Integrating Ecosystem Engineering and Food Web Ecology: Testing the Effect of Biogenic Reefs on the Food Web of a Soft-Bottom Intertidal Area.
The potential of ecosystem engineers to modify the structure and dynamics of food webs has recently been hypothesised from a conceptual point of view. Empirical data on the integration of ecosystem engineers and food webs is however largely lacking. This paper investigates the hypothesised link based on a field sampling approach of intertidal biogenic aggregations created by the ecosystem engineer Lanice conchilega (Polychaeta, Terebellidae). The aggregations are known to have a considerable impact on the physical and biogeochemical characteristics of their environment and subsequently on the abundance and biomass of primary food sources and the macrofaunal (i.e. the macro-, hyper- and epibenthos) community. Therefore, we hypothesise that L. conchilega aggregations affect the structure, stability and isotopic niche of the consumer assemblage of a soft-bottom intertidal food web. Primary food sources and the bentho-pelagic consumer assemblage of a L. conchilega aggregation and a control area were sampled on two soft-bottom intertidal areas along the French coast and analysed for their stable isotopes. Despite the structural impacts of the ecosystem engineer on the associated macrofaunal community, the presence of L. conchilega aggregations only has a minor effect on the food web structure of soft-bottom intertidal areas. The isotopic niche width of the consumer communities of the L. conchilega aggregations and control areas are highly similar, implying that consumer taxa do not shift their diet when feeding in a L. conchilega aggregation. Besides, species packing and hence trophic redundancy were not affected, pointing to an unaltered stability of the food web in the presence of L. conchilega.
Department of Biology, Marine Biology Research Group, Ghent University, Ghent, Belgium.
Bart
B
De Smet
CNRS, UMR 7208 BOREA, Muséum National d'Histoire Naturelle, Paris, Cedex 05, France; Station Marine de Dinard, USM 404, Muséum National d'Histoire Naturelle, Dinard, France.
Jérôme
J
Fournier
Department of Biology, Marine Biology Research Group, Ghent University, Ghent, Belgium.
Marleen
M
De Troch
Department of Biology, Marine Biology Research Group, Ghent University, Ghent, Belgium.
Magda
M
Vincx
Department of Biology, Marine Biology Research Group, Ghent University, Ghent, Belgium.
Jan
J
Vanaverbeke
D000465:Algorithms; D000818:Animals; D059001:Aquatic Organisms / Q000502:physiology; D018533:Biomass; D002247:Carbon Isotopes / Q000378:metabolism; D003247:Conservation of Natural Resources / Q000379:methods; D055669:Ecological and Environmental Phenomena; D017753:Ecosystem; D020387:Food Chain; D005602:France; D005843:Geography; D008962:Models, Theoretical; D009587:Nitrogen Isotopes / Q000378:metabolism; D009792:Oceans and Seas; D011077:Polychaeta / Q000502:physiology*
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes