Abstract
Spiders are common generalist predators in terrestrial ecosystems, half of which are web-builders living among vegetations and on the ground. Web spiders have diverse foraging mode and microhabitat requirement, and their ecological parameters can be easily obtained. Owing to these characteristics, they are ideal subject for studying impact by deer on ecosystems. We examined the underlying mechanisms of the effects of deer on forest-dwelling web spiders, as well as its further effect on insects. Spiders living on vegetations decreased with increasing deer density, which was caused by the reduction of vegetations as web support, not by the decrease in prey abundance. The rate of decrease in the kleptoparasitic spider Argyrodes that parasitize web spiders was greater than that of its host. In contrast, web spiders on the ground increased with deer density, probably because the reduction of ground vegetation cover favored these spiders. Furthermore, aerial insects derived from the soil increased by decreasing web spiders on vegetations. The work for theoretical generalization of these interaction chains is required in the future.
