种群生存力分析研究进展和趋势

种群生存力分析（PVA）是正在迅速发展的新方法，已成为保护生物学研究的热点。它主要研究随机干扰对小种群绝灭的影响，其目的是制定最小可存活种群（MVP），把绝灭减少到可接受的水平。随机干扰可分四类；统计随机性，环境随机性，自然灾害和遗传随机性。确定MVP的方法有三种：理论模型，模拟模型，模拟模型和岛屿生物地理学方法。理论模型主要研究理想或特定条件下随机因素对种群的影响；模拟模型是利用计算机模拟种群绝灭过程；岛屿生物地理学方法主要分析岛屿物种的分布和存活，证实分析模型和模拟模型。已有大量的文献研究统计随机性，环境随机性和自然灾害的行为特征，但遗传因素与种群生存力之间的关系还不清楚。建立包括四种随机性的综合性模型，广泛地检验PVA模型，系统地研制目标种的遗传和生态特性以及MVP的实际应用是PVA的发展趋势。

Advance in population viability analysis

Population viability analysis(PVA)is a quickly developing new technique and has become a central issue of conservation biology. It mainly probes into effects of extinction for small polulations by stochastic perturbations and its goal is to establish a minimum viable population that reduces risk of an extinction to an acceptable level.The stochastic perturbations can be classified into four kinds:demographic stochasticity,environmental stochasticity. natural catastrophes and genetic stochasticity.There are three approaches to determining MVP:theoretical models.simulation models and island biogeography method.The theoretical models mainly analysize effects of stochastic perturbations on MVP under ideal or given conditions.The simulation models use computer to simulate the extinction processes for populations.and the island biogeography method analysizes distribution and survival of species on islands,and testifies theoretical models and simulation models.There are a great number of literatures that study behaVior characteristics of demographic stochasticity.environmental stochasticity and natural catastrophes.But the relationships between genetic factors and population viability are not clearly known. The developmental trend of population viability analysis is to build a comprehensive model that includes four kinds of stochasticity,widely to test PVA models,systematically to study genetic and ecological characteristics of target species and explore PVA's application in conservation practices.