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Spiders in the agricultural landscape

diversity, recolonisation, and body condition

Öberg, Sandra (2007). Spiders in the agricultural landscape. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2007:25
ISBN 978-91-576-7324-4
[Doctoral thesis]

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Abstract

Spiders in agroecosystems play a role in natural pest suppression and contribute to biodiversity. In this thesis I have investigated if and when spiders recolonise cereal fields in spring when they have the potential to suppress establishing pest aphid populations. Furthermore, the influence of different environmental factors on spiders has been investigated to understand how it might be possible to provide suitable conditions for enhancement of their populations. Linyphiid spiders recolonised fields after being negatively affected by sowing in spring, while lycosid spiders were unaffected. Conversely, lycosids showed a recolonisation in winter cereals after overwintering, but not linyphiids. But linyphiid migratory patterns also differed over time, because they were positively influenced by landscape heterogeneity in the beginning of spring but not at the end. Diversity of lycosid and linyphiid spiders was positively influenced by perennial crops and forest in the surrounding landscape. Field margins were found to be a key habitat for the diversity of both spider families. Lycosid abundance was affected on the habitat scale and linyphiid abundance on the larger landscape scale, which can be explained by the families' different modes of dispersal. Farming systems, conventional or organic, contained different compositions of lycosid and linyphiid species. The dominant lycosid and linyphiid species were more abundant at organic sites. Body condition of Pardosa (Lycosidae) turned out to be superior in landscapes dominated by large fields with annual crops, irrespective of farming system, perhaps because of less competition for available resources. This thesis provides evidence that spiders are present in crop fields early in spring when they have the opportunity to suppress establishing aphid pests. Different spider species were associated with different farming systems, but the abundances of the most common species were enhanced by organic management. A diverse landscape with easy access to perennial crops and field margins will augment both number of species and individuals of spiders.

Authors/Creators:Öberg, Sandra
Title:Spiders in the agricultural landscape
Subtitle:diversity, recolonisation, and body condition
Year of publishing :2007
Volume:2007:25
Number of Pages:29
Papers/manuscripts:
NumberReferences
ALLI. Öberg, S. & Ekbom, B. 2006. Recolonisation and distribution of spiders and carabids in cereal fields after spring sowing. Annals of Applied Biology 149, 203-211. II. Öberg, S., Mayr, S. & Dauber, J. Landscape effects on recolonisation patterns of spiders in arable fields. (Submitted). III. Öberg, S., Ekbom, B. & Bommarco, R. 2007. Influence of habitat type and surrounding landscape on spider diversity in Swedish agroecosystems. Agriculture, Ecosystems and Environment. In press. IV. Öberg, S. Diversity of spiders after spring sowing – influence of farming system and habitat type. Journal of Applied Entomology. In press. V. Öberg, S. Influence of landscape and farming system on body condition and fecundity of wolf spiders. (Manuscript).
Place of Publication:Uppsala
ISBN for printed version:978-91-576-7324-4
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:araneae, lycosidae, linyphiidae, landscape, ecology, cereal crops, fields, habitats, farming systems, fertility, pest control, predation, predators, body condition
Keywords:Araneae, Lycosidae, Linyphiidae, landscape ecology, cereal crops, field margin, farming system, fecundity, pest management, generalist predators
URN:NBN:urn:nbn:se:slu:epsilon-1500
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-1500
ID Code:1359
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
Deposited By: Sandra Öberg
Deposited On:06 Mar 2007 00:00
Metadata Last Modified:02 Dec 2014 10:11

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