Moran M D, Hurd L E
Ecology Program, School of Life and Health Sciences, University of Delaware, 19716, Newark, DE, USA.
Department of Biology, Washington and Lee University, 24450, Lexington, VA, USA.
Oecologia. 1994 Aug;98(3-4):269-273. doi: 10.1007/BF00324214.
We investigated the short-term response of an arthropod assemblage to elevated generalist predator densities by introducing Chinese mantids (Tenodera sinensis) to field plots in a replicated, controlled experiment. Abundances of carnivorous arthropods were reduced by mantids to a greater extent than herbivores, and cursorial spiders emigrated from treatment plots in greater numbers than from controls. Initially, this emigration consisted only of small spiders that were demonstrated in the laboratory to be prey for mantids. Thus, the initial response of an arthropod assemblage to increased predators, densities was increased interactions among predators, which caused decline in predator population densities in a shorter time than competition for prey would require. Predator avoidance behavior must be considered together with intraguild predation and competition when interpreting the outcome of predator manipulations. Shortterm experiments may be more valuable than longer term studies in detecting this effect.
我们通过在重复的对照实验中将中华大刀螂（Tenodera sinensis）引入田间地块，研究了节肢动物群落对多食性捕食者密度升高的短期反应。肉食性节肢动物的数量被螳螂减少的程度比草食性节肢动物更大，并且游走性蜘蛛从处理地块迁出的数量比从对照地块迁出的更多。最初，这种迁出仅由小型蜘蛛组成，实验室证明这些小型蜘蛛是螳螂的猎物。因此，节肢动物群落对捕食者密度增加的初始反应是捕食者之间的相互作用增加，这导致捕食者种群密度在比猎物竞争所需时间更短的时间内下降。在解释捕食者操纵的结果时，必须将捕食者回避行为与公会内捕食和竞争一起考虑。在检测这种效应方面，短期实验可能比长期研究更有价值。
