Determining baselines in wetlands

The Ramsar Convention has formalised the concept of determining baselines in wetlands asa means of ascertaining change in the ecological character of wetlands. This has generallybeen based on the assignment of a baseline or reference condition at a point in time wheresuitable data is available. In some instances, this has been equated with a pre-disturbancestate. At the same time, there have also been difficulties in describing the natural successionand variability within these states. This reflects a difficulty to come to grips with theecological processes that shape and change wetlands in both short and longer time periods.The advent of global change, including climate change, has further complicated efforts toascertain the ecological condition of wetlands and to determine when a wetland haschanged adversely in response to human activities. In response, attempts are being made topredict the future condition of wetlands under climate change and to identify thresholds forwhat is generally seen as adverse change. A fundamental stumbling block has been theextent of information on which to base such assessments.