Wetlands of the Lower Clarence Floodplain. Northern Coastal New South Wales R. L. PRESSEY (Communicated by P. ADAM) PRESSEY, R. L. Wetlands of the lower Clarence floodplain, northern coastal New South Wales. Proc. Linn. Soc. N.S.W. Ill (3), 1989: 143-155. The wetlands on the lower Clarence floodplain, on the far north coast of New South Wales, were mapped and described during a detailed survey in 1982. The survey identified 755 wetlands with a total area of about 14,700 ha. Most wetlands were smaller than 10 ha but the relatively few large wetlands made up most of the total area. Open water occupied only 5% of the total wetland area at the time of the survey although some open water occurred in 45% of wetlands. The most important plant families, in terms of extent and frequency of occurrence, were Poaceae (covering 23% of the wet-land area, occupying 82% of the total number of wetlands), Cyperaceae (20% area, 36% number), Myrtaceae (17% area, 36% number), Polygonaceae (12% area, 76% number) and Juncaceae (10% area, 75% number). Most wetlands were fringed by dense stands of herbaceous plants but, due to clearing, had few trees on their margins. Ninety-eight percent of wetlands were grazed to some extent and 92% of the total wet-land area was affected by drainage. Most wetlands are seasonal with relatively small catchments. Only 28% had catchments on the bedrock slopes surrounding the flood-plain. Most catchments have been completely cleared for agriculture. Most wetlands are freehold tenure. R. L. Pressey, New South Wales National Parks and Wildlife Service, P.O. Box 1967, Hurstville, Australia 2220; manuscript received 1 November 1988, accepted for publication 15 March 1989. KEYWORDS: Wetlands, survey, plant taxa, catchments, Clarence floodplain. Introduction The coastal wetlands of New South Wales have been mapped and classified in a number of broad-scale surveys. Hannah's (1968) landscape approach dealt mainly with the wetlands of the dune systems and was restricted to the north coast. West et ai, (1985) mapped and classified the vegetation of the State's estuarine wetlands. The surveys of Goodrick (1970) and the Coastal Council of New South Wales (1985) were of dunal, estu-arine and floodplain wetlands along the whole coast. The Coastal Council study simply delineated wetlands for the purposes of development controls under State Environmen-tal Planning Policy No. 14. Goodrick's survey provided a useful classification based on dominant vegetation and water regime and is the best overview of wetlands on the coastal floodplains. It does not, however, provide sufficiently detailed information on individual floodplain wetlands for conservation or management. On the Clarence floodplain, none of the previous local, more detailed studies of flora and fauna has covered the wetlands comprehensively. They have concerned only one or a few wetlands and have had a variety of purposes and approaches. For example, Broome (1978) surveyed waterbirds in several areas and two environmental impact statements (Clarence River County Council, 1978, 1980) include vegetation maps and descriptions of some large wetlands. Most other publications on the Clarence floodplain wetlands deal with soils and specific occurrences of birds (Pressey, 1981). Wetland surveys for the National Parks and Wildlife Service, designed to be both detailed and comprehensive, covered the lower floodplains of the Hunter, Clarence and Macleay Rivers in 1981, 1982 and 1984, respectively, and the coastal lowlands of Tweed Shire in 1986. The main aims of these surveys were to: plot wetlands with accuracy and, in the PROC. LINN. SOC. N.S.W., 111 (3), 1989
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