Self-Organization and Vegetation Collapse in Salt Marsh Ecosystems
Van de Koppel, J.; van der Wal, D.; Bakker, J.P.; Herman, P.M.J. (2005). Self-Organization and Vegetation Collapse in Salt Marsh Ecosystems. American Naturalist 165(1): E1-E12 In: The American Naturalist. George W. Salt/University of Chicago: Salem, Mass.. ISSN 0003-0147; e-ISSN 1537-5323, more |   |
| Keywords | Ecosystems
Water bodies > Inland waters > Wetlands > Marshes > Salt marshes
Brackish water; Fresh water |
| Abstract | Complexity theory predicts that local feedback processes may strongly affect the organization of ecosystems on larger spatial scales. Whether complexity leads to increased resilience and stability or to increased vulnerability and criticality remains one of the dominant questions in ecology. We present a combined theoretical and empirical study of complex dynamics in mineralogenic salt marsh ecosystems that emerge from a positive feedbackbetween clay accumulation and plant growth. Positive feedback induces self-organizing within the ecosystem, which buffers for the strong physical gradient that characterizes the marine-terrestrial boundary, and improves plant growth along the gradient. However,as a consequence of these self-organizing properties, salt marshesapproach a critical state as the edge of the salt marsh and the adjacent intertidal flat becomes increasingly steep and vulnerable to wave attack. Disturbance caused, for instance, by a storm may induce a cascade of vegetation collapse and severe erosion on the cliff edge, leading to salt marsh destruction. Our study shows thaton short timescales, self-organization improves the functioning of salt marsh ecosystems. On long timescales, however, self-organization may lead to destruction of salt marsh vegetation. |
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