29 research outputs found
Distribution patterns of deep-sea benthopelagic fish off the 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 habitats from 400-700 m depth and deeper ones, determined by a change in fish communities.Se han caracterizado y comparado la estructura y la diversidad de la ictiofauna nectobentónica de los fondos oceánicos de la costa sur de Portugal a partir de los valores de biomasa -en kg/(milla náutica)²- de diez especies de teleósteos y siete especies de condrictios. Las diferencias de biomasa entre las distintas especies nectobentónicas encontradas fueron determinadas por intervalos de profundidad y épocas de muestreo. Los resultados vienen a demostrar que, incluso por intervalos de profundidad de 100 m, hay diferencias significativas entre las comunidades de peces, y que hay algunas especies que contribuyen en la mayoría de estas diferencias. Sin embargo, no se pudo encontrar ninguna diferencia significativa entre épocas y tampoco entre los años de muestreo. Existe una separación entre los tipos de habitat del talud entre 400-700 m de profundidad y otros situados en zonas más profundas, resultado de un cambio en las comunidades piscícolas.Instituto Español de Oceanografí
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
An assessment of the state of conservation planning in Europe
Expanding and managing current habitat and species protection measures is at the heart of the European biodiversity strategy. A structured approach is needed to gain insights into such issues is systematic conservation planning, which uses techniques from decision theory to identify places and actions that contribute most effectively to policy objectives given a set of constraints. Yet culturally and historically determined European landscapes make the implementation of any conservation plans challenging, requiring an analysis of synergies and trade-offs before implementation. In this work, we review the scientific literature for evidence of previous conservation planning approaches, highlighting recent advances and success stories. We find that the conceptual characteristics of European conservation planning studies likely reduced their potential in contributing to better-informed decisions. We outline pathways towards improving the uptake of decision theory and multi-criteria conservation planning at various scales, particularly highlighting the need for (a) open data and intuitive tools, (b) the integration of biodiversity-focused conservation planning with multiple objectives, (c) accounting of dynamic ecological processes and functions, and (d) better facilitation of entry-points and co-design practices of conservation planning scenarios with stakeholders. By adopting and improving these practices, European conservation planning might become more actionable and adaptable towards implementable policy outcomes
Linking like with like: optimising connectivity between environmentally-similar habitats
Habitat fragmentation is one of the greatest
threats to biodiversity. To minimise the effect of fragmentation on biodiversity, connectivity between otherwise isolated habitats should be promoted. However,
the identification of linkages favouring connectivity is not trivial. Firstly, they compete with other land uses, so they need to be cost-efficient. Secondly, linkages for one species might be barriers for others, so they should effectively account for distinct mobility requirements. Thirdly, detailed information on the auto-ecology of most of the species is lacking, so linkages need being defined based on surrogates. In order to address these challenges we develop a
framework that (a) identifies environmentally-similar habitats; (b) identifies environmental barriers (i.e.,
regions with a very distinct environment from the areas to be linked), and; (c) determines cost-efficient linkages between environmentally-similar habitats, free from environmental barriers. The assumption is that species with similar ecological requirements occupy the same environments, so environmental similarity provides a rationale for the identification of the areas
that need to be linked. A variant of the classical minimum Steiner tree problem in graphs is used to address c). We present a heuristic for this problem that is capable of handling large datasets. To illustrate the
framework we identify linkages between environmentally-similar protected areas in the Iberian Peninsula. The Natura 2000 network is used as a positive ‘attractor’ of links while the human footprint is used as ‘repellent’ of links.Wecompare the outcomes of our approach with cost-efficient networks linking protected areas that disregard the effect of environmental
barriers. As expected, the latter achieved a smaller area covered with linkages, but with barriers that can significantly reduce the permeability of the landscape for the dispersal of some species
Updating known distribution models for forecasting climate change impact on endangered species
To plan endangered species conservation and to design adequate management programmes, it is necessary to predict their
distributional response to climate change, especially under the current situation of rapid change. However, these
predictions are customarily done by relating de novo the distribution of the species with climatic conditions with no regard
of previously available knowledge about the factors affecting the species distribution. We propose to take advantage of
known species distribution models, but proceeding to update them with the variables yielded by climatic models before
projecting them to the future. To exemplify our proposal, the availability of suitable habitat across Spain for the endangered
Bonelli’s Eagle (Aquila fasciata) was modelled by updating a pre-existing model based on current climate and topography to
a combination of different general circulation models and Special Report on Emissions Scenarios. Our results suggested that
the main threat for this endangered species would not be climate change, since all forecasting models show that its
distribution will be maintained and increased in mainland Spain for all the XXI century. We remark on the importance of
linking conservation biology with distribution modelling by updating existing models, frequently available for endangered
species, considering all the known factors conditioning the species’ distribution, instead of building new models that are
based on climate change variables only.Ministerio de Ciencia e Innovación and FEDER (project CGL2009-11316/BOS
The performance of Protected Areas for biodiversity under climate change
Global environmental changes have been driving large-scale shifts in the distributions of species and in the composition of biological communities. This has thrown the continuing value of Protected Areas (PAs) into question, given that PAs remain static, whereas species move, and they are predicted to continue to move under future climate scenarios. We consider empirical evidence on the observed performance of PAs during the last 40 years of anthropogenic climate change. Despite some losses of populations and species, PAs have continued to accommodate many species, which have shifted to higher elevations, to polewards-facing aspects, and into cooler microhabitats within PAs as the climate has warmed. Even when species have declined in some PAs, they often remain more abundant inside than outside PAs. Furthermore, losses from some PAs are offset by increases in others. As species expand their ranges polewards across fragmented landscapes in response to climate warming, the majority are disproportionately colonizing PAs as they go. Hence, PA networks are acting as stepping-stones of suitable breeding conditions and facilitating range shifts, with many species remaining protected across PA networks as a whole. Finally, there is some evidence that appropriate management of PAs may be able to slow climate-related declines and accelerate expansions. The 40-year track record of species responding to environmental change in PAs suggests that networks of PAs have been essential to biodiversity conservation and are likely to continue to fulfil this role in the future. The challenge for managers will be to consider the balance between retaining current species and encouraging colonization by new species
Projected Range Contractions of European Protected Oceanic Montane Plant Communities: Focus on Climate Change Impacts Is Essential for Their Future Conservation
Global climate is rapidly changing and while many studies have investigated the potential impacts of this on the distribution of montane plant species and communities, few have focused on those with oceanic montane affinities. In Europe, highly sensitive bryophyte species reach their optimum occurrence, highest diversity and abundance in the northwest hyperoceanic regions, while a number of montane vascular plant species occur here at the edge of their range. This study evaluates the potential impact of climate change on the distribution of these species and assesses the implications for EU Habitats Directive-protected oceanic montane plant communities. We applied an ensemble of species distribution modelling techniques, using atlas data of 30 vascular plant and bryophyte species, to calculate range changes under projected future climate change. The future effectiveness of the protected area network to conserve these species was evaluated using gap analysis. We found that the majority of these montane species are projected to lose suitable climate space, primarily at lower altitudes, or that areas of suitable climate will principally shift northwards. In particular, rare oceanic montane bryophytes have poor dispersal capacity and are likely to be especially vulnerable to contractions in their current climate space. Significantly different projected range change responses were found between 1) oceanic montane bryophytes and vascular plants; 2) species belonging to different montane plant communities; 3) species categorised according to different biomes and eastern limit classifications. The inclusion of topographical variables in addition to climate, significantly improved the statistical and spatial performance of models. The current protected area network is projected to become less effective, especially for specialised arctic-montane species, posing a challenge to conserving oceanic montane plant communities. Conservation management plans need significantly greater focus on potential climate change impacts, including models with higher-resolution species distribution and environmental data, to aid these communities’ long-term survival
Introducing Spatio-Temporal Conservation Units: Models for Flexible Optimization of Species Persistence Under Climate Change
Anticipating the effects of climate change on biodiversity and integrating them in planning protocols for the future are fundamental strategies to increase the effectiveness of conservation efforts. With climate change, species require dispersal skills to follow displacements of their suitable climates and therefore, spatial conservation interventions need to consider such dynamics. In general, common planning frameworks identify networks of conservation areas seemed important for species range shifts. However, it is highly unlikely that all the areas in a network present synchronous conservation value. Furthermore, given the continuous (spatial and temporal autocorrelated) nature of threats and ecological processes, the value of each area is largely dependent on the state of the neighboring areas in the recent past. In this study, a family of three models centered on the prioritization (not of single areas but) of temporal chains of areas as conservation units is presented. These models drive the use of financial investments through time in order to maximize the persistence of biodiversity in dynamic environments. Alike the most typical approaches, the here introduced models allow investments to be transferred between areas losing conservation relevancy to the areas that gain relevancy. A fictitious (but plausible) conservation plan for ten mammal species in Iberian Peninsula up to 2080 is used to illustrate the setting-up and outputs of the models. Results evidence that the conservation effectiveness achieved in each model depends on singular spatio-temporal distribution relationships among species and between species and distinct land-uses. Planners should then investigate the sensitivity of their goals to distinct decision-support tools even when driven by similar designs and constraints
Cost-effective monitoring of biological invasions under global change: a model-based framework
1. Ecological monitoring programmes are designed to detect and measure changes in biodiversity and ecosystems. In the case of biological invasions, they can contribute to anticipating risks and adaptively managing invaders. However, monitoring is often expensive because large amounts of data might be needed to draw inferences. Thus, careful planning is required to ensure that monitoring goals are realistically achieved.
2. Species distribution models (SDMs) can provide estimates of suitable areas to invasion. Predictions from these models can be applied as inputs in optimization strategies seeking to identify the optimal extent of the networks of areas required for monitoring risk of invasion under current and future environmental conditions. A hierarchical framework is proposed herein that combines SDMs, scenario analysis and cost analyses to improve invasion assessments at regional and local scales. We illustrate the framework with Acacia dealbata Link. (Silver-wattle) in northern Portugal. The framework is general and applicable to any species.
3. We defined two types of monitoring networks focusing either on the regional-scale management of an invasion, or management focus within and around protected areas. For each one of these two schemes, we designed a hierarchical framework of spatial prioritization using different information layers (e.g. SDMs, habitat connectivity, protected areas). We compared the performance of each monitoring scheme against 100 randomly generated models.
4. In our case study, we found that protected areas will be increasingly exposed to invasion by A. dealbata due to climate change. Moreover, connectivity between suitable areas for A. dealbata is predicted to increase. Monitoring networks that we identify were more effective in detecting new invasions and less costly to management than randomly generated models. The most cost-efficient monitoring schemes require 18% less effort than the average networks across all of the 100 tested options.
5. Synthesis and applications. The proposed framework achieves cost-effective monitoring networks, enabling the interactive exploration of different solutions and the combination of quantitative information on network performance with orientations that are rarely incorporated in a decision support system. The framework brings invasion monitoring closer to European legislation and management needs while ensuring adaptability under rapid climate and environmental change
New Paradigms for Modern Biogeography Conservation
Biodiversity conservation is a relatively recent, synthetic field that applies the principles of ecology, biogeography, population genetics, economics, sociology, anthropology, philosophy, and other theoretical disciplines to the maintenance of biodiversity worldwide.
Conservation biogeography concerns the application of biogeographical principles, theories, and analyses, being those concerned with the distributional dynamics of taxonomic units individually and collectively up with their relevant limiting processes, to problems concerning biodiversity conservation.
Systematic conservation planning is a comprehensive and scientifically sound method aimed at providing decision support for choices between alternate conservation actions. Spatially, it entails a set of stages for choosing, locating, configuring, and implementing conservation actions (protected areas in particular), such that the benefits of the actions therein exceed specified amounts of ideal protection of biodiversity features and processes. Optimization procedures are key in providing planners the very best efficient and effectiveness solutions.
Aichi Target 11 refers to a global protected area coverage target, established under the Convention on Biological Diversity in 2010. It states that, by 2020, at least 17% of terrestrial areas and 10% of coastal and marine areas need to be protected through effective, ecologically representative and well-connected systems of protected areas and other effective area-based conservation measures. For 2030 a new target is being developed with preliminary advices supporting a 30% protected area coverage for both terrestrial and coastal/marine realms.
Global change entangles the worldwide impact of human activity on the key processes that govern the functioning of the biosphere. These include the climate system, stability of the ozone layer, cycles of elements and materials (such as nitrogen, carbon, phosphorus, or water), the balance and distribution of species, and ecosystems and their underlying processes