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hij Teacher Resource Bank Environmental Studies Unit 1 ENVS1 The Living Environment Teachers Notes Copyright © 2008 AQA and its licensors. All rights reserved. The Assessment and Qualifications Alliance (AQA) is a company limited by guarantee registered in England and Wales (company number 3644723) and a registered charity (registered charity number 1073334). Registered address: AQA, Devas Street, Manchester M15 6EX. Dr Michael Cresswell, Director General. Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 Unit 1 ENVS1 The Living Environment Introduction These Teachers’ Notes are intended to expand upon Unit 1: The Living Environment by providing greater detail of the topics to be covered and how these should be developed. Examples included in the specification must be covered. Where specific examples are not given, suitable examples should be chosen to illustrate the principles and issues that are included in the specification. This guide includes suitable examples that may be used (in italics) but others may be used if preferred eg if the candidates or teachers have particular experience or knowledge. It is anticipated that the use of carefully selected examples may reduce total teaching effort by enabling a number of issues to be covered in a single situation. This will also help candidates to appreciate the holistic, inter-connected nature of the subject and prepare them for the study of broader issues such as sustainability in A2. Case study example. Minsmere RSPB reserve, Suffolk. Issues in the Specification which could be covered: Rationale for wildlife conservation Species inter-dependence Problems caused by introduced species Eradication of competitors Legal protection of habitats and species Captive breeding and release programmes Habitat management, especially plagioclimaxes The role of Governmental and voluntary organisations Threatened habitats in the UK Adaptation to the environment Ecological succession Visitor management klm Copyright © 2008 AQA and its licensors. All rights reserved. 1 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 UNIT 1 – The Living Environment An introduction to the biodiversity of life on Planet Earth. The reasons why the conservation of life on Earth is important are investigated, as are the methods which may be used to achieve effective conservation. Conservation in the UK, coral reefs, Antarctica and tropical rainforests are used to develop these issues further. Life Processes in the Biosphere allows consideration of the ecological relationships between organisms and their abiotic and biotic environments in order to understand conservation problems further and how these may be managed. 3.1.1 forLife Life Earth 3.1.1 Conditions Conditions for onon Earth The features of planet Earth which provide conditions that permit the existence and continued support of living organisms. The main conditions which allow life to survive Availability of water Water is essential for all life – physiological solvent, transport, coolant. The anomalous expansion on freezing (ice floats) prevents many water bodies from freezing solid. The high specific heat capacity of water moderates temperature change. Water provides aquatic habitats. Appropriate temperature range For liquid water, enzyme function. Suitable ambient gases Carbon dioxide, nitrogen in the pre-life atmosphere (NB oxygen was not abundant). Light Sunlight for photosynthesis, source of energy for the water cycle. How the presence of life on Earth has brought about environmental change Atmospheric oxygen The production of oxygen and its interaction with UV to form the ozone layer. Atmospheric carbon dioxide Reduction of CO2 levels and the importance of this in maintaining global temperatures as the sun has become brighter. 2 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 Conservation 3.1.2 Wildlife Wildlife Conservation The rationale for wildlife conservation Educational reasons By studying wildlife, we can learn much about ourselves, the wider environment and how we may improve human technologies (biomimetics). eg bird flight and aircraft wing design–aelerons and wing-tip fins Bird bone structure and tubular bridges – light, hollow and strong Humpback whale flippers and ship rudder design Aesthetic/recreational Enjoyment of wildlife. eg birdwatching, whalewatching , ecotourism Moral reasons Many people believe other organisms have a right to live and it is wrong to kill unnecessarily. eg the moral responsibility to protect the planet for future generations Ethical reasons In more affluent societies it is not necessary to exploit wildlife for food, but in some societies it is an essential part of the diet. eg collection of wild birds’ eggs and ‘bushmeat’ Economic benefits Medical Physiological research with wild animals may help the study of human diseases. eg squid – nerve function, armadillos – leprosy vaccine, sea urchins – drug of non-inherited birth abnormalities) teratology (study Development of medicines. eg opium poppy – morphine pain killer; rosy periwinkle – vincristine –cancer treatment Food resources Domestication of new species. eg perennial maize, salt-resistant spinach species, water buffalo Wild varieties for breeding programmes. eg disease-resistant rice varieties found in India, drought-resistant maize, cold-resistant pineapples klm Copyright © 2008 AQA and its licensors. All rights reserved. 3 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Species for biological control. eg parasitic wasps, predatory beetles, bacteria Other materials Timber, resins, fibres, cosmetics, fuels. eg turpentine, cosmetics, vegetable oils Earth’s life-support systems The life-support systems that allow life to survive on Earth are partly maintained by living organisms. Maintenance of the atmosphere Oxygen and carbon dioxide levels are regulated by photosynthesis and respiration. Nutrient cycling eg decomposition The role of plants in the hydrological cycle Transpiration, interception. Species inter-dependence The survival of many species relies upon the services which are provided by other species. Food supplies Pollination eg by insects Seed dispersal eg by birds and mammals Habitat provision eg birds nesting in trees 4 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… How humans threaten wildlife Deliberate exploitation Food eg overfishing of cod, swordfish, tuna, sharks, bushmeat Fashion eg spotted cats for coats, turtles shells for jewellery, crocodiles for leather for shoes and handbags Pets and entertainment eg tropical plants, tropical fish, parrots, reptiles Furniture and ornaments eg mahogany and teak furniture, ivory, coral, turtleshell Traditional medicines eg tigers, snakes, bear bile Other products eg whale oils for cosmetics Accidental harm from other activities Unintentional deaths caused by human activities eg fishing by-catch of tuna/dolphin, roadkill, animals killed in fields during silage cutting/harvesting Introduced species Predators eg mink – water vole, cane toads in Australia, oceanic islands with no indigenous mammals – introduced cats, rats; snakes introduced onto Guam Competitors eg grey squirrel – red squirrel, Rhododendrons, Japanese knotweed, oceanic islands with no indigenous mammals – introduced goats, rabbits Disease eg Dutch elm disease Eradication of predators and competitors eg bears, wolves, foxes , agricultural pests, otters, birds of prey klm Copyright © 2008 AQA and its licensors. All rights reserved. 5 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Habitat change: the inability to survive habitat alteration eg wetland drainage, selectively logged forests, changes to river flow due to canalisation or reservoir flow regulation, pollution Species have particular habitat requirements and may not be able to survive change. Competitor species may be better able to survive the changes. Examples of particular adaptations may be used from: ‘Adaptation to the Environment’ Habitat destruction Deforestation, expansion of farmland, urbanisation, mineral extraction, flooding by reservoirs. Conservation methods Legal protection The types of laws and agreements to prevent or manage exploitation, damaging activities and trade Trade controls CITES (Convention on International Trade in Endangered Species). Ban or control of trade between countries in endangered animals, plants or their products. eg ivory, whale products, spotted cat skins, turtles Appendix 1: complete ban on trade (except by special licence). eg tiger, blue whale, all rhinoceros species Appendix 2: restricted trade. eg Honduras mahogany, great white shark Banning damaging activities Wildlife & Countryside Act (1981 & 1984) eg protection of wild birds and their nests, many mammals eg shrews, dormice, badgersand their setts Legal establishment of protected areas The Wildlife & Countryside Act (1981 & 1984) allows the establishment of SSSIs (Sites of Special Scientific Interest). Sustainable management of exploitation IWC (International Whaling Commission) aims to control (not ban) whaling to ensure sustainable exploitation. 6 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Captive breeding and release The roles of zoos, botanic gardens and seed banks in conserving species and maintaining biodiversity, and the problems involved. The problems of captive breeding and release programmes Problems keeping some species in captivity huge size eg whales specific food requirements eg pandas, insect-eating birds, anteaters complicated species interactions eg plants with symbiotic mycorrhizal root fungi, large blue butterfly overwinters in an ants’ nest Breeding problems in captivity Small gene pool and inbreeding eg Hawaiian goose Hybridisation eg between closely related plants kept in greenhouses,African and Indian lions Some have unknown breeding ‘triggers’ eg daylength, nutritional status, space for courtship displays Artificial methods to increase breeding success Artificial insemination, egg, sperm and embryo storage. Embryo transfer (from a female of a rare species to females of closely related more common species to increase the number of young produced) eg transfer of bongo embryos to eland Micro-propagation of plants. Difficulties with release into the wild Lack of a suitable habitat, the original threat still exists, lack of hunting skills, lack of immunity to local diseases, inability to recognize food/predators, difficulty integrating into social groups/inability to establish territory. eg red kite, otter, white-tailed eagle, scimitar horned oryx, golden lion tamarin klm Copyright © 2008 AQA and its licensors. All rights reserved. 7 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Habitat conservation Habitat protection Nature Reserves and protected areas to prevent disturbance or damage to an existing habitat Creation of National and Local Nature Reserves and reserves of conservation charities. eg Studland Heath NNR, Winterton Dunes NNR, Minsmere RSPB reserve, Slimbridge WWT reserve Gloucestershire, Loch Garten RSPB reserve Scotland National Parks in many countries outside UK (in UK, National Parks are primarily to protect landscape). eg Masai Mara, Kenya; Serengeti, Tanzania; Great Barrier reef, Australia Habitat management To maintain a habitat by counteracting undesirable change eg ecological succession, culling or removal of dominant or introduced predatorsand competitors removal of rhododendron and bracken from heathland and moorland removal of willow carr woodland on Catfield fen, Norfolk, to encourage swallowtail butterflies removal of invasive scrub from Magdalen Hill Down, Hampshire, for butterfly conservation: brown argus,green hairstreak, chalk-hill blue To increase its wildlife value by making the conditions more suitable for the desired species eg providing bird/bat boxes, raising the water table in a wetland habitat, increasing habitat diversity, biological corridors such as hedgerows To restore valuable damaged habitats Biodiversity Action Plans provide multi-agency, coordinated approach to species conservation. eg conifer plantation removal to re-establish heathland in the New Forest; flooding of previously draine Habitat creation Altering an unsuitable habitat so that the desired species can survive there eg woodland planting, pond creation.d wetlands 8 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Conservation in the UK The role of government organisations in protecting sites of ecological importance and endangered species Natural England, Countryside Council for Wales or equivalent: SSSI, NNR, MNR, SPA, SAC. DEFRA: Ramsar Sites, agri-environmental schemes. UK designations Designation of a protected area restricts the damaging activities which may take place. (N.B. Many areas have multiple designations to give additional or different types of protection.) Sites of Special Scientific Interest (SSSIs) Areas of particular interest because of their plants, animals, geographical or geological features. eg Bure Marshes, Norfolk National Nature Reserves are usually SSSIs which are good examples of important habitats with complete communities of species. eg Studland Heath, Dorset Local Nature Reserves are owned or controlled by local authorities for the benefit of wildlife and the public Marine Nature Reserve eg Lundy Island, Skomer International designations Ramsar sites Wetlands of international importance. eg Minsmere RSPB reserve, Exe Estuary Current European designations including: Special Protection Areas (SPAs) as a result of the EU Birds Directive. eg The Solent, Exe Estuary, parts of the Bristol Channel, Humber Estuary Special Areas of Conservation (SACs) as a result of the EU Habitats Directive. eg forest mires in the New Forest klm Copyright © 2008 AQA and its licensors. All rights reserved. 9 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Agri-environmental schemes Agri environmental systems provide financial support to farmers to reward and encourage environmentally beneficial development. The Single Farm Payment replaces previous schemes such as Environmentally Sensitive Areas (ESA) and the Countryside Stewardship Scheme (CSS) with the Environmental Stewardship Scheme (ESS). The aims of the Environmental Stewardship Scheme: Conserve wildlife (biodiversity) Maintain and enhance landscape quality and character Protect the historic environment Promote public access and understanding Protect natural resources Three options within the ESS: Entry Level Stewardship A fixed payment is made for environmentally beneficial management eg over-wintering stubbles, beetle banks, hedgerow stone wall and ditch management, field buffer strips, wild bird seeds, low input grasslands, protected archaeological sites, reduced soil erosion, protection of in-field trees Organic Entry Level Stewardship Similar to Entry Level Stewardship but with a higher payment level. Higher Level Stewardship Extra payments for more complex management or projects such as hedgerow restoration. eg flower-rich grass margins, unharvested conservation field headlands for winter bird food, restoration of wet grassland for waders and wildfowl, water meadow restoration, maintenance or restoration of saltmarsh, sand dunes, hedgerows, moorland, traditional orchards, ponds, woodlands, public access Species Recovery Programme A programme run by Natural England to conserve particular endangered species. eg dormouse, greater horseshoe bat, red squirrel, skylark, red kite, lady’s slipper orchid 10 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… The role of voluntary organisations and pressure groups World Wide Fund for Nature (WWF) Public awareness raising, lobbying industry and governments, education, funding for environmental projects Royal Society for the Protection of Birds (RSPB) Public awareness raising, lobbying industry and governments, education, reserve purchase and management, research grants to fund other conservation organisations, joint activities with other conservation organisations. Bird conservation is the focus of activities but broader issues are covered. klm Copyright © 2008 AQA and its licensors. All rights reserved. 11 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… UK habitats Introduction to UK habitats Most important wildlife habitats in the UK are semi-natural and have been affected by human activities. Many are plagioclimaxes. Long-term management has produced communities of wildlife species that thrive as long as the management practices are maintained. Management practices and species that benefit include: Farming: • Grazing eg wildflowers that survive as grazing controls taller plants • field boundary maintenance. eg hedges act as biological corridors for dormice; hawthorn berries provide food for redwings Hunting and fishing: • maintenance of cover; eg small woodlands which provide cover for pheasants have dead wood in which woodpeckers find food • moorland and heathland burning. eg red grouse and silver-studded blue butterflies feed on young heather Woodland management – coppicing, pollarding. Regular cutting of areas in a cycle increases habitat diversity. eg dormouse, bluebells, wood white butterfly Threatened habitats in the UK Candidates should be familiar with the activities and land-use changes which threaten the natural and traditional habitats and landscapes and be able to use examples to illustrate these. Habitat destruction which changes landuse. eg Urban expansion, wetland drainage to create farmland, quarrying, flooding to create reservoirs Change in management practices. eg Intensification of agriculture: removal of hedgerows, use of pesticides, drainage, use of fertilizers, ploughing of pasture change from broadleaf to conifer woodland abandoned coppiced woodland, ungrazed grassland Candidates should have brief knowledge of the main controlling ecological features including examples of threatened species to illustrate their importance. 12 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Broadleaf woodland The climax community for most of UK. eg deforestation for agriculture/urban expansion. Loss of species diversity and wide age structure through commercial management. Conversion to conifer plantations Wetlands Areas of shallow open water, marshes and bogs. eg drainage for farmland, urban developments or as a result of aquifer over- exploitation Peat bogs exploited for garden soil conditioner Heathland Infertile sand/gravel soils. eg urban expansion, conifer plantations, golf courses Hedgerows Field boundaries (relict woodland or deliberately planted). eg removal for field enlargement, road widening. Replaced with fences or cut (brashed) much lower/thinner to reduce maintenance costs Chalk grassland Dry, shallow, alkaline soils. eg converted to arable, conifer plantations, reduced grazing allowing scrub encroachment Hay meadows Grasslands harvested for livestock feed after annual wildflowers have produced seed. eg ‘improved’ by use of fertilisers, weedkillers and cutting for silage Coastal habitats Estuaries, sand-dunes, beaches, rocky shores. eg port developments, recreation and tourism, coastal defences, sewage, oil and industrial pollutants klm Copyright © 2008 AQA and its licensors. All rights reserved. 13 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Conservation abroad Candidates should have brief knowledge of the details of the main ecological features, importance to humans, threats and conservation efforts for the following ecosystems. Tropical rainforest Main ecological features High productivity and biodiversity, climatic stability. Importance to humans Timber, wildlife conservation, medicines, climate control, carbon sequestration, soil conservation, catchment management, indigenous peoples. Threats eg agricultural expansion, unsustainable timber exploitation, mineral extraction,HEP schemes, climate change Conservation efforts Protected areas eg Korup rainforest, Cameroon; Rio Bravo rainforest Belize Sustainable management Certified by the Forest Stewardship Council (FSC) and Smartwood eg Selective logging, replanting with native species, seed trees left Coral reefs Main ecological features Coral polyps with symbiotic algae requiring warm, clear, shallow water with high light levels and constant salinity. Importance to humans Wildlife conservation, fisheries, coastal erosion protection, medicines, tourism. Threats eg physical damage by anchors, rubbish, swimmers and divers; unsustainable fishing – overfishing, dynamite, cyanide; coral souvenirs; increase in suspended sediment from soil erosion on land and dredging; climate change causing raised temperatures, sea-level rise and ‘bleaching’; pollution, eg oil, pesticides, fertilisers, litter. Conservation efforts Protected areas eg Great Barrier Reef National Park, Australia 14 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.2 cont… Management practices eg Fixed mooring buoys, anchoring ban, diver education, fishing controls, control of agriculture – soil erosion, agrochemicals, ban on coral removal Antarctica Main features Large landmass with unique climate and seasonal changes, surrounded by highly productive ocean. Importance to humans Wildlife conservation, symbolic importance to humans as ‘the last unspoilt continent’. Threats eg climate change, uncontrolled tourism, litter, oil pollution, overfishing, whaling, mineral exploitation Conservation efforts eg Antarctic Treaty No territorial claims recognised No resource exploitation No military activities Waste removal Tourism controls klm Copyright © 2008 AQA and its licensors. All rights reserved. 15 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 Life Processes in the Biosphere Adaptation to the environment To be able to survive, all species must be well adapted to the physical and biological environment. Most organisms can only survive within a relatively narrow range of conditions called their Range of Tolerance. Species’ adaptations affect their ability to survive environmental change and control management practices in habitats protected for wildlife Abiotic and biotic factors Abiotic factors Candidates should be able to use suitable examples (from habitats studied elsewhere in the Specification if possible). The distribution of species is controlled by abiotic factors. This knowledge can guide habitat management to make conditions more suitable. Abiotic factors include: temperature eg bacteria around volcanic vents, trout in oxygenated rivers light eg shade-loving forest plants pH eg cowslips on limestone soils, lichens. water eg amphibians require wet conditions for breeding mineral nutrients eg insect-eating plants can survive nitrogen-deficient soils turbulence and physical damage. eg brown seaweeds on rocky shores 16 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 cont… Species interdependence and abiotic factors The abiotic factors which affect a species may be controlled or modified by other species living in the same habitat. eg in a woodland reduced light levels due to shading change in light wavelengths due to absorption by chlorophyll increased humidity due to transpiration reduced wind velocities as trees act as windbreaks increased availability of mineral nutrients due to decomposition Biotic factors Candidates should be able to use suitable examples (from habitats studied elsewhere in the Specification if possible). The distribution of species is controlled by biotic factors including: Acquiring food /avoidance of predation eg species in tropical rainforests where the high productivity creates reliable food supplies and therefore competition – specialised feeding mechanisms – birds’ beaks. The high predator numbers necessitate defence mechanisms – bad taste, toxins, thorns, camouflage Symbiotic nutrition eg algae and coral polyps on coral reefs, cellulose-digesting bacteria in many herbivores Pollination eg by insects, bats Seed dispersal eg squirrels and acorn of oak trees, fruit bats and fruit seeds of tropical trees Disease is a density-dependent factor which maintains the health of the surviving population. klm Copyright © 2008 AQA and its licensors. All rights reserved. 17 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 cont… Species interdependence and biotic factors Candidates should understand that species interdependence often requires conservation of communities of species rather than individual species. Some biotic factors make survival less likely. eg competition for food, disease, predation Other interrelationships have developed to be become beneficial to both species involved. eg pollination where the plants benefit by the transfer of reproductive cells while the pollinator receives food as nectar In seed dispersal, the plant benefits by seeds being carried. Seeds often travel longer distance and seeds can be larger than if dispersal is by wind. The animal gains food from eating some of the seeds or from the surrounding fruit. Symbiotic nutrition includes cellulose-digesting bacteria in many animals. The bacteria have a controlled suitable environment with reliable food supplies while the animals gain nutrition from a source which couldnot otherwise be digested. Nutrient from dead organic matter are released during the breakup by detritivores and subsequent breakdown by decomposers. Plants can then utilize the nutrients again which ensures future food supplies for the detritivores and decomposers. 18 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 cont… Grouping organisms Organisms can be categorized in many ways that help to understand their roles and interrelations Basic ecological terms Species A group of organisms that resemble one another more closely than members of other groups and form a reproductively isolated group that produce fertile offspring. eg oak trees (Quercus robur), house sparrow (Passer domesticus) Population All the individuals of a species living in a particular area. eg all of the oak trees in a deciduous woodland/all the house sparrows in a town Community The populations of all the species living in a particular area. eg the sum of all the plants and animals: such as oak trees, ash trees, holly bushes, hazel bushes, grasses, mosses, sparrow hawks, sparrows, blue tits, voles, earthworms, fungi etc in a woodland Ecosystem The community of organisms, their inter-relationships and interactions with their abiotic environment. eg the community of species in a woodland, their inter-relationships and interactions with energy, water and nutrient cycles Habitat The place where a particular organism lives. eg the mole lives in the soil within a grassland Niche That part of a habitat which is inhabited by an organism and the role which it plays within the ecosystem. eg the tawny owl is a nocturnal carnivore, nesting in holes in hollow trees, feeding on small mammals and birds Biome A large geographical region, in which a characteristic, unique community of species lives. eg deciduous broadleaf woodlands of western Europe Biosphere That part of the planet inhabited by living organisms. Soils of the lithosphere, liquid water and the troposphere klm Copyright © 2008 AQA and its licensors. All rights reserved. 19 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 cont… Changes in ecosystems An understanding of natural changes that occur in ecosystems helps in the understanding of the impact of human activities and therefore helps to develop conservation strategies. Temporal changes: ecological succession Primary succession involves the changes from pioneer species which colonise an environment through the seral stages to the climax community. Changes in abiotic factors lead to more favourable conditions and increasing species diversity as illustrated by the succession from bare rock to woodland in a lithosere and from freshwater to woodland in a hydrosere. The major changes in abiotic factors, the general types of organisms present and their adaptations should be understood rather than details of particular species. The influence of climatic, edaphic (soil) and biotic (including anthropogenic) factors on the rate and direction of seral change. Changes are slower if the abiotic conditions are less suitable for life – too hot/cold, too dry or if the availability of plant nutrients is a limiting factor. Changes are usually slower during the early stages of succession. The climax community produced is controlled by the climate. eg water present all year – generally woodland distinct wet and dry seasons – grassland wet and acidic – blanket bog The concept of deflected succession with reference to the main plagioclimax communities influenced by human activity, illustrated by grassland and coppiced woodland. Most habitats in the UK are plagioclimaxes produced by grazing, burning, mowing or cutting. eg grassland, heathland, moorland, reedbeds and coppiced woodland 20 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 cont… Diversity and ecological stability The assessment of species diversity is important in monitoring environmental change, damage and the success of conservation efforts. Species diversity in the context of ecological stability. Species diversity is often low in extreme environments which are dominated by abiotic factors, where populations may fluctuate dramatically. eg environments with few food sources and few predators – arctic fox/snowshoe hare; snowy owl/lemming Higher diversity in less hostile environments results in more stable populations in which populations are dominated by biotic factors. eg tropical rainforests and coral reefs Calculation of an index of diversity, eg Simpson’s diversity Index D= N (N − 1) Σ n (n − 1) where N = total number of organisms of all species and n = total number of organisms of a particular species Σ = sum of Estimates of the total number of species that exist. Predictions can be based upon the past rate of discovery. The gradual reduction in the ease with which new species can be found can be used to estimate the total number of species that exist. The relative ease with which new species are found in ecosystems which have not been thoroughly studied, eg tropical rainforest or deep ocean, suggest that most species that actually exist have yet to be found. klm Copyright © 2008 AQA and its licensors. All rights reserved. 21 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.3 cont… Populations Population dynamics An understanding of population dynamics is important in monitoring species’ survival, breeding success and in assessing Maximum Sustainable Yields of exploited species. Population change in terms of reproduction, mortality and migration The population size of an area is controlled by the numbers of births and deaths and movements in and out of the area. The number of births is controlled by the natural reproductive potential of the species. The number of deaths (mortality rate) is mainly controlled by environmental factors that prevent some of the individuals that are born from surviving. Factors affecting mortality rates Density independent factors eg drought, flood, volcanic eruption Density dependent factors eg food supply, disease Density dependent factors become more important as the population density increases, until the mortality rate forms a long-term balance with the birth rate. Sigmoidal population growth curve Candidates should understand the factors controlling population growth in the lag, logarithmic and stable, fluctuating stages of the sigmoidal growth curve. Carrying capacity The maximum population size that can be supported indefinitely without damaging or over-exploiting the environment. Homeostatic regulation of population size The mortality rate changes if the population is above or below the carrying capacity to return the population to the carrying capacity. Predator-prey population relationships. eg snowy owl – lemming, arctic fox – snowshoe hare Artificial population control (culling) may be necessary to conserve species or habitats where natural control mechanisms no longer exist. eg culling red deer in Scotland where wolves no longer exist 22 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.4 Land Resources The conservation of landscape for informal public enjoyment The landscape may be conserved for informal public enjoyment. Since communities of plants and associated animals are an important part of the landscape, landscape conservation often results in wildlife conservation. The enhancement of the environment for amenity use and the organisations involved Landscape protection Conserving the aesthetic appeal of the environment involves the maintenance of features that are natural or have been produced by human activities and give the countryside its character. eg woodlands, hedgerows, stone walls, in-field trees, ditches, banks, ponds, river features Landscape enhancement Restoration and development of countryside features can enhance its character. eg planting small woodland areas, replacing conifers with mixed indigenous species, ‘soft’ riverbank management, restoring river meanders Visitor management This should involve the provision of facilities without damaging the character of the countryside. eg paths, waymarks, car parks, information, space zoning, time zoning, recreational facilities klm Copyright © 2008 AQA and its licensors. All rights reserved. 23 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.4 cont… Governmental organisations Natural England/ Countryside Council for Wales Designated areas These are areas with controls and regulations to protect them from undesirable change including: • preventing undesirable change eg forest clearance, urban expansion, afforestation • continuation of desirable activities eg traditional farming practices: grazing chalk grassland and moorland, maintaining field boundaries National Parks National Parks in the UK are extensive areas, each with their own managing authority. The aims of National Parks are to: • • • conserve and enhance their natural beauty, wildlife and cultural heritage promote opportunities for the understanding and enjoyment of their special qualities maintain the rural economy. eg Dartmoor, Snowdonia, Broads, Peak District, Lake District, Exmoor, Pembrokeshire Coast, Brecon Beacons, Yorkshire Dales, North York Moors, Northumberland National Parks in other countries are usually established primarily for wildlife conservation. AONBs (Areas of Outstanding Natural Beauty) AONBs are designated solely for their landscape qualities for the purpose of conserving and enhancing their natural beauty (which includes landform and geology, plants and animals, landscape features and the rich history of human settlement over the centuries). eg Cannock Chase, Forest of Bowland, Gower, Bodmin Moor, Cotswolds, Chilterns, North Downs DEFRA (or equivalent) Environmental Stewardship Scheme – Entry Level Includes management and protection of historic and landscape features. eg hedgerows, stone walls, archaeological sites, in-field trees Environmental Stewardship Scheme – Higher Level eg public access provision such as footpaths, bridleways, educational access 24 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.4 cont… Local authorities (and others) Country Parks Country Parks are areas of countryside, usually near urban centres, with facilities for their enjoyment by the public for informal recreation. Many are redeveloped derelict industrial sites or have other uses such as plantations or reservoirs. any suitable examples Non-governmental organizations National Trust Details of activities. eg Land ownership and management, Operation Neptune (purchase and protection of coastlines) Land-use conflicts Causes of land-use conflicts The competition for land resources in the UK leading to conflicts involving proposed, adjacent or multiple land uses and therefore impacts upon the environment. Major causes of land-use conflicts Urban expansion eg London and its satellite towns Transport developments: New/enlarged roads eg Twyford Down, Newbury bypass, A66, M6 toll road Proposed/enlarged airports eg Heathrow, Stanstead Port developments eg Dibden Bay in Southampton Water, oil terminals at Milford Haven Mining /quarrying eg limestone in the Peak District, china clay from Dartmoor Harnessing energy Windfarms eg in areas of scenic beauty, where bird strikes are likely, where noise or radio interference may cause problems klm Copyright © 2008 AQA and its licensors. All rights reserved. 25 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.4 cont… Power stations eg Dinorwig HEP station in Snowdonia National Park. Recreation and tourism eg recreation pressure in National Parks. Methods of resolving land-use conflicts Legislative methods: Statutory planning controls and restrictions. Planning applications are granted if they are appropriate within local and national planning strategies of the local planning authority and the Government. Areas with very strict planning controls National Parks Virtually no new urban developments unless they are essential/desirable for the existing local community/economy. Green Belts around some large urban areas To prevent urban sprawl, formation of conurbations, encourage use of brownfield sites. But they can cause congested development, loss of green space, excessive land prices and ‘leap-frog’ developments outside the green belt, hence the move to ‘green wedges’. Public inquiries When there is disagreement and for all large developments. New major roads, power stations, airports, mines. Environmental Impact Assessments (EIA). Ensure that environmental impacts are considered in the planning process. Use of the Leopold matrix to illustrate how the importance of individual issues can be quantified and compared. Space zoning Allocation of different areas for activities that would conflict. eg Recreational activities on many lakes and coastal areas Poole Harbour – areas for water skiing, jetskis, dinghies, windsurfing, swimming, wildlife conservation, scuba diving, quiet recreation Time zoning Allocation of different time periods for activities that would conflict. eg lakes used for recreation in the summer and as wildfowl reserves in the winter 26 Copyright © 2008 AQA and its licensors. All rights reserved. klm Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 3.1.4 cont… Economic methods Cost benefit analysis. A monetary value is ascribed to each of the costs and benefits of a proposal. Costs include: • • • direct costs eg labour to build a by-pass indirect costs eg the value of the wetland area that could have been created by the labour forceif they weren't building the by-pass intangibles eg what is the value of the haymeadow that is going to disappear under the by pass ? Benefits include reduced noise, congestion, vibration, air pollution etc in the by-passed village. Costs are subtracted from the benefits. If benefits exceed the costs then the proposal may be recommended. Practical skills Candidates should have first-hand experience of measuring the following features of the biosphere Diversity and ecological stability Species diversity in the context of ecological stability Calculation of an index from the formula: N(N − 1) D= ∑ n(n − 1) where N = total number of organisms of all species and n = total number of organisms of a particular species Candidates should study appropriate examples drawn from fieldwork as far as possible klm Copyright © 2008 AQA and its licensors. All rights reserved. 27 Teacher Resource Bank / GCE Environmental Studies / Teachers’ Notes Unit 1 / Version 1.0 Measurement of population size and density Assessment of various habitats and biotic factors Candidates should have first-hand experience of: • methods used for measurement of populations • random sampling using quadrats to estimate species frequency • measuring species density and percentage cover • use of belt transects to record changes in species distribution • use of abundance scales and their limitations Methods and their limitations for the collection of aquatic, airborne and soil-dwelling organisms: • the mark - release - recapture (Lincoln Index) method of estimating population size using the formula: n1 × n 2 nm and an understanding of the assumptions made in the use of the technique 28 • kick sampling and nets for aquatic organisms • pitfall traps, pooters, sweep nets and beating trays for organisms in air or vegetation • light traps for night-flying moths • Tüllgren funnels for soil and litter organisms • extraction of earthworms from soil Copyright © 2008 AQA and its licensors. 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