Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models.
|Original language||English (US)|
|Number of pages||11|
|State||Published - Feb 2010|
Bibliographical noteFunding Information:
This research was funded by the US Geological Survey’s Natural Resources Preservation Program grant to GG and Hilary Neckles. We thank the US Geological Survey SCEP program, the University of Wisconsin-Madison Department of Botany, and the Society of Wetland Scientists for support to AL. David Manski, Bill Gawley, Bruce Connery, Karen Anderson, and Brook Childrey at Acadia National Park provided logistical, laboratory, GIS, and archival support. Christie Peschka, Megan Gahl, Liz Willey, Anna Kettel, Matt Kuchta, and Adam Flaaten helped collect field data. John Pastor, Charles Canham, and several anonymous reviewers made very helpful comments on earlier versions of this manuscript.
- Coastal peatland
- Patch size
- Sedge meadow