Landscape dynamics, conservation biology, and restoration ecology
 

 

Landscape ecology and restoration - John Volin, Paul Glaser, and I are investigating how spatially coupled feedbacks help create and maintain the patterned landscape characteristic of the central Everglades.  Over the coming decade, the United States plans to spend several billion dollars to help restore the Everglades by modifying hydrological flows. However, current models for the outcome of such modifications generally ignore the fundamental importance of feedbacks in peatlands. We are developing a model that incorporates spatially coupled, positive and negative feedbacks among vegetation, substrate, hydrology, biogeochemistry, and landforms, and asks how these feedbacks should contribute to the self-assembly of patterned landscapes under different flow regimes. 

We are testing the resulting predictions using stratigraphy, measurements of production, decomposition, hydrology, and biogeochemistry, and highly detailed GIS analyses in four different regions of the Everglades with radically different flow regimes, imposed by the emplacement of various water-control structures over the past 50 years. We hope to integrate our findings with landscape-level hydrological modeling by the USGS, South Florida Water District, and the National Park Service to predict the impact of different restoration scenarios on the patterning, biodiversity, and community- and landscape-level functioning of the central Everglades.

My students and I also study the ecology of a variety of endangered plant species and communities, focusing on the dynamics and determinants of species loss in some systems, and characterizing the ecological features of others needed for their successful conservation and restoration. Mark Leach and I have shown that short stature, small seed size, and N-fixation are positively correlated with local extinction in prairie remnants over the past 35 years, as expected based on fire suppression.  Laurie Stockmeier and I showed that rare species in fens are short-statured and grow on microsites that are sparsely covered as a result of P and N shortages induced by high rates of calcium carbonate precipitation. In Cyanea - the largest genus endemic to Hawaii - my colleagues and I showed that the probability of global extinction was coupled to limited geographic and ecological ranges, and to possession of highly specialized, long-tubed flowers.
 
Photographs:  TOP - Portrait of the scientist as a young man among Nymphaea; false-color satellite image of the central and southern Everglades, showing patterned landscape with streamlined tree islands and a series of water-control structures constructed over the last half-century; Gentiana puberula (Gentianaceae), one of the short-statured, small-seeded species that has undergone a massive decline in prairie remnants over the past several decades; and Ken Wood, Steve Perlman, and I ascending a waterfall in remote windward Kaua`i, searching for an extremely rare lobeliad recently discovered by them.
 
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