49 research outputs found
Revisiting the minimum set cover, the maximal coverage problems and a maximum benefit area selection problem to make climate‐change‐concerned conservation plans effective
1.Informed decisions for the selection of protected areas (PAs) are grounded in two general problems in Operations Research: the minimum set covering problem (minCost), where a set of ecological constraints are established as conservation targets and the minimum cost PAs are found, and the maximal coverage problem (maxCoverage) where the constraint is uniquely economic (i.e. a fixed budget) and the goal is to maximize the number of species having conservation targets adequately covered.
2.We adjust minCost and maxCoverage to accommodate the dynamic effects of climate change on species’ ranges. The selection of sites is replaced by the selection of time-ordered sequences of sites (climate change corridors), and an estimate of the persistence of each species in corridors is calculated according to the expected suitability of each site in the respective time period and the capacity of species to disperse between consecutive sites along corridors. In these problems, conservation targets are expressed as desired (and attainable) species persistence levels. We also introduce a novel problem (minShortfall) that combines minCost and maxCoverage. Unlike these two problems, minShortfall allows persistence targets to be missed and minimizes the sum of those gaps (i.e. target shortfalls), subject to a limited budget.
3.We illustrate the three problems with a case study using climatic suitability estimates for 10 mammal species in the Iberian Peninsula under a climate change scenario until 2080. We compare solutions of the three problems with respect to species persistence and PA costs, under distinct settings of persistence targets, number of target-fulfilled species and budgets. The solutions from different problems differed with regard to the areas to prioritize, their timings and the species whose persistence targets were fulfilled. This analysis also allowed identifying groups of species sharing corridors in optimal solutions, thus allowing important financial savings in site protection.
4.We suggest that enhancing species persistence is an adequate approach to cope with habitat shifts due to climate change. We trust the three problems discussed can provide complementary and valuable support for planners to anticipate decisions in order that the negative effects of climate change on species’ persistence are minimized
Effective conservation planning of Iberian amphibians based on a regionalization of climate-driven range shifts
Amphibians are severely affected by climate change, particularly in regions where droughts prevail and water availability is scarce. The extirpation of amphibians triggers cascading effects that disrupt the trophic structure of food webs and ecosystems. Dedicated assessments of the spatial adaptive potential of amphibian species under climate change are, therefore, essential to provide guidelines for their effective conservation. I used predictions about the location of suitable climates for 27 amphibian species in the Iberian Peninsula from a baseline period to 2080 to typify shifting species’ ranges. The time at which these range types are expected to be functionally important for the adaptation of a species was used to identify full or partial refugia; areas most likely to be the home of populations moving into new climatically suitable grounds; areas most likely to receive populations after climate adaptive dispersal; and climatically unsuitable areas near suitable areas. I implemented an area prioritization protocol for each species to obtain a cohesive set of areas that would provide maximum adaptability and where management interventions should be prioritized. A connectivity assessment pinpointed where facilitative strategies would be most effective. Each of the 27 species had distinct spatial requirements but, common to all species, a bottleneck effect was predicted by 2050 because source areas for subsequent dispersal were small in extent. Three species emerged as difficult to maintain up to 2080. The Iberian northwest was predicted to capture adaptive range for most species. My study offers analytical guidelines for managers and decision makers to undertake systematic assessments on where and when to intervene to maximize the persistence of amphibian species and the functionality of the ecosystems that depend on them.FC
Distribution patterns of deep-sea benthopelagic fish off Algarve coast, Portugal
The present study characterises and compares the structure and diversity of the deep-sea benthopelagic
ichthyofauna off the southern Portuguese coast, according to the biomass values –in
kg/(nautical mile)2– of ten teleost and seven chondrichthyan species.
The differences between the biomass of benthopelagic species were assessed by depth interval
and sampling season. It seems clear that even at 100 m depth intervals there are differences within
the fish assemblages, and that a few species make most of the contribution to such differences.
No traces of seasonality or even differences between the sampling years have been found.
There is a separation between slope habitat
A comparison of staining techniques to improve precision of age estimation from fish otoliths
A total of 30 pairs of sagitta otoliths of horse mackerel Trachurus trachurus were sampled from three length‐classes, and five staining methods were applied to each pair. Ten age estimates were obtained per fish, method and length‐class. Significant differences in age estimates were found between methods, due to the variable enhancement in the otolith pattern produced by each method. A method using amido‐schwartz as the staining reagent produced the best results in terms of precision of the age estimates
Protected areas in Central Mexico - are they fit in promoting species persistence under climate and land use changes?
Protected areas are among the most widely accepted methods to set aside biodiversity from their most impinging threats. However, protected areas are not always located such that their positive impacts over biodiversity are maximized. This drawback is especially significant and uncontrolled when intense climate-change dynamics stresses local biodiversity equilibrium. This study aims to weight plausible evolutive scenarios (up to 2040) of PA-effectiveness to secure the most suitable climates for 94 vertebrate species in Central Mexico, a region that, historically, has faced large biodiversity turnover rates. Effectiveness was appraised at two scales. For a set of species, effectiveness expresses the spatial matching of established protected areas (ePAs) with top priority areas (T17) obtained from an optmised area-selection protocol. For each single species, effectiveness relates the predicted trends of climate suitable areas within ePAs/T17 with trends outside ePAs/T17. Results show that aprox.54% of ePAs area occur within T17 and species present variable responses, with suitability gains up to 10% and potential climate suitability losses of aprox.30% within ePAs. A considerable high amount of T17 (aprox.74%) is left unprotected. By assuming the high-valued component of past conservation efforts, this study delivers a double-guidance for planners and decision-makers. First, it pinpoints the ePAs that will demand further conservation investments in the upcoming years. Second, it identifies the unprotected regions where most active conservation actions are needed to supplement ePAs for a climate-effective protected area network. The framework here-proposed gives decision-makers the means to undertake effective and robust decisions in a dynamic and uncertain world
Operations Research and cost-effective spatial conservation planning: data, models, tools and future directions
Biodiversity conservation questions human practices towards biodiversity and, therefore, largely conflicts with ordinary societal aspirations. Decisions on the location of protected areas, one of the most convincing conservation tools, reflect such a competitive endeavor. Operations Research (OR) brings a set of analytical models and tools capable of resolving the conflicting interests between ecology and economy. Recent technological advances have boosted the size and variety of data available to planners, thus challenging conventional approaches bounded on optimized solutions. New models and methods are requested to use such a massive amount of data in integrative schemes addressing a large variety of concerns. Here, we provide an overview on the past, present and future challenges that characterize spatial conservation models supported by OR. By enlarging the spatial, temporal, taxonomic and societal horizons of biodiversity conservation planners navigate around multiple bio-socioeconomic equilibria and are able to decide on cost-effective strategies to improve biodiversity persistence
Spatial adaptive responses of highly threatened European mammal species under climate change
Current species’ range displacements are mostly triggered by climate change but European landscapes are largely dominated by human activities. In this study we identify the most promising spatial adaptive trajectories (SATs) for the thirty most threatened non volant mammal species in Europe up to 2080 (under three climate and land change scenarios) and where/when SATs of each species synchronically converge. We found large contrasts on the persistence of species in SATs, with some species largely reliant on the functionality of areas where many SATs converge. Overall, SATs and convergence centers are not adequately covered by existing conservation areas and coincide with crop and arable lands, compromising species persistence. It is important to invest in the protection of SATs and convergence centers through a mix of conventional instruments and new collaborative forms with the socio-economy. Anticipative plans at long-term coupled with risk analysis offer decision–makers templates to prevent negative surprises
Dynamic selection of dispersal pathways for species persistence under climate change
Ongoing climate change is already affecting distributions of many species. Future impacts of climate change are expected to be even greater. Conservation planning methodologies are usually based on the assumption that species distributions change relatively slowly unless they are directly affected by human activities, but this assumption is inappropriate under climate change. To address this problem, we develop a model that, assuming a fixed budget limiting the selection of areas devoted to conservation, selects areas for each of different periods of time, and indicates how species disperse between selected areas on successive periods. These areas are termed dispersal pathways. Their effectiveness is assessed based on the performance to retain species suitable climates over time, and on the ability of species to disperse between the areas. The model identifies maximum effective dispersal pathways, limited to some given budget. We applied the model to nine Iberian species and considered four climate change and budgetary scenarios. Climate change scenarios assuming reductions of greenhouse gas emissions had relatively modest gains in species retention areas. But larger budgets for area selection translate in significantly better retention levels. Nevertheless, our model identified species that, regardless the high conservation investment attained with unlimited budget, have a very limited ability to disperse to climatically suitable areas. Connectivity enhancement and assisted colonization could be considered for such cases
Linking habitats for multiple species
a b s t r a c t The establishment of linkages between habitats is of great importance to avert the detrimental impacts of land fragmentation and climate change on biodiversity. Linkages need to be cost-efficient, and should account for specific dispersal requirements of species. Since cost-efficient linkages defined independently for each individual species are more costly than linkages optimised for multiple species, there is need for methods specifically designed to retrieve efficient linkages for multiple species. MulTyLink (Multiple Type Linkages) is a Cþþ open source program that defines cost-efficient linkages free of barriers for the species considered, and that allows species-specific dispersal requirements to be considered. Here we present, discuss and illustrate the algorithms used by MulTyLink to identify costefficient linkages for multiple species
Revisiting the minimum set cover, the maximal coverage problems and a maximum benefit area selection problem to make climate‐change‐concerned conservation plans effective
1. Informed decisions for the selection of protected areas (PAs) are grounded in two general problems in Operations Research: the minimum set covering problem (minCost), where a set of ecological constraints are established as conservation targets and the minimum cost PAs are found, and the maximal coverage problem (maxCoverage) where the constraint is uniquely economic (i.e., a fixed budget) and the goal is to maximize the number of species having conservation targets adequately covered.
2. We adjust minCost and maxCoverage to accommodate the dynamic effects of climate change on species’ ranges. The selection of sites is replaced by the selection of time-ordered sequences of sites (climate change corridors), and an estimate of the persistence of each species in corridors is calculated according to the expected suitability of each site in the respective time period and the capacity of species to disperse between consecutive sites along corridors. In these problems, conservation targets are expressed as desired (and attainable) species persistence levels. We also introduce a novel problem (minShortfall) that combines minCost and maxCoverage. Unlike these two problems, minShortfall allows persistence targets to be missed and minimizes the sum of those gaps (i.e., target shortfalls), subject to a limited budget.
3. We illustrate the three problems with a case study using climatic suitability estimates for ten mammal species in the Iberian Peninsula under a climate change scenario until 2080. We compare solutions of the three problems with respect to species persistence and PA costs, under distinct settings of persistence targets, number of target-fulfilled species, and budgets. The solutions from different problems differed with regard to the areas to prioritize, their timings and the species whose persistence targets were fulfilled. This analysis also allowed identifying groups of species sharing corridors in optimal solutions, thus allowing important financial savings in site protection.
4. We suggest that enhancing species persistence is an adequate approach to cope with habitat shifts due to climate change. We trust the three problems discussed can provide complementary and valuable support for planners to anticipate decisions in order that the negative effects of climate change on species’ persistence are minimized