Frequency is a simple vegetation attribute to measure because it only requires identification of the species in each quadrat, and does not require that individuals are distinguished, measured, or counted. Therefore, data collection is usually a more rapid procedure than for other vegetation attributes such as biomass, cover, or density, which involve counting or subjective quantification. This advantage is most apparent in rangeland vegetation characterized by a relatively low species richness, but diminishes in vegetation with complex species composition. Frequency values are determined for individual species because an overall frequency for the entire vegetation cannot be obtained, in contrast to other attributes such as biomass, cover, or density. Likewise, it is not possible to obtain a meaningful expression of species composition from frequency data because the absolute abundance is not measured, only the presence of a species is measured.
Frequency can be a sensitive method to detect vegetation changes at a site.
Its ease and speed of data collection means that frequency is suited to large areas, so it is sometimes adopted by State and Federal agencies for descriptive rangeland inventory or monitoring programs. Species Composition 3. Species composition, a commonly determined attribute, refers to the contribution of each plant species to the vegetation. It is regarded as an important indicator of ecological and management processes at a site.