but this time it to keep warm not to cool. Typical animals of cold deserts are, antelope, ground squirrels, jackrabbits and kangaroo rats.

Vegetation
Barrel Cactus (Ferocactus ssp)
This cactus is common in dry desert areas, they are native to North America, predominantly the Mojave Sonora and Chihuahua deserts. It has a cyndrilcal body 5-11feet round. The cactus has parallel ridges running down the sides with 3-4inch spines. It is a flowering cactus with green/yellow/red rings of blossoms that bloom in summer.

They store water and nutrients in the plant but actual water requirements are very low, filled with a slimy alkaline juice. The pulp can be made into a sweet food and Native Americans use the spines for fishing hooks,

Common Salt brush (Atriplex polycarpa)
Common salt brush is a common plant to the colder deserts of North America. It is a greyish shrub with many branches coming out from the base. The small white leaves cover the branches closely and are sharp spines clustered densely over the shrub, this helps to conserve water. Yellow flowers grow out from the stem. These plants can reach 2-3 feet and are very well adapted to the dry alkaline soils they are found in.

This plant has adapted over time to its dry conditions and is now a plant that actually favours dryer areas and does not tolerate wetter soils. Salt brush gets its name because it stores salt taken in from the soil in the leaves, which leave white deposits, these help to attract moisture from the air. The leaves are periodically shed to rid the plant of salt and also conserve moisture in times of drought.

This is a useful plant and is a good source of minerals for cattle, deer, rodents and pronghorns. They are a good shelter for birds and animals and can be used as a perch for larger birds. The plants are used by people for food and as a yellow dye.

Animals
Camel (Camelus spp)
There are two types of true camel in the world and both are found in hot deserts, these animals are so well adapted to life n the desert nearly all their characteristics are ideal for surviving in hot, dry barren areas. They are native to the dry and desert areas of Northern Africa and Asia,
Camels are quite distinctively identified by their humps the Arabian camel (Camelus dromedaries) has a single hump, and the Bactrian camel (Camelus bactrianus)) Camel has two humps. The hump is a reservoir for fatty tissue, when energy is needed the fat is metabolised, this process also produces water with the reaction of oxygen with metabolised fats. This means that camels can go weeks without water and up to a month without food. This makes them perfect animals for surviving long journey across arid desert.

The blood cells of camels have an oval shape, this shape means that cells do not explode when large amounts of water are taken in, it also helps to prevent dehydration. Camels retain most of their water and urine is thick syrup pretty much void of water and apparently faeces is so dry it can be used as fuel for fires.

The fair colored coat of the camel reflects sunlight helping it to keep cool and the legs are long to keep the body away from the hot sand. Camels can actually withstand body temperature changes above the normal level for mammals, fluctuating from 34 degrees C at night to 41 degrees C in the day.

Camels have long eyelashes, lots of hair around ear openings and nostrils that can close, these all help camels to withstand windblown sand.

Camels are now mostly domesticated and very few native species exist in the wild. There are 1.4 million domesticated Bactrian camels and only 1000 wild. Arabian camels have a population of 13 million all of which are now domesticated. A feral population of camels descended from camel taken over during the 1900 is now rife in Australia with a population count of 700,000, the Australian government have decided to start culling the population because they are using up limited resources need by farmers.

Desert Kangaroo Rat (Dipodomys deserti)
The desert kangaroo rat is one of 22 species of kangaroos rat recognised worldwide that has adapted to desert conditions. It is small (35cm including tail) which means it does not require much water for survival. The coat is light brown/yellow on top and white on the underside. The rat has large eye because of its nocturnal activity.

Most of the day is spent sleeping underground, the kangaroo rat build a series of tunnels and chambers below the surface where it is cooler. It comes out at night at periods when the air is cooler and moister.

The diet consists of seeds, leaves, stems and insects, the digestive system is adapted to convert food into water, and this improves chances of survival. The kangaroo rat has a specially adapted cheek pouch that can store food for several weeks.
This species is abundant and is not endangered.

Temperate Broadleaved Forests
Temperate broadleaved forests are highly diverse places with various levels of growth the characteristics of these biomes are tree which shed their leaves in winter.
Found in:

North America
Middle of Europe
Russia

These biomes are found at latitudes up to 23 degrees north and 38 degrees south, their positioning gives them varying periods of solar energy throughout the year; this gives these areas 4 distinct seasons (spring, summer, autumn, winter). Summers are characteristically mild and winters are relatively cool. These forests are mostly found close to oceans and this has a large effect on the temperature and precipitation in the area. Temperate broadleaved forests typically experience 14 inches of precipitation in winter and 18 inches in summer. Temperatures vary from –30 to 30 degrees but these extremes are rarely experienced in most places.

These forests are very diverse places with plants grown occurring at many levels and the presence of large numbers of plant species, the soils of temperate broadleaved forests often being nutrient rich. Due to the cooler winters, many animals in temperate broadleaved forest have adapted by hibernating through this season.
Species of plants typical to these areas include such species as Maple (Acer spp.), Beech (Fagus spp.), Oak (Quercus spp.), Hickory (Carya spp.), Basswood (Tilia spp.), Cottonwood (Populus spp.), Elm (Ulmus spp.), and Willow (Salix spp.). Squirrels, rabbits, skunks, birds, deer, mountain lion, bobcat, timber wolf, fox, and black bear represent fauna.

Vegetation
Oak (Quercus spp)
Oak trees are a dominant species in temperate broadleaved forests, there are hundreds of species considered to be Quercus but not all are true oak species. Oak as a Genus are native to the northern hemisphere, namely North America. The oaks can be split into 3 large groups, evergreen oaks, red oaks and white oaks, all species have similar characteristics from bark to leaves but each species has its own adaptations to changes in soil, temperature, weather patterns etc.

Oaks characteristically have lobed leaves, these can be softly lobed or serrated and some even have a single leaf outline. These trees being native to temperate regions shed their leaves during the colder months, this helps the tree to conserve moisture during the dryer season and also help the tree to shed excess toxins that have been stored in the leaves.

Oaks are important trees for the surrounding wildlife, as they tend to be a breeding ground for insects and share symbiotic reproductive relationships with a few particular species of wasp. The popularity of the oak amongst insects attracts larger birds and animals to these trees to feed. It is also a popular tree with birds and small mammals. Due to their longevity oaks are very popular trees for people, they can live for up to 1000 years if undisturbed and are majestic and strong trees that provide beautiful scenery, despite this oaks are on the decline because of changing land uses and the growth of the logging industry.

Carpet Moss (Mnium hornum)
This species of moss (one of thousands) is very common among the temperate broadleaved forests of North America and Europe. This moss will be found almost everywhere that you would find deciduous woodland. It is a simple rootless evergreen plant that will be seen growing on the ground, in streambeds and at the base of trees. The moss likes to be constantly moist and so absorb water through pores, which are continually open.

Carpet moss reproduces both sexually and asexually this means that reproduction occurs with eggs and sperm and fertilization. The simple plant can also reproduce if cut of from the main body of the plant. This gives moss a really good chance at establishment.

Mosses in general are resilient and hardy they rarely need to adapt too much to suit a specific area and are found in pretty much any environment on the planet.

Animals
European Red Squirrel (Sciurus vulgaris)
The European red squirrel is native as its name suggest to Europe, it is a tree dwelling omnivore and is part of the order Rotentia. The red squirrel is small in size and weighs about 250-340g it lives among the canopy of deciduous forest but are also know to move around the forest floor. They are red to brown in colour with white undersides; both males and females are the same size.

Red squirrels are adapted to their forest environment with large bushy tails that help with balance and also keep the animal warm during the colder winter months. The squirrels have specially jointed legs to improve mobility up and down tree trunks and their hands and feet are clawed for grip.

Squirrels shed their fur twice a year, in the summer they lose a warm winter coat and vice versa in the winter; this is to keep the animal at a stable temperature with the fluxuating temperatures that exits in a temperate broadleaved forest.

Unlike many animals of these environments, squirrels do not hibernate, they deal with the lack of food during the winter month by storing food, they will collect fruits nuts and seeds throughout the proliferous summer months and keep them hidden until needed. When the temperature drops right down the squirrel will not leave its nest (known as a drey) for several days without leaving and so need to have some source of food at this time.

Squirrels are important to their environment because they help to spread seeds from trees and shrubs when the digest and pass on the foods they have eaten.
European red squirrels are common in most of Europe except for Britain where the species is in massive decline and most know live farther north in Scotland. This is down to competition with the introduced American grey squirrel and habitat loss from land use change.

Coniferous Forests
Found in:

North America
Asia
Northern Europe

The coniferous forest biome exists within the northern hemisphere close to the polar region; it occupies large parts of Russia and Canada and is the largest of all the biomes.
Average temperatures in these areas are very cold. Winter is the longest season and during this time temperatures range from –54 to –1 degree centigrade. The weather is dominated by snow but there precipitation is generally low. The summers are short but get very warm with temperature ranging from –7 to 21 degrees, most precipitation falls as rain during the summer. Spring and autumn are short and cold.

The temperature and weather make coniferous forest biomes very harsh places and not much life survives at the cold temperatures. The vegetation is mainly made up of lichen, moss and conifers (pine, spruce, hemlock and fir) these forests darken the forest floor so there is little ground vegetation. Few animal species live in this tough environment; the animals most likely found are lynx, wolverines, bobcat, mink and snowshoe rabbit. This area is home to many insects and thus attracts birds such as finches, sparrows and crows. All species of flora and fauna need to show special adaptations to survive the difficult surroundings.

Vegetation
Conifers (Division: Pinophyta)
Conifers belong to the Class (Pinophyta), they do vary from species to species and some are more tolerant of others but in generally there are many similarities that all species have adapted to survive. Conifers tend to be tall trees, their long thin needles are shaped to protect the tree from evaporating and are waxy to protect from the cold. The needles on coniferous trees do not fall in the winter like broadleaves, they stay on all year; this means that these trees can absorb the suns energy from the earliest time possible.

Trees often grow tall and close together the height gets them closer to the sun to improve absorption and the dense growths of forests protects tree from harsh winds. The roots on conifers are shallow; this is to deal with the shallow, nutrient poor soils. The shape of the tree is well adapted to snow, the sloped limbs let snowfall of and onto the ground, and the weight of the snow if allowed to build up would damage the tree,

Conifers reproduce mainly through the production of seeds in cones, these form on the branches of the tree and develop over months. Eventually the cone opens and the seeds are dispersed onto the ground or a carried away on the wind. Some species (Pinus) take advantage of the presence of birds and pass their seeds on through food.

Animals
Bobcat (Felis rufus)
The bobcat is a carnivorous cat found mainly in the coniferous forests of Canada, larger than a house cat it weighs from 6-10kg and is known by its characteristically short tail. The bobcat had adapted to the coniferous forest in several ways, its coat is dense and keeps the cat warm during the long winter months. The bobcat’s coat also changes colour to suit the season. During winter when there is more snow and everything is lighter, the bobcat’s coat is tawny and grey. During summer the coat turns a reddish brown. The coat is always stripped or spotted. These features help bobcats to remain camouflaged while they hunt.

The cats have long sharp teeth and claws for tearing the flesh of their prey; they hunt silently and normally catch their prey in one pounce. The ears are able to swivel on the head, this allows the bobcat to hear prey all around, this is essential for its survival during the coldest months when food is most scarce.

Grizzly Bear (Ursus arctos horribilus)
The grizzly bear is a sub species of the brown bear which lives in areas of North America. The grizzly bear is very suitable to the environment of a coniferous forest and have adapted several features to aid their survival.

These bears are large mammals that can reach weights of 680kg, the diet consists of mainly plants (makes up 75% of diet) but bears are omnivorous and so are also known to eat insects, honey, small rodents and mammals and even carcases. To find food under the snow the grizzly bear needs to be able to dig, it has adapted a large muscular hump on its back to power the limbs when digging. This makes scavenging for food far more energy efficient. The paws also have large claws that help the bear to dig up hard soil.

The grizzly bear has a very thick coat that keeps it warm all year and helps to regulate temperature during the hibernation period. The coat also varies in colour from area to area suggesting that it helps with camouflage.
The bears also need to conserve energy during the coldest winter months, to do so they go into a state of false hibernation. It is not a true hibernation as the heat rate and temperature do not decrease by much and they are easily roused from their sleep, but it does conserve energy for the bear. Before the hibernation the bear will gain hundreds of kilograms in fat stored on their body. During the hibernation this fat is converted to energy.

Grassland
Found in:

North America
South America
Asia
South Africa

Grassland cover many areas over the globe, they are mainly situated at middle latitudes and are affected by seasonal change. They are mainly found inland situated away from the effects of large bodies of water.

Grasslands can be divided into different types, some are tropical and wet and others dry, the defining features of all of them is that grass dominates the landscape with little or no wood plants to be found and precipitation level is between 25 –75 cm. Grasslands tend to have two distinctive seasons a growing season and a dormant season, the summer brings warm temperatures and increased rainfall (but not enough to support trees and shrubs). During this time grasses spur into life from the effects of the sun and increased precipitation.
Wet grasslands are dominated by tall grasses and have moist, humid climates; the increased precipitation from evaporation allows these grasses to grow to heights of 6-10 feet.

The dryer grasslands experience bigger extremes of temperature and weather can be very erratic. Grassland temperatures can vary through out the year (–40 degrees F to 70 degrees F from winter to summer). Long periods of drought commonly cause fires in dry grasslands. The grasses are able to withstand fire damage because they grow from the top and not the bottom so can recover quite well in the aftermath of a fire.

The lack of cover from trees and shrubs means that wind blows straight through grasslands making them seem very windy, plant and animal species need to show special adaptations to dealing with low levels of precipitation, strong winds and varied temperatures.

Vegetation
Blue Grama Grass (Bouteloua grasilis)
Blue grama is a common grass associated with both tall and short grasslands of central North America. The plant can reach a height of 18 inches and grows in tufted bunches close together to form sod mats. The leaves of this grass are flat and grow to 1-10 inches out from the base. Flowers (which bloom jun–aug) grow from 7-18 inches and the ends look like crescent moons.
These plants are well adapted to grassland environments and can withstand the effects of drought, heat, cold, fires and grazing; they cope well and even prefer being in full sunlight. Blue Grama Grass has shallow roots, which allow the plant to absorb water quickly when it does rain. The shallow network of roots actually helps to bind the soil together and prevent it from being eroded by wind.

This grass is easily damages by ploughing; once the roots have been ploughed it can take decades for the plant to re establish. Blue grama can survive well in dry grasslands due to its ability to enter a dormant state during the cold dry winter and droughts.

Pampas Grass (Cortaderia selloana)
Pampas grass is a common tall grass of the flat plains of South America; this is a wet grassland area with larger vegetation than dry areas. Pampas grass can grow up to 12 feet tall; it grows in tussocks with dark green razor sharp leaves that extend up to 10 feet. This grass is well adapted to the warm damp climate of South America but can infact survive in almost any habitat, it grows well in sun, on damp or dry ground, deep or shallow soils. Its ability to adapt well to its surroundings makes it an abundant and dominant species in certain areas, its size shading out other vegetation.

During the colder winter months, the long leaves die back during frosts, the leaves then re-grow in spring. The key to pampas grass survival is its roots, the plant sends out deep root systems that dig down into the soil to gain access to water where other plants cant reach, meaning it can survive in even the driest of areas.

Animals
Coyote (Canis latrans)
Coyotes are members of the dog family that live in grasslands (as well as other habitats) in North America. The coyote’s features are similar to that of a wolf but coyotes are much smaller than wolves with a longer nose and ears. The coyote’s coat is generally grey to brown/yellow; the coats hues help the animal to camouflage in the long grasses when hunting or hiding.

The coyotes are well adapted to live in these often species poor dry conditions, this starts with their diet, coyotes are omnivores and will eat almost anything they find in their surroundings. In the grasslands of North America a coyotes diet mainly consists of rabbits, birds, gophers, prairie dogs, rodents, fruit and grasses. Coyotes will live in pacts but generally hunt alone, they can spend up to half an hour stalking prey through the grass with their incredible scene of smell before pouncing. They originally locate prey by rotating their ears back and forth to pick up the slightest sound.

As with many species of animal that live in wide open flat grasslands coyotes can run pretty fast either to catch prey or flee from danger and can reach speeds of up to 40mph.

During the winter months, coyotes survive by eating remains of dead animals and berries if normal food sources are scarce. The variable precipitation levels means that coyotes also need to be able to receive water through their diet and so supplement their diet with water bearing fruits in time of drought.

Saiga Antelope (Saiga tatarica)
Saiga antelope can be found on dry steppe grassland and semi-deserts around Mongolia, Kazakhstan and Kalmykia. This antelope is extremely well adapted to both the cold and dusty environment of the grasslands it inhabits. The large distinctive nose of this species serves functional essential to the saiga’s survival, during them summer months the complex nose structure filters out dust kicked up to protect its lungs and during the winter the nose heats up air before it is taken into the lungs; this allows the animal to conserve energy that would otherwise be lost through having to warm itself.

The coat of the Saiga antelope changes to suit it environment, during the summer the coat is tan and matches the golden/cinnamon hues of the grassland. During the winter the coat turns almost white and becomes 70% thicker with a warm woolly undercoat covered with a course protective overcoat. The two coats keep the animal warm when temperatures drop and protect from chilling winter winds in the open plains.

Saigas are herbivores; their diet is made up of mostly grasses, saltwort, sagebrush and lichens. These animals chew cud to extract as much nutrition as possible from the plants they eat.

Tundra
Found in:

(Arctic Circle)
Canada
Greenland
Russia
Northern Europe
Alaska

Tundra is vast, cold and stark, it exists at latitudes of 55-70 degrees north close to the Arctic Circle and covers nearly 20% of the lands surface, this is the coldest and driest of all the worlds’ biomes. At these latitudes the difference between seasons is massive. There are two main seasons, summer and winter, spring and autumn are so short that they are barely recognised as their own season.

During the winter, the land is dark for most of the time and the sun barley rises in the sky, temperatures can drop as low as –70º C, the ground is permanently frozen up to 100cm below the surface (permafrost). In summer temperatures sit between 3º-16ºC, the sun is visible for most of the day; this causes some of the ice to melt, resulting in a land covered with lakes, bogs and marshes, (the water cannot penetrate the frozen ground beneath).

Due to the freezing temperatures and lack of precipitation (just 6-10 inches a year!), very little can grow in the tundra and the landscape id dominated by low growing plants such as moss, lichen, heaths and small shrubs, there are virtually no trees save a few scattered low growing birches and willow; the lack of tall vegetation makes this a very windy open space.

The extremely harsh environment means that few species of flora and fauna inhabit the tundra, it is a very species poor area as for any species to survive here they need to have made some drastic adaptations. Some of the species that have been able to do this are, shrews, hares, rodents, wolves, foxes bears, deer and caribou. During the summer, the melted ice attracts species of insect and migrating birds such as harlequin ducks, sandpipers and plovers.

The tundra is a carbon dioxide sink, this means that it absorbs more CO2 that it puts out, this is because that it too cold for plants to decompose and release CO2 when the die. The reduction in ice volume that is occurring in the tundra is causing large amounts of stored CO2 to be released to the atmosphere.

Vegetation
Arctic Moss (Calliergon giganteum)
This moss exists within the Arctic Circle in tundra biomes. It is an aquatic plant that forms in the many lakebeds, fens and bogs across the tundra surface. This is a very common plant in theses environments due to its slow growth, cold resistance and ability to store nutrients.
Arctic moss is a bryophyte, it is non-vascular and does not circulate fluids, and this helps the plant to survive in these harsh conditions. The plant reproduces via shoots and spores that need to be kept moist to survive.

The arctic moss is a very slow growing plant, it average growth is 1cm a year, this is in reaction to the reduced growth period in the tundra (50-60 days a year), the leaves live for up to 4 years and shoots up to 9 years.

During the winter the moss goes into a period of dormancy, it stores nutrients so that when the sun comes it can start to grow quickly to utilise the most of the short summer. Living underwater the moss is protected from the strong winds on the surface; its roots carpet and warm the ground, which prepares the ground for other plants to grow.

Arctic Willow (Salix arctica)
Arctic Willow is one of the few tree species that can inhabit the arctic tundra, mainly found in North America, North Canada and North Alaska; this plant thrives in the cold, dry climate of the tundra. It is generally found in cold, dry open places as well as sedge meadows and edges of pools.

This tree only grows to a height of approximately 15-20cm and tends to hug close to the ground to protect itself from strong winds. The leaves are small, oval and pointed, with light green tops and dark green undersides. The leaves have adapted to the cold by growing hairs, which help to prevent evaporation or freezing.

This tree does not have any taproots, only shallow lateral roots. This is because the ground is frozen so close to the surface that no roots could penetrate far down the flowers are unisex and bloom in spring so there is enough time spent in summer to gather energy, the tree uses the constant wind presence to help reproduce as the flowers are forces upwards where they are blown by the wind.

During the summer the tundra is infested with insects all wanting to feed on low volumes of vegetation, the arctic willow protects itself by producing a pesticide to keep insects away so it can grow.

Animals
Caribou (Rangifer tarandus)
Caribou are often more popularly known as reindeer, they inhabit arctic and mountain tundra in places like North Greenland, Scandinavia and Russia. Caribou are members of the deer family, they stand up to 120cm at the shoulder and unlike most deer both males and females have antlers.

Caribou coats are lightweight with hollow hairs, this helps to trap heat close to its body, during the summer coats are dark brown in colour getting lighter towards the winter, they have long ruffs of hair under their necks to help keep warm. The hooves have adapted to suit the unstable ground, they are large and spread, so the caribou can walk competently on snow and through marshy ground.

Caribou can survive in even the harshest of climates, they migrate 100s-1000s of miles to find feeding grounds, travelling in massive herds helps to keep them warm. When vegetation is scarce caribou seem to be able to smell plants under the snow and dig with their frost paws in the snow to get at food. One of the most useful adaptations of the caribou is its ability to lower its metabolic rate and go into a state of semi-hibernation to conserve energy when conditions get really harsh

Snowy Owl (Nyctea scandiaca)
The snowy owl is found in circumpolar tundra, it breeds on coastal areas of Alaska, Canada, Greenland and northern parts of Scandinavia and Russia. These birds like areas of open tundra from sea level to elevations of about 300m.

The snowy owl has very light feathers from cream to grey to white, the feathers are also marked with dark spots and stripes, this provides birds (especially females) with camouflage when nesting and incubating eggs. The owls’ legs and feet are also covered in feathers, which keeps the animal warm through the coldest months.

Snowy owls are carnivorous and feed on a diet of mainly lemmings and mice but will also eat if available, rabbits sea birds and fish. They sit at an elevated point and watch and listen for signs of prey, both sight and hearing are highly attuned and the owl can swivel its head round 270º to view a vast area. The claws are long and sharp, which can tear apart a small mammal in an instant. Unlike most owls, snowy owls are diurnal which means they are active throughout the day.

Snowy owls are known to migrate south in periods of reduced food availability but always return to their northern homes in spring.

Ocean
This marine biome is the largest on the planet as oceans cover 70% of the earths surface, the four oceans are:

Pacific Ocean
Atlantic Ocean
Indian Ocean
Arctic Ocean

The oceans have an average temperature of 3.8º C, but it is hard to gage a true figure as water is constantly moving, mixing, heating and cooling. The temperature of oceans varies massively from place to place, near the equator they are constantly warm and clear whilst near Polar Regions the water is so cold that the surface is frozen.
There are 4 zones to oceans;

Intertidal - this is where ocean meets land this could be rocky coats or beaches, the landscape of this area is constantly changing from the effect of tidal movement, the waters are warmer here than anywhere else as the shallow waters heat faster and are effected by land temperature. The usual inhabitants of intertidal areas are; snails, crab, starfish, invertebrates, seaweed, algae and molluscs.

Pelagic – this is the surface water further from land, the water here is deeper and cooler than intertidal areas, there is less diversity in this area with floating seaweeds and plankton being the dominant vegetation, fish, whales, and dolphin come here to feed.

Benthic – this zone lies below the pelagic and waters continue to get colder the deeper the water. This zone has a bottom layer of sand, silt and dead organic matter; these deeper waters receive less light and are abundant in species such as bacteria, fungi, sponges, anemones, worms and fish.

Abyssal – This is the deepest zone of the ocean, it is also the coldest and darkest. At these depths the water pressure is very high, abyssal zones are high in oxygen but low in nutrients and are abundant with species of fish and insects.

In addition to the 4 oceanic zones there are two other areas that are part of the marine biome:

Coral reefs – these occur in warm, shallow waters and are often located along the edges of continents, the dominant species here is obviously coral. Coral is made up of algae and polyp, which work together for food and energy. As the nutrient level in the bottom is so poor corals gather energy from algae photosynthesis as well as the polyps sending out tentacles to eat plankton. Coral reefs are home to many species of invertebrates, fish, urchins, octopus and starfish.

Estuaries – estuaries exist where ocean and freshwater meet, often through rivers and streams, here the waters mix giving varied salinity to the water. This creates a unique environment that supports large communities of algae, seaweed, marsh grasses and invertebrates; this attracts many species of bird to estuaries periodically.

Vegetation
Seaweeds
There are about 10,500 species of seaweed in the ocean; they are grouped into 3 types, green, brown and red. Seaweed needs two factors to exist, seawater and sunlight. Seaweeds are photosynthetic algae and are not considered true plants, as they do not have a vascular system, they are generally found on rocky shores and close to the land, this is because the water gets too dark further out for them to survive.

The seaweed needs to have a firm point of attachment, this is either the ocean floor or a rock so it does not float out to sea and perish. Despite this some species of seaweed have actually adapted and become free-floating with the aid of air filled sacs, this way the plant can constantly float at the surface and lap up sunlight. Other species have adapted to life in rock pools, attaching to rocks, the seaweed s have become able to live in areas of constantly changing temperatures and salt levels.

Animals
Fish
Fish are aquatic vertebrates typically cold blooded and lacking four limbs; they inhabit all areas of the ocean from the surface to the deepest darkest depths. Fish cover a wide array of genus and species but are generally characterised by certain features, they have 2 sets of paired fins and 1 or 2 dorsal fins, scales covering the body, gills and eggs are fertilised externally. There are always however exceptions and variations to the rule, especially as there are about 24,600 known species of fish in the oceans.

Of these 24,600…

23,000 are bony fish
850 are sharks rays and chimeras
85 are hagfish and lampreys

Every detail of fish can vary in one way or another and most species have developed special adaptations to suit their particular environment and needs. Sizes can vary from 8mm up to 16m long and fish come in a variety of shapes and colours. Fish can be herbivorous, carnivorous or omnivorous and will have species adaptations to suit.

Some fish have even developed adaptations to warm their body temperature even in cold waters, this gives a significant advantage to these species and they seem to be larger hunter species of the family Lamnidae. Other species such as the mudskipper have adapted to survive out side of the ocean and breath air for a period.

Ocean mammals
Ocean mammals are creatures that evolved out of the oceans but since returned to the water. There are 5 groups of marine mammal:

Order Sirenia: the manatee, dugong.
Order Carnivora, family Ursidae: the polar bear
Order Carnivora, infrafamily Pinnipedia: the seal, sea lion, and walrus
Order Carnivora, family Mustelidae: the Sea Otter and Marine Otter
Order Cetacea: the whale, dolphin, and porpoise

http://en.wikipedia.org/wiki/Marine_mammal

Ocean mammals have back bones that have developed for movement on land and so tend to move in the water by moving their spines up and down (unlike fish whose spines move side to side) this can restrict manoeuvrability in the water, (this is why ocean mammals have horizontal caudal fins and fish have vertical ones). Ocean mammals also breathe air; they come to the surface take in air and absorb the oxygen during submergence. Ocean mammals are also known to have hair; the amount varies from small wisps of hair on the heads of whales, to the full coats of polar bears and marine otters.

Marine mammals are warm-blooded and are all insulated with a thick layer of blubber that prevents heat loss (with the exception of polar bears and marine otters who rely solely on thick warm coats). These mammals tend to regulate their body temperature higher than the surrounding water to keep warm.

References:
http://www.blueplanetbiomes.org/world_biomes.htm
http://ths.sps.lane.edu/biomes/index1.html
http://www.ucmp.berkeley.edu/exhibits/biomes/index.php
http://www.worldbiomes.com/biomes_aquatic.htm
http://seaweed.ucg.ie/algae/seaweeds.lasso
http://www.cotf.edu/ete/modules/msese/earthsysflr/dforest.html