Chapter 3.1

what forms biodiversity?

species richness, species evenness, habitats, species and genetic

resilience

the capacity of an ecosystem to withstand disturbance and still maintain the same functions of organisms working together to maintain a balanced ecosystem

species diversity

is a product of the number of species and their relative proportions

diversity index

gives a quantité estimate of biological variability in space or time and describes and compares communities

what can you compare with the diversity index

two similar ecosystems , two communities within an ecosystem or the same ecosystem over time

what could low diversity index indicate

evidence of pollution, eutrophication or recent colonisation of a site

why is it important to check the diversity index in the same community

to identify wether change is natural due to succession, or caused by human activity

what does high diversity index show?

where there is greater richness and evenness

simpsons reciprocal index

a numerical value that can be used to measure species richness and species evenness

genetic diversity

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

what does more individuals mean for genetic diversity

the more individuals means higher genetic diversity and thus a bigger gene pool

what does more populations mean for genetic diversity?

each population will have a different total genetic make up, and will maximise genetic diversity

habitat diversity

the range of different habitats per unit area in a particular ecosystem or biome

complexity of an ecosystem

the more complex the food web, the more resilient it is to the loss of one species or a reduction in its population size

stage of succession

the ear,keep stages of succession has low biodiversity and is less resilient

omitting factors and stability

a change in raw materials, water

age of the ecosystem

the older the ecosystem, the greater the biodiversity is likely to be

habitat diversity example

tropical rainforests are high in habitat diversity as there are many ecological niches due to the layering of the forests

what are the advantages of high biodiversity

resilience and stability due to the range of plants present, genetic diversity so resilience to disease

but why does high biodiversity not always equate to a healthy ecosystem?

diversity could be the result of fragmentation of a habitat when species richness is due to pioneer species invading bare areas quickly