Population viability analysis in conservation biology: precision and uses

Five types of population viability analysis (PVA) models have been developed for estimating extinction risk of endangered species. They are analytic model, deterministic single-population model, stochastic single-population model, metapopulation model and spatially explicit model. The choice of PVA model types for endangered species depends on life history of the species studied and data available on the species. Compared with other tools in conservation practice, PVA is relatively precise and quantitative tool. However, poor quality of data and unclear assumptions on populations of some endangered species could influence precision of predictions of PVA models, therefore, PVA models should be used with cautions. PVA models have been increasingly used in conservation plans and management of endangered species in western countries. It has been used for (1) predicting future population size of endangered species; (2) evaluating extinction risk of endangered species in a given time; (3) assessing conservation options and determining which options will make endangered species persistence longer; (4) exploring effects of assumptions on small population demography,and (5) guiding field data collection for endangered species. Few PVA studies have been conducted on endangered species in China, compared with the disproportionally high number of endangered species in China. There is an urgent need for building PVA models specifically for endemic endangered species and conservation issues in China.