Evaluating population connectivity for species of conservation concern in the American Great Plains

Habitat loss and fragmentation are widely recognized as among the most important threats to global biodiversity. New analytical approaches are providing an improved ability to predict the effects of landscape change on population connectivity at vast spatial extents. This paper presents an analysis of population connectivity for three species of conservation concern [swift fox (Vulpes velox); lesser prairie-chicken (Tympanuchus pallidicinctus); massasuaga (Sistrurus catenatus)] across the American Great Plains region. We used factorial least-cost path and resistant kernel analyses to predict effects of landscape conditions on corridor network connectivity. Our predictions of population connectivity provide testable hypotheses about the location of core habitats, corridors, and barriers to movement. The results indicate that connectivity is more sensitive to a species’ dispersal ability than variation in landscape resistance to movement. Thus, it may prove difficult to optimize conservation strategies to maintain population connectivity for multiple species with disparate dispersal abilities and independent distributions.     

三江源地区雪豹保护优先区规划

为了将有限资源合理投放到关键区域, 实现物种保护成效的最大化, 找出质量最好的栖息地及它们之间的迁徙通道是制定保护规划的第一步。本研究以三江源的雪豹(Panthera uncia)栖息地为对象, 基于野外调查数据和高分辨率卫星遥感数据, 利用物种分布模型、保护规划模型和连通度分析工具, 找出了三江源地区雪豹的核心栖息地分布和潜在迁徙通道位置, 分析了目前保护中的潜在威胁, 并提出了针对三江源西、中、东三块区域的不同保护对策。结果表明: (1)三江源西部核心栖息地比较小而破碎, 但迁徙通道较多且没有明显窄点, 未来应关注青藏线的潜在阻碍作用, 同时应防范道路沿线的野生动物盗猎; (2)中部区域横跨玉树-杂多-囊谦的雪豹栖息地是三江源最大的核心雪豹栖息地, 在连通其他种群中也处于中心地位, 应通过种群监测确定其健康稳定, 对开发、偷猎等威胁防微杜渐, 保持其源种群的作用; (3)东部区域人口密度高, 受人类活动的影响最大, 需保证阿尼玛卿、年保玉则两块核心栖息地的质量, 并重点监测甘德县境内的省道处雪豹的迁徙通道是否畅通。三江源地区雪豹栖息地总体质量较好, 建议将维持核心源种群的稳定性, 保持种群间迁徙通道的畅通作为三江源的雪豹景观保护工作的整体目标。未来应充分利用天地一体化监测手段, 开展重要保护物种栖息地状况的评估和预警, 尤其是非保护地区域物种核心栖息地的开发建设活动。     

Sampling bias in snow leopard population estimation studies

Accurate assessments of the status of threatened species and their conservation planning require reliable estimation of their global populations and robust monitoring of local population trends. We assessed the adequacy and suitability of studies in reliably estimating the global snow leopard (Panthera uncia) population. We compiled a dataset of all the peer-reviewed published literature on snow leopard population estimation. Metadata analysis showed estimates of snow leopard density to be a negative exponential function of area, suggesting that study areas have generally been too small for accurate density estimation, and sampling has often been biased towards the best habitats. Published studies are restricted to six of the 12 range countries, covering only 0.3–0.9% of the presumed global range of the species. Re-sampling of camera trap data from a relatively large study site (c.1684 km²) showed that small-sized study areas together with a bias towards good quality habitats in existing studies may have overestimated densities by up to five times. We conclude that current information is biased and inadequate for generating a reliable global population estimate of snow leopards. To develop a rigorous and useful baseline and to avoid pitfalls, there is an urgent need for (a) refinement of sampling and analytical protocols for population estimation of snow leopards (b) agreement and coordinated use of standardized sampling protocols amongst researchers and governments across the range, and (c) sampling larger and under-represented areas of the snow leopard's global range.     

Identifying core habitats and corridors for giant pandas by combining multiscale random forest and connectivity analysis

Habitat loss and fragmentation are widely acknowledged as the main driver of the decline of giant panda populations. The Chinese government has made great efforts to protect this charming species and has made remarkable achievements, such as population growth and habitat expansion. However, habitat fragmentation has not been reversed. Protecting giant pandas in a large spatial extent needs to identify core habitat patches and corridors connecting them. This study used an equal‐sampling multiscale random forest habitat model to predict a habitat suitability map for the giant panda. Then, we applied the resistant kernel method and factorial least‐cost path analysis to identify core habitats connected by panda dispersal and corridors among panda occurrences, respectively. Finally, we evaluated the effectiveness of current protected areas in representing core habitats and corridors. Our results showed high scale dependence of giant panda habitat selection. Giant pandas strongly respond to bamboo percentage and elevation at a relatively fine scale (1 km), whereas they respond to anthropogenic factors at a coarse scale (≥2 km). Dispersal ability has significant effects on core habitats extent and population fragmentation evaluation. Under medium and high dispersal ability scenarios (12,000 and 20,000 cost units), most giant panda habitats in the Qionglai mountain are predicted to be well connected by dispersal. The proportion of core habitats covered by protected areas varied between 38% and 43% under different dispersal ability scenarios, highlighting significant gaps in the protected area network. Similarly, only 43% of corridors that connect giant panda occurrences were protected. Our results can provide crucial information for conservation managers to develop wise strategies to safeguard the long‐term viability of the giant panda population.     

Where will species on the move go? Insights from climate connectivity modelling across European terrestrial habitats

Climate change can induce species range shifts. However, the intensity of climate change, the intrinsic dispersal ability of species and the anthropization of landscapes are impeding species movements in most cases. In this context, preserving and promoting climate corridors for species to migrate from their current habitats to their future climatically similar habitats is an important strategy for preventing species extinction. Climate connectivity modelling is a tool that can identify these potential movement pathways. Here, we aimed to model connectivity between climate analogues across Europe under various ecological assumptions and climate change scenarios, in order to identify areas of high potential connectivity and to quantify variation in connectivity across a range of hypotheses. We also overlapped connectivity maps with protected areas to determine whether climate connectivity was sufficiently protected. We showed that climatic connectivity did not differ much between different scenarios of climate change, but was strongly dependent on species’ dispersal assumptions. It was also relatively similar to a scenario of non-climatic connectivity. Therefore, it may be feasible to anticipate the effect of climate change on species movements regardless of the future trajectory of climate, but the implementation of protection strategies for multiple species will certainly prove complex. Overall, protected areas were located in the regions of high and stable connectivity, but some countries lack the appropriate protection schemes, especially regarding strong protections. Our results have the potential to serve in the construction of land cover change scenarios to identify the best strategies to improve climate connectivity.     

A multispecies approach reveals hot spots and cold spots of diversity and connectivity in invertebrate species with contrasting dispersal modes

Genetic diversity is crucial for species’ maintenance and persistence, yet is often overlooked in conservation studies. Species diversity is more often reported due to practical constraints, but it is unknown if these measures of diversity are correlated. In marine invertebrates, adults are often sessile or sedentary and populations exchange genes via dispersal of gametes and larvae. Species with a larval period are expected to have more connected populations than those without larval dispersal. We assessed the relationship between measures of species and genetic diversity, and between dispersal ability and connectivity. We compiled data on genetic patterns and life history traits in nine species across five phyla. Sampling sites spanned 600 km in the northwest Mediterranean Sea and focused on a 50‐km area near Marseilles, France. Comparative population genetic approaches yielded three main results. (i) Species without larvae showed higher levels of genetic structure than species with free‐living larvae, but the role of larval type (lecithotrophic or planktotrophic) was negligible. (ii) A narrow area around Marseilles, subject to offshore advection, limited genetic connectivity in most species. (iii) We identified sites with significant positive contributions to overall genetic diversity across all species, corresponding with areas near low human population densities. In contrast, high levels of human activity corresponded with a negative contribution to overall genetic diversity. Genetic diversity within species was positively and significantly linearly related to local species diversity. Our study suggests that local contribution to overall genetic diversity should be taken into account for future conservation strategies.     

Connectivity and gene flow among Eastern Tiger Salamander (Ambystoma tigrinum) populations in highly modified anthropogenic landscapes

Fragmented landscapes resulting from anthropogenic habitat modification can have significant impacts on dispersal, gene flow, and persistence of wildlife populations. Therefore, quantifying population connectivity across a mosaic of habitats in highly modified landscapes is critical for the development of conservation management plans for threatened populations. Endangered populations of the eastern tiger salamander (Ambystoma tigrinum) in New York and New Jersey are at the northern edge of the species’ range and remaining populations persist in highly developed landscapes in both states. We used landscape genetic approaches to examine regional genetic population structure and potential barriers to migration among remaining populations. Despite the post-glacial demographic processes that have shaped genetic diversity in tiger salamander populations at the northern extent of their range, we found that populations in each state belong to distinct genetic clusters, consistent with the large geographic distance that separates them. We detected overall low genetic diversity and high relatedness within populations, likely due to recent range expansion, isolation, and relatively small population sizes. Nonetheless, landscape connectivity analyses reveal habitat corridors among remaining breeding ponds. Furthermore, molecular estimates of population connectivity among ponds indicate that gene flow still occurs at regional scales. Further fragmentation of remaining habitat will potentially restrict dispersal among breeding ponds, cause the erosion of genetic diversity, and exacerbate already high levels of inbreeding. We recommend the continued management and maintenance of habitat corridors to ensure long-term viability of these endangered populations.     

Habitat suitability and connectivity implications for the conservation of the Persian leopard along the Iran–Iraq border

Habitat fragmentation has major negative impacts on wildlife populations, and the connectivity could reduce these negative impacts. This study was conducted to assess habitat suitability and structural connectivity of the Persian leopard along the Iran–Iraq border (i.e., the Zagros Mountains) and compare the situation of identified core habitats and connectivity with existing conservation areas (CAs). An ensemble modeling approach resulting from five models was used to predict habitat suitability. To identify core habitats and corridors along the Iran–Iraq border, factorial least‐cost path analyses were applied. The results revealed that topographic roughness, distance to CAs, annual precipitation, vegetation/cropland density, and distance to rivers were the most influential variables for predicting the occurrence of the Persian leopard in the study area. By an estimated dispersal distance of 82 km (suggested by previous studies), three core habitats were identified (two cores in Iran and one core in Iraq). The largest cores were located in the south and the center of the study area, which had the highest connectivity priorities. The connectivity from these cores was maintained to the core within the Iraqi side. Only about one‐fifth of detected core habitats and relative corridors were protected by CAs in the study area. Detected core habitats and connectivity areas in this study could be an appropriate road map to accomplish the CAs network along the Iran–Iraq border regarding Persian leopard conservation. Establishing transboundary CAs, particularly in the core habitat located in the center of the study area, is strongly recommended to conserve existing large carnivores, including the Persian leopard.     

Climate change and plant dispersal along corridors in fragmented landscapes of Mesoamerica

Climate change is a threat to biodiversity, and adaptation measures should be considered in biodiversity conservation planning. Protected areas (PA) are expected to be impacted by climate change and improving their connectivity with biological corridors (BC) has been proposed as a potential adaptation measure, although assessing its effectiveness remains a challenge. In Mesoamerica, efforts to preserve the biodiversity have led to the creation of a regional network of PA and, more recently, BC. This study evaluates the role of BC for facilitating plant dispersal between PA under climate change in Mesoamerica. A spatially explicit dynamic model (cellular automaton) was developed to simulate species dispersal under different climate and conservation policy scenarios. Plant functional types (PFT) were defined based on a range of dispersal rates and vegetation types to represent the diversity of species in the region. The impacts of climate change on PA and the role of BC for dispersal were assessed spatially. Results show that most impacted PA are those with low altitudinal range in hot, dry, or high latitude areas. PA with low altitudinal range in high cool areas benefit the most from corridors. The most important corridors cover larger areas and have high altitude gradients. Only the fastest PFT can keep up with the expected change in climate and benefit from corridors for dispersal. We conclude that the spatial assessment of the vulnerability of PA and the role of corridors in facilitating dispersal can help conservation planning under a changing climate.     

Reproductive output and duration of the pelagic larval stage determine seascape-wide connectivity of marine populations

Connectivity among marine populations is critical for persistence of metapopulations, coping with climate change, and determining the geographic distribution of species. The influence of pelagic larval duration (PLD) on connectivity has been studied extensively, but relatively little is known about the influence of other biological parameters, such as the survival and behavior of larvae, and the fecundity of adults, on population connectivity. Furthermore, the interaction between the seascape (habitat structure and currents) and these biological parameters is unclear. We explore these interactions using a biophysical model of larval dispersal across the Indo-Pacific. We describe an approach that quantifies geographic patterns of connectivity from demographically relevant to evolutionarily significant levels across a range of species. We predict that at least 95% of larval settlement occurs within 155?km of the source population and within 13 days irrespective of the species' life history, yet long-distant connections remain likely. Self-recruitment is primarily driven by the local oceanography, larval mortality, and the larval precompetency period, whereas broad-scale connectivity is strongly influenced by reproductive output (abundance and fecundity of adults) and the length of PLD. The networks we have created are geographically explicit models of marine connectivity that define dispersal corridors, barriers, and the emergent structure of marine populations. These models provide hypotheses for empirical testing.     

三江源和祁连山国家公园雪豹种群的遗传结构分析

掌握遗传信息对濒危物种的保护和管理具有重要意义。本研究在我国雪豹重要分布区祁连山和三江源国家公园分别采集粪便样品,利用mtDNA的cyt b基因、微卫星多态性位点进行了雪豹的物种鉴定、个体识别和种群遗传结构评估。在采集286份疑似雪豹粪便样品中,成功的对86份雪豹样品进行了扩增鉴定,利用微卫星位点进行个体识别获得41只雪豹个体,其中祁连山国家公园26只,三江源国家公园15只。通过等位基因数、有效等位基因数、观测杂合度、期望杂合度、多态信息含量等指标进行种群遗传多样性评估,认为雪豹种群遗传多样性相对较低,但祁连山国家公园雪豹种群遗传多样性相对较高。STRUCTURE进行群体遗传结构分析表明,4个种群可以划分为3个遗传类群,祁连山国家公园的种群（YCW和QLS）与三江源国家种群(DC和SJ)的遗传差异,可能与种群间的地理隔离存在明显的相似性。     

African Wild Dog Dispersal and Implications for Management

Successful conservation of species that roam and disperse over large areas requires detailed understanding of their movement patterns and connectivity between subpopulations. But empirical information on movement, space use, and connectivity is lacking for many species, and data acquisition is often hindered when study animals cross international borders. The African wild dog (Lycaon pictus) exemplifies such species that require vast undisturbed areas to support viable, self-sustaining populations. To study wild dog dispersal and investigate potential barriers to movements and causes of mortality during dispersal, between 2016 and 2019 we followed the fate of 16 dispersing coalitions (i.e., same-sex group of ≥1 dispersing African wild dogs) in northern Botswana through global positioning system (GPS)-satellite telemetry. Dispersing wild dogs covered ≤54 km in 24 hours and traveled 150 km to Namibia and 360 km to Zimbabwe within 10 days. Wild dogs were little hindered in their movements by natural landscape features, whereas medium to densely human-populated landscapes represented obstacles to dispersal. Human-caused mortality was responsible for >90% of the recorded deaths. Our results suggest that a holistic approach to the management and conservation of highly mobile species is necessary to develop effective research and evidence-based conservation programs across transfrontier protected areas, including the need for coordinated research efforts through collaboration between national and international conservation authorities. © 2020 The Wildlife Society.     

In the shadows of snow leopards and the Himalayas: density and habitat selection of blue sheep in Manang,Nepal

There is a growing agreement that conservation needs to be proactive and pay increased attention to common species and to the threats they face. The blue sheep (Pseudois nayaur) plays a key ecological role in sensitive high‐altitude ecosystems of Central Asia and is among the main prey species for the globally vulnerable snow leopard (Panthera uncia). As the blue sheep has been increasingly exposed to human pressures, it is vital to estimate its population dynamics, protect the key populations, identify important habitats, and secure a balance between conservation and local livelihoods. We conducted a study in Manang, Annapurna Conservation Area (Nepal), to survey blue sheep on 60 transects in spring (127.9 km) and 61 transects in autumn (134.7 km) of 2019, estimate their minimum densities from total counts, compare these densities with previous estimates, and assess blue sheep habitat selection by the application of generalized additive models (GAMs). Total counts yielded minimum density estimates of 6.0–7.7 and 6.9–7.8 individuals/km² in spring and autumn, respectively, which are relatively high compared to other areas. Elevation and, to a lesser extent, land cover indicated by the normalized difference vegetation index (NDVI) strongly affected habitat selection by blue sheep, whereas the effects of anthropogenic variables were insignificant. Animals were found mainly in habitats associated with grasslands and shrublands at elevations between 4,200 and 4,700 m. We show that the blue sheep population size in Manang has been largely maintained over the past three decades, indicating the success of the integrated conservation and development efforts in this area. Considering a strong dependence of snow leopards on blue sheep, these findings give hope for the long‐term conservation of this big cat in Manang. We suggest that long‐term population monitoring and a better understanding of blue sheep–livestock interactions are crucial to maintain healthy populations of blue sheep and, as a consequence, of snow leopards.     

Dispersal corridors for plant species in the Poyang Lake Basin of southeast China identified by integration of phylogeographic and geospatial data

Measuring the dispersal of wildlife through landscapes is notoriously difficult. Recently, the categorical least cost path algorithm that integrates population genetic data with species distribution models has been applied to reveal population connectivity. In this study, we use this method to identify the possible dispersal corridors of five plant species (Castanopsis tibetana, Schima superba, Cyclocarya paliurus, Sargentodoxa cuneata, Eomecon chionantha) in the Poyang Lake Basin (PLB, largely coinciding with Jiangxi Province), China, in the late Quaternary. The results showed that the strongest population connectivity for the five species occurred in the Wuyi Mountains and the Yu Mountains of the eastern PLB (East Corridor) during the late Quaternary. In the western PLB, populations of the five species were connected by the Luoxiao Mountains and the Jiuling Mountains (West Corridor) but with a lower degree of connectivity. There were some minor connections between the eastern and the western populations across the Gannan Hills. When the corridors of five species were overlaid, the East Corridor and the West Corridor were mostly shared by multiple species. These results indicate that plant species in the PLB could have responded to the Quaternary climate changes by moving along the East Corridor and the West Corridor. Given that dispersal corridors have seldom been considered in the governmental strategies of biodiversity conservation in the PLB, preserving and restoring natural vegetation along these corridors should be prioritized to mitigate the effects of anthropogenic climate change by facilitating migration of plant species and other biota.     

Multispecies assessment of core areas and connectivity of desert carnivores in central Iran

Aim

Central Iran is a priority area for biodiversity conservation, which is threatened by encroachment on core habitats and fragmentation by roads. The goal of this study was to identify core areas and connectivity corridors for a set of desert carnivores by predicting habitat suitability and calculating resistant kernel, factorial least‐cost path modelling and graph network indices.

Location

Iran.

Methods

We used an ensemble model (EM) of habitat suitability methods to predict the potential habitats of leopard, cheetah, caracal, wild cat, sand cat and grey wolf and used resistant kernel and factorial least‐cost path modelling to identify important core habitats and corridors between patches. We also used a graph network analysis to quantify the importance of each core patch to landscape connectivity.

Results

Potential habitats of the studied carnivores appeared to be strongly influenced by prey density, annual precipitation, topographical roughness, shrubland density and anthropogenic factors. Most of the core patches were covered by protected areas and no‐hunting areas. This may be attributed to the relatively high resistance outside protected areas leading to isolated occupied patches. Patch importance to connectivity was significantly correlated with patch extent, density of dispersing individuals and probability of occurrence in the core patch.

Main conclusions

Our findings revealed that prey abundance in core habitat is critically important, and has higher influence than habitat area per se. In addition, our analysis provided the first map of landscape connectivity for multiple species in Iran and revealed that conserving these species requires integrated landscape‐level management to reduce mortality risk and protect core areas and linkages among them. These results will assist the development of multispecies conservation strategies to protect core areas for carnivores.

     

Comparative landscape genetics of two river frog species occurring at different elevations on Mount Kilimanjaro

Estimating population connectivity and species' abilities to disperse across the landscape is crucial for understanding the long‐term persistence of species in changing environments. Surprisingly, few landscape genetic studies focused on tropical regions despite the alarming extinction rates within these ecosystems. Here, we compared the influence of landscape features on the distribution of genetic variation of an Afromontane frog, Amietia wittei, with that of its more broadly distributed lowland congener, Amietia angolensis, on Mt. Kilimanjaro, Tanzania. We predicted high gene flow in the montane species with movements enhanced through terrestrial habitats of the continuous rainforest. In contrast, dispersal might be restricted to aquatic corridors and reduced by anthropogenic disturbance in the lowland species. We found high gene flow in A. wittei relative to other montane amphibians. Nonetheless, gene flow was lower than in the lowland species which showed little population structure. Least‐cost path analysis suggested that dispersal is facilitated by stream networks in both species, but different landscape features were identified to influence connectivity among populations. Contrary to a previous study, gene flow in the lowland species was negatively correlated with the presence of human settlements. Also, genetic subdivision in A. wittei did not coincide with specific physical barriers as in other landscape genetic studies, suggesting that factors other than topography may contribute to population divergence. Overall, these results highlight the importance of a comparative landscape genetic approach for assessing the influence of the landscape matrix on population connectivity, particularly because nonintuitive results can alter the course of conservation and management.     

四川邛崃山脉雪豹与散放牦牛潜在分布重叠与捕食风险评估

由雪豹(Panthera uncia)捕食散放家畜引起的人兽冲突是目前中国雪豹保护面临的主要挑战之一。四川邛崃山脉地处雪豹分布范围的东南缘, 本研究以邛崃山中部的自然保护区群为研究区, 收集了2014-2018年红外相机调查和动物粪便DNA分析中采集到的雪豹与散放牦牛的分布位点, 使用MaxEnt物种分布模型预测两物种在研究区内的潜在分布范围, 以两物种分布重叠的程度作为评估雪豹捕食家畜潜在风险的指标, 从而识别雪豹-家畜冲突的高危区域。结果表明, 在邛崃山中部的保护区群中, 模型预测的雪豹适宜栖息地面积为871.14 km ², 牦牛适宜栖息地面积为988.41 km ², 二者重叠面积达534.47 km ², 主要分布在研究区西部的高山草甸地区, 占域内雪豹适宜栖息地总面积的61.35%。研究区域内总体上可能存在较高的雪豹-家畜冲突风险。在这些自然保护区以及新建的大熊猫国家公园的管理规划中, 应把高山放牧作为对区内野生雪豹种群的关键威胁之一, 重点关注模型预测的人兽冲突高危区域, 通过改变社区牧业管理方式、发展社区替代生计等方式, 降低潜在冲突的风险。     

CLIMATE‐DRIVEN DIVERSIFICATION AND PLEISTOCENE REFUGIA IN PHILIPPINE BIRDS: EVIDENCE FROM PHYLOGEOGRAPHIC STRUCTURE AND PALEOENVIRONMENTAL NICHE MODELING

Avian diversification in oceanic archipelagos is largely attributed to isolation across marine barriers. During glacial maxima, lowered sea levels resulted in repeated land connections between islands joined by shallow seas. Consequently, such islands are not expected to show endemism. However, if climate fluctuations simultaneously caused shifts in suitable environmental conditions, limiting populations to refugia, then occurrence on and dispersal across periodic land bridges are not tenable. To assess the degree to which paleoclimate barriers, rather than marine barriers, drove avian diversification in the Philippine Archipelago, we produced ecological niche models for current‐day, glacial maxima, and interglacial climate scenarios to infer potential Pleistocene distributions and paleoclimate barriers. We then tested marine and paleoclimate barriers for correspondence to geographic patterns of population divergence, inferred from DNA sequences from eight codistributed bird species. In all species, deep‐water channels corresponded to zones of genetic differentiation, but six species exhibited deeper divergence associated with a periodic land bridge in the southern Philippines. Ecological niche models for these species identified a common paleoclimate barrier that coincided with deep genetic structure among populations. Although dry land connections joined southern Philippine islands during low sea level stands, unfavorable environmental conditions limited populations within landmasses, resulting in long‐term isolation and genetic differentiation. These results highlight the complex nature of diversification in archipelagos: marine barriers, changes in connectivity due to sea level change, and climate‐induced refugia acted in concert to produce great species diversity and endemism in the Philippines.     

Anticipating changes to future connectivity within a network of marine protected areas

Continental boundary currents are projected to be altered under future scenarios of climate change. As these currents often influence dispersal and connectivity among populations of many marine organisms, changes to boundary currents may have dramatic implications for population persistence. Networks of marine protected areas (MPAs) often aim to maintain connectivity, but anticipation of the scale and extent of climatic impacts on connectivity are required to achieve this critical conservation goal in a future of climate change. For two key marine species (kelp and sea urchins), we use oceanographic modelling to predict how continental boundary currents are likely to change connectivity among a network of MPAs spanning over 1000 km of coastline off the coast of eastern Australia. Overall change in predicted connectivity among pairs of MPAs within the network did not change significantly over and above temporal variation within climatic scenarios, highlighting the need for future studies to incorporate temporal variation in dispersal to robustly anticipate likely change. However, the intricacies of connectivity between different pairs of MPAs were noteworthy. For kelp, poleward connectivity among pairs of MPAs tended to increase in the future, whereas equatorward connectivity tended to decrease. In contrast, for sea urchins, connectivity among pairs of MPAs generally decreased in both directions. Self‐seeding within higher‐latitude MPAs tended to increase, and the role of low‐latitude MPAs as a sink for urchins changed significantly in contrasting ways. These projected changes have the potential to alter important genetic parameters with implications for adaptation and ecosystem vulnerability to climate change. Considering such changes, in the context of managing and designing MPA networks, may ensure that conservation goals are achieved into the future.     

A model-based framework for assessing the vulnerability of low dispersal vertebrates to landscape fragmentation under environmental change

Environmental changes are driving rapid geographic shifts of suitable environmental conditions for species. These might survive by tracking those shifts, however successful responses will depend on the spatial distribution of suitable habitats (current and future) and on their connectivity. Most herptiles (i.e., amphibians and reptiles) have low dispersal abilities, and therefore herptiles are among the most vulnerable groups to environmental changes. Here we assessed the vulnerability of herptile species to future climate and land use changes in fragmented landscapes. We developed and tested a methodological approach combining the strengths of Species Distribution Models (SDMs) and of functional connectivity analysis. First, using SDMs we forecasted current and future distributions of potential suitable areas as well as range dynamics for four herptile species in Portugal. SDM forecasts for 2050 were obtained under two contrasting emission scenarios, translated into moderate (low-emissions scenario) or large (high-emissions scenario) changes in climate and land use conditions. Then, we calculated and analysed functional connectivity from areas projected to lose environmental suitability towards areas keeping suitable conditions. Landscape matrix resistance and barrier effects of the national motorway network were incorporated as the main sources of fragmentation. Potential suitable area was projected to decrease under future conditions for most test species, with the high-emissions scenario amplifying the losses or gains. Spatiotemporal patterns of connectivity between potentially suitable areas signalled the most important locations for maintaining linkages and migration corridors, as well as potential conflicts due to overlaps with the current motorway network. By integrating SDM projections with functional connectivity analysis, we were able to assess and map the vulnerability of distinct herptile species to isolation or extinction under environmental change scenarios. Our framework provides valuable information, with fairly low data requirements, for optimizing biodiversity management and mitigation efforts, aiming to reduce the complex and often synergistic negative impacts of multiple environmental change drivers. Implications for conservation planning and management are discussed from a global change adaptation perspective.