The 'Carex' Fen vegetation of northern New South Wales

Abstract

The floristic composition and extent of 'Carex'-dominated fens in the New South Wales New England Tablelands Bioregion and Barrington Tops area (lat 28°41'S-31°55'S; long 151°23'E-152°05'E) together with outliers from the central west (Coonabarabran) are described from 81 full floristic survey sites. These fens contained 234 vascular plant taxa of which 27% were exotic. Then fens were dominated by herbaceous vegetation (96% of taxa). Cluster analysis of cover-abundance scores of vascular plant taxa from 81 pots placed within 71 separate 'Carex' fens revealed three alliances: 1) 'Carex appressa', 2) 'Scirpus polystachyus' - 'Carex tereticaulis' and 3) 'Carex gaudichaudiana' and seven communities: 1) 'Carex appressa' - 'Stellaria angustifolia' Fen 2) 'Carex appressa' Fen 3) 'Scirpus polystachyus' - 'Carex appressa' Fen 4) 'Carex tereticaulis' Fen 5) 'Carex gaudichaudiana' - 'Isachne globosa' Fen 6) 'Carex' sp. Bendemeer - 'Carex gaudichaudiana' Fen 7) 'Carex' gaudichaudiana' - ' Glyceria australis' Fen The distribution of alliances showed a pattern of east-west separation. The most easterly alliance shares many features with the 'Carex gaudichaudiana' Alliance of the Monaro Region of the southern NSW while the other alliances have no counterparts within the current literature. We estimate that up to 5 000ha of fen vegetation survive in the New England Bioregion of which 90% is on grazed land and only 0.2% is within conservation reserves. Seven outstanding examples of fens remain; most are examples of Community 5, with one representing Community 6 and none representing the other five communities. Many of these are not secured, and none of those within reserves are in their 'natural' state. We therefore strongly encourage measures to allow closure of drains, the opening of dams, and the rehabilitation of important fens such as Bishops, Racecourse and New Country Swamps.