Species distribution modeling in the tropics: problems, potentialities, and the role of biological data for effective species conservation

In this paper we aim to investigate the problems and potentialities of species distribution modeling (SDM) as a tool for conservation planning and policy development and implementation in tropical regions. We reviewed 123 studies published between 1995 and 2007 in five of the leading journals in ecology and conservation, and examined two tropical case studies in which distribution modeling is currently being applied to support conservation planning. We also analyzed the characteristics of data typically used for fitting models within the specific context of modeling tree species distribution in Central America. The results showed that methodological papers outnumbered reports of SDMs being used in an applied context for setting conservation priorities, particularly in the tropics. Most applications of SDMs were in temperate regions and biased towards certain organisms such as mammals and birds. Studies from tropical regions were less likely to be validated than those from temperate regions. Unpublished data from two major tropical case studies showed that those species that are most in need of conservation actions, namely those that are the rarest or most threatened, are those for which SDM is least likely to be useful. We found that only 15% of the tree species of conservation concern in Central America could be reliably modelled using data from a substantial source (Missouri Botanical Garden VAST database). Lack of data limits model validation in tropical areas, further restricting the value of SDMs. We concluded that SDMs have a great potential to support biodiversity conservation in the tropics, by supporting the development of conservation strategies and plans, identifying knowledge gaps, and providing a tool to examine the potential impacts of environmental change. However, for this potential to be fully realized, problems of data quality and availability need to be overcome. Weaknesses in current biological datasets need to be systematically addressed, by increasing collection of field survey data, improving data sharing and increasing structural integration of data sources. This should include use of distributed databases with common standards, referential integrity, and rigorous quality control. Integration of data management with SDMs could significantly add value to existing data resources by improving data quality control and enabling knowledge gaps to be identified

An operational definition of the biome for global change research

CITATION: Conradi, T. et al. 2020. An operational definition of the biome for global change research. New Phytologist, 227:1294–1306, doi:10.1111/nph.16580.The original publication is available at https://nph.onlinelibrary.wiley.comBiomes are constructs for organising knowledge on the structure and functioning of the world’s ecosystems, and serve as useful units for monitoring how the biosphere responds to anthropogenic drivers, including climate change. The current practice of delimiting biomes relies on expert knowledge. Recent studies have questioned the value of such biome maps for comparative ecology and global-change research, partly due to their subjective origin. Here we propose a flexible method for developing biome maps objectively. The method uses range modelling of several thousands of plant species to reveal spatial attractors for different growth-form assemblages that define biomes. The workflow is illustrated using distribution data from 23 500 African plant species. In an example application, we create a biome map for Africa and use the fitted species models to project biome shifts. In a second example, we map gradients of growth-form suitability that can be used to identify sites for comparative ecology. This method provides a flexible framework that (1) allows a range of biome types to be defined according to user needs and (2) enables projections of biome changes that emerge purely from the individualistic responses of plant species to environmental changes.Publisher's versio

Investigating the ecological and economic consequences of marine climate change in UK waters

Climate change is of concern for both marine biodiversity and the human societies that are supported by it. Predictive models are required to assess potential responses of socio-ecological systems to climate change, implement measures to enhance their adaptability, and ensure the persistence of marine species and the livelihoods that depend on them. This requires a combination of modelling techniques, making use of a variety of data while dealing with uncertainty at many stages of the modelling procedure. This thesis explores the impact of climate change on a marine socio-ecological system, in particular through climate-induced shifts in species’ distributions. It further aims to explore sources of uncertainty in projecting models under climate change. Ecological and economic research techniques are applied to a set of species predominantly inhabiting UK waters, using projections of climate change for 2050. Ensemble projections suggest polewards shifts in species at an average rate of 27 and 42 km per decade for demersal and pelagic species respectively. Uncertainties concerning alternative, valid data sources and modelling procedures, notably species distribution models, contribute variation to predictions, and a multi-model approach is advocated to incorporate uncertainties and prevent bias through model selection. Predictions help identify increased risk of over-fishing through bycatch and indicate likely changes in environmental suitability of protected areas. Results also demonstrate how an index of agreement may be used to promote the tractability and application of projections by non-specialist communities. Furthermore, total maximum catch potential within UK waters is predicted to decrease by 2050, resulting in a median decrease in profitability between 2005 and 2050 of 10%, dependent on alterations in key costs such as fuel price. This thesis highlights the tight link between climate change impacts at ecological and socio-economic levels. Although adaptive capacity might be enhanced by switching gear or altering fishing patterns, rebuilding fish stocks to sustainable level will both improve their resilience to multiple threats and improve the resilience of fishers to withstand changes in distribution and catch

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

Ecological Connectivity for Amphibians Under Climate Change

Campos, F. S., Lourenço-de-Moraes, R., Ruas, D. S., Mira-Mendes, C. V., Franch, M., Llorente, G. A., ... Cabral, P. (2019). Searching for Networks: Ecological Connectivity for Amphibians Under Climate Change. Environmental Management, 65(1), 46-61. https://doi.org/10.1007/s00267-019-01240-0Ecological connectivity depends on key elements within the landscape, which can support ecological fluxes, species richness and long-term viability of a biological community. Landscape planning requires clear aims and quantitative approaches to identify which key elements can reinforce the spatial coherence of protected areas design. We aim to explore the probability of the ecological connectivity of forest remnants and amphibian species distributions for current and future climate scenarios across the Central Corridor of the Brazilian Atlantic Forest. Integrating amphibian conservation, climate change and ecological corridors, we design a landscape ranking based on graph and circuit theories. To identify the sensitivity of connected areas to climate-dependent changes, we use the Model for Interdisciplinary Research on Climate by means of simulations for 2080–2100, representing a moderated emission scenario within an optimistic context. Our findings indicate that more than 70% of forest connectivity loss by climate change may drastically reduce amphibian dispersal in this region. We show that high amphibian turnover rates tend to be greater in the north-eastern edges of the corridor across ensembles of forecasts. Our spatial analysis reveals a general pattern of low-conductance areas in landscape surface, yet with some well-connected patches suggesting potential ecological corridors. Atlantic Forest reserves are expected to be less effective in a near future. For improved conservation outcomes, we recommend some landscape paths with low resistance values across space and time. We highlight the importance of maintaining forest remnants in the southern Bahia region by drafting a blueprint for functional biodiversity corridors.authorsversionpublishe

Impact of climate change on extinction risk of montane tree species.

The potential impacts of climate change on many species worldwide remains unknown, especially in those tropical regions that are centers of endemism and are highly biodiverse. This thesis provides an insight into the extinction risk of selected tree species using different species distribution modelling techniques and reviewing the current conservation status on montane forest in the Tropical Andes. Starting with a global analysis, the potential impacts of climate change on montane ecoregions is investigated, by identifying those that are more vulnerable to the expected changes in temperature and precipitation, from global predictions under different climate change scenarios. It then gives an insight on the current and potential threats to biodiversity in the Andean region, including the identification of those that are most likely to be responsible for increasing the extinction risk of the species. With the use of the IUCN Red List Categories and Criteria, selected tree species were assessed to identify their extinction risk. Information on the species’ current distribution was collated and used to estimate their potential distribution under climate change, by using different modelling techniques. These results were used to reassess the species using the IUCN Red List and establish the changes in Red List Category. Lastly, it provides a discussion that integrates all the results obtained throughout the thesis, to explore the implications for conservation, in order to highlight the overriding importance of including threatened tree species to target conservation efforts in the region, while considering the uncertainties that surround predictions under climate change scenarios, modelling techniques and the use of the IUCN Red List

Species distribution modeling in the tropics: problems, potentialities, and the role of biological data for effective species conservation

In this paper we aim to investigate the problems and potentialities of species distribution modeling (SDM) as a tool for conservation planning and policy development and implementation in tropical regions. We reviewed 123 studies published between 1995 and 2007 in five of the leading journals in ecology and conservation, and examined two tropical case studies in which distribution modeling is currently being applied to support conservation planning. We also analyzed the characteristics of data typically used for fitting models within the specific context of modeling tree species distribution in Central America. The results showed that methodological papers outnumbered reports of SDMs being used in an applied context for setting conservation priorities, particularly in the tropics. Most applications of SDMs were in temperate regions and biased towards certain organisms such as mammals and birds. Studies from tropical regions were less likely to be validated than those from temperate regions. Unpublished data from two major tropical case studies showed that those species that are most in need of conservation actions, namely those that are the rarest or most threatened, are those for which SDM is least likely to be useful. We found that only 15% of the tree species of conservation concern in Central America could be reliably modelled using data from a substantial source (Missouri Botanical Garden VAST database). Lack of data limits model validation in tropical areas, further restricting the value of SDMs. We concluded that SDMs have a great potential to support biodiversity conservation in the tropics, by supporting the development of conservation strategies and plans, identifying knowledge gaps, and providing a tool to examine the potential impacts of environmental change. However, for this potential to be fully realized, problems of data quality and availability need to be overcome. Weaknesses in current biological datasets need to be systematically addressed, by increasing collection of field survey data, improving data sharing and increasing structural integration of data sources. This should include use of distributed databases with common standards, referential integrity, and rigorous quality control. Integration of data management with SDMs could significantly add value to existing data resources by improving data quality control and enabling knowledge gaps to be identified