Transcript Edexcel A2 Biology - KingsfieldBiology

Conservation
AQA A2 Biology
Unit 4 Populations and
energy
Conservation of:
Wildlife
Habitats
Biodiversity
What is Biodiversity?
The Variety of Life in all it’s manifestations.
Or: The variety of organisms at all levels:
Genetic
Species
Populations
Usually measured as species richness
How do we conserve Biodiversity?
Legislation
- International Conventions
- European Directives
- UK Laws
Habitat Management
Legislation:
The Rio Earth Summit, 1992, produced the
International Convention on Biological
Diversity.
152 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
Coppicing
Grazing
Mowing
Scrub clearance
Burning
Coppicing
This is a traditional
form of woodland
management.
Trees are cut close to
form stools from
which new poles
regenerate.
This increases light
levels and species
diversity in the wood.
Coppiced and Pollarded trees
Grazing
Grassland is best
managed by grazing.
This keeps grasses short
allowing other plant
species to compete
successfully.
Grazing also causes
poaching providing
bare earth for seed
germination
Mowing
Used where it is not practical to graze a site.
Mowing 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
Scrub such as brambles,
shrubs and young trees
can be cut back
manually.
Some scrub cover is
sometimes left for
nesting birds and
invertebrates such as
butterflies.
Burning
This is a technique
often used on
heathlands as it
encourages the
regeneration of plants
such as heather and
gorse.