Plant communities of the upper Murrumbidgee catchment in New South Wales and the Australian Capital Territory.

Abstract

Native vegetation of the upper Murrumbidgee catchment in southeast NSW and the Australian Capital Territory (ACT) was classified into 75 plant communities across 18 NSW Vegetation Classes within nine Structural Formations. Plant communities were derived through numerical analysis of 4,106 field survey plots including 3,787 plots from 58 existing survey datasets and 319 new plots, which were sampled in under surveyed ecosystems. All plant communities are described at a level appropriate for discrimination of threatened ecological communities and distinct vegetation mapping units.The classification describes plant communities in the context of the upper Murrumbidgee catchment and surrounding landscapes of similar ecological character. It incorporates and, in some instances, refines identification of plant communities described in previous classifications of alpine vegetation, forest ecosystems, woodlands and grasslands across the Australian Alps and South Eastern Highlands within the upper Murrumbidgee catchment. Altitude, precipitation, soil saturation, lithology, slope, aspect and landscape position were all important factors in guiding plant community associations.Nine Threatened Ecological Communities under Commonwealth, NSW and ACT legislation occur in the upper Murrumbidgee catchment. This study has also identified five additional plant communities which are highly restricted in distribution and may require active management or protection to ensure their survival. Armstrong et al., Plant communities, upper Murrumbidgee al. 2009). In the development of the United States National Vegetation Classification System, Grossman et al. (1998) noted that vegetation classification ideally should be based on the analysis of high quality field data spanning the full geographic and environmental range of related vegetation, and the subsequent US National Vegetation Classification Standard Version 2.0 (FGDC 2008) proposed that natural vegetation types be derived from analysis of field plot data, with these data providing the fundamental information for the numerical description of types. CunninghamiaWithin NSW, many natural resource management decisions are made by Catchment Management Authorities (CMAs) based on information and assessment at the scale of broad catchments. Within the Murrumbidgee CMA area and the ACT, the upper Murrumbidgee River catchment contains a diverse range of landscapes and vegetation types which are subject to ongoing land-use pressures including clearing of native vegetation for farming and urban development, urban expansion and ongoing pastoral management. The upper Murrumbidgee catchment has a relatively high density of existing vegetation survey plot data collected by previous vegetation studies, ranging from specific conservation reserve surveys to a large regional inventory of forest ecosystems on public lands, but to date it has not had a systematic classification of all plant communities across all Structural Formations across all tenures.This study aimed to classify and des...

Quantifying uncertainty in the identification of endangered ecological communities

“…The implications of this focus on dominant species is likely to vary depending on the degree to which patterns F I G U R E 6 Posterior distribution of the parameter estimates for beta regression models of expert judgments of the probability of (a) restoration success and (b) low condition in species dominance correlate with overall composition across the landscape. In this study, the dominant overstorey species occurs in a wide range of vegetation communities (Armstrong et al, 2013) and assessing this species alone would over-estimate the true distribution, a pattern consistent with the higher rate of false positives among experts. In this instance a wider range of ecosystems will be protected than was intended, but in other situations the converse could be true, and such outcomes may undermine confidence in ecological community regulations.…”

“…Other studies have found that experience is not always a good predictor of performance (Burgman et al, 2011). Our facilitated discussions suggested that first-hand experience and prior knowledge of other vegetation classifications (Armstrong, Turner, McDougall, Rehwinkel, & Crooks, 2013;Costin, 1954;Gellie, 2005;Tozer et al, 2010) potentially contribute to individual-specific models of what constitutes CTGW, particularly among some experienced experts. While individual models are potentially valid interpretations of vegetation distribution and ecosystem processes, individuals with strongly held prior opinion may be less receptive to the detail of the Final Determinations, which may not be helpful when interpreting legally binding community descriptions.…”

Annual mowing maintains plant diversity in threatened temperate grasslands

“…There are two dominant native perennial grass types within our study region: Themeda triandra (C 4 ) dominated and Austrostipa / Rytidosperma spp . (C 3 ) dominated, which differ in community composition (Armstrong, Turner, McDougall, Rehwinkel, & Crooks, ) and might therefore have different responses to mowing. Thus, to quantify dominant grass type, we also recorded the percentage cover of these grass taxa to the nearest 10% within each subplot.…”

Animal welfare outcomes of helicopter-based shooting of deer in Australia

“…The second operation targeted fallow deer (Dama dama) in the Australian Capital Territory (ACT), over 4 days in June 2019 (Operation B). The operational area is characterised by native grasslands, Pinus radiata plantations and areas of native woodland (primarily red stringybark (Eucalyptus macrorhyncha) and scribbly gum (Eucalyptus haemastoma), as well as red-anthered wallaby grass (Rytidosperma pallidum), tall grass-shrub dry sclerophyll open forest on loamy ridges and grassy woodland (Armstrong et al 2013;ACT Government GeoHub 2018). The climate is temperate, and there was sheep and cattle grazing on some properties.…”