Bioclimatic Suitability Research Articles

Using species distribution models to locate the potential cradles of the allopolyploid Gypsophila bermejoi G. López (Caryophyllaceae).

Polyploidy has been an influential force in plant evolution, playing a crucial role in diversification. Differences in polyploid and diploid distributions have been long noted, with polyploid taxa especially abundant in harsh environments. These plants have higher photosynthetic rates and/or higher tolerance to water deficits. Moreover, there is data pointing to an increase in the rate of unreduced gamete formation by plants under conditions of stress. Accordingly, a higher frequency of polyploid individuals would be expected in populations living under extreme environments, a phenomenon that may be relevant when considering the origin of allopolyploid species. Hybridization between distinct autopolyploids is known to produce allopolyploids and hence, a high frequency of compatible autopolyploids in an area could enhance the formation of stable populations of the corresponding allopolyploid hybrid. Here we consider the allopolyploid species Gypsophila bermejoi G. López and its parental taxa G. struthium L. subsp. struthium and G. tomentosa L. We have used Species Distribution Models to locate areas with low bioclimatic suitability for both parental taxa during the Last Glacial Maximum (LGM), hypothesizing that the rate of tetraploid hybrid formation would be higher than expected where low suitability areas of both parental species overlap. We selected those areas taking into account the strict gypsophyllic nature of these taxa. There is data pointing to a post-glacial origin of the current G. bermejoi populations and according to our hypothesis, such locations could be centers for hybrid tetraploid formation or potential cradles of this species. Indeed, potential Mid-Holocene cradles were also identified in this manner. The evolution of bioclimatic suitability in both LGM and Mid-Holocene cradles was studied to assess the possible survival of the hybrids, and the current distribution of G. bermejoi proved to be consistent with our hypothesis.

Global bioclimatic suitability for the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), and potential co-occurrence with major host crops under climate change scenarios

The fall armyworm, Spodoptera frugiperda, is a highly invasive species native to North America that is rapidly spreading to other parts of the world. Since its first discovery outside its native range, the species has rapidly spread to more than 26 countries in Africa and has been recently discovered in India, demonstrating its high potential to spread and invade. This species can have massive damage to crops, especially maize, posing major socioeconomic challenges. While its spread is attributed to transportation in fruits and vegetables, its invasiveness is attributed to its high capacity to adapt in different environments. With expected climate change scenarios, it is possible that this species will invade other areas to the planet, thus increasing the damage to major agricultural crops. This paper aims to understand the global potential for the spread of the species and its associated impacts on major host plants, globally. For this, the article is based on modelling the distribution of species, combining records of occurrence of species globally and bioclimatic variables to identify the areas that are climatically suitable for species in present and future scenarios under climate change. Simulations indicate that there is an enormous climatic potential for the spread of the species, with potential increases between 12 and 44% in the future, mostly affecting border areas between the USA and Canada, Sub-Saharan Africa and central Europe. This spread will increase the potential for interactions between the fall armyworm and its main host plants, thus increasing the potential crop damage globally.

Distribution of Bactrocera oleae (Rossi, 1790) throughout the Iberian Peninsula based on a maximum entropy modelling approach

AbstractThe Iberian Peninsula (Portugal and Spain) is a great production area of olives. The fruit production can be severely affected by the olive fruit fly, Bactrocera oleae (Rossi, 1790) (Diptera). Detailed geographical distribution maps of key pests, such as B. oleae, are essential for their integrated management. Although different sources reporting the occurrence of B. oleae are available for sub‐regions of Portugal and Spain, the data available are dispersed and centralisation of this information considering the Iberian Peninsula as a faunistic geographical unit is currently lacking. In this work, we built two distribution maps of B. oleae throughout the Iberian Peninsula, one based on occurrence sites and another based on its bioclimatic habitat suitability. After modelling the bioclimatic suitability of B. oleae using a maximum entropy model, three potential distribution areas beyond the previously known occurrence range of the olive fruit fly were identified corresponding to the autonomous community of Galicia (Spain), the Spanish and Portuguese sides of the International Douro Natural Park, and the autonomous community of Castilla y León (Spain). Interestingly, each region houses nowadays autochthonous olive cultivars. The drivers that most contributed to the model were the precipitation of the coldest quarter and the precipitation of driest month which agrees with the B. oleae bioecology. Although our approach is not fully‐comprehensive in terms of occurrence sites, we show how a maxent modelling approach can be useful to identify potential risk areas of B. oleae occurrence throughout a target geographical extent such as the Iberian Peninsula.

Geographic shifts in the bioclimatic suitability for Aedes aegypti under climate change scenarios in Colombia

The Dengue, Chikungunya and Zika viruses are arboviruses predominantly transmitted to humans through the bite of the female mosquito Aedes aegypti. Currently, the vector represents a potential epidemiological risk in several Latin American and Pacific countries. However, little is known about the geographical distribution and bioclimatic suitability of this mosquito in the projected climate change scenarios in Colombia. Using a species distribution model of maximum entropy (MaxEnt) based on presence-only records obtained from Global Biodiversity Information Facility (GBIF), land elevation obtained from Shuttle Radar Topography Mission (SRTM) and bioclimatic variables (WorldClim), we produced environmental suitability maps of this mosquito vector for present and future geographic distribution. The future distribution were constructed based on the Community Climate System Model (CCSM4) for the years 2050 and 2070, projected according to the Representative Concentration Pathways (RCP) 2.6, 4.5 and 8.5 described by the Intergovernmental Panel on Climate Change (IPCC). For the current conditions, Colombia has ~140,612.8 square km of areas with the possible presence of the vector; however, for the future, this will be reduced by more than 30%. For the future conditions, the suitable areas for A. aegypti decreased compared to the present, mainly for the year 2070 under RCP scenarios 4.5 and 8.5, however, the probability of mosquito occurrence increases in some departments of Colombia. Areas susceptible to the presence of A. aegypti are affected by climate change. The Caribbean and Andean regions have a high probability of mosquito distribution; therefore, control and epidemiological surveillance are required in these areas. The results can serve as an input to define preventive and control measures, especially in areas with a higher risk of contracting the virus.

Four climate change scenarios for Gypsophila bermejoi G. López (Caryophyllaceae) to address whether bioclimatic and soil suitability will overlap in the future.

Climate change has altered the global distribution of many species. Accordingly, we have assessed here the potential shift in the distribution of Gypsophila bermejoi G. López under distinct scenarios of future climate change, this being a species endemic to the Iberian Peninsula. For strict gypsophiles, climatic changes affecting their potential area of distribution could be critical if the new range is not overlapped with suitable soils. Thus, the narrow bioclimatic niche and the endemic nature of this plant could make this species particularly vulnerable to climate change. We used the Maximum Entropy (MaxEnt) method to study the potential distribution of this taxon under four different scenarios of climate change, pin-pointing relevant changes in the potential distribution of this plant and enabling possible future areas of refuge to be assessed. Such scenarios are defined according to four Representative Concentration Pathways (RCPs) [, which represent different trends in the concentration of atmospheric carbon dioxide. As a result, we predict notable changes in the potential distribution of G. bermejoi, and the overlap between soil and bioclimatic suitability would be affected. We also used a Principal Component Analysis (PCA) to model the bioclimatic niche of this species, comparing it with that of its parental taxa. The evolution of bioclimatic suitability was assessed at the current locations of G. bermejoi and as this plant is a strict gypsophile, we generated suitability maps for sites with gypsum soils. Ultimately, this study identifies relevant changes in the potential distribution of G. bermejoi under specific climatic scenarios, observing remarkable differences in the outcomes of the different climate change scenarios. Interestingly, in some scenarios the bioclimatic suitability of G. bermejoi will be enhanced at many locations and even in the worst scenario some possible refuge areas were identified. G. bermejoi behaves more like a hardy survivor than as early victim.

Comparison of model selection technique performance in predicting the spread of newly invasive species: a case study with Batrachochytrium salamandrivorans

Species distribution models (SDMs) increasingly have been used to anticipate the spread of invasive species. However, these models are powerful conservation tools only if they are biologically relevant, and thus validation of these models is essential. Here, we evaluate four model selection frameworks for their ability to identify a best fit model of spread under low data conditions early in an invasion, specifically testing the efficacy of methods that utilize absence data in addition to presence data in evaluating models. We test this question using a simulation where we generated data with varying confidence in the accuracy of the absence data, as absences in early invasions may become presences in the future, and increasing quantity of observation data to test the models. We create these simulations based on a real-world example of a newly emergent, invasive fungal pathogen, Batrachochytrium salamandrivorans (Bsal). The simulation demonstrated that AIC and Likelihood consistently outperform both Kappa and AUC in selecting the true model as the best model when data are limited and absence data are low quality, with AIC providing the most conservative results due to penalties for overparameterization. With these results, we then used these techniques to compare five candidate models for predicting the spread of Bsal. Consistent with the simulation, the best fit model of the candidate models for Bsal was inconsistent across the four metrics. However, AIC, which performed best in the simulation study, suggested that the spread of Bsal into Western Europe was best predicted by a combination of bioclimatic suitability, salamander richness, and number of salamander imports. Our results highlight the difficulty in evaluating predictive models when data are limited and of low quality, as with a newly invasive species, but show that these challenges can be partially addressed with the appropriate model selection approach. Use of this approach is critical as SDMs of invasive species are often used to inform conservation policy and efforts before the invasion spreads, when limited data are available.

Historical and event-based bioclimatic suitability predicts regional forest vulnerability to compound effects of severe drought and bark beetle infestation.

Vulnerability to climate change, and particularly to climate extreme events, is expected to vary across species ranges. Thus, we need tools to standardize the variability in regional climatic legacy and extreme climate across populations and species. Extreme climate events (e.g., droughts) can erode populations close to the limits of species' climatic tolerance. Populations in climatic-core locations may also become vulnerable because they have developed a greater demand for resources (i.e., water) that cannot be enough satisfied during the periods of scarcity. These mechanisms can become exacerbated in tree populations when combined with antagonistic biotic interactions, such as insect infestation. We used climatic suitability indices derived from Species Distribution Models (SDMs) to standardize the climatic conditions experienced across Pinus edulis populations in southwestern North America, during a historical period (1972-2000) and during an extreme event (2001-2007), when the compound effect of hot drought and bark beetle infestation caused widespread die-off and mortality. Pinus edulis climatic suitability diminished dramatically during the die-off period, with remarkable variation between years. P.edulis die-off occurred mainly not just in sites that experienced lower climatic suitability during the drought but also where climatic suitability was higher during the historical period. The combined effect of historically high climatic suitability and a marked decrease in the climatic suitability during the drought best explained the range-wide mortality. Lagged effects of climatic suitability loss in previous years and co-occurrence of Juniperus monosperma also explained P.edulis die-off in particular years. Overall, the study shows that past climatic legacy, likely determining acclimation, together with competitive interactions plays a major role in responses to extreme drought. It also provides a new approach to standardize the magnitude of climatic variability across populations using SDMs, improving our capacity to predict population's or species' vulnerability to climatic change.

Potential spatial interaction of the invasive species Harmonia axyridis (Pallas) with native and endemic coccinellids

AbstractBiological invasions represent a serious menace to local species assemblages, mainly due to interspecific relationships such as competition and predation. One important invasive species worldwide is Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), which has invaded many regions of the world, threatening the native and endemic coccinellid assemblages due to negative interspecific interactions. These interactions have been widely studied at a local scale, but have been less studied at regional scales. Our aim was to estimate and analyse the potential spatial interaction associated with the co‐occurrence of H. axyridis with native and endemic species in Chile, considering bioclimatic and land cover variables. First, we created species distribution models (SDM) for H. axyridis, native and endemic coccinellids and six representative coccinellid species using maximum entropy technique. Then, we overlapped each SDM with land cover types to estimate the bioclimatic suitability within each land cover type. Finally, we identified the co‐occurrences of organisms according to the SDM and the land cover types, estimating in what land covers H. axyridis and the other coccinellids are more likely to co‐occur. Our results show that the suitable area for H. axyridis occurs from 30° to 42°S in Chile, while for native and endemic species this area is greater. The six selected species are mainly concentrated in central Chile, but differ in their potential suitable areas; Adalia angulifera Mulsant and Scymnus bicolor (Germain) have the largest range, and Mimoscymnus macula (Germain) has the most restricted one. The highest level of potential spatial interactions with H. axyridis occurs in central Chile, specifically in croplands and scrublands, and the lowest in primary native forest for all the species. Our results provide a spatially explicit baseline for coccinellid conservation and management of this invasive species.

Zika: Probability of establishment of its vector, Aedes aegypti, in Chile

The Zika virus has raised world alarm in recent years, representing a major public health problem. In this study we evaluated the potential risk of exposure to Zika virus in Chile, associated with the probability of establishment of the vector Aedes aegypti in the country. Niche modelling techniques were used to project the bioclimatic requirements of the vector (global niches), identifying zones of high suitability for the species within the country. Then, the potential distribution of the vector in Chile was overlapped with the human population density, estimating the risk associated to the potential co-occurrence of both in a spatially explicit manner. We identified bioclimatic suitability for A. aegypti in continental Chile, from the northern tropical area to temperate regions, mainly in coastal zones. The exposed population could reach 1.8 million people, with 1.3 million in a medium level of potential risk and 21,000 in a high level. These results support that there is a significant probability of success for the Zika virus main vector to colonize continental Chile in case of an introduction. Therefore, prevention, monitoring, and control play an important role in avoiding the arrival of this vector to our country.

Projections of Future Suitable Bioclimatic Conditions of Parthenogenetic Whiptails

This paper highlights the results of bioclimatic-envelope modeling of whiptail lizards belonging to the Aspidoscelis tesselata species group and related species. We utilized five species distribution models (SDM) including Generalized Linear Model, Random Forest, Boosted Regression Tree, Maxent and Multivariate Adaptive Regression Splines to develop the present day distributions of the species based on climate-driven models alone. We then projected future distributions of whiptails using data from four climate models run according to two greenhouse gas concentration scenarios (RCP 4.5 and RCP 8.5). Results of A. tesselata species group suggested that climate change will negatively affect the bioclimatic habitat and distribution of some species, while projecting gains in suitability for others. Furthermore, when the species group was analyzed together, climate projections changed for some species compared to when they were analyzed alone, suggesting significant loss of syntopic areas where suitable climatic conditions for more than two species would persist. In other words, syntopy within members of the species group will be drastically reduced according to future bioclimatic suitability projections in this study.

Climate change and biological invasions: evidence, expectations, and response options.

A changing climate may directly or indirectly influence biological invasions by altering the likelihood of introduction or establishment, as well as modifying the geographic range, environmental impacts, economic costs or management of alien species. A comprehensive assessment of empirical and theoretical evidence identified how each of these processes is likely to be shaped by climate change for alien plants, animals and pathogens in terrestrial, freshwater and marine environments of Great Britain. The strongest contemporary evidence for the potential role of climate change in the establishment of new alien species is for terrestrial arthropods, as a result of their ectothermic physiology, often high dispersal rate and their strong association with trade as well as commensal relationships with human environments. By contrast, there is little empirical support for higher temperatures increasing the rate of alien plant establishment due to the stronger effects of residence time and propagule pressure. The magnitude of any direct climate effect on the number of new alien species will be small relative to human-assisted introductions driven by socioeconomic factors. Casual alien species (sleepers) whose population persistence is limited by climate are expected to exhibit greater rates of establishment under climate change assuming that propagule pressure remains at least at current levels. Surveillance and management targeting sleeper pests and diseases may be the most cost-effective option to reduce future impacts under climate change. Most established alien species will increase their distribution range in Great Britain over the next century. However, such range increases are very likely be the result of natural expansion of populations that have yet to reach equilibrium with their environment, rather than a direct consequence of climate change. To assess the potential realised range of alien species will require a spatially explicit approach that not only integrates bioclimatic suitability and population-level demographic rates but also simulation of landscape-level processes (e.g. dispersal, land-use change, host/habitat distribution, non-climatic edaphic constraints). In terms of invasive alien species that have known economic or biodiversity impacts, the taxa that are likely to be the most responsive are plant pathogens and insect pests of agricultural crops. However, the extent to which climate adaptation strategies lead to new crops, altered rotations, and different farming practices (e.g. irrigation, fertilization) will all shape the potential agricultural impacts of alien species. The greatest uncertainty in the effects of climate change on biological invasions exists with identifying the future character of new species introductions and predicting ecosystem impacts. Two complementary strategies may work under these conditions of high uncertainty: (i) prioritise ecosystems in terms of their perceived vulnerability to climate change and prevent ingress or expansion of alien species therein that may exacerbate problems; (ii) target those ecosystem already threatened by alien species and implement management to prevent the situation deteriorating under climate change.

Systems to establish bioclimatic analogies to predict the area of adaptability of plant species to new environments: The case of Moringa oleifera Lam. in Chile

Adaptability of a species to new territories is generally assessed by costly trial and error in situ experiments distributed throughout different agroclimatic environments. Nowadays climatic data are available to allow the construction of climatic maps based on data provided through world or local networks of climatic weather stations. The objective of this work was to establish a bioclimatic protocol, based on current and available sources of climate information, to make rapid surveys of suitability for plant species in a given environment. Moringa oleifera Lam. species, native from India, was chosen considering its rusticity and the increasing interest on this species due to its multiple uses, nutritional value, and medicinal properties. The first phase of this work was a compilation of data from climatic downscaling (WorldClim), University of East Anglia database (CRU), FAO database, and an historic datasets from Chilean meteorological stations. This information was used to test two different models to compare bioclimatic profiles, considering relevant climatic variables for plant adaptation: maximum and minimum temperatures, accumulated degree days, frost regime, and air humidity. The first approach, based on climatic analogy, was to compare each of these variables between Chilean and foreign localities, and the second, based on bioclimatic suitability, focus on the degree of meeting the minimum bioclimatic requirements by the species in each locality. This paper provides some tools to make this kind of comparisons. Both approaches were tested using M. oleifera as target. Both approaches were complementary and prove to be useful for identifying potential areas where the species could be cultivated. The use of these approaches suggested the existence of some bioclimatic suitability for this species in the coastal areas with mild winters and frosts, from 27° to 37° S lat.

Incidencia del clima local en los procesos de planificación territorial: Análisis bioclimático de la Costa del Sol Occidental de Málaga (España)

Normal 0 21 false false false MicrosoftInternetExplorer4 Frente al excesivo consumo energetico en el acondicionamiento termico residencial, este estudio investiga la implicancia del clima local en las estrategias de expansion urbana, asi como su grado de afeccion a las condiciones de confort, en el contexto mediterraneo espanol de la Costa del Sol Occidental. Para ello se realiza un analisis bioclimatico territorial, identificando los diversos climas locales existentes y las diferentes respuestas biologicas asociadas a cada uno de ellos. Con estos resultados se elabora una clasificacion del lugar desde la optica de la idoneidad bioclimatica. Esta herramienta ha permitido evaluar los procesos de planificacion territorial, concluyendose que el 80,6% del suelo urbano y urbanizable no se beneficia de las condiciones climaticas mas favorables, las cuales constituyen el 47,3% del territorio analizado. Esta informacion, puesta al servicio de mejorar las condiciones termicas de las ciudades, puede ser util en el diseno y distribucion de futuras areas urbanas.

Conservation of grassland butterflies in Finland under a changing climate

This paper examines the potential impact of climate change on grassland butterfly species in Finland. It combines multiple climate change scenarios and different impact models for bioclimatic suitability to capture multi-faceted aspects of uncertainty. It also evaluates alternative options to enhance the adaptation of grassland biodiversity. Due to the long-term decline of semi-natural grasslands, their current extent in Finland is much lower than the minimum level estimated to ensure the survival of butterfly species. Projected locations of the climatically most suitable areas for butterfly species varied considerably between different modelling techniques and climate change scenarios. This uncertainty needs to be taken into account in planning adaptation responses. Analysis of potential adaptation options considered the promotion of existing measures based on the agri-environmental scheme (AES), as well as new measures, including species translocation and dispersal corridors. Current AES options were compared using a cost-effectiveness analysis (CEA). The CEA results indicated that buffer zones are the most cost-effective AES measure, although environmental fallows and buffer zones had broadly similar cost-effectiveness. The cost of translocation was relatively modest compared to that of dispersal corridors, due to the high number of habitat stepping stones required along potential dispersal corridors. A questionnaire survey of Finnish farmers revealed that a third of the respondents supported increases in nature conservation. Thus, large increases of the uptake of biodiversity-related AES measures among farmers may prove to be difficult. Given the small areas currently assigned for such measures, the prospects for the adaptation of grassland butterflies to climate change in Finland appear unfavourable.

Site-specific conditions influence plant naturalization: The case of alien Proteaceae in South Africa

The outcome of plant introductions is often considered in binary terms (invasive or non-invasive). However, most species experience a time lag before naturalization occurs, and many species become naturalized at some sites but not at others. It is therefore important to understand the site-specific mechanisms underlying naturalization. Proteaceae is an interesting case as some species are widespread invaders, while others, despite a long history of cultivation, show no signs of naturalization. At least 26 non-native Proteaceae species have been introduced to, and are cultivated in, South Africa. We mapped populations and examined differences between naturalized and non-naturalized populations (e.g. propagule pressure, land use and bioclimatic suitability). Of the 15 species surveyed, 6 were naturalized at one or more sites. Of these, Hakea salicifolia is most widely cultivated, but is only naturalizing in some areas (32 naturalized populations out of 62 populations that were surveyed). We found propagule pressure to be the most important determinant of naturalization for H. salicifolia. However, in suboptimal climatic conditions, naturalization only occurred if micro-site conditions were suitable, i.e. there was some disturbance and water available. For the other naturalized species there were few sites to compare, but we came to similar conclusions – Banksia integrifolia only naturalized at the site where it was planted the longest; Banksia serrata only naturalized at a site influenced by fire regimes; while Banksia formosa naturalized at sites with high propagule pressure, absence of fires and where there is no active clearing of the plants. Naturalization of Proteaceae in South Africa appears to be strongly mediated by site-specific anthropogenic activities (e.g. many planted individuals and water availability). More broadly, we argue that invasion biology needs to focus more closely on the mechanisms by which species and pathways interact to determine the likelihood and consequence of an invasion.

Casuarina cunninghamiana in the Western Cape, South Africa: Determinants of naturalisation and invasion, and options for management

Alien species that are desirable and commercially important in some parts of the landscape but damaging invaders in other parts present a special challenge for managers, planners, and policy-makers. Casuarina cunninghamiana (Casuarinaceae), native to the eastern and north-eastern coasts of Australia, has been cultivated in South Africa for more than a century. This study explores the invasion ecology of C. cunninghamiana in the south-western part of the Western Cape. We examined differences between naturalized and non-naturalized populations (e.g. the roles of propagule pressure, land use and bioclimatic suitability), assessed invasion risk, and provide recommendations for control.Naturalisation was observed in 81% of the populations surveyed. In climatically suitable areas, propagule pressure and distance to water bodies and water courses were significant predictors of naturalisation — naturalisation was most likely to occur within 100m from the nearest planted individual and close to water bodies and water courses. The species has also naturalized in regions with suboptimal bioclimatic conditions, but then only very close (<10m) to planted trees. Based on our findings we recommend: 1) the immediate removal of female trees from within 100m of water bodies and water courses; 2) all future sales and plantings to be restricted to male plants; and 3) the development of a management strategy (potentially including biological control) to control existing invasions and limit future spread. If these steps are taken, we believe it would be possible to maintain the beneficial uses the species has in some locations without incurring substantial negative impacts in other locations.

Evaluating the combined threat of climate change and biological invasions on endangered species

Climate change and invasive species are two major biodiversity threats expected to provoke extinctions of many species in the future. This study evaluates the joint threat posed by climate change and two invasive species: the zebra mussel (Dreissena polymorpha) and the signal crayfish (Pacifastacus leniusculus), on the distribution of two endangered freshwater species: the depressed river mussel (Pseudanodonta complanata) and the white-clawed crayfish (Austropotamobius pallipes), at the scale of Europe. We expected the native species to experience a gradual contraction over time in their geographic range size, while the invasive species would maintain or increase their spread; therefore, their overlap would increase, further threatening the conservation of the native species. To test these three hypotheses, ensemble species distribution models (SDMs) were calibrated with current distributions and projected onto present and 2050 future climatic scenarios. In agreement with our expectations, the 2050 scenarios suggested D. polymorpha may strongly benefit from climate changes (increase of 15–20% in range size), while the depressed river mussel would experience a considerable loss (14–36%), the overlap between both mussels increasing up to 24%. Although both crayfishes were predicted to be negatively affected by climate changes, the contraction was more severe for the invasive P. leniusculus (up to 32% decrease in range size). Moreover, the overlap between both crayfishes decreased by 13–16%, which may reduce the pressure upon the native A. pallipes. This study illustrates how SDMs can assist in management of endangered species over large spatial and temporal scales by identifying current and future areas of shared bioclimatic suitability and potential refugia.

Application of bioclimatic models coupled with network analysis for risk assessment of the killer shrimp, Dikerogammarus villosus, in Great Britain

In this study we use a combination of techniques to assess the general risk of invasion by the aquatic invader Dikerogammarus villosus in Great Britain at multiple scales. First, bioclimatic models (Support Vector Machine algorithm) were used to identify regions showing the highest climatic match with the European range of the species, and that might be at highest risk of initial colonization if provided with propagules. The model showed that nearly 60% of Great Britain shows the minimum bioclimatic suitability for the species, particularly southern and eastern England. Afterwards, a Network Analysis was used to model the natural spatio-temporal spread of the killer shrimp in the Great Ouse River catchment (SE England), the first region invaded by this species. This model suggested that the northern part of the catchment, including two relevant Ramsar sites (Ouse Washes and Wicken fen) are at serious risk of being invaded in the short-term (<5 years). Taking into account the rapid spread of the killer shrimp in other European countries, its broad environmental tolerance, the high climate suitability of broad areas of Great Britain to the species, the current spread of other Ponto-Caspian species, and the high natural and artificial connectivity of the hydrological network, we conclude that D. villosus is very likely to continue its spread in Great Britain, dramatically affecting the native biodiversity. The multi-scale approach proposed in this study combines large-scale bioclimatic models with local-scale dispersal models, providing managers with a powerful spatial and temporal basis for informed decision-making.

Potential responses of terrestrial biodiversity in Southern Africa to anthropogenic climate change

Key studies supported by species-level data collection have provided early indications of the potential implications of unmitigated change for the ecosystems and biodiversity of southern Africa. These suggest a significant threat to biodiversity, both from changing bioclimatic suitability and changing atmospheric CO2 level that seems to affect the competitive balance between woody and herbaceous plants in the dominant savanna biome of this region. Modeling efforts suggest significant implications of unmitigated climate change for this region, but assumptions underpinning methods such as bioclimatic modeling must be recognized, some of which might lead to over estimates of the rate and extent of the potential impacts. General trends and level of coincidence between various types of studies do support a high degree of concern for a substantial portion of southern African biodiversity under unmitigated climate-change scenarios. The most significant changes in ecosystem structure (both increases and decreases in woody plant cover), and associated faunal diversity changes, are projected in the dominant savanna vegetation type in this region, while the most significant biodiversity loss is projected for the winter rainfall region. Follow-up work to detect early signs of climate change identify regions of high- and low-potential impacts, and experimental work to test some important hypotheses relating to the future evolution of climate-change impacts across the region are very few and urgently required.

BioMove – an integrated platform simulating the dynamic response of species to environmental change

BioMove simulates plant species' geographic range shifts in response to climate, habitat structure and disturbance, at annual time steps. This spatially explicit approach integrates species' bioclimatic suitability and population‐level demographic rates with simulation of landscape‐level processes (dispersal, disturbance, species' response to dynamic dominant vegetation structure). Species population dynamics are simulated through matrix modelling that includes scaling demographic rates by climatic suitability. Dispersal functions simulate population spread. User‐specified plant functional types (PFTs) provide vegetation structure that determines resource competition and disturbance. PFTs respond annually through dispersal, inter‐PFT competition and demographic shifts. BioMove provides a rich framework for dynamic range simulations.