The global relationship between climate, net primary production and the diet of spiders
Article first published online: 24 MAR 2011
© 2011 Blackwell Publishing Ltd
Global Ecology and Biogeography
Volume 21, Issue 2, pages 100–108, February 2012
How to Cite
Birkhofer, K. and Wolters, V. (2012), The global relationship between climate, net primary production and the diet of spiders. Global Ecology and Biogeography, 21: 100–108. doi: 10.1111/j.1466-8238.2011.00654.x
- Issue published online: 9 JAN 2012
- Article first published online: 24 MAR 2011
- diet breadth;
- diet composition;
- generalist predators;
- more-individuals hypothesis;
- predator–prey interactions;
- prey specialization;
- species–energy theory
Aim We compiled data on prey utilization of spiders at a global scale to better understand the relationship between current climate or net primary production (NPP) and diet breadth, evenness and composition in spiders. We test whether the productivity and the diversity–climatic-stability (DCS) hypotheses focusing on diversity patterns may also explain global patterns in prey utilization by web-building and cursorial spiders.
Location A global dataset of 95 data points from semi-natural and natural terrestrial habitats spanning 41.3° S to 56.1° N.
Methods We collected data on spider prey (29 groups, mostly order-level invertebrate taxa) through extensive literature research to identify the relationship between climatic conditions and NPP and spider diets based on 66 studies of prey composition in 82 spider species.
Results The number of prey groups in spider diets was positively related to NPP, after accounting for differences in sampling effort in the original studies. In general, diet breadth was significantly higher for spider species in tropical environments. Prey individuals in spider diets were more evenly distributed among different prey groups in warmer environments with lower fluctuations in precipitation. Collembola and other spiders were more common prey for spiders with a cursorial hunting mode. Myriapoda and Collembola were more common prey in cooler climates with more stable precipitation, whereas Isoptera, Lepidoptera, Psocoptera and Coleoptera showed the opposite pattern.
Main conclusions The positive relationship between diet breadth and NPP and the negative relationship between prey evenness and seasonality in precipitation support the productivity and the DCS hypotheses, respectively. This effect on global patterns of invertebrate predator–prey interactions suggests that trophic interactions between spiders and their prey are sensitive to climatic conditions. Climatic conditions may not only affect spider community composition, but also considerably alter the functional role of these abundant invertebrate predators in terrestrial ecosystems.