Abstract:

【Objective】 The objective of this study aimed at the effects of hedgerow species on ground-dwelling spider population in agricultural fields. 【Method】 Using pitfall trapping, the effects of four hedgerow plant species, which serve as undisturbed and permanent semi-natural habitats, on ground-dwelling spider activity density (a parameter of population density and relative activity) were investigated. Samples were collected over two winter wheat and two summer maize growing seasons during 2005-2007 in trial field 1 (slope gradient of 20%) and field 2 (slope gradient of 12%) at the Ziyang Experimental Site in Sichuan Province, China. The hedgerow species evaluated were Amorpha fruticosa (field 1), Vetiveria zizanioides (field 1), Eulaliopsis binata (field 2), and Medicago sativa (field 2). 【Result】 Activity density of ground-dwelling spiders was significantly higher in the hedgerow strips than in the bare soil strips during the winter wheat season. Activity density of ground-dwelling spiders was also higher in the hedgerow strips than in the bare soil strips during the summer maize season, however, activity density differed significantly only between Eulaliopsis and Medicago strips and bare soil strips. No significant difference was found in activity density of ground-dwelling spiders in the crop fields between hedgerow and control plots during the winter wheat or summer maize seasons.【Conclusion】The results suggest that hedgerows could serve as important overwintering sites for ground-dwelling spiders during the winter wheat season. However, the presence of hedgerow strips did not significantly increase the activity density of ground-dwelling spiders within the crop fields.

Key words: hedgerow, ground-dwelling spider, activity density, pitfall trapping