Rewilding (HL IB ESS OLD COURSE - IGNORE)

Rewilding

• Human activities such as deforestation and overharvesting of resources can disrupt, damage and destabilise ecosystems

• Conservation efforts at the ecosystem level aim to restore ecosystem stability by restoring natural ecosystem processes

  • These processes may include:

    • Predator-prey relationships

    • Seed dispersal

    • Nutrient cycling

• This type of ecosystem restoration project is also known as rewilding

• Restoration strategies may involve:

  1. Species reintroduction

     • Reintroduction of apex predators will reduce herbivore populations and allow the restoration of habitat vegetation

     • This may boost the diversity of plant species

     • This, in turn, enhances total biodiversity

       • For example, wolves were reintroduced to Yellowstone National Park, USA

       • The wolves help to control deer populations

       • This has allowed certain types of vegetation to recover

     • Reintroducing keystone species can improve the structure of an ecosystem

       • For example, beavers have been reintroduced to parts of the UK

       • Beavers build dams

       • These dams create large wetland areas that support diverse wildlife

  2. Improving habitat connectivity

     • This involves connecting fragmented habitats to allow free movement of species

     • Creating wildlife corridors, such as hedgerows on farmland, connects small pockets of habitat

     • This allows wildlife to roam over larger areas, increasing the resources available

     • This allows larger population sizes to establish

  3. Stopping agriculture

     • Allowing land previously used for farming to return to its natural state

       • For example, the Knepp Estate in England has been rewilded

       • This former farmland now supports wild ponies, pigs and longhorn cattle

       • These species promote biodiversity by disturbing soils, dispersing seeds and grazing on vegetation, so no single plant species dominates

  4. Limiting human influence

     • This may involve preventing the harvesting of resources, e.g. by logging or fishing

     • Ecological management techniques, e.g. controlled grazing or burning, may be used to restore a habitat

     • The aim is to minimise direct human management and let ecosystems self-regulate as much as possible