https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Survival of Casuarina cunninghamiana on a recovering sand-bed stream in the Wollombi Valley of coastal New South Wales https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20468 15 cm more likely to survive the bankfull flood. The percentage of seedlings partially buried by sediment was significantly higher (d.f. = 14; W = 13; p = 0.016) after flood compared to before flood. Seedling density was positively correlated with the amount of bare ground prior to the flood (r = 0.61; p = 0.02), but this relationship was no longer significant after flood (r = 0.18; p = 0.53). 37% of the seedlings surveyed showed evidence of grazing. Our results confirm that hydrogeomorphic processes associated with a bankfull flood affect the survival of Casuarina cunninghamiana seedlings. The management implications of our findings are discussed in terms of riparian revegetation techniques and the geomorphic recovery of over-widened sand-bed streams.]]> Wed 11 Apr 2018 17:17:23 AEST ]]> Hunter Valley Weeping Myall Woodland - is it really definable and defendable with and without Weeping Myall (Acacia pendula)? https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28284 Threatened Species Conservation (TSC) Act 1995 and the Commonwealth Environment Protection and Biodiversity Conservation (EPBC) Act 1999. Uncertainty regarding the provenance of Weeping Myall (Acacia pendula) in the Hunter has led to questioning of the place of Hunter Valley Weeping Myall Woodland CEEC in State and Commonwealth legislation. A recent publication has endorsed its legislative listing, largely based on the co-association of Weeping Myall with a range of other semi-arid species in some parts of the Hunter Valley. We counter this argument and show that the semi-arid species present in low rainfall areas on Permian sediments of the Hunter Valley floor are in fact more widespread than previously documented. Through examination of distributional records, we demonstrate that these species display no fidelity to purported Hunter Valley Weeping Myall Woodland, but instead occur in a range of other vegetation communities across much of the central and upper Hunter Valley. Habitat suitability modelling undertaken for Acacia pendula shows there to be nearly 900 times the 200 ha of pre-European extent, or 20 times the area of occupancy previously estimated for this community. We also revisit an earlier ordination analysis which showed a divergence in sample data potentially representative of Hunter Valley Weeping Myall Woodland. We add new samples and provide a revised classification of the purported community, which shows that sample plots from two forms of Hunter Valley Weeping Myall Woodland are floristically indistinguishable from comparative data in 20-25 year old mining rehabilitation forests of Eucalyptus cladocalyx, and native grasslands derived predominantly from landscapes of Eucalyptus crebra and Eucalyptus moluccana. Relevant legislation requires any threatened community to be identifiable based on a particular species assemblage and its area of occupancy. We question whether Hunter Valley Weeping Myall Woodland is recognisable with and without the presence of Acacia pendula. We argue that the identification of Hunter Valley Weeping Myall Woodland is unachievable without the visual cue of Acacia pendula, and note that for some time regional botanists have used this species' presence as a de facto diagnostic tool to identify this community; in fact, there are no examples of the community having been identified as such in the absence of Acacia pendula. Finally, following from our ordination results, and the presence of key diagnostic species within more widespread grassy woodlands and derived native grasslands, we suggest that 200 years of anthropogenic disturbance across the Hunter Valley has sufficiently masked any distributional pattern of western semi-arid species that might have once occurred. We contend that there is little value in conserving a purported community that cannot be confidently delineated in numerical classifications, lacks a consistent and diagnostic suite of characteristic species, and for which there is uncertainty over the origins of its dominant, flagship species, Acacia pendula.]]> Sat 24 Mar 2018 07:41:24 AEDT ]]>