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Environmental Studies
Unit 1 ENVS1 The Living Environment
Teachers Notes
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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
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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.
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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
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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
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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
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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.
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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
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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
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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
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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
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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.
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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.
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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
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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
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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
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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
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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.
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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.
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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
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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
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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.
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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
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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
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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
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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
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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
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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
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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
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