Limits...
Impediments to the success of management actions for species recovery.

Ng CF, Possingham HP, McAlpine CA, de Villiers DL, Preece HJ, Rhodes JR - PLoS ONE (2014)

Bottom Line: We found that the unwillingness of dog owners to restrain their dogs at night (a social impediment), the effectiveness of wildlife crossings to reduce vehicle collisions (a technological impediment) and the unavailability of areas for restoration (a land-use impediment) significantly reduced the effectiveness of our actions.In the presence of these impediments, achieving successful recovery may be unlikely.In some cases, it may also be worth considering whether investing in reducing or removing impediments may be a cost-effective course of action.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, Australia; Australian Research Council Centre of Excellence for Environmental Decisions, The University of Queensland, Brisbane, Queensland, Australia; National Environmental Research Program Environmental Decisions Hub, The University of Queensland, Brisbane, Queensland, Australia.

ABSTRACT
Finding cost-effective management strategies to recover species declining due to multiple threats is challenging, especially when there are limited resources. Recent studies offer insights into how costs and threats can influence the best choice of management actions. However, when implementing management actions in the real-world, a range of impediments to management success often exist that can be driven by social, technological and land-use factors. These impediments may limit the extent to which we can achieve recovery objectives and influence the optimal choice of management actions. Nonetheless, the implications of these impediments are not well understood, especially for recovery planning involving multiple actions. We used decision theory to assess the impact of these types of impediments for allocating resources among recovery actions to mitigate multiple threats. We applied this to a declining koala (Phascolarctos cinereus) population threatened by habitat loss, vehicle collisions, dog attacks and disease. We found that the unwillingness of dog owners to restrain their dogs at night (a social impediment), the effectiveness of wildlife crossings to reduce vehicle collisions (a technological impediment) and the unavailability of areas for restoration (a land-use impediment) significantly reduced the effectiveness of our actions. In the presence of these impediments, achieving successful recovery may be unlikely. Further, these impediments influenced the optimal choice of recovery actions, but the extent to which this was true depended on the target koala population growth rate. Given that species recovery is an important strategy for preserving biodiversity, it is critical that we consider how impediments to the success of recovery actions modify our choice of actions. In some cases, it may also be worth considering whether investing in reducing or removing impediments may be a cost-effective course of action.

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Related in: MedlinePlus

The total investment required to attain the target growth rate.When we include (dashed line) and exclude (solid line) impediments to the success of the actions.
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pone-0092430-g003: The total investment required to attain the target growth rate.When we include (dashed line) and exclude (solid line) impediments to the success of the actions.

Mentions: As we increased the target growth rate, the total investment required increases (Fig. 3). This increase in required investment is very rapid at the point at which the optimal strategy shifts toward habitat restoration (i.e., at a growth rate of around 0.97 when impediments are present and a growth rate of 0.99 when they are absent) (Fig. 3). Therefore, a low growth rate can be achieved relatively cheaply, but achieving growth rates closer to one is considerably more expensive. However, for a given target growth rate, the level of investment required was also considerably higher when we incorporated impediments to the success of the actions than when we did not (Fig. 3). For instance, a population growth rate of 0.97 can be obtained for an investment of AU$25 million in the presence of impediments, but only AU$9 million when they are not present (Fig. 3). However, since the growth rate that we will actually achieve is uncertain, the actual investment required to attain these growth rates is also uncertain (Figure 4). When we take into account uncertainty in parameter estimates, the estimated level of investment required to achieve a population growth rate of 0.97 ranges from around AU$3 million to around AU$1 billion with a 95% probability in the presence of impediments, but from around AU$1 million to around AU$100 million with a 95% probability in the absence of impediments. The presence of impediments in this case also increases the level of uncertainty at the upper end of the estimates of investment required.


Impediments to the success of management actions for species recovery.

Ng CF, Possingham HP, McAlpine CA, de Villiers DL, Preece HJ, Rhodes JR - PLoS ONE (2014)

The total investment required to attain the target growth rate.When we include (dashed line) and exclude (solid line) impediments to the success of the actions.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3974711&req=5

pone-0092430-g003: The total investment required to attain the target growth rate.When we include (dashed line) and exclude (solid line) impediments to the success of the actions.
Mentions: As we increased the target growth rate, the total investment required increases (Fig. 3). This increase in required investment is very rapid at the point at which the optimal strategy shifts toward habitat restoration (i.e., at a growth rate of around 0.97 when impediments are present and a growth rate of 0.99 when they are absent) (Fig. 3). Therefore, a low growth rate can be achieved relatively cheaply, but achieving growth rates closer to one is considerably more expensive. However, for a given target growth rate, the level of investment required was also considerably higher when we incorporated impediments to the success of the actions than when we did not (Fig. 3). For instance, a population growth rate of 0.97 can be obtained for an investment of AU$25 million in the presence of impediments, but only AU$9 million when they are not present (Fig. 3). However, since the growth rate that we will actually achieve is uncertain, the actual investment required to attain these growth rates is also uncertain (Figure 4). When we take into account uncertainty in parameter estimates, the estimated level of investment required to achieve a population growth rate of 0.97 ranges from around AU$3 million to around AU$1 billion with a 95% probability in the presence of impediments, but from around AU$1 million to around AU$100 million with a 95% probability in the absence of impediments. The presence of impediments in this case also increases the level of uncertainty at the upper end of the estimates of investment required.

Bottom Line: We found that the unwillingness of dog owners to restrain their dogs at night (a social impediment), the effectiveness of wildlife crossings to reduce vehicle collisions (a technological impediment) and the unavailability of areas for restoration (a land-use impediment) significantly reduced the effectiveness of our actions.In the presence of these impediments, achieving successful recovery may be unlikely.In some cases, it may also be worth considering whether investing in reducing or removing impediments may be a cost-effective course of action.

View Article: PubMed Central - PubMed

Affiliation: School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, Australia; Australian Research Council Centre of Excellence for Environmental Decisions, The University of Queensland, Brisbane, Queensland, Australia; National Environmental Research Program Environmental Decisions Hub, The University of Queensland, Brisbane, Queensland, Australia.

ABSTRACT
Finding cost-effective management strategies to recover species declining due to multiple threats is challenging, especially when there are limited resources. Recent studies offer insights into how costs and threats can influence the best choice of management actions. However, when implementing management actions in the real-world, a range of impediments to management success often exist that can be driven by social, technological and land-use factors. These impediments may limit the extent to which we can achieve recovery objectives and influence the optimal choice of management actions. Nonetheless, the implications of these impediments are not well understood, especially for recovery planning involving multiple actions. We used decision theory to assess the impact of these types of impediments for allocating resources among recovery actions to mitigate multiple threats. We applied this to a declining koala (Phascolarctos cinereus) population threatened by habitat loss, vehicle collisions, dog attacks and disease. We found that the unwillingness of dog owners to restrain their dogs at night (a social impediment), the effectiveness of wildlife crossings to reduce vehicle collisions (a technological impediment) and the unavailability of areas for restoration (a land-use impediment) significantly reduced the effectiveness of our actions. In the presence of these impediments, achieving successful recovery may be unlikely. Further, these impediments influenced the optimal choice of recovery actions, but the extent to which this was true depended on the target koala population growth rate. Given that species recovery is an important strategy for preserving biodiversity, it is critical that we consider how impediments to the success of recovery actions modify our choice of actions. In some cases, it may also be worth considering whether investing in reducing or removing impediments may be a cost-effective course of action.

Show MeSH
Related in: MedlinePlus