BIOL 1070 Lecture Notes - Lecture 4: Canadian Biodiversity Strategy, Earth Summit, Species Richness
Document Summary
Biodiversity: biodiversity is often used as a non-technical term, which refers to the different scales of biological variation. In general, biodiversity comprises three scales of variation: genetic, species, and ecosystem. Species richness: species richness is defined as the number of species present in a defined area such as a community or ecosystem. The appropriate sampling intensity required to estimate richness is determined by plotting the number of new species observed with each sampling unit. Sampling species richness is complete when the species area curve is saturated (levels off at 55 plots in the figure below). Abundance: species abundance refers to how common a species is in a defined area and can be measured as percent cover, biomass or frequency of individuals per species. Relative abundance is a term that refers to the comparison of the species abundance within a defined area and relates to the evenness of distribution of individuals among species in a community.