Tree island pattern formation in the Florida Everglades

Ecological Complexity
By: , and 

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Abstract

The Florida Everglades freshwater landscape exhibits a distribution of islands covered by woody vegetation and bordered by marshes and wet prairies. Known as “tree islands”, these ecogeomorphic features can be found in few other low gradient, nutrient limited freshwater wetlands. In the last few decades, however, a large percentage of tree islands have either shrank or disappeared in apparent response to altered water depths and other stressors associated with human impacts on the Everglades. Because the processes determining the formation and spatial organization of tree islands remain poorly understood, it is still unclear what controls the sensitivity of these landscapes to altered conditions. We hypothesize that positive feedbacks between woody plants and soil accretion are crucial to emergence and decline of tree islands. Likewise, positive feedbacks between phosphorus (P) accumulation and trees explain the P enrichment commonly observed in tree island soils. Here, we develop a spatially-explicit model of tree island formation and evolution, which accounts for these positive feedbacks (facilitation) as well as for long range competition and fire dynamics. It is found that tree island patterns form within a range of parameter values consistent with field data. Simulated impacts of reduced water levels, increased intensity of drought, and increased frequency of dry season/soil consuming fires on these feedback mechanisms result in the decline and disappearance of tree islands on the landscape.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Tree island pattern formation in the Florida Everglades
Series title Ecological Complexity
DOI 10.1016/j.ecocom.2016.03.007
Volume 26
Year Published 2016
Language English
Publisher Elsevier
Publisher location Amsterdam
Contributing office(s) Patuxent Wildlife Research Center
Description 8 p.
First page 37
Last page 44
Country United States
State Florida
Other Geospatial Everglades
Online Only (Y/N) N
Additional Online Files (Y/N) N
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