A4.2 Conservation of Biodiversity Flashcards
(91 cards)
biodiversity
amount of biological or living diversity per unit area
includes the concept of species diversity, habitat diversity and genetic diversity
ecosystem diversity
range of different habitats or number of ecological niches per unit area in an ecosystem
what does conservation of ecosystem lead to
the conservation of species and genetic diversity
species diversity
variety of species per unit area
includes number of species and their relative abundance
genetic diversity
range of genetic material present in a gene pool or population of a species
large gene pool
high genetic diversity
small gene pool
low genetic diversity
richness
refers to the number of a species in an area
evenness
relative abundance of each species
high abundance
similar abundance of all species
similar amounts of all species
low abundance
one or a handful of species dominate
lower complexity
simpsons reciprocal index
diversity indices which are used to describe and compare communities
what can simpsons reciprocal index be used to assess
whether the impact of human development on ecosystems is sustainable or not
why does low diversity occur
pollution, eutrophication or recent colonisation
what happens in distributed sites
artificially increased species richness due to mixing of habitats that are usually spatially separate
simpsons reciprocal index formula
D = N(N-1) / sum n(n-1)
points to note for simpsons reciprocal index
2 different areas can be compared using it
comparisons must be made between areas containing the same type of organism in the same ecosystem
what does a high D value symbolise
that its a stable or ancient site
more evenness
what does a low D value symbolise
disturbance and dominance of only one species cause by humans activities
how many species are predicted to be on earth and how many have been discovered
predicted - 100 million
discovered - 9 million
what does fossilisation tell us
fossilisation is extremely rare
tells us history of life
radiometric dating
measures amounts of naturally occurring radioactive substances
what is radiometric dating used for
are accurately dated to give clues about the community of organisms living at a particular time in the past
what does evidence for fossils suggest
there are currently more species alive on earth today than at any time in the past