IB ESS Topic 3.1

biodiversity

a combination of the species diversity, genetic diversity and habitat diversity of an ecosystem

variation

the differences, either physical or genetic, between individuals of a species

simpson's diversity index

a measure of diversity between similar ecosystems

species diversity

the number of species (richness) and their relative proportions (evenness) in a community

genetic diversity

the range of genetic material present in a gene pool or population of a species

conservation

the act of preserving nature - attempting to save habitats, species and biodiversity in general

2/3

the proportion of living species which are found in tropical rainforests

ecosystem complexity

creates stability and resilience to change in an ecosystem - there are many pathways for energy flow

limiting factors

environmental conditions that limit the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem - when there are few of these, biodiversity is likely to be high (and vice versa)

lungs of the Earth

rainforests - they are called this because they are thought to produce around 40% of the oxygen that animals breath

low genetic diversity

caused by small populations or declining diversity - makes a species prone to extinction as they may not be able to adapt to change

low population density

some species need a large area to hunt - if there are only a few organisms over a large territory this may make them prone to extinction, especially if habitats become fragmented