一个孑遗类群——尖舌苣苔族(Klugieae)物种的居群绝灭速率及其指示意义

Population extinction rates of species in a relict group Klugieae,with special reference to its phylogeny and the destruction degree of its habitat

本文通过对尖舌苣苔族（Ｋｌｕｇｉｅａｅ）的５个属中１２个种５９个地方居群消长动态的统计分析，计算了该族各属物种的居群绝灭速率。在１２０年的时间区间内，尖舌苣苔族物种的居群绝灭速率和生境受破坏程度呈正相关。显然，一个类群物种的居群绝灭速率对于该类群分布地区环境的受破坏程度具有较强的指示意义。尖舌苣苔族各属物种的居群绝灭速率与其系统发育年龄和进化程度密切相关。进化水平较低，即系统发育上比较原始的类群，其居群绝灭速率往往较高；进化水平较高，即系统发育上比较年青的类群，其居群绝灭速率则低。地区性特有类群，尤其是特有属更容易遭受绝灭的危险。藉此，可在短时期内比较准确地了解该类群的濒危过程。

By means of statistic analysis on the dynamic state of the enrichment and declination of 59 local populations in 12 surviving species in Klugieae from China,the population extinction rate is calculated using the formula of R (%/20 years)= (1-Wi/W i-1 )×100. During the period of 120 years from 1870 to 1990,the population extinction rate of species in Klugieae sharply increased while their habitats became severely fragmented. The population extinction rates of species in different groups are correlated with their phylogeny. The primitive groups have higher population extinction rate than the derivative groups. The endemic groups, especially the endemic genera are inclined to suffer higher extinction than the widely distributed genera.