Khamis, K, Brown, LE, Hannah, DM et al. (1 more author) (2015) Experimental evidence that predator range expansion modifies alpine stream community structure. Freshwater Science, 34 (1). 66 - 80. ISSN 2161-9549
Abstract
Climate change is projected to facilitate altitudinal range expansions of ‘lowland’ taxa, creating novel species interactions. However, how range shifts will alter biotic interactions and community structure in alpine streams is not well understood. In the Pyrénées, climate-induced physicochemical habitat change is hypothesized to facilitate the colonization of high-altitude streams by Perla grandis, a carnivorous stonefly. A field-based experiment was conducted in mesocosm channels beside a hillslope spring (2000 m asl) in the Taillon-Gabiétous catchment, French Pyrénées. The influence of P. grandis predation on community structure, feeding trait composition, body-size spectrum, and algal chlorophyll a concentration was examined. Gut contents were analyzed and used to identify consumed prey. Total invertebrate density was not significantly reduced by P. grandis, but Baetis spp. densities were depressed in the treatment channels through a combination of direct consumption and predator avoidance (emigration/drift). However, despite fewer grazers in the predator treatment channels, the magnitude of the trophic cascade effect on basal resources (measured as chlorophyll a density) was comparable between treatment and control channels. The results of this experiment suggest that size/species-specific predation, intraguild predation, and interference competition are the likely mechanisms that altered the body-size spectrum in treatment channels. In synergy with climate-driven physicochemical habitat change, the extinction risk of some range-restricted taxa (prey and other predators) could be increased where P. grandis colonization occurs. Hence, conservation efforts are required to ensure that additional anthropogenic stressors (e.g., nutrient enrichment, cattle trampling, hydropower development, ski runs, and tourism) are limited to minimize further pressures on these unique and sensitive habitats.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2015, The Society for Freshwater Science. This is an author produced version of a paper published in Freshwater Science. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | climate change; mesocosm; intraguild predation; Perla grandis; Pyrenees; food web; body size; enemy release |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Geography (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 29 Sep 2015 15:56 |
Last Modified: | 18 Jan 2018 21:49 |
Published Version: | http://dx.doi.org/10.1086/679484 |
Status: | Published |
Publisher: | University of Chicago Press/Society for Freshwater Science |
Identification Number: | 10.1086/679484 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:85270 |