ECOLOGICAL FUNCTIONS AND HUMAN-VALUES IN WETLANDS - A FRAMEWORK FOR ASSESSING FORESTRY IMPACTS

The term ''value'' usually connotes something of use or desirable to Homo sapiens. Values ascribed to many wetlands include providing habitats for fishing, hunting, waterfowl, timber harvesting, wastewater assimilation, and flood control, to name a few. These perceived values arise directly from the ecological functions found within the wetlands. Ecosystem functions include hydrologic transfers and storage of water, biogeochemical transformations, primary productivity, decomposition, and community/habitat. An analysis of the relationship among wetland functions and values showed that over-utilization or intensive removal of wetland values (e.g., timber harvesting with drainage), can often result in a loss of specific wetland functions. An assessment procedure comparing changes in wetland function from both a disturbed and reference wetland was developed. This approach scales the wetland functions in a reference system to 100% and then compares the altered wetlands' functional response. Methods to analyze wetland functions in the field are outlined along with examples of the effects of forestry activities on wetland response.