Mallees of the Southern Mallee district of South Australia : a ute guide

51 page(s

The role of plant provenance in restoration ecology under climate change

"Thesis submitted for the degree of Doctor of Philosophy""October 2012"Includes bibliographical references.1. Introduction and aims of thesis -- 2. Testing the "local provenance" paradigm: a common garden experiment in Cumberland Plain Woodland, Sydney, Australia -- Appendix -- 3. What role does 'home-site' advantage play in restoration ecology under heatwave conditions? -- Appendix -- 4. Intraspecific responsiveness to elevated CO2 of two widespread native Australian species, Acacia falcata and Eucalyptus crebra -- 5. How far is it to your local? A survey on local provenance use in New South Wales -- Appendix A -- Appendix B -- 6. Discussion and conclusion -- Appendix. Papers accepted for publication during candidature Ethics Committee Approval.The rapidly changing climate poses a challenge for many land management and conservation activities. In particular, the need to ensure future sustainability of revegetated communities has focused attention on the critical decision as to where to source seed (and other propagules). Traditionally, industry 'best' practice has adhered to the principle of sourcing propagation material locally. This practice has been based on a perception that locally-sourced material is adapted to local conditions and will therefore confer superior plant performance. Additionally, the use of local provenance is often considered desirable as a means of 'preserving' the genetic integrity of local populations, reducing risks of outbreeding depression. In situations where source populations are small and inbred and where the environment is rapidly changing (a situation we are currently facing), this 'local is best' practice needs to be challenged. Moreover, sourcing seed from genetically-impoverished populations with little adaptive potential is increasingly being viewed as more detrimental to restoration success than potential outbreeding depression. Improved seed-sourcing guidelines, developed in the context of changing environmental conditions and based on empirical evidence, are urgently needed to support restoration projects that are sustainable in the long term. This thesis explores the 'local is best' paradigm using field and glasshouse experiments. In Chapter 2, I describe a common garden experiment comparing the establishment success of different provenances (one local vs four non-local provenances) of six widespread species (Acacia falcata, Bursaria spinosa ssp. spinosa, Eucalyptus crebra, E. tereticornis, Hardenbergia violacea and Themeda australis), all community dominants and / or widely used in restoration projects on the Cumberland Plain, western Sydney. In Chapter 3, I describe an experiment designed to test the establishment success of four provenances each of E. tereticornis and T. australis under both current and simulated future temperature conditions for 2050 in western Sydney. In Chapter 4, I describe a glasshouse experiment comparing the survival and early growth rates of three provenances each of Acacia falcata and Eucalyptus crebra under ambient and elevated CO2. In Chapter 5, I describe the results of a survey (conducted in New South Wales) investigating understanding of local provenance issues among restoration practitioners. The overall results and conclusions of the research are summarized in the final Chapter. Little evidence was found that local provenance plants had superior establishment success in the field studies. In the glasshouse experiment, intraspecific variation was found between the provenances for both species, regardless of the CO2 treatment. The results of the survey identified several inconsistencies of practice and belief within the restoration industry and that the definition of 'local provenance' is very flexible. The majority of respondents are in favour of a review of seed-sourcing policy/guidelines to allow for the inclusion of non-local provenance material. Overall, this research provides empirical support to challenge the validity of the strict adherence to the 'local is best' paradigm in general, but particularly on the Cumberland Plain, and underpins the need for improved seed sourcing guidelines.Mode of access: World Wide Web.1 online resources (viii, 266 pages) illustrations (some coloured), map

How far is it to your local? A survey on local provenance use in New South Wales

The decision as to where to source seed is one of the most critical in restoration projects. Locally collected seed is often recommended, or even contractually required, because it is assumed to be adapted to local conditions and therefore result in superior survival and growth rates, conferring a greater probability of restoration success. The perceived advantages, which include retaining the genetic 'integrity' of the site, are centred around the avoidance of outbreeding depression and hybridization. These traditional reasons for using locally collected seed need to be reconsidered in the light of rapidly changing climatic and other environmental conditions; plants that are locally adapted now may not be locally adapted in future. Understanding the current usage of local provenance is pivotal to discussions on its appropriateness under climate change. We present the results of a survey of restoration practitioners in New South Wales on attitudes and practices in relation to the use of local provenance. We found that whilst the majority of practitioners preferentially use local provenance seeds, the actual definition of local provenance varied amongst respondents. Whilst 80% of participants believe that projections of future climate change are relevant to restoration projects, there is an apparent reluctance to actively manage for this eventuality. However, many respondents are in favour of a review of seed-sourcing policy/guidelines to allow for the inclusion of non-local provenance material. Implications of the survey for potential changes to guidelines to better prepare for anticipated changing conditions are discussed.8 page(s

How ready are we to move species threatened from climate change? Insights into the assisted colonization debate from Australia

Assisted colonization, the intentional movement of species beyond their native range, has been proposed as a climate change adaptation tool for biodiversity conservation. The risks and benefits of its implementation are still being debated but already the climate is changing, species are moving and the pressure on at-risk species must therefore be increasing. However, instances where moving species beyond their natural range purely for conservation purposes due to climate change are few, and the opportunity for science to inform practice is limited. Here we survey active participants in flora translocations and/or flora conservation in Australia in order to investigate the gap between theoretical and conceptual ideas about assisted colonization and to gauge preparedness for its implementation. We found that actions that mitigate proximal threats are preferred over those that move species beyond their current range. A lack of knowledge of species biology and ecology is an impediment to the acceptance of assisted colonization. In addition, prohibitive costs and the potential increased risk of the spread of diseases, pests and/or pathogens are viewed as more important obstacles of successful assisted colonization than potential for invasion at the recipient site. Full approval from all stakeholders at the source and recipient sites was found to be the most important factor for the successful assisted colonization of flora.9 page(s

Turning up the heat on the provenance debate : testing the 'local is best' paradigm under heatwave conditions

A key aspect of successful restoration projects is the sourcing of propagation material suited to the environmental and biotic conditions of the proposed planting site. Traditionally, the use of propagules collected locally has been advocated for revegetation on the assumption that this material is better adapted to local conditions. A rapidly changing climate, however, is challenging the assumption that the use of local genetic stock will provide the best restoration outcome in the long term. We tested the 'local is best' paradigm using open top chambers to simulate the predicted summer temperatures for 2050 in western Sydney, Australia. We compared the establishment success of Eucalyptus tereticornis and Themeda australis, dominant species in Cumberland Plain Woodland, grown from local versus non-local seed. All plants survived an exceptional summer heatwave and few differences between temperature treatments were found. No evidence of local superiority was found for survival or growth of non-reproductive tissues of either species. However, local provenance plants of E.tereticornis suffered significantly greater herbivory in the ambient temperature treatment than one non-local provenance, and local provenance plants of T.australis demonstrated significant superiority to most non-local provenances in all categories of reproductive growth. For both species, the provenances from warmer climates demonstrated comparable, and often better, growth performance than the local provenance plants.12 page(s

Testing the "local provenance" paradigm : a common garden experiment in Cumberland Plain Woodland, Sydney, Australia

Seed for restoration projects has traditionally been sourced locally to "preserve" the genetic integrity of the replanted site. Plants grown from locally sourced seeds are perceived to have the advantage of being adapted to local conditions, and the use of local provenance is a requirement of many restoration projects. However, the processes of climate change and habitat fragmentation, with the subsequent development of novel environments, are forcing us to reconsider this basic tenet of restoration ecology. We tested the "local provenance is best" paradigm, by comparing the performance of plants grown from local with non-local seed sources within a common garden experiment. We selected six species representing a range of growth forms (Acacia falcata, Bursaria spinosa ssp. spinosa, Eucalyptus crebra, E. tereticornis, Hardenbergia violacea and Themeda australis) from an assemblage known as the Cumberland Plain Woodland, a threatened community in western Sydney. Multiple provenances were collected from within the range of each species and grown at two field sites on the Cumberland Plain. Growing time varied between species and ranged from 7months to 2years. With the exception of B. spinosa, and to a lesser extent T. australis, we found little evidence that local provenance plants were superior to distant provenances in terms of survival and establishment.9 page(s

Assisted colonization as a climate change adaptation tool

Assisted colonization is a form of conservation translocation which introduces species at risk from extinction to new habitats, beyond their current range, in anticipation of more suitable conditions. Identifying which species, communities and ecosystems may benefit most from assisted colonization in coming decades is a key goal for conservation. Climate change is expected to lead to the loss or movement of suitable habitat for a range of species and anticipating which can be effectively conserved through assisted colonization is critical. Here, we identify a series of scenarios that may predispose terrestrial species to the need for assisted colonization in order to reduce extinction risk resulting from anthropogenic climate change and assemble a list of traits commonly associated with at-risk species. These traits may help to provide broad-scale guidance on how to select species to target for assisted colonization as a conservation management response to climate change. We also identify six key themes associated with successful conservation translocations including recipient site selection and preparation, a clear understanding of species biology and ecology, and taking lessons from invasive species research.9 page(s

Embedding biodiversity research into climate adaptation policy and practice

Addressing climate change risks requires collaboration and engagement across all sectors of society. In particular, effective partnerships are needed between research scientists producing new knowledge, policy-makers and practitioners who apply conservation actions on the ground. We describe the implementation of a model for increasing the application and useability of biodiversity research in climate adaptation policy and practice. The focus of the program was to increase the ability of a state government agency and natural resource practitioners in Australia to manage and protect biodiversity in a changing climate. The model comprised a five-stage process for enhancing impact (i) initiation of research projects that addressed priority conservation policy and management issues; (ii) co-design of the research using a collaborative approach involving multiple stakeholders; (iii) implementation of the research and design of decision tools and web-based resources; (iv) collaborative dissemination of the tools and resources via government and community working groups; and (v) evaluation of research impact. We report on the model development and implementation, and critically reflect on the model's impact. We share the lessons learnt from the challenges of operating within a stakeholder group with diverse objectives and criteria for success, and provide a template for creating an environmental research program with real world impact

Characterization of Multidrug-Resistant Escherichia coli Isolates from Animals Presenting at a University Veterinary Hospital▿†

In this study, we examined molecular mechanisms associated with multidrug resistance (MDR) in a collection of Escherichia coli isolates recovered from hospitalized animals in Ireland. PCR and DNA sequencing were used to identify genes associated with resistance. Class 1 integrons were prevalent (94.6%) and contained gene cassettes recognized previously and implicated mainly in resistance to aminoglycosides, β-lactams, and trimethoprim (aadA1, dfrA1-aadA1, dfrA17-aadA5, dfrA12-orfF-aadA2, blaOXA-30-aadA1, aacC1-orf1-orf2-aadA1, dfr7). Class 2 integrons (13.5%) contained the dfrA1-sat1-aadA1 gene array. The most frequently occurring phenotypes included resistance to ampicillin (97.3%), chloramphenicol (75.4%), florfenicol (40.5%), gentamicin (54%), neomycin (43.2%), streptomycin (97.3%), sulfonamide (98.6%), and tetracycline (100%). The associated resistance determinants detected included blaTEM, cat, floR, aadB, aphA1, strA-strB, sul2, and tet(B), respectively. The blaCTX-M-2 gene, encoding an extended-spectrum β-lactamase (ESβL), and blaCMY-2, encoding an AmpC-like enzyme, were identified in 8 and 18 isolates, respectively. The mobility of the resistance genes was demonstrated using conjugation assays with a representative selection of isolates. High-molecular-weight plasmids were found to be responsible for resistance to multiple antimicrobial compounds. The study demonstrated that animal-associated commensal E. coli isolates possess a diverse repertoire of transferable genetic determinants. Emergence of ESβLs and AmpC-like enzymes is particularly significant. To our knowledge, the blaCTX-M-2 gene has not previously been reported in Ireland