These include numbers of species, genetic diversity, chemical diversity, and ecosystem diversity. Biodiversity exists at multiple levels of organization, and is measured in different ways depending on the goals of those taking the measurements.

The number of described species is estimated to be 1.5 million with about 17,000 new species being described each year. Biodiversity is negatively correlated with latitude for most taxa, meaning that biodiversity is higher in the tropics.

biodiversity — the variety of a biological system, typically conceived as the number of species, but also applying to genes, biochemistry, and ecosystems. secondary plant compound — a compound produced as a byproduct of plant metabolic processes that is typically toxic, but is sequestered by the plant to defend against herbivores. genetic diversity — the variety of genes and alleles in a species or other taxonomic group or ecosystem; the term can refer to allelic diversity or genome-wide diversity. number of described species — estimated to be 1.5 million with about 17,000 new species being described each year.