Abstract:
Several state and federal agencies have identified Oregon's coastal wetlands as
priority areas for conservation, and in some cases have specifically singled out
nontidal (mostly palustrine) wetlands as a major concern. Recent research has
highlighted the need to study and manage wetlands from a regional perspective that
considers the distribution of wetlands within the framework of watersheds and
ecoregions. Public planning and awareness of coastal palustrine wetlands has been
limited by their small size and the lack of digital National Wetlands Inventory (NWI)
coverage in the upper reaches of coastal watersheds where many are located.
This research was designed to test hypotheses about physiographic and derived
topographic variables associated with mapped palustrine wetlands. The study assumed that certain variables were more significant than others in characterizing
these wetlands, and sought to identify relationships among variables that were
indicative of wetland distributions across watersheds and ecoregions. A three phase
approach was demonstrated for characterizing palustrine wetland size and degree of
isolation that included designing an enhanced NWI geodatabase of palustrine wetland
polygons, creating watershed profiles and wetland demographic statistics, and
analyzing the data using exploratory data analysis in the form of decision tree
modeling. This study confirmed the ability to provide information on the geographical
distributions and relationships existing among environmental variables and mapped
wetland polygons. An enhanced understanding of these characteristics has
applications for conservation planning including sustainable wetland creation and
restoration.
