Showing papers by "Simon J. Judd published in 2008"

The extraordinary nature of the Great Western Woodlands

Abstract: This study has been undertaken to inform all those individuals, communities and organisations with an interest in the Great Western Woodlands. The authors hope the report will act as a catalyst to bring people together to discuss the central challenges that must be met if the nature of the region is to be conserved. Stakeholders include residents of local communities, Traditional Owners, local shire councils, the Western Australian and Federal Governments, mining and tourism companies, four-wheel drive clubs, apiarists, wildlife enthusiasts, conservation organisations and scientists. It is time to look more closely at the futureof the Great Western Woodlands, and to develop a comprehensive plan to protect it.

Diversity of a semi-arid, intact Mediterranean ecosystem in southwest Australia

Abstract: . The drier parts of the Mediterranean biome of southwest Australia contain the largest remaining Mediterranean woodlands and shrublands on Earth. Despite this, there has been no formal, comprehensive assessment of their biodiversity. The region abuts the southwest Australian floristic region which has received much scientific attention. The aim of this paper is to provide the first general overview of the biodiversity of part of this intact, yet relatively unknown, Mediterranean ecosystem. We do this by synthesizing data from State Government agencies and published research. We found that, like other parts of southwest Australia, the region has globally significant levels of plant species diversity. More than 2400 plant species, including 291 species considered threatened, have been recorded, representing one-sixth of all Australia’s vascular plant species. Eleven of Australia’s 23 major vegetation groups are represented even though the region covers less than 1% of continental Australia. We documented 170 vertebrate species, including 31 threatened species, with a particularly high richness of reptile species (n = 46). We highlight how little is known about this region. For example, 116 vertebrate species not recorded in the region probably occur there based on their habitat requirements and known distributions. An examination of plant and vertebrate diversity in the region, using a half degree latitude and longitude grid cells, showed a highly heterogeneous pattern of species richness and vulnerability, with a general decline in species richness from southwest to northeast. Conservation strategies that rely on capturing the highest levels of biodiversity in a series of protected areas are unlikely to guarantee protection for all species given these high levels of heterogeneity. Instead, a region-wide conservation plan should involve targeted ecological research, consideration of ecological processes and stakeholder consultation.

Character of extracellular polymeric substances and soluble microbial products and their effect on membrane hydraulics during airlift membrane bioreactor applications.

Abstract: The effect of extracellular polymeric substances and soluble microbial products developed from wastewater and mature landfill leachate biomass was assessed using a pilot-scale membrane bioreactor operating polymeric and ceramic air-lift sidestream multichannel membranes. The plant was operated under identical conditions of sludge retention time, system hydrodynamics ,and parity of food-to-microorganism ratios. Biomass samples were extracted and fractionated (fixed and bound material, carbohydrate and protein extracts) and chemically and physically analyzed with the feedwaters. Both ceramic and polymeric membranes were tested and the critical flux (J(C)) determined according to the classical flux-step analysis. Although permeability (K) of both materials reduced with increasing flux (J), the ceramic material had a higher resistance to fouling, demonstrating a higher K (by a factor of 1.2 and 3.2 for wastewater and leachate, respectively, at J of 30 L x m(-2) x h(-1)) and lower fouling rate (dP/dt) (by more than an order of magnitude at the same J) than the polymeric membrane. Evidence suggests that deterioration of membrane permeability resulting from leachate biomass arises from the feedwater itself, rather than the products derived from the biomass, and that colloidal and/or soluble total organic carbon is primarily responsible for it.