Spider diversity in cereal fields: comparing factors at local, landscape and regional scales
Article first published online: 28 SEP 2005
Journal of Biogeography
Volume 32, Issue 11, pages 2007–2014, November 2005
How to Cite
Clough, Y., Kruess, A., Kleijn, D. and Tscharntke, T. (2005), Spider diversity in cereal fields: comparing factors at local, landscape and regional scales. Journal of Biogeography, 32: 2007–2014. doi: 10.1111/j.1365-2699.2005.01367.x
- Issue published online: 28 SEP 2005
- Article first published online: 28 SEP 2005
- biological control;
- landscape composition;
- organic farming;
- regional variation;
- scale effects
Aim Factors acting at various scales may affect biodiversity, demanding analyses at multiple spatial scales in order to understand how community richness is determined. Here, we adopted a hierarchical approach to test the contribution of region, landscape heterogeneity, local management (organic vs. conventional) and location within field (edge vs. centre) to the species richness and abundance of spiders in cereals.
Location Three regions of western and central Germany: Leine Bergland, Soester Boerde, and Lahn-Dill Bergland.
Methods Forty-two paired organic and conventional winter wheat fields were compared. Field pairs were located in areas ranging from structurally simple to structurally complex landscapes. In May and June 2003, spiders were sampled using pitfall traps. Linear mixed models were used to determine the relationship of spider diversity and abundance with regional spatial factors and landscape heterogeneity within a 500-m radius, as well as with local management and within-field location.
Results Within-field location of the traps and landscape heterogeneity were the best predictors of species richness: more species were found in field edges and in heterogeneous landscapes. Region and local management had no effect on species richness. Activity density was higher in field edges and differed among regions.
Main conclusions The diversity of farmland spiders was influenced by differences at two of the spatial scales (edge vs. centre, simple vs. complex landscapes), but not at the two others (field management, region), emphasizing the importance of analyses at a variety of spatial scales for an adequate explanation of patterns in biodiversity. Our study suggests that promoting heterogeneity in land use at landscape scales is one of the keys to promoting spider diversity in agroecosystems.