Non-random food-web assembly at habitat edges increases connectivity and functional redundancy

Abstract

Habitat fragmentation dramatically alters the spatial configuration of landscapes, with the creation of artificial edges affecting community structure and dynamics. Despite this, it is not known how the different food webs in adjacent habitats assemble at their boundaries. Here we demonstrate that the composition and structure of herbivore-parasitoid food webs across edges between native and plantation forests are not randomly assembled from those of the adjacent communities. Rather, elevated proportions of abundant, interaction-generalist parasitoid species at habitat edges allowed considerable interaction rewiring, which led to higher linkage density and less modular networks, with higher parasitoid functional redundancy. This was despite high overlap in host composition between edges and interiors. We also provide testable hypotheses for how food webs may assemble between habitats with lower species overlap. In an increasingly fragmented world, non-random assembly of food webs at edges may increasingly affect community dynamics at the landscape level.

Keywords

edge effects; food-web structure; generalism; host; native forest; network dissimilarity; parasitoid; plantation forest; rewiring of interactions; species composition

Published in

Ecology
2017, Volume: 98, number: 4, pages: 995-1005 Publisher: WILEY

SLU Authors

• Frost, Carol

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    
  • University of Canterbury

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1002/ecy.1656

Permanent link to this page (URI)

https://res.slu.se/id/publ/94192