Ground-dwelling spider assemblages inhabiting riparian forests and hedgerows in an agricultural landscape
American Midland Naturalist
Generalist predators, such as spiders, play an important role as natural enemies in agroecosystems and, given the annual disturbance of most field crops, these predators typically re-colonize fields from adjacent habitats such as hedgerows or riparian forests. To test whether the biota of these source habitats differed, we collected ground-dwelling spiders (Araneae) from thin (<15 m) riparian forests, wide (>50 m) riparian forests and hedgerows (<15 m wide) located next to soybean or corn fields in south-west Ohio. Pitfall traps collected spiders at the stream edge, the interior of forests or hedgerows and the agricultural edge. Rarefaction analysis and non-metric multidimensional scaling (NMDS) ordination tested how spider diversity and community structure, respectively, differed between hedgerows and riparian forests and by trap location. Wide riparian forests harbored a higher diversity of spiders than thin riparian forests and hedgerows contained the lowest spider diversity. The latter result may be due in part to the invasive honeysuckle shrub Lonicera maackii in hedgerows, which can reduce habitat complexity on the ground-layer. Ordination analysis revealed the spider community found at the edge of hedgerows is distinct from other trap locations, as was the spider assemblage located adjacent to the stream, the latter containing some hygrophilous species. The spider fauna at the edge of hedgerows contained several species typically found in high densities in agricultural plots, supporting the need for these habitat features in an agricultural landscape.
Author(s): Buddle, CM; Higgins, S; Rypstra, AL
Journal: American Midland Naturalist