Global wetland inventory - current status and future priorities

This assessment is based on reviews of the extent of wetland inventory in s even regions of the world. A key conclusion is that little is still known a bout the extent and condition of the global wetland resource. It was not po ssible to make reliable overall estimates of the size of the wetland resour ce globally or regionally. Previous estimates range from 5.3 to 9.7 million km(2) but present analyses now suggest a tentative minimum of 12.8 km(2). Recommendations focus on the need for national inventory programmes and the inclusion of basic information on the location and extent of each wetland and its major ecological features as a forerunner to collecting further man agement-oriented information. Thus, the following core data should be colle cted: area and boundary, location, geomorphic setting, general description, soil characteristics, water regime, water quality, and biotic characterist ics. Further, the development of standardized methods for data collection, collation and storage are called for. These should address the use of remot ely sensed data and storage of information in electronic formats, including Geographic Information Systems and recording key information in a meta-dat abase. Habitats of priority for future inventory are seagrasses, coral reef s, salt marshes and coastal flats, mangroves, arid-zone wetlands, peatlands , rivers and streams, and artificial wetlands.