Water Planning Ecology
Water Planning Ecology
Tibby J.,University of Adelaide |
Barr C.,University of Adelaide |
Marshall J.C.,Water Planning Ecology |
Marshall J.C.,Griffith University |
And 13 more authors.
Journal of Quaternary Science | Year: 2017
Few Australian wetlands have persisted since the Last Glacial Maximum, with fewer still in existence through the entire last glacial cycle. The absence of wetlands, which itself indicates periods of moisture deficit, means there are few continuous climate and environmental change records covering this critical period. The lack of wetland persistence also raises the question of how plant and animal species that require permanent wetlands survived the last glacial cycle. Sixteen wetlands have been cored and dated on North Stradbroke Island (Minjerribah) – a large east Australian sand island – with basal dates reported from 10 sites for the first time. These wetlands range in age to over 200 000 years old, with six dating to the Last Glacial Maximum or earlier. There is no evidence of a stratigraphic discontinuity in the radiocarbon-based age–depth profiles, suggesting continuous deposition of highly organic sediment through the period covered by these ages (c. 40 ka). The persistence of these wetlands suggests that for much of the last 40 000 years, and for perhaps much longer, the regional moisture balance has been positive. Over the last glacial cycle, persistently wet conditions may have provided a refuge from regional drying, and thus contributed to the high genetic diversity of rainforest plants in the region. Vegetation and climate records from these sites will allow hypothesis testing about the drivers of both local and regional climate variability. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Cook B.D.,Water Planning Ecology |
Cook B.D.,Frc environmental Pty Ltd. |
Abrams K.M.,University of Adelaide |
Marshall J.,Water Planning Ecology |
And 5 more authors.
Australian Journal of Zoology | Year: 2012
Recent research suggests that alluvial aquifers in southern and eastern Australia may contain a diverse subterranean aquatic fauna (i.e. stygofauna). However, to date only a limited number of alluvial aquifers have been studied and little molecular data are available to assess species-level diversity and spatial patterns of genetic variation within stygofaunal species. In this paper, we present the initial results of a stygofaunal survey of the Burdekin River alluvial aquifer in Queensland, extending the northern range of alluvial aquifers along the east coast of Australia that have been investigated. The survey resulted in the collection of bathynellid stygofauna (Syncarida: Bathynellacea) and genetic analyses were conducted to determine species level diversity using the mitochondrial cytochrome oxidase subunit I (COI) gene. We further investigated the phylogenetic relationships of the species with bathynellids from western and southern Australia to assess the generic status of species. Four highly divergent COI lineages within the Parabathynellidae and one lineage within the Bathynellidae were found. These lineages did not group within any described genera, and phylogenetic analyses indicated that both local radiations and the retention of a lineage that was more apical in the genealogy account for the diversity within the Parabathynellidae in the Burdekin River alluvial aquifer. Most COI lineages were sampled from only a single bore, although one taxon within the Parabathynellidae was found to be more widespread in the aquifer. Haplotypes within this taxon were not shared among bores (ST≤0.603, P0.001). Overall, the high species diversity for bathynellaceans from an alluvial aquifer reported here, and surveys of bathynellaceans in several other alluvial systems in south-eastern Australia, suggests that groundwater ecosystems of eastern Australia may contain high stygofaunal diversity by Australian and world standards, particularly at the generic level for parabathynellids. © CSIRO 2012.
McNeil V.H.,Water Planning Ecology |
Raymond M.A.A.,Water Planning Ecology
Proceedings of the Royal Society of Queensland | Year: 2013
In Australia the precautionary principle is one of the guiding tenets of ecologically sustainable development, and implies the need to defi ne acceptable limits for water chemistry, if necessary on the basis of current scientifi c information. Groundwater chemistry is diffi cult to characterise with certainty because of the many interacting controls, which may contribute to the typically high variability. A desktop methodology is presented, which partitions a large, diverse catchment, the Fitzroy River Basin, into reasonably homogeneous groundwater chemistry zones on the basis of an extensive historical dataset, collected opportunistically at irregular intervals. A dual approach was adopted for assessment, with multivariate analysis supported conceptually by a range of environmental factors and presented as GIS background layers. Surface water samples were included in the multivariate analysis to defi ne areas of interaction. Assessment was based on salinity and the major ions, which are reasonably insensitive to sampling and storage protocols, and the data were checked for reliability through chemical balance and independent salinity measures. The data were sorted into water types using cluster and principal component analysis, and then bores were classifi ed with their predominant water type and plotted as a map layer for visual comparison with conceptual criteria of geology, climate and land use. Spatial bias in the sampling necessitated subjective judgement in delineation of zonal boundaries, decisions on degree of subdivision, and explanation of uncertainty across the basin. This enabled the defi nition of 44 discrete groundwater chemistry zones in the Fitzroy Basin. Although the study is too broad scale to evaluate processes, it indicated that the groundwater contains two major chemical sequences, each evolving through a wide range of salinity. One is consistent with chemical weathering of Palaeozoic or basaltic rocks or derived alluvium in humid areas, and the other is a more sodic sequence associated with sub-coastal, quartz rich terrains such as sandstones and granites.