TY  - JOUR
A1  - Martin, Emily A.
A1  - Reineking, Björn
A1  - Seo, Bumsuk
A1  - Steffan-Dewenter, Ingolf
T1  - Pest control of aphids depends on landscape complexity and natural enemy interactions
JF  - PeerJ
N2  - Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1) the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2) the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the effectiveness of aphid natural pest control.
KW  - insect populations
KW  - metaanalysis
KW  - biodiversity-ecosystem functioning
KW  - cabbage Brassica oleracea var. capitata
KW  - proportion of seminatural habitat
KW  - South Korea
KW  - land use intensification
KW  - trophic interactions
KW  - agroecosystems
KW  - biological control
KW  - agricultural landscapes
KW  - pest
KW  - biodiversity
KW  - herbivores
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148393
VL  - 3
IS  - e1095
ER  - 
TY  - JOUR
A1  - Gámez-Virués, Sagrario
A1  - Perović, David J.
A1  - Gossner, Martin M.
A1  - Börschig, Carmen
A1  - Blüthgen, Nico
A1  - de Jong, Heike
A1  - Simons, Nadja K.
A1  - Klein, Alexandra-Maria
A1  - Krauss, Jochen
A1  - Maier, Gwen
A1  - Scherber, Christoph
A1  - Steckel, Juliane
A1  - Rothenwöhrer, Christoph
A1  - Steffan-Dewenter, Ingolf
A1  - Weiner, Christiane N.
A1  - Weisser, Wolfgang
A1  - Werner, Michael
A1  - Tscharntke, Teja
A1  - Westphal, Catrin
T1  - Landscape simplification filters species traits and drives biotic homogenization
JF  - Nature Communications
N2  - Biodiversity loss can affect the viability of ecosystems by decreasing the ability of communities to respond to environmental change and disturbances. Agricultural intensification is a major driver of biodiversity loss and has multiple components operating at different spatial scales: from in-field management intensity to landscape-scale simplification. Here we show that landscape-level effects dominate functional community composition and can even buffer the effects of in-field management intensification on functional homogenization, and that animal communities in real-world managed landscapes show a unified response (across orders and guilds) to both landscape-scale simplification and in-field intensification. Adults and larvae with specialized feeding habits, species with shorter activity periods and relatively small body sizes are selected against in simplified landscapes with intense in-field management. Our results demonstrate that the diversity of land cover types at the landscape scale is critical for maintaining communities, which are functionally diverse, even in landscapes where in-field management intensity is high.
KW  - land-use intensity
KW  - community functional-responses
KW  - body-size
KW  - agricultural intensification
KW  - sustainable intensification
KW  - managed grasslands
KW  - biodiversity
KW  - diversity
KW  - heterogenity
KW  - butterflies
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141925
VL  - 6
IS  - 8568
ER  -