PRODUCTIVITY, DISTURBANCE AND FOOD WEB STRUCTURE AT A LOCAL SPATIAL SCALE IN EXPERIMENTAL CONTAINER HABITATS
PRODUCTIVITY, DISTURBANCE AND FOOD WEB STRUCTURE AT A LOCAL SPATIAL SCALE IN EXPERIMENTAL CONTAINER HABITATS
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DOI：
10.2307/3545016
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发表时间：
1992-11-01
期刊：
影响因子：
3.4
通讯作者：
PIMM, SL
中科院分区：
文献类型：
--
作者：
JENKINS, B;KITCHING, RL;PIMM, SL
我们报告的实验结果，使用充满水的容器模拟自然树洞放置在亚热带雨林。实验和自然系统中的能量来源都是碎屑叶。这一特征允许控制系统的生产率，并测量对食物网结构各个方面的影响。减少十倍和百倍的能量输入会使食物链的长度减少一个额外的环节。主要的捕食者在生产力较低的栖息地单位不太普遍。在生产力较低的生境单元中发现了营养链较少、物种较少的食物网。在食物网组装过程中，物种数量、营养链和最常见的被捕食物种的丰度都有所增加。有趣的是，低降雨量造成的自然扰动导致物种数量、营养链和食物链长度在36周时暂时减少。在最具生产力的系统中，对食物链长度的影响最为显著。这表明在食物网组装过程中，在局部空间尺度上的动态约束的影响。虽然相对较长的食物链只有在生产力最高的系统中才有可能，但这些系统特别容易受到外部扰动的影响。
We report the results of an experiment using water-filled container analogues of natural treeholes placed in a subtropical rainforest. The source of energy in both experimental and natural systems is detrital leaves. This feature allows the productivity of the systems to be controlled and the effects on various aspects of food web structure to be measured. Ten-fold and hundred-fold reductions in energy input reduced food chain lengths by an extra link. The principal predator was less prevalent in less productive habitat units. Food webs with fewer trophic links and fewer species were found in habitat units that were less productive. Numbers of species, trophic links and abundance of the most common prey species increased during food web assembly. Interestingly, a natural perturbation created by low rainfall caused numbers of species, trophic links and food chain length to be temporarily reduced at 36 weeks. The effect on food chain length was most marked in the most productive system. This demonstrated the influence of dynamic constraints at a local spatial scale during food web assembly. While relatively long food chains were possible only in the most productive systems, these systems were especially vulnerable to external perturbations.