短柄五加濒危趋势和致濒因素的初步分析

研究了短柄五加种群致濒的因素和机制 .1)通过环境筛分析 ,认为短柄五加种群在 5～ 8a和 11～ 12a两个年龄阶段受到强烈的环境筛过滤作用 ,这两个阶段可能是濒危的关键阶段 .2 )通过对短柄五加种群生物量增长过程中关键因子的分析 ,确定了影响种群生物量的主导生境因子 ,主要是群落类型、群落郁闭度和坡度、坡向等 .影响种群增长的主导生境因子的脆弱性 ,增大了短柄五加种群濒危的趋势 .3)通过对短柄五加种子生态及生殖生态的初步分析 ,认为种群实生苗更新失败是短柄五加种群濒危的重要因素 .4)放牧、采挖和对次生落叶阔叶林的砍伐等人类活动 ,加快了短柄五加种群濒危的速度 .图 1表 3参 11

ANALYSIS OF ENDANGERING PROCESS AND FACTORS OF ACANTHOPANAX BRACHYPUS POPULATION

Acanthopanax brachypus is an endangered plant. In general, the understanding of population endangering factors and their mechanism can offer a theoretical base for developing conservation strategies. By analyzing static life-table, the result showed that A. brachypus population was greatly influenced by environmental sieve. By multiple linear regressive model, the key habitat factors significantly correlated to population biomass were known, i.e., community type, crown density, slope and exposure, which were not stable and might increase the endangered possibility of A. brachypus population. By studing seed ecology of A. brachypus, it was concluded that the failure of seedling regeneration was one of the important endangering factors. At last, human disturbance dimension which can increase the endangering probability of A. brachypus, was also discussed. Fig 1, Tab 3, Ref 11