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Spatial complexity reduces interaction strengths in the meta-food web of a river floodplain mosaic

Ecology

By:
, ,
DOI: 10.1890/14-0733.1

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Abstract

Theory states that both the spatial complexity of landscapes and the strength of interactions between consumers and their resources are important for maintaining biodiversity and the 'balance of nature.' Spatial complexity is hypothesized to promote biodiversity by reducing potential for competitive exclusion; whereas, models show weak trophic interactions can enhance stability and maintain biodiversity by dampening destabilizing oscillations associated with strong interactions. Here we show that spatial complexity can reduce the strength of consumer-resource interactions in natural food webs. By sequentially aggregating food webs of individual aquatic habitat patches across a floodplain mosaic, we found that increasing spatial complexity resulted in decreases in the strength of interactions between predators and prey, owing to a greater proportion of weak interactions and a reduced proportion of strong interactions in the meta-food web. The main mechanism behind this pattern was that some patches provided predation refugia for species which were often strongly preyed upon in other patches. If weak trophic interactions do indeed promote stability, then our findings may signal an additional mechanism by which complexity and stability are linked in nature. In turn, this may have implications for how the values of landscape complexity, and the costs of biophysical homogenization, are assessed.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Spatial complexity reduces interaction strengths in the meta-food web of a river floodplain mosaic
Series title:
Ecology
DOI:
10.1890/14-0733.1
Volume
96
Issue:
1
Year Published:
2015
Language:
English
Publisher:
Ecological Society of America
Contributing office(s):
Western Fisheries Research Center
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Ecology
First page:
274
Last page:
283
Online Only (Y/N):
N
Additional Online Files(Y/N):
N