| Abstract |
Wetlands pose unusual challenges for monitoring programs. The enormous spatial and temporal variability that is typical of wetlands requires that large numbers of samples be collected if the wetland community is to be properly characterized. However, access problems severely limit the ability to easily sample wetlands. Nonetheless, the need for more vigorous wetland sampling efforts is compelling. Many undisturbed wetlands are characterized by exceptional biological productivity, but at the same time, can easily accumulate contaminants from a wide area. This is partly because most wetlands are located in a topographically low, depositional environment and have long hydraulic detention times. The combination of normally great productivity and large potential for exposure to unnatural stresses suggests a need for extensive monitoring, so remedial action may be taken if wetlands begin to show signs of functional impairment. However, wetlands seldom are monitored in a geographically extensive, comparative manner. This chapter begins with discussions of considerations for wetland monitoring programs, and later discusses differences that may occur among wetland types and regions, using as an example an analysis of existing bird databases. |
