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Title: Consumer trait variation influences tritrophic interactions in salt marsh communities
Abstract

The importance of intraspecific variation has emerged as a key question in community ecology, helping to bridge the gap between ecology and evolution. Although much of this work has focused on plant species, recent syntheses have highlighted the prevalence and potential importance of morphological, behavioral, and life history variation within animals for ecological and evolutionary processes. Many small‐bodied consumers live on the plant that they consume, often resulting in host plant‐associated trait variation within and across consumer species. Given the central position of consumer species within tritrophic food webs, such consumer trait variation may play a particularly important role in mediating trophic dynamics, including trophic cascades. In this study, we used a series of field surveys and laboratory experiments to document intraspecific trait variation in a key consumer species, the marsh periwinkleLittoraria irrorata, based on its host plant species (Spartina alternifloraorJuncus roemerianus) in a mixed species assemblage. We then conducted a 12‐week mesocosm experiment to examine the effects ofLittorariatrait variation on plant community structure and dynamics in a tritrophic salt marsh food web.Littorariafrom different host plant species varied across a suite of morphological and behavioral traits. These consumer trait differences interacted with plant community composition and predator presence to affect overall plant stem height, as well as differentially alter the density and biomass of the two key plant species in this system. Whether due to genetic differences or phenotypic plasticity, trait differences between consumer types had significant ecological consequences for the tritrophic marsh food web over seasonal time scales. By altering the cascading effects of the top predator on plant community structure and dynamics, consumer differences may generate a feedback over longer time scales, which in turn influences the degree of trait divergence in subsequent consumer populations.

 
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NSF-PAR ID:
10196871
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Ecology and Evolution
Volume:
5
Issue:
13
ISSN:
2045-7758
Format(s):
Medium: X Size: p. 2659-2672
Size(s):
p. 2659-2672
Sponsoring Org:
National Science Foundation
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