Effects of silvicultural activities on wetland biogeochemistry

The unique biogeochemistry of wetlands either causes or influences many lan dscape functions that are valued by society. Because of their critical ecol ogical role and the importance of wetlands to commodity and noncommodity va lues, we have reviewed the current state of knowledge regarding influences of silviculture on nutrient circulation, transformation, and retention in f orested wetlands. Our approach was to contrast riverine and depressional sy stems. Globally, there are few generalizations that can be made regarding t he effects of silvicultural disturbance. This conclusion is primarily a res ult of too few studies on the mechanisms and processes controlling ecosyste m responses. Most work to date has focused solely on characterizing respons es of state variables, and therefore a basis for integration is often lacki ng. While studies do show that water quality functions are not degraded as a result of harvesting, many other aspects of ecosystem functionality are n ot clarified. As examples, there are significant gaps in our understanding of biogeochemical controls on net primary productivity, organic matter turn over, and hydrologic interactions. Considerable research is warranted to pr ovide information for effective resource management and conservation.