Cunninghamia : A Journal of Plant Ecology for Eastern Australia, Volume 7, Issue 1 (2001)
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The vegetation of Kinchega National Park (latitude 32°18'–32°40'S and longitude 142°10'–142°25'E) in far western New South Wales was assessed using intensive quadrat sampling and mapped using extensive ground truthing and interpretation of aerial photographs and Landsat Thematic Mapper satellite images. Three hundred and fifty two species of vascular plants were recorded from this survey, which, together with other records indicates the presence of 503 species from 69 families including 100 (20%) exotic species. Fifteen vegetation communities were identified and mapped, the most widespread being Maireana species low open-shrubland, Acacia victoriae open-shrubland and Eucalyptus largiflorens openwoodland. The Park also contains a number of rare or threatened species and vegetation communities. One hundred and fifty years of grazing by introduced herbivores coupled with the impact of a modified hydrological regime has resulted in degradation of many of these communities.
The vegetation of Narran Lake Nature Reserve (4527 ha) in the central north of New South Wales approximately 30 km west of Cumborah (29°43', 147°29') in the Walgett Shire on the North Western Plains and the Darling River Plains Bioregion is described. Seven communities are defined based on flexible UPGMA analysis of cover-abundance scores of all vascular plant taxa. These communities are mapped based on ground truthing, air photo interpretation and geological substrate. All communities are simple in structure being primarily woodlands, shrublands and herbfields. Communities are: 1) Mixed Low Woodlands, 2) Mulga Low Woodlands, 3) Triodia Hummock Grasslands, 4) Chenopod Low Open Shrublands, 5) Ephemeral Herbfields, 6) Riparian Open Forests, and 7) Lignum Shrubby Thickets. A total of 325 taxa were recorded including two species listed under the NSW Threatened Species Conservation Act (1995), Lepidium monoplocoides and Goodenia macbarroni. An additional 11 species are considered to be at their geographic limit or disjunct in their distribution; 11% are exotic in origin.
Clearing of native woody vegetation in the New South Wales northern wheatbelt was mapped for the period 1985–2000. The study area comprises the Moree 1:250,000 scale map sheet and portions of adjacent map sheets. Unpublished draft mapping of native woody vegetation types, based on 1985 aerial photography and a large set of floristic data from field surveys, was used as a baseline for this study. Mapping of clearing was carried out by intensive visual interpretation of Landsat TM satellite imagery. Systematic validation, which compared the satellite interpretation to low-level aerial photography at randomly allocated point locations, showed that the method was highly accurate in detecting vegetation clearing including in the open woodlands and shrublands that characterise much of the study area. Comparisons with previously published mapping of statewide clearing patterns, based on an automated classification of Landsat TM imagery, showed that our intensive visual interpretation detected substantially more clearing. Average annual clearing rates were 8 times higher that those derived from the previous mapping.
Results of the study show that substantial clearing of native woody vegetation is continuing in the northern wheatbelt. Over 110,000 ha of native woody vegetation were cleared between 1985 and 2000. Clearing rates were highest in the four year monitoring period that preceded the introduction of the Native Vegetation Conservation Act. The subsequent two year monitoring period saw substantially lower clearing rates, though further monitoring is needed to determine if this trend will continue. An analysis of spatial patterns highlighted continued high rates of loss in the most depleted parts of the study area. Results for individual vegetation types indicate that regrowth open shrublands and woodlands and Coolabah (Eucalyptus coolabah) dominated woodlands were the most heavily cleared.
Senecio garlandii F. Muell. ex Belcher (Asteraceae) is a perennial subshrub found mainly on rocky outcrops in the South Western Slopes, New South Wales. It is listed as vulnerable in state, national and international listings. An assessment of its conservation status found i) Senecio garlandii has been recorded from about ten localities, ii) it has a relatively large (225 km) north to south distribution from Temora, NSW to Chiltern, Vic., iii) most populations were either within the reserve system (Ulandra, The Rock, Table Top Nature Reserves) or in areas managed for conservation, iv) large populations (> 30,000 individuals) were recorded at The Rock and Table Top Nature Reserves, v) the species appeared capable of regenerating in both the absence and presence of fire, and vi) the populations did not appear to be under direct threat.
However, the known localities were highly disjunct and only three localities had substantiated recordings of large populations, while others had very small populations (e.g. < 200 individuals at Ulandra Nature Reserve). In addition, the species was largely restricted to rocky outcrops and on these it was generally restricted to the upper parts of the east- to south-facing talus slopes, often immediately below cliff lines (a small area of occupancy). Application of the IUCN red list criteria would indicate that Senecio garlandii should not be classified as vulnerable. Monitoring is needed to determine whether the populations are in decline or otherwise.
As a consequence of vegetation survey carried out in sandstone environments of the upper Hunter Valley over recent years, a number of new populations of significant plant species have been recorded. The opportunity is taken here to document some of these finds, and also to suggest some revisions to the current conservation risk codes. Twenty-three species are discussed: Acacia bulgaensis, Angophora euryphylla, Callitris rhomboidea, Banksia penicillata, Cynanchum elegans, Eucalyptus aenea, Eucalyptus dealbata, Eucalyptus fergusonii subsp. dorsiventralis, Eucalyptus nubila, Eucalyptus prominula, Gonocarpus longifolius, Grevillea johnsonii, Grevillea montana, Melaleuca groveana, Pomaderris bodalla, Pomaderris brunnea, Pomaderris precaria, Pomaderris queenslandica, Pomaderris reperta, Pomaderris sericea, Prostanthera cryptandroides subsp. cryptandroides, Prostanthera hindii, and Rulingia procumbens. Voucher specimens have been lodged for new populations of all taxa (except some populations of Cynanchum elegans) at State herbaria.
Kinchega National Park reserves significant stands of Eucalyptus largiflorens open woodland on the Darling River floodplain, low open Maireana pyramidata shrubland and Casuarina pauper/Alectryon oleifolius open woodland on dune systems. We identify four key issues for the conservation of flora in Kinchega National Park, western NSW. These are:
1) There is an urgent need to initiate regeneration in a number of long-lived perennial trees and shrubs. Failure to do so will lead to local population declines and extinction in a number of species. Reduction in grazing impacts of rabbits and goats is needed. Some degree of rabbit control has been achieved over the last few years through a combination of the effects of the rabbit calicivirus disease (RCD) and an extensive rabbit control program for the reserve.
2) The need to initiate a water plan of management for the reserve to overcome the problem of changes in water flows, flood periodicity and flood magnitude that have occurred in response to water regulation activities on the Darling River.
3) Management of several threatened species and ecological communities on the reserve, in particular the nationally vulnerable species Acacia carneorum and Solanum karsense. Kinchega NP is the only conservation reserve containing populations of these species and these populations are significant for both species.
4) Management of weeds, in particular those with bird-dispersed fruits as these species have the potential to become severe problems on the park.
Other issues that are likely to be significant in the future are salinity impacts and the interaction between grazing pressure, regeneration and climate change.
Australian subtropical rainforests and plant populations have become increasingly fragmented since European settlement. Managing relict populations and remnants within the landscape matrix is dependent upon our understanding of plant reproductive biology. The incidence of autogamous self-compatibility and dioecy was investigated in subtropical rainforests, near Taree, in the Manning Valley (northern New South Wales). The proportion of dioecious species in rainforests of the region is high (~17%), but varies among sites. The potential for hermaphroditic species to self-pollinate was examined by bagging inflorescences in the field. Of the > 30 species (in 14 families) studied, nine species exhibited high levels of selfcompatibility. These were predominantly pioneer and edge species, but other pioneer species were self-incompatible. Different behaviour occurred within families. Twenty species (in 13 families) regenerated from basal coppice or root suckers following bushfire. The significance of knowledge of reproductive biology for management is discussed.