Human Impact on the Environment Flashcards
Extinction
Loss of species
Reasons for species becoming extinct/endangered
Natural selection
Non-contiguous populations - too small
Loss of habitat - deforestation
Overhunting by humans
Competition - alien species, interspecific
Pollution from humans - oil
Conservation
Protection, preservation, management, and restoration of natural habitats and their communities.
Conservation methods
Protecting habitats e.g. nature reserves
Gene and sperm banks
Seed banks
Rare breed societies
Species reintroduction e.g. Red Kite in Wales
International Organisations e.g. WWFN
Legislation e.g. EU Habitats Directive
Ecotourism - educate and conserve
Monoculture
Growth of large numbers of the same crops in an area
Pesticides
Include chemicals which kill the growth of weeds, fungi, and insects
Chemical fertilisers
Include the elements NPK and increase plant growth
Why is monoculture bad?
Provides only one type of habitat, reducing biodiversity
Reduce soil fertility as roots grow to same length, increasing need for fertilisers
Grown close together, dieases, uses more pesticides
Overgrazing
Cause soil compaction, reducing air spaces and inhibitng nitrogen fixing and nitrifying bacteria, leading to loss of soil fertility. Water unable to penetrate, growth inhibited.
Ways of increasing biodiversity in farming
Organic farming - reduces need for fertilisers and pesticides, different crops, more habitats
Set-aside schemes - land set aside for wildlife
Legislation - increase in hedgerows provides habitats and food
Deforestation
Complete loss of tress in an area. Land is used for agriculture, building. Trees cut faster than they grow.
Consequences of deforestation
Soil erosion
Lowland flooding
Desertification
Habitat loss
Decrease in biodiversity
Climate change
Methods of forest management
Coppicing
Selective cutting
Long rotation time
Methods of preserving fish stocks
Regulating mesh size
Quotas
Exclusion zones
Legislation limiting size of fishing fleets
Fishing alternative
Use lines not nets
Intensive fish farming
Fish are bred and mature in enclosed ponds. Factors are controlled. Warm water increases growth.
