Carex Sedgeland of the New England Tableland, Nandewar, Brigalow Belt South and NSW North Coast Bioregions - endangered ecological community listing

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Carex Sedgeland of the New England Tableland, Nandewar, Brigalow Belt South and NSW North Coast Bioregions is the name given to the ecological community characterised by the species assemblage listed in paragraph 2. These Bioregions are as defined by Thackway and Cresswell (1995).

2. Carex Sedgeland of the New England Tableland, Nandewar, Brigalow Belt South and NSW North Coast Bioregions is characterised by the following assemblage of species:

3. The total species list of the community is considerably larger than that given above, with many species present in only one or two sites or in low abundance. The species composition of a site will be influenced by the size of the site, recent rainfall or drought condition and by its disturbance history. The number of species, and the above ground relative abundance of species will change with fire and grazing regime. At any one time, above ground individuals of some species may be absent, but the species may be represented below ground in the soil seed banks or as dormant structures such as bulbs, corms, rhizomes, rootstocks or lignotubers. The list of species given above is of vascular plant species; the community also includes micro-organisms, fungi, cryptogamic plants and a diverse fauna, both vertebrate and invertebrate. These components of the community are poorly documented.

4. Carex Sedgeland comprises fens dominated by sedges, grasses and semi-aquatic herbs. The dominant species are Carex appressa, Stellaria angustifolia, Scirpus polystachyus, Carex gaudichaudiana, Carex sp. Bendemeer, Carex tereticaulis and Isachne globosa, either as single species or in combinations. Other common species include Geranium solanderi var. solanderi, Haloragis heterophylla, Lythrum salicaria, Epilobium billardierianum subsp. hydrophilum and Persicaria hydropiper (Hunter and Bell 2009).

5. Carex Sedgeland mainly occurs in drainage depressions in valley floors, frost hollows, and undulating terrain between 440 and 1360 m in altitude. It occurs on a variety of lithologies including granite, basalt, metasediments, acid volcanics, sandstone and Aeolian sands (Hunter and Bell 2009). Carex Sedgeland occurs as a part of a mosaic of native vegetation communities including swamps, bogs, wetlands, grasslands, and sclerophyll forests (Costin 1954; Benson and Ashby 2000; Hunter and Bell 2007; Bell et al. 2008). Carex Sedgeland is mostly found at higher altitude on tablelands but may extend onto the slopes. The size of these fens is usually small (< 0.1 ha) but may be as large as 32.5 ha (Hunter and Bell 2009). Carex Sedgeland falls within the general formation of montane bogs and fens (Beadle 1981, Keith 2004).

6. Carex Sedgeland includes the fen communities; C1 Carex appressa–Stellaria angustifolia, C2 Carex appressa, C3 Scirpus polystachyus–Carex appressa, C4 Carex tereticaulis, C5 Carex gaudichaudiana–Isachne globosa, and Carex sp. Bendemeer–Carex gaudichaudiana of Hunter and Bell (2009), but does not include those communities dominated only by Carex gaudichaudiana which are a part of the Carex gaudichaudiana Alliance of Costin (1954). This last community is a part of the Montane Peatlands and Swamps of the New England Tableland, NSW North Coast, Sydney Basin, South East Corner, South Eastern Highlands and Australian Alps bioregions which is currently listed as an Endangered Ecological Community under the Threatened Species Conservation Act 1995. Carex Sedgeland is also described as Sedge fens of areas of impeded drainage of the Nandewar and New England Tablelands Bioregion ID 582 by Benson (unpub data). Carex Sedgeland often grades into dense Pennisetum alopecuroides tussock grassland.

7. Carex Sedgeland of the New England Tableland, Nandewar, Brigalow Belt South and NSW North Coast Bioregions has been recorded from the local government areas of Armidale Dumaresq, Coonabarabran, Glen Innes Severn, Guyra, Gwydir, Inverell, Liverpool Plains, Tamworth, Uralla and Walcha and may occur elsewhere in these bioregions.

8. Carex Sedgeland occupies a total estimated extent of 5000 ha which is estimated to be a 50% decline in extent since European settlement. Less that 100 ha is currently represented in conservation reserves in NSW (Hunter and Bell 2009). Clearing and draining for agriculture has removed or degraded many fens. Other fens have dams built along their drainage channels with 20% of fens surveyed by Hunter and Bell (2009) having one or more dams present.

9. Carex Sedgeland is known to contain the Vulnerable species Lysimachia vulgaris var. davurica and several undescribed herbaceous species that may also be threatened. These species are Eryngium sp. Little Llangothlin NR (D.M. Bell 56), Leiocarpa sp. Uralla (D.M. Bell NE 54142), Carex sp. Bendemeer (D.M. Bell 296) and Carex sp. Tingha (D.M. Bell 339).

10. Threats to Carex Sedgeland include clearing, changes in groundwater flow, fertilizer application, trampling and grazing by domestic stock. These threats are escalating due to the intensification of agriculture in northern NSW. Climate change may exacerbate threats for example through effects on water flow and fire regimes. Fens are sensitive to small changes in groundwater flow (Weltzin et al. 2000: Van Diggelen 2006). Intensive livestock grazing changes the species dominance of fens and facilitates the invasion of introduced species (Costin 1954). In combination with the addition of superphosphate, grazing also leads to an increase in exotic annuals, loss of native perennials and decreased abundance of native forbs (Hobbs and Yates 1999, Lunt et al. 2007). Other threats include the invasion of exotic perennial grass species including Eragrostis curvula (African Lovegrass), Nassella neesiana (Chilean Needlegrass), and Nassella trichotoma (Serrated Tussock) (Hunter and Bell 2009). Other herbaceous exotic species that also threaten this community include Holcus lanatus (Yorkshire Fog), Cirsium vulgare (Scotch Thistle), Rumex crispus (Curled dock), Trifolium repens (White Clover) and Rubus angocandicans (Blackberry) (Hunter and Bell 2009). ‘Alteration to the natural flow regimes of rivers and streams and their floodplains and wetlands’, ‘Anthropogenic Climate Change’, ‘Clearing of native vegetation’ and ‘Invasion of native plant communities by exotic perennial grasses’ are listed as Key Threatening Processes under the Threatened Species Conservation Act 1995.

11. Carex Sedgeland in the New England Tableland, Nandewar, Brigalow Belt South and NSW North Coast Bioregions is not eligible to be listed as a Critically Endangered Ecological Community.

12. Carex Sedgeland in the New England Tableland, Nandewar, Brigalow Belt South and NSW North Coast Bioregions is eligible to be listed as an Endangered Ecological Community as, in the opinion of the Scientific Committee, it is facing a very high risk of extinction in New South Wales in the near future, as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2010:

Clause 19 Reduction in ecological function of the ecological community

The ecological community has undergone, is observed, estimated, inferred or reasonably suspected to have undergone or is likely to undergo within a time span appropriate to the life cycle and habitat characteristics of its component species:

(b) a large reduction in ecological function,

as indicated by any of the following:

(d) change in community structure,

(e) change in species composition,

(f) disruption of ecological processes,

(g) invasion and establishment of exotic species,

(h) degradation of habitat.

Dr Richard Major
Chairperson
Scientific Committee

Proposed Gazettal date: 15/04/11
Exhibition period: 15/04/11 - 10/06/11

References:

Beadle NCW (1981) The vegetation of Australia. Cambridge University Press, Cambridge.

Bell DM, Hunter JT, Haworth RJ (2008) Montane lakes (Lagoons) of the New England Tablelands Bioregion. Cunninghamia 10, 475-492.

Benson JB, Ashby EM (2000) Vegetation of the Guyra 1: 100 000 map sheet New England Bioregion, New South Wales. Cunninghamia 6, 747-872.

Costin AB (1954) A Study of the Ecosystems of the Monaro Region of New South Wales with Special Reference to Soil Erosion. Government Printer, Sydney.

Hobbs RJ, Yates C (1999) Temperate eucalypt woodlands in Australia: biology, conservation, management and restoration. Surrey Beatty and Sons, Sydney.

Hunter JT, Bell DM (2007) Vegetation of montane bogs in eastern flowing catchments of northern New England, New South Wales. Cunninghamia 10, 77-92.

Hunter JT, Bell DM (2009) The Carex Fen vegetation of northern New South Wales. Cunninghamia 11, 49-64.

Keith DA (2004) Ocean Shores to Desert Dunes: the native vegetation of New South Wales and the ACT. Department of Environment and Conservation, Sydney.

Lunt ID, Eldridge DJ, Morgan JW, Witt GB (2007) Turner Review. A framework to predict the effects fof livestock grazine and grazing exclusion on conservation values in natural ecosystems in Australia. Australian Journal of Botany 54, 401-415.

Thackway R, Cresswell ID (1995) An interim biogeographic regionalisation for Australia: a framework for setting priorities in the National Reserve System Cooperative Program. (Version 4.0. ANCA: Canberra.)

Van Diggelen R, Middleton B, Bakker J, Grootjans A, Wassen M. (2006) Fens and floodplains of the temperate zone: Present status, threats, conservation and restoration. Applied Vegetation Science 9, 157-162.

Weltzin JF, Pastor J, Harth C, Bridgham SD, Updegraff K, Chapin CT (2000) Response of bog and fen plant communities to farming and water-table manipulations. Ecology 81, 3454-3478.