Biodiversity and Endemism
Biodiversity is the variety of all living organisms in an area. It includes species diversity (the number of different species, and abundance of each species in a area) and genetic diversity (the variety of alleles within a specie). Conservation is needed to help maintain biodiversity. Endemism is when an specie is unique to a single place, such as the giant tortoise.
Species diversity can be measured, and compared to different habitats. The number of different species in an area is species richness, the higher the number of species, the greater the specie richness. But it gives no indication of abundance of each species. Count the number of species and the abundance of each species, then use the biodiversity index to calculate the species diversity.
This is easily, Choose an area to sample, to avoid bias do it randomly. For plants use a quadrant, insects use a sweep net, for ground insects use a pitfall trap, and aquatic animals use a net.
Diversity within a specie is the variety shown by an individual of the species. Individuals of the same species vary because they have different alleles. Genetic diversity is the variety of alleles in the same gene pool of a population. The greater the variety the greater the genetic diversity.
To measure it looks at two things, Phenotype and genotype. For phenotype look at the characteristics of the organism. Such as there is a greater genetic diversity in eye colour in northern Europe. To measure genotype you need a sample of the organisms DNA.