ORCID Profile
0000-0002-3164-8948
Current Organisation
University of Tasmania
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Publisher: Elsevier BV
Date: 12-2010
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/AR04213
Abstract: In the dryland cropping areas of southern Australia, at risk from dryland salinity, tree belts can improve water management by taking up water unused by crops, with the risk that crop yield will be reduced through competition. As there are few direct markets for tree products grown in the medium to low rainfall areas, the design of agroforestry systems becomes important in reducing the trade-off in crop yield. This study examined some factors that influence the trade-off between crop yield and deep-drainage control in order to develop design guidelines for medium to low rainfall agroforestry. Twenty-one sites in the grain-growing region of Western Australia and southern New South Wales were surveyed over 2 years for crop yields, tree leaf area index, and estimated recharge, providing data from 32 tree–crop interfaces on the relative influence of environmental factors and farming system characteristics on the trade-off between water management and crop yield. The factors most strongly correlated with higher yields were water-gaining sites, orientation that provided shelter from southerly to north-westerly (S, SW, W, NW) winds, and tree age ( years). The factors most strongly correlated with the area of cropped land protected against deep drainage were tree age ( years), lighter soil types, and low rainfall ( mm). Economic analysis of the trade-off required to produce a particular deep-drainage reduction target produced 3 groups of sites: (1) those where trees resulted in a gross margin increase of $15/ha and an estimated deep-drainage reduction of 52% (n = 3), (2) those with a gross margin loss of $49/ha and estimated deep-drainage reduction of 47% (n = 11), and (3) those with a gross margin loss of $163/ha and a deep-drainage reduction of 37% (n = 18). None of the 3 sites in the first group were in the most favourable class in both years, highlighting the vulnerability of a relatively fixed farming system to climate variability.
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/AR04204
Abstract: This research investigated the potential to domesticate an Australian native grass (Microlaena stipoides) to produce a perennial grain crop. Perennial grain crops offer a new solution to the long-standing problems of salinity and soil erosion associated with conventional cropping systems based on annual plants. Seed yield and its components (culm number, spikelet number per culm, seed set, seed weight) were measured in 46 accessions of Microlaena stipoides (microlaena, meadow or weeping rice grass) from Western Australia and New South Wales to quantify potentially useful variation in the species. A high degree of variability was found to exist, with a 20-fold range in seed yield (0.1–2.4 g lant), 5-fold range in seed weight (129–666 mg per 100 seeds), 2-fold range in spikelet number (14–30 per culm), 8-fold range in seed set (12–98%), and a 5-fold range in culm number (11–59 per plant). Seed yield was positively and significantly (P 0.05) correlated with culm number, seed set, and seed weight (r 0.55 for all). No correlation was found between seed yield and spikelet number per culm (r = –0.14). The range in seed yield and its components suggests that there is sufficient variation within microlaena to make selections for higher yielding lines. This variation will enable breeders to exploit genetic ersity more efficiently and identify useful accessions for further work. High priority traits for future work include synchronous maturity and resistance to shattering.
Publisher: Public Library of Science (PLoS)
Date: 24-11-2014
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/WR13206
Abstract: Context Since the introduction of fallow deer (Dama dama) to Tasmania in the early 1830s, the management of the species has been conflicted the species is partially protected as a recreational hunting resource, yet simultaneously recognised as an invasive species because of its environmental impact and the biosecurity risk that it poses. The range and abundance of fallow deer in Tasmania has evidently increased over the past three decades. In the 1970s, it was estimated that ~7000–8000 deer were distributed in three distinct subpopulations occupying a region of ~400 000 ha (generally centred around the original introduction sites). By the early 2000s, the estimated population size had more than tripled to ~20 000–30 000 deer occupying 2.1 million ha. No study has attempted to predict what further growth in this population is likely. Aims The purpose of our study was to provide a preliminary estimate of the future population range and abundance of fallow deer in Tasmania under different management scenarios. Methods We developed a spatially explicit, deterministic population model for fallow deer in Tasmania, based on estimates of demographic parameters linked to a species distribution model. Spatial variation in abundance was incorporated into the model by setting carrying capacity as a function of climate suitability. Key results On the basis of a conservative estimate of population growth for the species, and without active management beyond the current policy of hunting and crop protection permits, abundance of fallow deer is estimated to increase substantially in the next 10 years. Uncontrolled, the population could exceed 1 million animals by the middle of the 21st century. This potential increase is a function both of local increase in abundance and extension of range. Conclusions Our results identify areas at high risk of impact from fallow deer in the near future, including ecologically sensitive areas of Tasmania (e.g. the Tasmanian Wilderness World Heritage Area). Implications The research approach and results are presented as a contribution to debate and decisions about the management of fallow deer in Tasmania. In particular, they provide a considered basis for anticipating future impacts of deer in Tasmania and prioritising management to mitigate impact in ecologically sensitive areas.
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/AR04195
Abstract: Scenario planning was used to identify issues and drivers of change that are relevant to community efforts to improve regional prospects in the Western Australian Wheatbelt. The region, some 20 million hectares in area, is under pressure to respond to a variety of environmental (salinity, erosion, acidification, bio ersity decline), economic (declining agricultural terms of trade), and social forces (rural decline, isolation). Regional strategic plans have been increasingly seen as the means of achieving sustainability in the face of these challenges, but until recently typically had single-activity outlook and timeframes of up to a decade into the future. Systematic futures-based research has been used in various regions to avoid reliance on business-as-usual as the default strategy, and to identify opportunities and challenges not presently apparent. The Avon River Basin, the central region of the Wheatbelt, was selected as the geographic focus of the project, and the time horizon was set at 2050. The project was developed by a group of 50 stakeholders from the basin, with expertise and strategic interests across a wide range of economic, social, and environmental themes. Through a series of workshops the stakeholders identified critical issues and their attendant drivers, then documented relevant past trends. Four regional scenarios, Saline Growth, Grain and Drain, Landcare Bounty, and Harmony with Prosperity, were developed based on positive and negative combinations of 2 clusters of uncertain and important drivers: environmental change and access to new markets. Common opportunities, threats, and critical success factors for the Avon River Basin region out to 2050 were also identified. We also found that the stakeholders have a tendency to strive for positive outcomes despite negative initial conditions. This resulted in 4 scenarios that were superficially similar due to the regional scale of analysis and the continuation of agricultural industries as significant shapers of economy, society, and environment. However, each scenario represents profoundly different outcomes for the residents and communities of the Avon River Basin in 2050. The triple-bottom line outcomes for the Avon River Basin in 2050 were estimated to be in the range 4.9–9.7 Mt of wheat (currently 4.0), 46 000–66 000 people (currently 43 000), and 10–30% of farmland salinised (currently 6). The application of these results to other regions in Australia is discussed.
Publisher: Wiley
Date: 25-08-2019
DOI: 10.1111/JBI.13684
Publisher: Elsevier BV
Date: 09-2013
Publisher: Wiley
Date: 19-11-2016
DOI: 10.1002/ESE3.101
Publisher: IUCN
Date: 30-11-2017
Publisher: Wiley
Date: 07-11-2014
DOI: 10.1111/COBI.12409
Abstract: Recent conservation planning studies have presented approaches for integrating spatially referenced social (SRS) data with a view to improving the feasibility of conservation action. We reviewed the growing conservation literature on SRS data, focusing on elicited or stated preferences derived through social survey methods such as choice experiments and public participation geographic information systems. Elicited SRS data includes the spatial distribution of willingness to sell, willingness to pay, willingness to act, and assessments of social and cultural values. We developed a typology for assessing elicited SRS data uncertainty which describes how social survey uncertainty propagates when projected spatially and the importance of accounting for spatial uncertainty such as scale effects and data quality. These uncertainties will propagate when elicited SRS data is integrated with biophysical data for conservation planning and may have important consequences for assessing the feasibility of conservation actions. To explore this issue further, we conducted a systematic review of the elicited SRS data literature. We found that social survey uncertainty was commonly tested for, but that these uncertainties were ignored when projected spatially. Based on these results we developed a framework which will help researchers and practitioners estimate social survey uncertainty and use these quantitative estimates to systematically address uncertainty within an analysis. This is important when using SRS data in conservation applications because decisions need to be made irrespective of data quality and well characterized uncertainty can be incorporated into decision theoretic approaches.
Publisher: Elsevier BV
Date: 2011
Publisher: Informa UK Limited
Date: 09-2013
Publisher: Wiley
Date: 12-01-2009
Publisher: Public Library of Science (PLoS)
Date: 16-03-2015
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/HR02901A_BR
Publisher: Elsevier BV
Date: 05-2013
Publisher: Elsevier BV
Date: 09-2015
No related grants have been discovered for Edward Lefroy.