Small scale ecosystems (WJEC Eduqas GCSE Geography B): Revision Note

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The notes on this page cover part 3.1.3 of the WJEC Eduqas GCSE B Geography.

3.1.3 - How are small-scale ecosystems in the UK managed and used?

• The characteristics of one small-scale ecosystem in the UK.

• The benefits of the ecosystem for local communities.

• The challenges of managing the ecosystem and how different stakeholders perceive its value.

Characteristics of a small-scale ecosystem

Leigh Woods

• Leigh Woods is a deciduous woodland

• Located in Bristol, to the west of the Avon Gorge

  • It is the largest area of ancient woodland in the city

• The National Trust and Forestry Commission manage the woodland

• It is a National Nature Reserve and Site of Special Scientific Interest (SSSI)

  • The woods are also part of the Avon Gorge Woodlands Special Area of Conservation

Leigh Woods food web

• It provides a variety of habitats for plants, insects and animals

• Producers include:

  • Tree species: ash, beech, oak and chestnut

  • Other plants: Holly, fern, bluebells, wild garlic

  • There are also lichens and mosses 

• Primary consumers include:

  • Insects

  • Rabbits

  • Deer

  • Squirrel (though they may eat larvae/caterpillars if conditions are harsh)

• Secondary consumers include:

  • Frogs

  • Voles

  • Fox

  • Badgers

• Tertiary consumers include:

  • Foxes

  • Birds of prey such as kestrels

• Animals can be in more than one trophic level: For example, a fox will eat both primary consumers, such as rabbits and secondary consumers, such as voles

• There are also many decomposers (fungi), which are vital to the nutrient cycle

Leigh Woods nutrient cycle

Interdependence

• The biotic and abiotic parts of the woodland are linked through the nutrient cycle and food webs

• Trees such as the rowan rely on birds eating the berries to disperse their seeds

  • Some berries are dropped during the flight in a new location

  • The seeds have an indigestible coating, which means that seeds which are eaten are deposited in droppings

• Oak trees rely on squirrels burying the acorns to store for winter

  • Acorns, which are forgotten, then germinate

• The trees in the woodland are mostly deciduous

  • In autumn, the trees lose their leaves

  • This covers the ground in a thick layer

  • The layer of leaves decomposes, adding nutrients to the soil

• A shrub layer of brambles, grass, bracken and other plants is the main producer

• In spring, before the trees come into leaf, more light reaches the woodland floor, allowing bluebells and daffodils to flower

Benefits and challenges of the ecosystem

Benefits of Leigh Woods

Biodiversity

• The woods provide a habitat for many rare and nationally scarce animal and plant species

  • There are seven of the UK's 17 bat species

  • Scarce insects found in the woods include:

    • False darkling beetles

    • Pauper pug and silky wave moths

    • White-letter hairstreak butterflies

  • Bullfinches, marsh tits and song thrushes

  • There are several species of whitebeam tree which only grow in this area, including the Wilmott's whitebeam

  • The woodlands are known for the limestone rock plants, including:

    • Bristol rock-cress and western spiked speedwell

Recreation and leisure

• The forest is a vital public space for recreation and leisure

• The visitors are mainly local people from East Sussex

• The forest area includes:

  • Historical and cultural features include Stokeleigh Camp hillfort

  • Disused celestine quarries and tramway

  • The Clifton Suspension Bridge

• It is popular with visitors for:

  • Mountain biking, including the Yer Tiz, Keener and Gert Lush trails

  • Running - there is a 'RunTogether' route created by England Athletics

  • Walking – the 'Feel good forest trail' created with the WWF

  • Orienteering

• The benefits for people may include:

  • Improved well-being

  • Increased fitness

  • Permeable surfaces to reduce surface runoff

  • Reduced pollution levels

  • Reduced temperatures in hot weather

Challenges of the ecosystem

• A stable ecosystem is one where all the biotic and abiotic components are in balance so that the populations remain constant

• This may take hundreds of years to develop, but the balance can be disturbed very suddenly

• Disruptions to the woodland ecosystem can be the result of either natural events or human activity

  • These disruptions can make managing the ecosystem challenging

Natural events

• Natural events may include:

  • Wildfires caused by lightning

  • Climate change (though it can be argued that this is human-induced)

  • Spread of invasive species

  • Disease

  • Extreme weather events: Flood or drought

• Like many deciduous woodlands in the UK, Leigh Woods have been affected by ash dieback

  • Over 1000 species are dependent on ash, including wood mice, wrens, bats, lichen and beetles

  • It is a significant tree for about 89 invertebrate species, including the endangered Violet Click beetle and the Hawk Moth caterpillar

• The removal and death of ash trees impacts all of these species, which then has a knock-on effect on the species which feed on them

• Woodpeckers, other birds and small mammals which feed on the insects living on and in ash trees may experience a population decrease

• This would then impact owls and other birds of prey, which feed on the smaller birds and mammals

Human activities

• Human activities may include:

  • Deforestation

  • Hunting of animals/birds

  • Introduction of invasive species

  • Hedgerow removal

  • Changes to water supply/drainage patterns or temperature

  • Addition of chemicals: Fertilisers/herbicides/pesticides

  • Fires used to clear land

  • Accidental fires caused by barbecues or litter

  • Unauthorised trail use by mountain bikers

    • This leads to erosion and damage to ground plants

  • Increased traffic and car parking issues

    • The installation of pay and display machines has reduced visitor numbers to manageable levels

Views of stakeholders

• Leigh Woods is managed by the National Trust and Forestry Commission

• The location in Bristol means that there are many stakeholders who have views on how the ecosystem should be managed

Conservation groups

• These include groups such as Abbots Leigh Wildlife Group

• Their priority is the conservation and enhancement of the natural environment and biodiversity

Local residents

• There are mixed views which mainly focus on preserving the woodlands

• The main concerns include:

  • Urban sprawl

  • Increased traffic

  • Loss of wildlife habitats

Local councils

• Needs to ensure that infrastructure and housing meet local needs

• Want to make rail improvements 'Metrowest'

  • Has an agreement with the Forestry Commission that another area of the forest will be raised to SSSI standards to compensate for the loss of woodland due to the railway

Other groups

• At the edge of the woodland, planning permission has been granted for 700 allotments

• Allotment holders argued that the allotments were beneficial for:

  • Their health

  • Mental well-being

• Many people opposed the allotments due to:

  • The creation of road access

  • Shipping containers are being used for storage