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Wong M.R.,Monash University | Morgan J.W.,La Trobe University | Wong N.K.,Trust for Nature | Cavagnaro T.R.,University of Adelaide
Agriculture, Ecosystems and Environment | Year: 2015

Feedbacks between plants, microbes and their growth traits are important in the maintenance of nutrient cycling functions. Despite this, there is little understanding of the role of these relationships in the transitions between alternate vegetation states in semi-arid and arid lands. We investigated the relationships between vegetation, soil nutrients and soil microbes across grasslands and agricultural fields described within an existing conceptual state-and-transition model of agricultural de-intensification in the semi-arid Riverine Plains grasslands of south-eastern Australia. Sites represented the proposed transition from annual exotic pastures to native perennial grasslands with agricultural de-intensification. Microbial community composition was assessed using phospholipid fatty acid analysis (PLFA).The native grassland state and the native pasture state were characterized by a higher fungal to bacterial ratio (F:B). The native grassland state had a slightly lower bacterial PLFA biomass whilst the native pasture state had a slightly higher fungal PLFA biomass, although these differences were non-significant. Only the recently cultivated, heavily grazed state was characterized by high soil nutrient availability (soil P and K) and leaf traits indicating rapid growth and resource utilization (high SLA, low LDMC). Thus, the association of these ecosystem properties with a lower F:B was not as close as expected. States with a higher F:B were not characterized by higher total soil C or C:N as hypothesized.This study further extends our knowledge of the association between fungal dominance and agricultural de-intensification to a semi-arid system with relatively old, nutrient poor soils. It highlights the need for a better understanding of the mechanistics behind this association and the implications for C cycling and storage in such systems. © 2014 Elsevier B.V.

Lindenmayer D.B.,Australian National University | Gibbons P.,Australian National University | Bourke M.,The Thomas Foundation | Burgman M.,University of Melbourne | And 24 more authors.
Austral Ecology | Year: 2012

Effective biodiversity monitoring is critical to evaluate, learn from, and ultimately improve conservation practice. Well conceived, designed and implemented monitoring of biodiversity should: (i) deliver information on trends in key aspects of biodiversity (e.g. population changes); (ii) provide early warning of problems that might otherwise be difficult or expensive to reverse; (iii) generate quantifiable evidence of conservation successes (e.g. species recovery following management) and conservation failures; (iv) highlight ways to make management more effective; and (v) provide information on return on conservation investment. The importance of effective biodiversity monitoring is widely recognized (e.g. Australian Biodiversity Strategy). Yet, while everyone thinks biodiversity monitoring is a good idea, this has not translated into a culture of sound biodiversity monitoring, or widespread use of monitoring data. We identify four barriers to more effective biodiversity monitoring in Australia. These are: (i) many conservation programmes have poorly articulated or vague objectives against which it is difficult to measure progress contributing to design and implementation problems; (ii) the case for long-term and sustained biodiversity monitoring is often poorly developed and/or articulated; (iii) there is often a lack of appropriate institutional support, co-ordination, and targeted funding for biodiversity monitoring; and (iv) there is often a lack of appropriate standards to guide monitoring activities and make data available from these programmes. To deal with these issues, we suggest that policy makers, resource managers and scientists better and more explicitly articulate the objectives of biodiversity monitoring and better demonstrate the case for greater investments in biodiversitymonitoring. There is an urgent need for improved institutional support for biodiversity monitoring in Australia, for improved monitoring standards, and for improved archiving of, and access to, monitoring data. We suggest that more strategic financial, institutional and intellectual investments in monitoring will lead to more efficient use of the resources available for biodiversity conservation and ultimately better conservation outcomes. © 2011 The Authors. Journal compilation © 2011 Ecological Society of Australia.

Thomson J.R.,University of Canberra | Maron M.,University of Queensland | Grey M.J.,La Trobe University | Catterall C.P.,Griffith University | And 12 more authors.
Diversity and Distributions | Year: 2015

Aim: Strongly interacting species have disproportionately large ecological effects relative to their abundances or biomass. We previously developed two conceptual models that described how one such strong interactor, the Australian bird the noisy miner Manorina melanocephala: (1) establishes resident high-density and hyperaggressive colonies and (2) in doing so, affects other biota and ecosystem processes. Here, we evaluate parts of those models relating to noisy miner habitat preferences and effects on bird assemblages using data from across the geographical range of the miner. Location: Eastern Australia. Methods: Avian-assemblage data were compiled for 2 128 survey transects (distributed over > 1.3 × 106 km2) and were linked to variables reflecting productivity, local habitat structure and landscape context. Predictors were chosen based on the models, although detailed data for some variables were unavailable at such large scales. We used hierarchical Bayesian models that included observation models to account for different survey effort coupled with potentially nonlinear, spatially-explicit process models. Conclusions: Noisy miner densities increased with proximity to forest edges (higher densities on forest edges and open sites), in low rainfall areas, and in vegetation dominated by trees with blade-shaped rather than needle-shaped leaves. The presence of noisy miners at even relatively small densities (> 0.6 individuals ha-1) depressed both species richness and the abundances of smaller (< 63 g) bird species, by 50% on average. There were positive associations between densities of noisy miners and the abundance and richness of larger-bodied (> 63 g) bird species. In areas with higher mean rainfall, the associations between noisy miners and small- and large-bird species were more negative and less positive, respectively. © 2015 John Wiley & Sons Ltd.

Vesk P.A.,University of Melbourne | Robinson D.,Trust for Nature | Van Der Ree R.,University of Melbourne | Wilson C.M.,University of Melbourne | And 2 more authors.
PLoS ONE | Year: 2015

Background: Considerable resources are spent on habitat restoration across the globe to counter the impacts of habitat loss and degradation on wildlife populations. But, because of time and resourcing constraints onmany conservation programs, the effectiveness of these habitat restoration programs in achieving their long-termgoals of improving the population viability of particular wildlife species is rarely assessed andmany restoration programs cannot demonstrate their effectiveness.Without such demonstration, and in particular demonstrating the causal relationships between habitat restoration actions and demographic responses of the target species, investments in restoration to achieve population outcomes are of uncertain value. Approach: Here, we describe an approach that builds on population data collected for a threatened Australian bird - the Grey-crowned Babbler Pomatostomus temporalis - to evaluate how effectively targeted habitat restoration work improves its viability. We built upon an extensive historical survey by conducting surveys 13 years later at 117 sites stratified by presence/ absence of restoration works and by detection or not of birds in the first survey. Our performance metric was the number of individuals in a social group, which is both a measure of local abundance and directly related to breeding success.We employed an occupancy model to estimate the response of Grey-crowned Babbler social group size to the effects of time, restoration works, local habitat as measured by the density of large trees, and distance to the nearest other known group of babblers. Results and implications: Babbler group size decreased over the survey period at sites without restoration works, but restoration works were effective in stemming declines where they were done. Restoration was responsible for a difference of about one bird per group of 3-5 individuals; this is an important effect on the reproductive success of the social group. Effectiveness of restoration works targeted at the Grey-crowned Babbler was only demonstrable by sampling through time and including control sites without restoration works. This work demonstrates that while calls for better monitoring of restoration are valid, scope exists to recover a signal of effectiveness from opportunistic retrospective analyses. © Copyright: 2015 Vesk et al.

Cullen B.,Trust for Nature | Inglis T.,Trust for Nature | Arbon K.,Trust for Nature | Robinson D.,Trust for Nature
Victorian Naturalist | Year: 2013

With over two thirds of Victoria in private ownership, the value of private land conservation is pivotal to the future of the state's biodiversity. Trust for Nature has been working for 40 years to protect conservation values on private land across Victoria. The Trust has worked with over 1000 landholders to permanently protect 52 287 ha with legally-binding conservation covenants. In the same period, Trust for Nature has strategically purchased 111 properties, currently retaining 46, representing an additional 42 842 ha of under permanent protection. The Trust has also been involved in major conservation campaigns. Through these and other measures, Trust for Nature has been actively involved in the conservation of some of Victoria's most threatened species and communities, including within urban landscapes.

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