Editing Ecology and Population Dynamics (section)

== 3. Biodiversity Metrics ==

Biodiversity is a measure of the variety of life in a particular habitat or ecosystem. It is a critical indicator of ecological health and resilience. Ecologists do not just count the number of species; they use specific metrics to evaluate the structure of a community.

* '''Species Richness:''' The simple count of how many different species are present in a given area.
* '''Species Evenness:''' A measure of the relative abundance of the different species making up the richness of an area. An ecosystem where one species makes up 90 percent of the population has low evenness, even if the richness is high.
* '''Simpson's Diversity Index:''' A descriptive mathematical measure that combines both richness and evenness to provide a single diversity score. It represents the probability that two individuals randomly selected from a sample will belong to different species.

High biodiversity generally correlates with high ecosystem stability. A diverse food web offers multiple overlapping energy pathways; if one species declines, others can often compensate, preventing the entire system from collapsing.