A LevelGeographyAQARevision Notes6. Ecosystems Under Stress6.6 Local Ecosystems6.6.3 Issues & Management of Change

Issues & Management of Change (AQA A Level Geography)

Revision Note

Jacque Cartwright

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Geography Content Creator

Urban Redevelopment of Wasteland

  • Economic, social and political changes produces challenges to the urban environment
  • These constant challenges create urban wastelands of one form or another
  • Wastelands themselves become threatened, as these circumstances change
    • They may be cleared for new developments
    • Transformed through invasive, non-native (alien) species
    • Protected/managed in order to benefit local communities or to protect endangered species
    • Redevelopment can destroy the wasteland ecosystem e.g. draining of a pond, vegetation removed with waste rubble, nesting of bats as buildings are bulldozed etc.
    • New land formed through regreening of wasteland
    • Change of land use from waste to agriculture 

Invasive Species & Wasteland

  • Invasive alien plant species, such as Japanese knotweed and Himalayan balsam, have a devastating impact
  • These species interrupt natural succession and restrict biodiversity by out-competing native species
    • Japanese knotweed grows to over 2m (7ft) in height
    • The roots push their way through joints in concrete, cavity walls, weaknesses in the broken mortar, between paving slabs or bricks and can also damage drains and sewers
  • It can only be effectively treated by spraying with strong herbicides and then burning the weed and roots
    • This not only kills the plant, but also kills all other plants and insects in the vicinity
    • This has a knock-on effect particularly on pollinators such as the honey bee
  • Animal invasive species are also a threat
    • The common red squirrel in the UK was virtually wiped out by the introduction of the more aggressive and disease carrying American grey squirrel
    • The release of the grey squirrel into the wild was unplanned 
      • First introduced to England from North America in 1876 as an ornamental species to populate the grounds of stately homes
      • By 1930, the damage caused by the grey squirrel was recognised and it became illegal to release a grey squirrel to the wild
    • Grey squirrels live in higher densities and cause considerable damage to nesting birds and trees
    • In the urban environment grey squirrels raid bird feeders, bins and have been known to damage roofs

Conservation & Use of Wasteland

  • Government policy, in the UK, focuses on using brownfield sites for new developments within urban environment
  • However, the often thriving ecosystem that has developed, is usually overlooked and endangered
  • This does conserve greenfield sites outside the urban area and reduce urban sprawl
  • There is now a call for identification of brownfield sites that require conservation rather than development
  • Research is through pressure groups and charities such as Buglife, the Wildlife Trust and the RSPB
  • As a result, several sites have been protected (e.g. Canvey Wick, Essex was the first brownfield site to be  designated an SSSI)
  • Local communities are claiming areas of urban wastelands as valuable ecological assets, such as:
    • Leisure and recreation
    • Education
    • Urban farms  etc. 

Exam Tip

Remember to use appropriate, specific and located examples for this topic. The 93 hectare Canvey Wick in Essex was the first brownfield site to be designated as a Site of Special Scientific Importance (SSSI).  Canvey Wick was a landfill and oil refinery site, that closed in the 1980s and then lay derelict. In 2005, it was designated as a SSSI and transformed into a nature reserve. The area is rich in plants, insects and animals, with more species per m² than on any other site in the UK. It has even been referred to as ‘England’s Brownfield Rainforest’.

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    Jacque Cartwright

    Author: Jacque Cartwright

    Jacque graduated from the Open University with a BSc in Environmental Science and Geography before doing her PGCE with the University of St David’s, Swansea. Teaching is her passion and has taught across a wide range of specifications – GCSE/IGCSE and IB but particularly loves teaching the A-level Geography. For the last 5 years Jacque has been teaching online for international schools, and she knows what is needed to pass those pesky geography exams.