4.2.1 Biodiversity

• biodiversity: the variety of living organisms in an area
• community: all the populations of different species living together in a habitat/area
• gene pool: the sum of all the genes and alleles in a population
• genetic diversity: the variety of alleles in a population/ species
• habitat: the place where an organism lives
• habitat diversity: the number of different habitats in an area
• population: the number of individuals of one species in an area
• proportion of polymorphic gene loci: a measure of genetic biodiversity
• simpson's index of diversity: a measure of diversity that considers both species r
• species diversity: a measure of species richness and species eveness
• species eveness: the relative abundance of different species in an area
• species richness: the number of different species found within an area
• belt transect: a line along a sampled area upon which quadrats are placed at intervals to determine the abundance of organisms in an ecosystem
• line transect: a line along a sampled area. The species touching the transect at regular intervals are recorded to determine the abundance and distribution of organisms in an ecosystem
• non-random sampling: a sampling method in which a sample is not chosen randomly. 3 types: opportunistic, stratified and systematic
• opportunistic sampling: non-random sampling that involves drawing a sample from part of the population that is conveniently available
• pitfall trap: a device used to catch small ground surface vertebrates. It consists of a container buried beneath the ground and a roof structure
• pooters: a device used to collect small insects. Consists of two tubes, one connecting the holding chamber to a mouthpiece (with a filter) and other to an inlet tube
• quadrat: a square grid used to measure the distribution of organisms in a habitat. 2 types: point quadrat and frame quadrats
• random sampling: a sampling method used to avoid bias
• stratified sampling: type of non-random sampling which populations are divided into strata and a random sample is taken from each, proportional to its size
• sweep nets: a funnel-shaped net used to catch insects and other small animals
• systematic sampling: a type of non-random sampling in which samples are taken from different regions of a habitat e.g. along a transect