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Food-web structure in relation to environmental gradients and predator-prey ratios in tank-bromeliad ecosystems

Dézerald, Olivier and Leroy, Céline and Corbara, Bruno and Carrias, Jean-François and Pelozuelo, Laurent and Dejean, Alain and Céréghino, Régis Food-web structure in relation to environmental gradients and predator-prey ratios in tank-bromeliad ecosystems. (2013) PLoS ONE, 8 (8). 1-8. ISSN 1932-6203

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Official URL: http://dx.doi.org/10.1371/journal.pone.0071735

Abstract

Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators: prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests.

Item Type:Article
Additional Information:Thanks to Public Library of Science editor. The definitive version is available at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0071735
HAL Id:hal-00913931
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Other partners > AgroParisTech (FRANCE)
French research institutions > Centre de Coopération Internationale en Recherche Agronomique - CIRAD (FRANCE)
French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
French research institutions > Institut National de la Recherche Agronomique - INRA (FRANCE)
French research institutions > Institut de Recherche pour le Développement - IRD (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
Other partners > Université Blaise Pascal - UBP (FRANCE)
Other partners > Université des Antilles et de la Guyane (FRANCE)
Laboratory name:
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Deposited By: Régis Cereghino
Deposited On:04 Dec 2013 14:32

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