Investigating biodiversity (Estimating biodiversity samples (Choose a site…
Variety of living organisms in an area
1. Habitat diversity
- A habitat is an area inhabited by a species
It includes physical factors like the soil, temperature range and the living (biotic factors), like the availability of food or presence of predators
Habitat diversity is the number of different habitats in an area.
2. Species diversity
A species is a group of organisms with similar characteristics able to reproduce and provide fertile offspring.
Species diversity is the number of different species (species richness) and the abundance of each species (species evenness)
3. Genetic diversity
Genetic diversity is the variation of alleles within a species or a population of speices
To make sure the sample is not biased it should be random.
This could be done by gridding the field and using a random number generator to pick coordinates
Collecting data on Biodiversity
Usually means finding out the number of different species in a habitat or number of individuals in each species.
However, this is too time consuming to count every individual organism in a habitat.
Instead a sample is taken
Taken when theres a lot of variety in the sample and you want to make sure that all areas are sampled
3 types of Non-random sampling
2. Opportunistic sampling
Samples chosen by investigator
Simple to carry out but data will be biased
3. Stratified sampling
different areas of a habitat are identified and sampled separately in proportion to their part of a habitat as a whole
1. Systematic sampling
When samples are taken at fixed intervals, often along a line
Estimating biodiversity samples
Choose a site to sample E.g. An area within a habitat
Record the number of different species or number of individuals within a species
Use the correct equipment eg transect or pitfall trap
Take as much samples as possible
all samples need to be random
Calculate mean in each sample and multiply it by the size of the whole habitat
Always use the same sampling technique when sampling diffrent habitats
Species richness and species evenness