热带次生林2种不同捕食策略地表蜘蛛的种内、种间竞争强度及土壤N的调节作用

为了进一步了解热带森林生态系统中不同捕食策略蜘蛛的种内、种间关系以及环境资源对其的调节作用,采用室内微生态系统,对蜘蛛个体密度和弹尾目数量变化对不同捕食策略蜘蛛功能群种内、种间竞争关系的影响进行了研究。研究发现:在猎物弹尾目数量丰富的微生态系统中,蜘蛛个体数增加可导致主动捕食策略的游走型狼蛛科死亡率显著升高,被动捕食策略的结网型六疣蛛科生物量生长呈现明显的负增长,非同种蜘蛛组合的混合功能群中蜘蛛群落生物量的损失量显著增大。在弹尾目数量较少的微生态系统中,蜘蛛个体数增加使游走型蜘蛛的死亡率显著升高,生物量的损失量显著增大,但对结网型蜘蛛的死亡率和生物量生长没有显著影响,非同种蜘蛛组合的混合功能群中蜘蛛的死亡率显著增高、生物量则出现正增长状况。由此表明,游走型蜘蛛的种内竞争方式主要体现在个体死亡率,结网等待型蜘蛛则更多表现在生物量的损失上,不同种蜘蛛种间竞争受食物资源的影响,蜘蛛死亡主要以游走型蜘蛛为主。

The Competition of Different Strategy Spiders and the Regulating Effect of Soil N in Tropical Secondary Forest

In order to further understand the relationship of different forage strategy spiders and the regulating factors,the study was performed as a microcosm experiment in two soils with different nitrogen content.The paper studied interspecific and intraspecific competition under the influence of Collembola abundance and spider individual density.The study demonstrated that wandering spiders ’ mortality rate could increase with spider individual density,while sit-and-wait spiders ’ biomass variation displayed a significant negative increase in CK treatment.Individual density of mixed species spiders has no influence on mortality,but the biomass variation expressed negative growth.In the ＋ N treatment,wandering spiders ’ individual density significantly influenced the mortality rate and biomass variation,while sit-and-wait spiders ’ individual density has no influence on mortality rate and biomass variation.Increasing individual density of mixed species spiders would lead to higher mortality rate and positive biomass variation.The intraspecific competition of wandering spiders usually displayed on mortality rate,but the sit-and-wait spider ’ s intraspecific competition mainly displayed on biomass variation.The interspecific competition between mixed species was shown on the mortality rate change,and wandering spiders had a higher mortality rate.