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Title: Negative outcomes of novel trophic interactions along mangrove range edges

Tropicalization is a phenomenon that is changing the structure of ecosystems around the world. Mangrove encroachment is a particular form of tropicalization that may have cascading consequences for resident fauna in subtropical coastal wetlands. There is a knowledge gap regarding the extent of interactions between basal consumers and mangroves along mangrove range edges and the consequences of these novel interactions for consumers. This study focuses on the key coastal wetland consumers,Littoraria irrorata(marsh periwinkle) andUca rapax(mudflat fiddler crabs), and their interactions with encroachingAvicennia germinans(black mangrove) in the Gulf of Mexico, USA. In food preference assays,Littorariaavoided consumingAvicenniaand selectively ingested leaf tissue from a common marsh grass,Spartina alterniflora(smooth cordgrass), a preference that was also previously documented inUca. The quality ofAvicenniaas a food source was determined by measuring the energy storage of consumers that had interacted with eitherAvicenniaor marsh plants in the lab and the field.LittorariaandUcaboth stored ~10% less energy when interacting withAvicennia, despite their different feeding behaviors and physiologies. The negative consequences of mangrove encroachment for these species at the individual level suggest that there may be negative population‐level effects as encroachment continues. Many studies have documented shifts in floral and faunal communities following mangrove replacement of salt marsh vegetation, but this study is the first to identify physiological responses that may be contributing to these shifts.

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Author(s) / Creator(s):
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Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Medium: X
Sponsoring Org:
National Science Foundation
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