liigirikkust

Liigirikkust is a biodiversity metric that captures the variety of species in a defined area, habitat type, or ecosystem. It is expressed as the number of distinct species observed in the sample, plot, or landscape, and is often used alongside abundance-based measures to describe community structure.

Measurement and estimation typically involve standardized surveys, such as plots, transects, or exhaustive inventories. To compare across studies with different sampling effort, techniques like rarefaction curves or estimators such as Chao1 are used. In ecological studies, alpha diversity refers to local species richness, beta diversity to species turnover between sites, and gamma diversity to regional richness.

Determinants of liigirikkust include habitat heterogeneity, area, productivity, climate, and disturbance regimes. The arrangement of habitats, island-like landscapes, and historical factors such as colonization and extinction also shape observed richness. Higher richness is often associated with complex, productive environments and with larger, less fragmented areas, though exceptions occur due to sampling and historical contingencies.

Applications of liigirikkust include biodiversity assessments, conservation prioritization, ecological monitoring, and restoration evaluation. It serves as a straightforward indicator of how many species exist in a given context, which can guide management decisions and trend analyses when combined with other metrics.

Limitations of the metric include its insensitivity to species abundances and ecological roles; it can be strongly affected by sampling effort and taxonomic resolution, seasonality, and detectability. Therefore, liigirikkust is commonly interpreted together with evenness, functional diversity, and phylogenetic diversity metrics to provide a fuller picture of biodiversity.