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BIODIVERSITY (MAINTAINING BIODIVERSITY (Factors affecting biodiversity…
BIODIVERSITY
MAINTAINING BIODIVERSITY
Factors affecting biodiversity include deforestation (reduces the number of trees, and if a specific tree is felled then diversity is reduced), agriculture and climate change
Biodiversity is maintained because of: aesthetic reasons, with plants enriching our lives and providing inspiration; economic reasons, because it is important to conserve organisms that we use to make things and ecological reasons as all organisms are interdependent on others for their survival
Biodiversity is maintained by in-situ conservation (within the natural habitat) and ex-situ conservation (outside the natural habitat)
In-situ conservation includes wildlife reserves and marine conservation zones, and ex-situ conservation includes botanic gardens seed banks, and captive breeding programmes
Conservation agreements include the International Union for the Conservation of Nature which publishes the Red List, detailing the current conservation status of threatened animals and established the Convention of International Trade which regulates the international trade of wild plants and animal specimens and their products
The Rio Convention requires countries to develop national strategies for sustainable development, takes steps to stabilise greenhouse gases in the atmosphere and aims to prevent the transformation of fertile land into desert and reduce the effects of drought - each convention contributes to maintaining biodiversity
MEASURING BIODIVERSITY
Measuring it plays an important part in conservation as it informs scientists of the species that are present, providing the baseline for the level of biodiversity in an area
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Species diversity takes into account the species richness which is the number of different species living in an area and the species evenness which is a comparison of the numbers of individuals of each species living in a community
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CALCULATING BIODIVERSITY
The simplest way to measure biodiversity is to count the number of species present - the species richness - but this method does not take into account the number of individuals present
Simpson's Index of Diversity is a better measure of biodiversity as it takes into account species richness and species evenness
The Index always results in a value between 0 and 1, where 0 represents no diversity and 1 represents infinite diversity
Although some habitats of low biodiversity are unable to support a large species diversity, these organisms that are present in the habitat can be highly adapted to the extreme environment of the habitat
GENETIC DIVERSITY
Species that contain greater genetic biodiversity are likely to be able to adapt to a change in their environment, and hence are less likely to become extinct
Factors that increase genetic diversity are mutations in the DNA which create a new allele, and interbreeding between populations which transfers alleles (gene flow)
Factors that decrease genetic biodiversity are selective breeding, rare breeds, captive breeding programmes, artificial cloning, natural selection, genetic bottlenecks, the founder effect and genetic drift
Genetic biodiversity can be calculated by measuring polymorphism, and the greater the proportion of polymorphic gene loci, the greater the genetic diversity