Detecting unacceptable change in the ecological character of Ramsar wetlands

Managers of Ramsar-listed wetlands throughout the world are committed to management that will promote the conservation and wise use of their wetland habitats. Part of the management process is a description of 'ecological character' as a benchmark against which a 'change in ecological character' can be assessed. Detecting unacceptable change is a difficult judgement, which depends upon an understanding of wetland ecosystem components, processes and services. This paper explores the development of conceptual models as a framework for describing the biophysical elements of ecological character of a wetland in a way that can be readily used for assessing changes. Ecosystem services are partially addressed but need further work to be more fully incorporated. We suggest development of models to identify components and key processes as well as drivers in the ecosystem. These models provide a description of a unique set of identifiers and a baseline against which unacceptable changes in biophysical character can be assessed. For an ecological character description to be useful for adaptive management, we suggest following the process, developed in a case study at Thomsons Lake, Western Australia, which: (i) provides a landscape context and identifies relevant spatial scales using a hierarchy of maps and aerial photographs; (ii) develops a conceptual ecological model with an accompanying synthesis of relevant biophysical data; and (iii) uses these as the basis for recognizing a unique set of wetland identifiers. The latter, together with critical processes, are the core biophysical elements of an ecological character description. Construction of a driver/stressor model facilitates the recognition of external drivers which create ecological stressors and lead to adverse ecological effects and loss of ecosystem services and benefits. It then follows that unacceptable changes in ecological character are those that result in a loss of identifiers, disrupt critical processes and reduce services or benefits