Suchergebnisse

Context
Reviews of climate change in Australia have identified that it is imposing additional stresses on biodiversity, which is already under threat from multiple human impacts.

Aims
The present study aimed to determine the contributions of several factors to the demise of the koala in the Eden region in south-eastern New South Wales and, in particular, to establish to what extent climate change may have exacerbated the decline.

Methods
The study built on several community-based koala surveys in the Eden region since 1986, verified through interviews with survey respondents. Historical records as far back as the late 19th century, wildlife databases and field-based surveys were used to independently validate the community survey data and form a reliable picture of changes in the Eden koala population. Analysis of the community survey data used a logistic model to assess the contribution of known threats to koalas, including habitat loss measured as changes in foliage projective cover, fire, increases in the human population and climate change in the form of changes in temperature and rainfall, to the regional decline of this species.

Key results
We found a marked, long-term shrinkage in the distribution of the koala across the Eden region. Our modelling demonstrated that a succession of multiple threats to koalas from land use (human population growth and habitat loss) and environmental change (temperature increase and drought) were significant contributors to this decline.

Conclusions
Climate change, particularly drought and rising temperatures, has been a hitherto hidden factor that has been a major driver of the decline of the koala in the Eden region.

Implications
Development of strategies to help fauna adapt to the changing climate is of paramount importance, particularly at a local scale.

Context
The impacts of climate change on the climate envelopes, and hence, distributions of species, are of ongoing concern for biodiversity worldwide. Knowing where climate refuge habitats will occur in the future is essential to conservation planning. The koala (Phascolarctos cinereus) is recognised by the International Union for Conservation of Nature (IUCN) as a species highly vulnerable to climate change. However, the impact of climate change on its distribution is poorly understood.


Aims
We aimed to predict the likely shifts in the climate envelope of the koala throughout its natural distribution under various climate change scenarios and identify potential future climate refugia.


Methods
To predict possible future koala climate envelopes we developed bioclimatic models using Maxent, based on a substantial database of locality records and several climate change scenarios.


Key results
The predicted current koala climate envelope was concentrated in south-east Queensland, eastern New South Wales and eastern Victoria, which generally showed congruency with their current known distribution. Under realistic projected future climate change, with the climate becoming increasingly drier and warmer, the models showed a significant progressive eastward and southward contraction in the koala's climate envelope limit in Queensland, New South Wales and Victoria. The models also indicated novel potentially suitable climate habitat in Tasmania and south-western Australia.


Conclusions
Under a future hotter and drier climate, current koala distributions, based on their climate envelope, will likely contract eastwards and southwards to many regions where koala populations are declining due to additional threats of high human population densities and ongoing pressures from habitat loss, dog attacks and vehicle collisions. In arid and semi-arid regions such as the Mulgalands of south-western Queensland, climate change is likely to compound the impacts of habitat loss, resulting in significant contractions in the distribution of this species.


Implications
Climate change pressures will likely change priorities for allocating conservation efforts for many species. Conservation planning needs to identify areas that will provide climatically suitable habitat for a species in a changing climate. In the case of the koala, inland habitats are likely to become climatically unsuitable, increasing the need to protect and restore the more mesic habitats, which are under threat from urbanisation. National and regional koala conservation policies need to anticipate these changes and synergistic threats. Therefore, a proactive approach to conservation planning is necessary to protect the koala and other species that depend on eucalypt forests.

Conservation efforts often focus on umbrella species whose distributions overlap with many other flora and fauna. However, because biodiversity is affected by different threats that are spatially variable, focusing only on the geographic range overlap of species may not be sufficient in allocating the necessary actions needed to efficiently abate threats. We developed a problem‐based method for prioritizing conservation actions for umbrella species that maximizes the total number of flora and fauna benefiting from management while considering threats, actions, and costs. We tested our new method by assessing the performance of the Australian federal government's umbrella prioritization list, which identifies 73 umbrella species as priorities for conservation attention. Our results show that the federal government priority list benefits only 6% of all Australia's threatened terrestrial species. This could be increased to benefit nearly half (or 46%) of all threatened terrestrial species for the same budget of AU$550 million/year if more suitable umbrella species were chosen. This results in a 7‐fold increase in management efficiency. We believe nations around the world can markedly improve the selection of prioritized umbrella species for conservation action with this transparent, quantitative, and objective prioritization approach.

Context Choosing the most effective combinations of actions to manage threatened species is difficult. Aims This study aimed to identify the most effective combinations of six management actions for reversing population declines of koala populations in three regional landscapes (Coastal, Riverine and Hinterland) in north-east New South Wales, Australia, based on expert-elicited knowledge. Methods A Bayesian network was used to combine continuous probability distributions representing the impact of specific management actions and combinations of actions. Data were derived from expert elicitation. Variation within and among expert judgements was captured by incorporating submodels of individual responses. We evaluated alternative management solutions to address four mortality factors (disease and injury, vehicle strikes, domestic dogs and wild dogs/dingoes (Canis familiaris), and two habitat-related management actions (restoration and protection). Key results We show that there are marked differences in the expected response of the koala populations to the various management options in the three regional landscapes over a 20-year period (2019–2039), and that multiple management actions are required to arrest and reverse the decline in koala populations of north-east NSW. Conclusions Management actions for koala conservation should be based on regional context. Our model, in conjunction with robust expert-elicitation procedures, allows decision makers to distinguish effective from ineffective combinations of management actions for threatened species management, and has been structured so that new data can be incorporated into the model. Implications Model design could be easily adapted to different species or conservation contexts, and updated as new evidence becomes available, making it valuable in adaptive management for local to regional-scale conservation problems.

Participatory approaches to forest management have been promoted as a means of returning rights historically removed, and as a way of managing natural resources sustainably, fairly, and to improve livelihoods in communities. Top-down models of community-based forest management take the perspective that if people feel ownership over, have a voice in decisions about, and can benefit from surrounding ecosystems, then they will be motivated to maintain and protect them. However, even participatory approaches, such as community-based forest management, may not always result in clear positive outcomes for involvement in decision making and forest conservation. We examine whether an Indonesian government initiative for community-based forest management was positively associated with community members' participation in local decision making and support for conservation and sustainable management of forest resources, in the context of state-owned lands. We used household questionnaire data to compare villages with and without a community forest, and community forests over time in a case study region of West Kalimantan. Analyzing forest visitations, conservation support, and indicators of procedural equity, we found no consistent association between having a community forest and higher levels of participation in decision making or household support for forest conservation. However, well-being indicators were positively associated with more active participation. The level of support for forest conservation was also positively related to households' leadership in village institutions and higher levels of well-being, particularly subjective well-being, land tenure, and material wealth. These social-demographic factors are important considerations when designing and implementing community-based forest management, which strives for fair and just decision-making processes along with forest conservation. The findings highlight how existing socioeconomic contexts factor into local institutions, and that accounting for these in program design and implementation may help address existing social inequalities that influence achieving joint social and ecological objectives.

Participatory approaches to forest management have been promoted as a means of returning rights historically removed, and as a way of managing natural resources sustainably, fairly, and to improve livelihoods in communities. Top-down models of community-based forest management take the perspective that if people feel ownership over, have a voice in decisions about, and can benefit from surrounding ecosystems, then they will be motivated to maintain and protect them. However, even participatory approaches, such as community-based forest management, may not always result in clear positive outcomes for involvement in decision making and forest conservation. We examine whether an Indonesian government initiative for community-based forest management was positively associated with community members' participation in local decision making and support for conservation and sustainable management of forest resources, in the context of state-owned lands. We used household questionnaire data to compare villages with and without a community forest, and community forests over time in a case study region of West Kalimantan. Analyzing forest visitations, conservation support, and indicators of procedural equity, we found no consistent association between having a community forest and higher levels of participation in decision making or household support for forest conservation. However, well-being indicators were positively associated with more active participation. The level of support for forest conservation was also positively related to households' leadership in village institutions and higher levels of well-being, particularly subjective well-being, land tenure, and material wealth. These social-demographic factors are important considerations when designing and implementing community-based forest management, which strives for fair and just decision-making processes along with forest conservation. The findings highlight how existing socioeconomic contexts factor into local institutions, and that accounting for these in program design and implementation may help address existing social inequalities that influence achieving joint social and ecological objectives.