银缕梅物种濒危度的定量分析

Quantitative analysis of risk size of plant species: a case of Shaniodendron subaequale

采用二级模糊综合评判法进一步分析现存个体和居群数均极少的中国金缕梅科一新属种──银缕梅的物种濒危度。首先挑选对小种群绝灭有影响的随机干扰因素，建立了包括２０个评价指标在内的因素集。然后通过对评价指标定量化和权分配一系列处理，并通过最初一、二层的综合评判，求得濒危度和保护等级，进而确定物种的濒危状态及其在省级和国家级的保护序次。研究结果表明，二级模糊综合评判的方法十分灵敏，可操作性强，它能比较准确地反映植物物种实际濒危状况。

he risk size of Shaniodendron subaequale M. B. Deng,H.T.Wei&X. Q. Wang,the new species of new genus of Hamamelidaceae,with less number in both existing individuals and populations was further analysed by using the method of Fuzzy Two-stage Comprehensive Evaluation and Fuzzy Two-type Subset Weight Allocation. Firstly,the factor set of stochactic perturbations includi ng 20 evaluation in dexes which a ffected the extinction for small population was established. And then,the risk size and the conservation grade in the province and throughout the country were calculated by the index quantification , weight allocation and initial 1～2 ladder Fuzzy Comprehensive Evaluation. The result shows that this methed is sensitive and operable in reflecting the actual endangered situation of plant specles.