11.1 Biodiversity Flashcards
What is Biodiversity
BD is the variety of living organisms in an area. It includes plants, animals, fungi and all things living.
Importance of BD
Essential in maintaining a balanced ecosystem for all organisms.
All species are interconnected and depend on one another. For example, trees provide a home for animals, animals eat plants, which in turn need fertile soil to grow, fungi help decompose dead plants and animals, returning nutrients to the soil.
In regions of reduced BD, these connections may not all be present which eventually harms all organisms.
Human activities such as farming and housing can lead to a reduction in BD.
At what levels can biodiversity be measured
Tropical, moist regions that are warm all year round have high levels of BD. The UK’s temperate climate has less biodiversity.
The closer to the equator, the the greater the BD. Before a major project can happen, an Environmental Impact Assessment is undertaken. BD can be studied at different levels:
Habitat
Species
Genetic
Habitat BD
Refers to number of different habitats found within an area. Each habitat can support a number of different species, therefore, in general, the greater the HBD, the greater the species biodiversity.
UK has large HBD, Antarctica has low HBD; countryside has high HBD, farmland has low HBD.
Species BD
2 components:
species richness - number of species living in a particular area.
species evenness - comparison of numbers of individuals of each species living in a community.
An area can differ in its species diversity even if it has the same number of species.
Genetic BD
Refers to variety of genes that make up a species.
Many genes have different versions (alleles) which leads to genetic BD within a species.
GBD can lead to to quite different characteristics being exhibited within a species.
GBD within a species allows for better adaptation to a changing environment and is likely to result in individuals who are resistant to disease.
