Yellow Gum Tall Woodland of the Murray River Floodplain - rejection of endangered ecological community listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to REJECT a proposal to list Yellow Gum Tall Woodland of the Murray River Floodplain as an ENDANGERED ECOLOGICAL COMMUNITY in Part 3 of Schedule 1 of the Act. Rejection of nominations is provided for by Part 2 of the Act.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Eucalyptus leucoxylon F. Muell. subsp. pruinosa (F. Muell. Ex. Miq.) Boland Yellow Gum is currently listed as a Vulnerable species on Part 1 of Schedule 2 under the Threatened Species Conservation Act 1995.
2. Yellow Gum (Eucalyptus leucoxylon subsp. pruinosa) dominates woodland vegetation found at some sites on the interface between the sandy rises and loamy clay flats on the alluvial plain within the Riverina bioregion in NSW. Known occurrences of the species in NSW are either within or adjacent to ecological communities that are currently listed as Endangered on Part 3 of Schedule 1 under the Threatened Species Conservation Act 1995. These include ‘Sandhill Pine Woodland in the Riverina, Murray-Darling Depression and NSW South Western Slopes bioregions’, ‘ Allocasuarina luehmannii Woodland in the Riverina and Murray-Darling Depression bioregions’ and ‘Inland Grey Box Woodland in the Riverina, NSW South Western Slopes, Cobar Peneplain, Nandewar and Brigalow Belt South Bioregions’.
3. Plant species that co-occur with E. leucoxylon subsp. pruinosa (Yellow Gum) in NSW include Eucalyptus microcarpa (Inland Grey Box), Allocasuarina luehmannii (Buloke), Myoporum platycarpum (Sugarwood), Chenopodium nitrariaceum, Maireana aphylla (Cottonbush), Rhagodia spinescens, Acacia oswaldii, Sclerolaena muricata, Atriplex semibaccata, Einadia nutans subsp. oxycarpa and Enchylaena tomentosa (Ruby Saltbush) (Benson et al. 2006). The small number of known occurrences of E. leucoxylon subsp. pruinosa in NSW are restricted, fragmented and degraded by overgrazing.
4. Stands of E.leucoxylon subsp. pruinosa and the co-occurring species listed above are currently recognised as a distinct association in a recent review and classification of vegetation in western NSW (Benson et al. 2006) on the basis of expert opinion derived from available information about occurrence of the species in NSW, field inspections to record associated species at selected locations in NSW and descriptions of woodlands containing E. leucoxylon in Victoria. Broad-scale vegetation surveys and mapping undertaken in the Riverina bioregion in NSW did not describe any assemblages dominated by E. leucoxylon subsp. pruinosa and most failed to record the species (Smith and Smith 1990; Porteners 1993; Horner et al. 2002; White et al. 2002; McNellie et al. 2005). White et al. (2002) note E. leucoxylon as a component of their ‘Temperate Plains Grassy Woodland’ Broad Vegetation Type, which is characterised by Eucalyptus microcarpa (Inland Grey Box) and a number of other less frequently occurring tree species. Similarly, E. leucoxylon may be an uncommon component of the broadly defined ‘Low Rises Woodland’ Ecological Vegetation Class in Victoria, although the species is currently not listed in the description of that unit (Department of Sustainability and Environment 2008). A vegetation survey of Buloke and Pine woodlands of semi-arid and dry sub-humid Victoria and nearby areas recorded E. leucoxylon as a component of four different woodland communities in association with E. microcarpa, E. largiflorens, E. camaldulensis and Allocasuarina luehmannii (Sluiter et al. 1997). Although their sampling was limited in NSW, Sluiter et al. (1997) recorded E. leucoxylon in NSW within a quadrat that was assigned to an assemblage dominated by A. luehmannii (Group 9).
5. Given an overall scarcity of relevant information, there remains considerable uncertainty whether the stands of E. leucoxylon in NSW dominate an assemblage of species that meets the definition of an ecological community under the Threatened Species Conservation Act 1995 and is distinct from other communities that may contain the species . An alternative explanation of the available information is that populations of E. leucoxylon simply occupy some of the ecotones between other assemblages. All but two of the associated species listed in paragraph 3 above are listed as characteristic of currently listed ecological communities that are known to occur within the area occupied by E.leucoxylon (see paragraph 2 above) .
6. There is currently insufficient evidence to draw a robust conclusion about the status of Yellow Gum Tall Woodland of the Murray River Floodplain, even though there is a possibility that such an assemblage may exist and may otherwise meet the criteria for listing under the Threatened Species Conservation Act 1995.
7. In view of the above, the Scientific Committee finds that the nominated Yellow Gum Tall Woodland of the Murray River Floodplain is not currently eligible to be listed as an Endangered Ecological Community in Part 3 of Schedule 1 of the Act.
Dr Richard Major
Chairperson
Scientific Committee
Proposed Gazettal date: 12/06/09
Exhibition period: 12/06/09 – 07/08/09
References:
Benson JS, Allen CB, Togher C, Lemmon J (2006) New South Wales vegetation classification and assessment. Part 1 Plant communities of the NSW western plains. Cunninghamia 9, 383-450.
Department of Sustainability and Environment (2008) EVC/Bioregion benchmark for vegetation quality assessment . Victorian Riverina bioregion. EVC 66: Low Rises Woodland. Accessed 10 June 2008.
Horner G, McNellie M, Nott TA, Vanzella B, Scleibs M, Kordas GS, Turner B, Hudspith TJ (2002) Native vegetation map report series No. 2. Dry Lake, Oxley, Hay, One Tree, Moggumbill and Gunbar 1:100000 map sheets. NSW Department of Land and Water Conservation, Parramatta.
McNellie M, Horner G, Nott TA, Vanzella B, Scleibs M, Kordas GS, Turner B, Hudspith TJ
(2005) Native vegetation map series. Deniliquin 1:250000 map sheet. NSW Department of Natural Resources, Parramatta.
Porteners MF (1993) Natural vegetation of the Hay Plain: Booligal-Hay and Deniliquin-Bendigo 1:250 000 maps. Cunninghamia 3, 1-122.
Sluiter IRK, Minchin PR, Jaensch SC (1997) The Buloke and Pine Woodlands of semi-arid and dry sub-humid Victoria and nearby areas. Ogyris Ecological Research Report No. 97/02
Smith P, Smith J (1990) Riparian Vegetation of the River Murray. Report to the Murray-Darling Basin Commission, Canberra. Margules and Partners Pty Ltd and Department of Conservation Forests and Lands.
White MD, Muir AM, Webster R (2002) The reconstructed distribution of indigenous vegetation types across the NSW Riverina. Report to the NSW National Parks and Wildlife Service. Ecology Australia, Fairfield, Victoria.