Conservation AQA A2 Biology Unit 4 Populations and energy

Conservation of: zWildlife zHabitats zBiodiversity

What is Biodiversity? The Variety of Life in all it’s manifestations. Or: The variety of organisms at all levels: zGenetic zSpecies zPopulations Usually measured as species richness

How do we conserve Biodiversity? zLegislation - International Conventions - European Directives - UK Laws zHabitat Management

Legislation: zThe Rio Earth Summit, 1992, produced the International Convention on Biological Diversity.The Rio Earth Summit z152 Countries signed this, committing them by law to adopt ways and means of protecting biodiversity.

European Response: EU Habitats Directive (1992) identifies  habitats in need of special protection (Annex 1)  priority species (Annex 2) Natura 2000 was also set up under the directive. Natura website This is a coherent network of protected sites containing the habitats and species listed in the directive.

UK Legislation Habitat Regulations (1994) implement the EU Habitats Directive These list and protect species and habitats of european importance Browse SACs on a map

Habitat Management The main aims of habitat management are: 1. To manage the process of ecological succession. 2. To maintain or increase biodiversity.

Habitat Management Techniques zCoppicing zGrazing zMowing zScrub clearance zBurning

Coppicing zThis is a traditional form of woodland management. zTrees are cut close to form stools from which new poles regenerate. zThis increases light levels and species diversity in the wood. Coppiced and Pollarded trees

Grazing zGrassland is best managed by grazing. zThis keeps grasses short allowing other plant species to compete successfully. zGrazing also causes poaching providing bare earth for seed germination

Mowing zUsed where it is not practical to graze a site. zMowing should take place 2-3 times a year, with the last cut as late as possible to let flowering species set seed.  Cuttings should be removed from the site to prevent nutrient enrichment of the soil which would encourage grasses to grow.

Scrub Clearance zScrub such as brambles, shrubs and young trees can be cut back manually. zSome scrub cover is sometimes left for nesting birds and invertebrates such as butterflies.

Burning zThis is a technique often used on heathlands as it encourages the regeneration of plants such as heather and gorse.