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Islands are global hotspots of both biodiversity and extinction. Invasive species are a primary threat, and the majority of islands have been invaded by more than one. Multispecies eradications are essential for conserving the biodiversity of these islands, but experience has shown that eradicating species at the wrong time can be disastrous for endemic species., Managers not only have to decide how to eradicate each invasive species, they need to determine when to target each species, and how to control multiple species with a limited budget. We use dynamic control theory to show that, when resources are limited, species should be eradicated in a particular order (an eradication schedule). We focus on a common invaded island ecosystem motif, where one invasive predator consumes two prey species (one endemic, one invasive), and managers wish to eradicate both invasives while ensuring the persistence of the endemic species. We identify the optimal eradication schedule for this entire class of problem. To illustrate the application of our solution, we also analyse a particular case study from California's Channel Islands., For any island ecosystem that shares this motif, managers should begin by allocating all of their resources towards invasive predator control. Only later should resources be shifted towards controlling the invasive prey. This shift should ideally be gradual, but an abrupt shift is very close to optimal. The Channel Islands case study confirms these findings. Targeting both species simultaneously is substantially suboptimal., We reach the robust conclusion that the same eradication schedule should be applied to any island with this ecosystem motif, even if the ecosystem contains different species to the Channel Islands case study., Synthesis and applications. Although very numerous, the world's invaded island ecosystems could be described by a limited range of invaded ecosystem motifs. By calculating robust optimal eradication schedules for each motif, the approach defined in this study could offer rapid decision-support for a large number of future conservation projects where specific data are scarce. [ABSTRACT FROM AUTHOR]

Although ecological assemblages frequently depart from neutral model predictions, these discrepancies have not been unambiguously attributed to neutral theory's core assumption: that community structure is primarily the result of chance variation in birth, death, speciation, and dispersal, rather than the manifestation of demographic differences among species. Using coral communities in Barbados from four time periods during the Pleistocene, we demonstrate that the neutral theory cannot explain coral community similarity distributions, species' regional abundance distributions, or their local occupancy. Furthermore, discrepancies between the neutral theory and the observed communities can be attributed to violation of the core assumption of species equivalence. In particular, species' variable growth rates are driving departures from neutral predictions. Our results reinforce an understanding of reef coral community assembly that invokes trade-offs in species' demographic strategies. The results further suggest that conservation management actions will fail if they are based on the neutral assumption that different coral species are equally able to create live coral cover in the shallow-water reef environment. These findings highlight the importance of developing biodiversity theory that can parsimoniously incorporate species differences in coral reef communities, rather than further elaborating neutral theory. [ABSTRACT FROM AUTHOR]

The optimal allocation of conservation resources between biodiverse conservation regions has generally been calculated using stochastic dynamic programming, or using myopic heuristics. These solutions are hard to interpret and may not be optimal. To overcome these two limitations, this paper approaches the optimal conservation resource allocation problem using optimal control theory. A solution using Pontryagin's maximum principle provides novel insight into the general properties of efficient conservation resource allocation strategies, and allows more extensive testing of the performance of myopic heuristics. We confirmed that a proposed heuristic (minimize short-term loss) yields near-optimal results in complex allocation situations, and found that a qualitative allocation feature observed in previous analyses (bang-bang allocation) is a general property of the optimal allocation strategy. [ABSTRACT FROM AUTHOR]

Much of conservation planning has focused on how we should prioritize areas for protection based on biodiversity and cost, but less is known about how we should prioritize areas based upon the level of threat they face. We discuss two opposing threat prioritization strategies: frontier conservation (prioritizing high‐threat areas) and wilderness conservation (prioritizing low‐threat areas). Using a temporally explicit model, we demonstrate that the best strategy depends on a variety of factors, including protection costs, heterogeneity in biodiversity, biodiversity–area relationships, the rate of biodiversity recovery, the rate of change in threats through time, and the timeframe within which we measure conservation outcomes. By quantitatively comparing the impact of these strategies, we aim to shift the debate away from a simple dichotomy of frontier versus wilderness, toward an understanding of the context‐specific benefits of each option, and a discussion of how threat combines with other factors to determine spatial conservation priorities. [ABSTRACT FROM AUTHOR]

Abstract: Payments to private landholders for providing biodiversity land can improve conservation outside protected areas. Input‐based payments are widely used despite evidence they are often ineffective at improving biodiversity outcomes. Meanwhile, little has been done to assess how to use outcome‐based payments to maximize biodiversity, despite growing academic interest. We compare different outcome‐based allocation methods to assess which returns the greatest benefits for biodiversity. We predicted the likely landholder actions in response to outcome‐based payments. We incorporated strategic interactions between landholders under four different funding allocation methods: the commonly applied “set‐price” allocation method; capacity‐based payments; proportional payment; and payment for change. We compared biodiversity outcomes (percentage change in abundance of a species of conservation interest), return on investment and cost‐effectiveness of each method. The set‐price allocation method, despite its common usage, is the least cost‐effective method that we test. Regardless of cost, it only results in better biodiversity outcomes than other methods under a very narrow range of conditions (high initial target species abundance and low profitability). The profitability of the property, and to a lesser degree initial population size, will influence which allocation method will perform best. Most perform well when the initial population of the species of conservation interest is very small and profitability negligible. Only one method—based on change in population—performs well across all scenarios. This method outperforms the others particularly when the property has a higher profitability and low initial numbers of animals. Policy implications. Pursuing conservation on private land using outcome‐based payments for biodiversity can result in varied levels of success depending on the allocation methods used to support payment decisions. Allocation method choice should be based on a transparent analysis that incorporates both the dynamics of the ecological system and interactions between individual landholders. This analysis can guide adoption of funding allocation methods that greatly increase biodiversity outcomes. [ABSTRACT FROM AUTHOR]

REDD+ presents novel options for conservation in the tropics, yet it is unclear how biodiversity-focused organizations or actors should react to these carbon-focused opportunities. Here, we critically assess for the first time the expected outcomes of five contrasting scenarios of engagement between a biodiversity actor and REDD+. We discover that in the Berau regency, Indonesia, it is usually beneficial for a biodiversity actor to react in some way to REDD+, but the preferred reaction depends on whether a REDD+ project is already developing in the region, and the scale and type of conservation objectives. In general, from a strict biodiversity perspective, the most cost efficient reaction to the presence of REDD+ is to use biodiversity funds to protect areas neglected by REDD+. Our results demonstrate that if biodiversity actors fail to adapt the way they pursue conservation in the tropics, REDD+ opportunities could go largely untapped. [ABSTRACT FROM AUTHOR]

Aim The critically endangered Cross River gorilla is a patchily distributed taxon for which habitat selection has been modelled only at coarse spatial scales, using remotely sensed landscape data and large-scale species distribution maps. These coarse-scale models fail to explain why Cross River gorillas ( CRG) display a highly fragmented distribution within what appears to be a large, continuous area of suitable habitat. This study aimed to refine our understanding of CRG habitat use to inform conservation planning both for the subspecies and for other fragmented species of conservation concern. Location Cross River gorillas occur only in a discontinuous distribution in the southern portion of the Cameroon- Nigeria border region, an area that represents one of Africa's biodiversity hotspots. This study was carried out in the Northern Mone- Mt. Oko region, part of the Mone/ Mbulu forest system located in the Manyu division of the South-west Province of Cameroon. Methods We used resource selection functions to understand habitat use by CRG at multiple scales. Specifically, we employed generalized additive models at the scale of the annual subpopulation range and conditional logistic regression at the scale of individual movements. Results Cross River gorillas habitat selection is highly scale dependent. Localized measures of habitat quality strongly influenced selection at the subpopulation or landscape scale, while human activity and food availability were the best predictors of selection at finer scales. Main conclusions Understanding why CRG do not occur in seemingly suitable habitat is crucial for designating critical habitat both within and between CRG subpopulations. Our results indicate that conservation planning to maintain critical habitat and connectivity among CRG populations will require an integrative, multi-scale planning approach incorporating large-scale landscape characteristics, human use patterns and CRG food availability. [ABSTRACT FROM AUTHOR]

Addressing the vulnerability of areas to habitat loss remains a challenge for conservation planners. Different areas are often assumed equally vulnerable to habitat loss or, worse, conservation attention focuses on remote, unproductive areas contributing little to minimizing biodiversity loss. Understanding vulnerability is crucial to planning but gathering the required information can be time consuming and expensive; and any data on vulnerability will be uncertain. We investigated the circumstances in which including vulnerability data produces better conservation decisions. We found that it is best to use existing information on vulnerability only when uncertainty is less than 20%-30%. With higher uncertainty and large spatial variance in vulnerability, it is best to improve vulnerability data before making conservation decisions. Otherwise, it is best to ignore vulnerability and consider only biodiversity value. Other important factors are whether reservation displaces or inhibits habitat loss and the correlation between biodiversity value and vulnerability. [ABSTRACT FROM AUTHOR]

One of the most pressing issues facing the global conservation community is how to distribute limited resources between regions identified as priorities for biodiversity conservation. Approaches such as biodiversity hotspots, endemic bird areas and ecoregions are used by international organizations to prioritize conservation efforts globally. Although identifying priority regions is an important first step in solving this problem, it does not indicate how limited resources should be allocated between regions. Here we formulate how to allocate optimally conservation resources between regions identified as priorities for conservation—the ‘conservation resource allocation problem’. Stochastic dynamic programming is used to find the optimal schedule of resource allocation for small problems but is intractable for large problems owing to the “curse of dimensionality”. We identify two easy-to-use and easy-to-interpret heuristics that closely approximate the optimal solution. We also show the importance of both correctly formulating the problem and using information on how investment returns change through time. Our conservation resource allocation approach can be applied at any spatial scale. We demonstrate the approach with an example of optimal resource allocation among five priority regions in Wallacea and Sundaland, the transition zone between Asia and Australasia. [ABSTRACT FROM AUTHOR]

Decision-makers increasingly use life-cycle assessment ( LCA) as a tool to measure the environmental sustainability of products. LCA is of particular importance in globalized agricultural supply chains, which have environmental effects in multiple and spatially dispersed locations., Incorporation of impacts on biodiversity that arise from agricultural production systems into environmental assessment methods is an emerging area of work in LCA, and current approaches have limitations, including the need for (i) improved assessment of impacts to biodiversity associated with agricultural production, (ii) inclusion of new biodiversity indicators (e.g. conservation value, functional diversity, ecosystem services) and (iii) inclusion of previously unaccounted modelling variables that go beyond land-use impacts (e.g. climate change, water and soil quality)., Synthesis and applications. Ecological models and understanding can contribute to address the limitations of current life-cycle assessment (LCA) methods in agricultural production systems and to make them more ecologically relevant. This will be necessary to ensure that biodiversity is not neglected in decision-making that relies on LCA. [ABSTRACT FROM AUTHOR]

Ecologists are often required to estimate the number of species in a region or designated area. A number of diversity indices are available for this purpose and are based on sampling the area using quadrats or other means, and estimating the total number of species from these samples. In this paper, a novel theory and method for estimating the number of species is developed. The theory involves the use of the Laplace method for approximating asymptotic integrals. The method is shown to be successful by testing random simulated datasets. In addition, several real survey datasets are tested, including forests that contain a large number (tens to hundreds) of tree species, and an aquatic system with a large number of fish species. The method is shown to give accurate results, and in almost all cases found to be superior to existing tools for estimating diversity. [ABSTRACT FROM AUTHOR]

Agencies charged with nature conservation and protecting built-assets from fire face a policy dilemma because management that protects assets can have adverse impacts on biodiversity. Although conservation is often a policy goal, protecting built-assets usually takes precedence in fire management implementation. To make decisions that can better achieve both objectives, existing trade-offs must first be recognized, and then policies implemented to manage multiple objectives explicitly. We briefly review fire management actions that can conflict with biodiversity conservation. Through this review, we find that common management practices might not appreciably reduce the threat to built-assets but could have a large negative impact on biodiversity. We develop a framework based on decision theory that could be applied to minimize these conflicts. Critical to this approach is (1) the identification of the full range of management options and (2) obtaining data for evaluating the effectiveness of those options for achieving asset protection and conservation goals. This information can be used to compare explicitly the effectiveness of different management choices for conserving species and for protecting assets, given budget constraints. The challenge now is to gather data to quantify these trade-offs so that fire policy and practices can be better aligned with multiple objectives. [ABSTRACT FROM AUTHOR]

Background. Conventional wisdom identifies biodiversity hotspots as priorities for conservation investment because they capture dense concentrations of species. However, density of species does not necessarily imply conservation 'efficiency'. Here we explicitly consider conservation efficiency in terms of species protected per dollar invested. Methodology/Principal Findings. We apply a dynamic return on investment approach to a global biome and compare it with three alternate priority setting approaches and a random allocation of funding. After twenty years of acquiring habitat, the return on investment approach protects between 32% and 69% more species compared to the other priority setting approaches. To correct for potential inefficiencies of protecting the same species multiple times we account for the complementarity of species, protecting up to three times more distinct vertebrate species than alternate approaches. Conclusions/Significance. Incorporating costs in a return on investment framework expands priorities to include areas not traditionally highlighted as priorities based on conventional irreplaceability and vulnerability approaches. [ABSTRACT FROM AUTHOR]

A new framework applied to 17 of the world's Mediterranean ecoregions reveals that investing in a sequence of conservation actions targeted towards specific threats will protect more species than just acquiring land for protected areas. [ABSTRACT FROM AUTHOR]