Defining biodiversity

Biodiversity refers to the variety of organisms in an area.

Levels of biodiversity:

• Habitat diversity - The number of habitats.
• Species diversity - The number of species and the number of individuals in each species.
• Genetic diversity - The variation in alleles within a population of a species.

High genetic biodiversity allows for better adaptation to a changing environment and resistance to disease.

Key terms related to biodiversity:

• Species - A group of organisms that can interbreed to produce fertile offspring.
• Habitat - The place where a species lives within an ecosystem.
• Community - The living organisms of all species found in a particular ecosystem at a particular time.
• Ecosystem - A relatively self-contained, interacting community of organisms and their environment.
• Niche - The role of an organism in an ecosystem, including its interactions and its method of obtaining energy.

Species richness and species evenness

Species richness and species evenness are measures of biodiversity.

Species richness:

• The total number of different species in a habitat.
• It is quantified by taking random samples and counting the species present.
• A higher species richness indicates greater diversity.

Species evenness:

• A comparison of the numbers of individuals of each species in a community.
• It is measured by taking samples and counting individuals of each species.
• More even abundances mean higher species evenness and diversity.