Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being

A dynamic subtropical coastal hotspot of benthic foraminifera in the Southeastern Mediterranean indicates early-stage tropicalization

Due to ongoing ocean warming, subtropical environments are becoming accessible to tropical species. Among these environments are the vermetid reefs of the Southeastern Mediterranean (SEM). In the last decades, these valuable coastal habitats witnessed the proliferation of numerous alien species of tropical origin. Among the meiofauna thriving on these reefs are benthic foraminifera, single cell marine organisms that make a significant contribution to global carbonate production. It has been widely recognized that benthic foraminifera, among other invasive species, thrive in the macroalgal cover, and it has been suggested that their populations are becoming a significant new source of sediment substrate. Here, we report on the first systematic assessment of the population size of the benthic foraminifera, allowing a comparison with data from the native tropical habitat of these species. Our study is based on a seasonal sampling of benthic foraminifera from confined sampling areas at four sites along the vermetid reef platforms of the Israeli SEM coast. Our survey reveals a patchy distribution of each species with peak population densities exceeding 100,000 specimens per m2, making the SEM a hotspot of benthic foraminifera, with population densities comparable to tropical coral reef environments. The assemblages of the SEM hotspot are dominated by cosmopolitan foraminiferal taxa and tropical invaders from the Indo-Pacific (e.g., Amphistegina lobifera, Pararotalia calcariformata, soritids, and Hauerina diversa). In contrast to foraminiferal hotspots in the tropics, which are completely dominated by larger symbiont-bearing taxa, the SEM hotspot stands out due to high abundances of non-symbiont-bearing species Textularia agglutinans and small miliolids. An intriguing observation is the significant heterogeneity in composition and density of foraminiferal assemblages between the vermetid reefs' southern and northern areas (Israel), indicating that the productivity of the dominant species are also modulated by local yet unknown environmental factors.

Water temperature affects somatic growth, body condition and oxygen and carbon otolith isotopes of stout whiting (Sillago robusta)

Ocean warming will continue to affect the growth, body condition and geographic distributions of marine fishes and understanding these effects is an urgent challenge for fisheries research and management. Determining how temperature is recorded in fish otolith carbonate, provides an additional chronological tool to investigate thermal histories, preferences and patterns of movement throughout an individual's life history. The influence of three water temperature treatments (22°C, 25°C, and 28°C) on hatchery-reared juvenile stout whiting, Sillago robusta, was tested using a controlled outdoor mesocosm system. Fish were measured for change in length and weight, and body condition was determined using bioelectrical impedance analysis. Sagittal otoliths were analysed for stable oxygen (δ18Ootolith) and carbon (δ13Cotolith) isotopes via isotope ratio mass spectrometry. Whiting kept at 22°C were significantly smaller and had diminished body condition compared to fish in 25°C and 28°C, which did not significantly differ from each other. The δ18O otolith values of stout whiting demonstrated a negative temperature-dependent fractionation relationship which was similar in slope but had a different intercept to the relationships reported for inorganic aragonite and other marine fish species. The δ13C otolith values also showed a negative relationship with water temperature, and the calculated proportion of metabolic carbon M in otoliths differed between fish reared in the coolest (22°C) and warmest (28°C) temperature treatments. Overall, the results suggest that stout whiting may have reached an upper growth threshold between 25°C and 28°C, and that growth and body condition may be optimised during warmer seasons and toward the northerly regions of their distribution. Otolith oxygen thermometry shows promise as a natural tracer of thermal life history, and species-specific fractionation equations should be utilised when possible to prevent errors in temperature reconstructions of wild-caught fish.

Contrasting range changes and drivers of four forest foundation species under future climate change in China

Forest foundation species, vital for shaping community structure and dynamics through non-trophic level interactions, are key to forest succession and sustainability. Despite their ecological importance, the habitat ranges of these species in China and their responses to future climate change remain unclear. Our study employed the optimal MaxEnt model to assess the range shifts and their essential drivers of four typical forest foundation species from three climatic zones in China under climate scenarios, including Acer tegmentosum, Acer pseudo-sieboldianum (temperate zone), Quercus glandulifera (subtropical zone), and Ficus hispida (tropical zone). The optimal MaxEnt model exhibited high evaluation indices (AUC values > 0.90) for the four foundation species, indicating excellent predictive performance. Currently, we observed that A. tegmentosum and A. pseudo-sieboldianum are predominantly inhabited temperate forest areas in northeastern China, Q. glandulifera is primarily concentrated in subtropical forests in southeastern China, and F. hispida is mainly distributed across the tropical forests in southern China. Climate factors, particularly temperature, emerged as the primary environmental factors influencing the potential range of forest foundation species. Moreover, precipitation strongly influenced the potential range of A. tegmentosum and A. pseudo-sieboldianum, while elevation exhibited a greater impact on the range of Q. glandulifera and F. hispida. Under future climate scenarios, suitable areas for A. tegmentosum and A. pseudo-sieboldianum tend to expand southward, F. hispida tends to expand northward, while Q. glandulifera exhibited a tendency to contract towards the center. This study advances our understanding of the spatial and temporal dynamics of forest foundation species in China under climate change, providing critical insights for conservation efforts and sustainable forest management practices.

Microplastics in Arctic waters of the Finnish Sámi area

We explored the presence of microplastics in the Finnish Arctic Sámi home area. A dialogue between Indigenous knowledge and scientific field work produced data about microplastics in remote wilderness aquatic ecosystems. Methods included geographical Indigenous knowledge analysis, water sampling with fraction filtration, and imaging Fourier transform infrared spectroscopy. The MPs found were small; the mean particle size was 126 ± 121 μm. Particle concentrations of MPs in freshwater and marine samples varied between 45 and 423 MPs m-3 and the most common polymer types were polyethylene, polypropylene, and polyethylene terephthalate. In conclusion, because microplastics are present even in the wilderness areas, their abundance should be monitored to assess plastic pollution in the relatively pristine Arctic environments. Sámi Indigenous knowledge proved to be a beneficial and important initiator, because locals recognize the possible sources and transport pathways of plastic litter, and practical sampling sites in the complex freshwater systems of the area.

Identifying protected areas in biodiversity hotspots at risk from climate and human-induced compound events for conserving threatened species

Anthropogenic pressure in areas of biodiversity importance erodes the integrity of the ecosystems they harbour, making features of biodiversity less buffered against extreme climatic events. We define the combination of these disturbances as compound events. We assessed compound event risk in protected areas (PAs) applying a spatial framework guided by criteria and quantitative thresholds associated with exposure to cyclones, drought, and intense human pressure. This assessment was used in a relational matrix to classify PAs with different risk of compound event occurrence. We identified PAs of higher conservation concern by quantifying the extent of human pressure in their surrounding landscape while harbouring large numbers of threatened vertebrate species. Of the 39,694 PAs assessed, very high risk of compound events was determined for 6965 PAs (17.5 %) related to cyclones and human pressure (mainly island hotspots), 6367 PAs (16 %) related to droughts and human pressure (island and continental hotspots), and 2031 PAs (5 %) to cyclones, drought and human pressure (mainly in island hotspots). From the subset of 2031 PAs assessed at very high risk, we identified 239 PAs of higher conservation concern distributed predominantly in the Caribbean Islands, Japan, North America Coastal Plain, Philippines, and Southwest Australia. Our work highlights PAs in the biodiversity hotspots where high risk of compound event occurrence poses a greater threat to species. We encourage researchers to adapt and apply this framework across other globally significant sites for conserving biodiversity to identify high risk-prone areas, and prevent further biodiversity decline.

Greenhouse gases emissions and global climate change: Examining the influence of CO2, CH4, and N2O

An in-depth analysis of the role of greenhouse gases (GHGs) in climate change is examined here along with their diverse sources, including the combustion of fossil fuels, agriculture, and industrial processes. Key GHG components such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are considered, along with data on emissions across various economic sectors. The consequences of climate change are also highlighted, ranging from more frequent and intense extreme weather events to rising sea levels and impacts on ecosystems and human health. The industrial revolution and unrestricted use of fossil fuels are key factors leading to an increase in GHG concentrations in the atmosphere. Global efforts to reduce emissions are considered, starting with the 1997 Kyoto Protocol and culminating in the 2015 Paris Agreement. The limited effectiveness of early initiatives is underscored, emphasizing the significant importance of the Paris Agreement that provides a global framework for establishing goals to reduce GHG emissions by country. The Green Climate Fund and other international financial mechanisms are also considered as essential tools for financing sustainable projects in developing countries. The global community faces the challenge and necessity for more ambitious efforts to achieve the set goals for reducing GHG emissions. Successful strategies are examined by Sweden, Costa Rica, and Denmark to achieve zero GHG emissions that integrate renewable energy sources and technologies. The importance of global cooperation for creating a sustainable future is also emphasized.

Biodiversity in changing environments: An external-driver internal-topology framework to guide intervention

Accompanying the climate crisis is the more enigmatic biodiversity crisis. Rapid reorganization of biodiversity due to global environmental change has defied prediction and tested the basic tenets of conservation and restoration. Conceptual and practical innovation is needed to support decision making in the face of these unprecedented shifts. Critical questions include: How can we generalize biodiversity change at the community level? When are systems able to reorganize and maintain integrity, and when does abiotic change result in collapse or restructuring? How does this understanding provide a template to guide when and how to intervene in conservation and restoration? To this end, we frame changes in community organization as the modulation of external abiotic drivers on the internal topology of species interactions, using plant-plant interactions in terrestrial communities as a starting point. We then explore how this framing can help translate available data on species abundance and trait distributions to corresponding decisions in management. Given the expectation that community response and reorganization are highly complex, the external-driver internal-topology (EDIT) framework offers a way to capture general patterns of biodiversity that can help guide resilience and adaptation in changing environments.

Temporal dynamics of climate change exposure and opportunities for global marine biodiversity

Climate change is exposing marine species to unsuitable temperatures while also creating new thermally suitable habitats of varying persistence. However, understanding how these different dynamics will unfold over time remains limited. We use yearly sea surface temperature projections to estimate temporal dynamics of thermal exposure (when temperature exceeds realised species' thermal limits) and opportunity (when temperature at a previously unsuitable site becomes suitable) for 21,696 marine species globally until 2100. Thermal opportunities are projected to arise earlier and accumulate gradually, especially in temperate and polar regions. Thermal exposure increases later and occurs more abruptly, mainly in the tropics. Assemblages tend to show either high exposure or high opportunity, but seldom both. Strong emissions reductions reduce exposure around 100-fold whereas reductions in opportunities are halved. Globally, opportunities are projected to emerge faster than exposure until mid-century when exposure increases more rapidly under a high emissions scenario. Moreover, across emissions and dispersal scenarios, 76%-97% of opportunities are projected to persist until 2100. These results indicate thermal opportunities could be a major source of marine biodiversity change, especially in the near- and mid-term. Our work provides a framework for predicting where and when thermal changes will occur to guide monitoring efforts.

On the cost-effectiveness of Nature-based Solutions for reducing disaster risk

The potential of ecosystem-based interventions, also known as Nature-based Solutions (NbS), for Disaster Risk Reduction (DRR) and Climate Change Adaptation (CCA) is now recognized by major national policies and international framework agreements. However, there is limited scientific evidence about their economic viability and equity impacts. We examined English-language peer-reviewed studies, published between 2000 and 2021, which undertook economic evaluations of NbS for DRR and CCA. Based on our results, 71 % of studies indicated that NbS have consistently proven to be a cost-effective approach to mitigating hazards and 24 % of studies found NbS cost-effective under certain conditions. The ecosystem-based interventions most frequently found effective in mitigating hazards are associated with mangroves (80 %), forests (77 %), and coastal ecosystems (73 %). Studies comparing the cost-effectiveness of NbS and engineering-based solutions for mitigating certain hazards showed that NbS are no less effective than engineering-based solutions. Among these studies, 65 % found that NbS are always more effective in attenuating hazards compared to engineering-based solutions and 26 % found that NbS are partially more effective. Our findings illustrate a range of factors, including the geographic locations of the NbS analyzed, their contribution to the restoration and increase of biodiversity, their property rights structure, their source of financing, and the economic methodologies employed to assess cost-effectiveness and distributional effects. The geographic location of the NbS observations included in this analysis was examined considering global projected temperature and precipitation changes.

Innovative and practical tools for monitoring and assessing biodiversity status and impacts of multiple human pressures in marine systems

Human activities at sea can produce pressures and cumulative effects on ecosystem components that need to be monitored and assessed in a cost-effective manner. Five Horizon European projects have joined forces to collaboratively increase our knowledge and skills to monitor and assess the ocean in an innovative way, assisting managers and policy-makers in taking decisions to maintain sustainable activities at sea. Here, we present and discuss the status of some methods revised during a summer school, aiming at better management of coasts and seas. We include novel methods to monitor the coastal and ocean waters (e.g. environmental DNA, drones, imaging and artificial intelligence, climate modelling and spatial planning) and innovative tools to assess the status (e.g. cumulative impacts assessment, multiple pressures, Nested Environmental status Assessment Tool (NEAT), ecosystem services assessment or a new unifying approach). As a concluding remark, some of the most important challenges ahead are assessing the pros and cons of novel methods, comparing them with benchmark technologies and integrating these into long-standing time series for data continuity. This requires transition periods and careful planning, which can be covered through an intense collaboration of current and future European projects on marine biodiversity and ecosystem health.

Ecological genetics of isolated loach populations indicate compromised adaptive potential

Many endangered species live in fragmented and isolated populations with low genetic variability, signs of inbreeding, and small effective population sizes - all features elevating their extinction risk. The flat-headed loach (Oreonectes platycephalus), a small noemacheilid fish, is widely across southern China, but only in the headwaters of hillstreams; as a result, they are spatially isolated from conspecific populations. We surveyed single nucleotide polymorphisms in 16 Hong Kong populations of O. platycephalus to determine whether loach populations from different streams were genetically isolated from each other, showed low levels of genetic diversity, signs of inbreeding, and had small contemporary effective population sizes. Estimates of average observed heterozygosity (HO = 0.0473), average weighted nucleotide diversity (πw = 0.0546) and contemporary effective population sizes (Ne = 10.2 ~ 129.8) were very low, and several populations showed clear signs of inbreeding as judged from relatedness estimates. The degree of genetic differentiation among populations was very high (average FST = 0.668), even over short geographic distances (<1.5 km), with clear patterns of isolation by distance. These results suggest that Hong Kong populations of O. platycephalus have experienced strong genetic drift and loss of genetic variability because sea-level rise after the last glaciation reduced connectedness among paleodrainages, isolating populations in headwaters. All this, together with the fact that the levels of genetic diversity and contemporary effective population sizes within O. platycephalus populations are lower than most other freshwater fishes, suggests that they face high local extinction risk and have limited capacity for future adaptation.

Vegetation redistribution is predicted to intensify soil organic carbon loss under future climate changes on the Tibetan Plateau

Vegetation redistribution may bring unexpected climate-soil carbon cycling in terrestrial biomes. However, whether and how vegetation redistribution alters the soil carbon pool under climate change is still poorly understood on the Tibetan Plateau. Here, we applied the G-Range model to simulate the cover of herbs, shrubs and trees, net primary productivity (NPP) and soil organic carbon density (SOCD) at the depth of 60 cm on Tibetan Plateau for the individual years 2020 and 2060, using climate projection for Representative Concentration Pathways (RCP) 4.5 and RCP8.5 scenarios with the RegCM4.6 model system. Vegetation redistribution was defined as the transitions in bare ground, herbs, shrubs and trees between 2020 and 2060, with approximately 57.9 % (RCP4.5) and 59 % (RCP8.5) of the area will redistribute vegetation over the whole Tibetan Plateau. The vegetation cover will increase by about 2.4 % (RCP4.5) and 1.9 % (RCP8.5), while the NPP and SOCD will decrease by about -14.3 g C m-2 yr-1 and -907 g C m-2 (RCP4.5), and -1.8 g C m-2 yr-1and -920 g C m-2 (RCP8.5). Shrubs and trees will expand in the east, and herbs will expand in the northwest part of the Plateau. These areas are projected to be hotspots with greater SOCD reduction in response to future climate change, and will include lower net plant carbon input due to the negative NPP. Our study indicates that the SOC pool will become a carbon source under increased air temperature and rainfall on the Tibetan Plateau by 2060, especially for the area with vegetation redistribution. These results revealed the potential risk of vegetation redistribution under climate change in alpine ecosystems, indicating the policymakers need to pay attention on the vegetation redistribution to mitigate the soil carbon emission and achieve the goal of carbon neutrality on the Tibetan Plateau.

Climate change may reveal currently unavailable parts of species' ecological niches

The ability of climatic niche models to predict species extinction risks can be hampered if niches are incompletely quantified. This can occur when niches are estimated considering only currently available climatic conditions, disregarding the fact that climate change can open up portions of the fundamental niche that are currently inaccessible to species. Using a new metric, we estimate the prevalence of potential situations of fundamental niche truncation by measuring whether current ecological niche limits are contiguous to the boundaries of currently available climatic conditions for 24,944 species at the global scale in both terrestrial and marine realms and including animals and plants. We show that 12,172 (~49%) species are showing niche contiguity, particularly those inhabiting tropical ecosystems and the marine realm. Using niche expansion scenarios, we find that 86% of species showing niche contiguity could have a fundamental niche potentially expanding beyond current climatic limits, resulting in lower-yet still alarming-rates of predicted biodiversity loss, particularly within the tropics. Caution is therefore advised when forecasting future distributions of species presenting niche contiguity, particularly towards climatic limits that are predicted to expand in the future.

Suitable habitat shifts and ecological niche overlay assessments among benthic Oplegnathus species in response to climate change

Climate change has had a significant impact on many marine organisms. To investigate the effects of environmental changes on deep-water benthic fishes, we selected the genus Oplegnathus and applied species distribution modeling and ecological niche modeling. From the last glacial maximum to the present, the three Oplegnathus species (O. conwayi, O. robinsoni, and O. peaolopesi) distributed in the Cape of Good Hope region of southern Africa experienced fitness zone fluctuations of 39.9%, 13%, and 5.7%, respectively. In contrast, O. fasciatus and O. punctatus, which were primarily distributed in the western Pacific Ocean, had fitness zone fluctuations of -6.5% and 11.7%, respectively. Neither the O. insignis nor the O. woodward varied by more than 5% over the period. Under future environmental conditions, the range of variation in fitness zones for the three southern African Oplegnathus species was expected to be between -30.8% and -26.5%, while the range of variation in fitness zones for the two western Pacific stonefish species was expected to remain below 13%. In addition, the range of variation in the fitness zones of the O. insignis was projected to be between -2.3% and 7.1%, and the range of variation in the fitness zones of the O. woodward is projected to be between -5.7% and -2%. The results indicated that O. fasciatus and O. punctatus had a wide distribution and high expansion potential, while Oplegnathus species might have originated in western Pacific waters. Our results showed that benthic fishes were highly adaptable to extreme environments, such as the last glacial maximum. The high ecological niche overlap between Oplegnathus species in the same region suggested that they competed with each other. Future research could explore the impacts of environmental change on marine organisms and make conservation and management recommendations.

Unravelling consumer acceptance of local food: Physical versus social distance and the important role of social identification

Including more locally grown products in our diet is a way to reduce our diets' environmental impact. Therefore, it is important to investigate how this can be effectively communicated on food products to increase consumer acceptance. We propose that product communication that focuses on decreasing the physical and social distance between the food producer and the consumer can result in consumers identifying more with the food producer, which, in turn, can increase the buying intention of food products. The current research comprises an online survey that includes an experimental design and a real-life assessment among 825 Dutch participants. Results of the experiment show that decreasing physical distance, but not social distance, increases consumers' intention to buy a food product. This effect can be explained by increased feelings of identification with a food producer. Moreover, the real-life assessment provides a first indication that both having a food producer living close by (physical distance) and personally knowing a food producer (social distance) might increase acceptance of the producer and the product, and highlights the relevance of perceived connection. These findings give insights into how food producers can market local food products to increase acceptance; communication on a decreased distance between consumers and the food producer is only effective when it results in more identification with the food producer. Perceived connection seems to be an essential part of the acceptance of local products.

Predicting the potential distribution change of the endangered Francois' langur (Trachypithecus francoisi) across its entire range in China under climate change

The Francois' langur (Trachypithecus francoisi) is a rare primate species indicated as endangered and distributed in karst areas in northern Vietnam and southwestern China. However, research limited to specific nature reserves or sites has hampered holistic conservation management. A comprehensive map of the potential distribution for the Francois' langur is essential to advance conservation efforts and ensure coordinated management across regions. Here, we used 82 occurrence records of Francois' langur surveyed in Guangxi, Guizhou, and Chongqing from 2017 to 2020, along with 12 environmental variables, to build the potential habitat model under current and future climate (2030, 2050, 2070, and 2090s) using maximum entropy models (MaxEnt). Our results indicated that (1) precipitation- and temperature-associated bioclimatic variables contributed the most to the distribution of Francois' langur. Vegetation, water sources, and anthropogenic variables also affected its distribution; (2) a total of 144,207.44 km2 of potential suitable habitat across the entire range in China was estimated by the current model. Moderate- and high-suitability habitats accounted for only 23.76% (34,265.96 km2) of the predicted suitable habitat and were mainly distributed in southwest Guangxi, east of Chongqing, and the border between Guizhou and Chongqing; (3) the suitable habitats of Francois' langur will contract considerably under future climate change, and the habitat centroid will move in the southeast direction with a shifting distance of approximately 2.84 km/year from current to 2100. The habitat prediction of Francois' langur and the main drivers proposed in this study could provide essential insights for the future conservation of this endangered species. The existing distribution areas should be monitored and protected, but conservation beyond existing habitats should also be a focus of effort, especially in future expansion areas. This would ensure effective and timely protection under climate change and anthropogenic pressures.

Within-population plastic responses to combined thermal-nutritional stress differ from those in response to single stressors, and are genetically independent across traits in both males and females

Phenotypic plasticity helps animals to buffer the effects of increasing thermal and nutritional stress created by climate change. Plastic responses to single and combined stressors can vary among genetically diverged populations. However, less is known about how plasticity in response to combined stress varies among individuals within a population or whether such variation changes across life-history traits. This is important because individual variation within populations shapes population-level responses to environmental change. Here, we used isogenic lines of Drosophila melanogaster to assess the plasticity of egg-to-adult viability and sex-specific body size for combinations of 2 temperatures (25 °C or 28 °C) and 3 diets (standard diet, low caloric diet, or low protein:carbohydrate ratio diet). Our results reveal substantial within-population genetic variation in plasticity for egg-to-adult viability and wing size in response to combined thermal-nutritional stress. This genetic variation in plasticity was a result of cross-environment genetic correlations that were often < 1 for both traits, as well as changes in the expression of genetic variation across environments for egg-to-adult viability. Cross-sex genetic correlations for body size were weaker when the sexes were reared in different conditions, suggesting that the genetic basis of traits may change with the environment. Furthermore, our results suggest that plasticity in egg-to-adult viability is genetically independent from plasticity in body size. Importantly, plasticity in response to diet and temperature individually differed from plastic shifts in response to diet and temperature in combination. By quantifying plasticity and the expression of genetic variance in response to combined stress across traits, our study reveals the complexity of animal responses to environmental change, and the need for a more nuanced understanding of the potential for populations to adapt to ongoing climate change.

Non-invasive biomonitoring of polar bear feces can be used to estimate concentrations of metals of concern in traditional food

The Arctic faces increasing exposure to environmental chemicals such as metals, posing health risks to humans and wildlife. Biomonitoring of polar bears (Ursus maritimus) can be used to quantify chemicals in the environment and in traditional foods consumed by the Inuit. However, typically, these samples are collected through invasive or terminal methods. The biomonitoring of feces could be a useful alternative to the current metal monitoring method within the Arctic. Here, we aim to 1) quantify the relationship between concentrations of metals in the feces and tissues (muscle, liver, and fat) of polar bears using predictive modeling, 2) develop an easy-to-use conversion tool for use in community-based monitoring programs to non-invasively estimate contaminant concentrations in polar bears tissues and 3) demonstrate the application of these models by examining potential exposure risk for humans from consumption of polar bear muscle. Fecal, muscle, liver, and fat samples were harvested from 49 polar bears through a community-based monitoring program. The samples were analyzed for 32 metals. Exploratory analysis indicated that mean metal concentrations generally did not vary by age or sex, and many of the metals measured in feces were positively correlated with the internal tissue concentration. We developed predictive linear regression models between internal (muscle, liver, fat) and external (feces) metal concentrations and further explored the mercury and methylmercury relationships for utility risk screening. Using the cross-validated regression coefficients, we developed a conversion tool that contributes to the One Health approach by understanding the interrelated health of humans, wildlife, and the environment in the Arctic. The findings support using feces as a biomonitoring tool for assessing contaminants in polar bears. Further research is needed to validate the developed models for other regions in the Arctic and assess the impact of environmental weathering on fecal metal concentrations.

Spatial match-mismatch between predators and prey under climate change

Climate change is driving a rapid redistribution of life on Earth. Variability in the rates, magnitudes and directions of species' shifts can alter spatial overlap between predators and prey, with the potential to decouple trophic interactions. Although phenological mismatches between predator requirements and prey availability under climate change are well-established, 'spatial match-mismatch' dynamics remain poorly understood. We synthesize global evidence for climate-driven changes in spatial predator-prey overlap resulting from species redistribution across marine and terrestrial domains. We show that spatial mismatches can have vastly different outcomes for predator populations depending on their diet specialization and role within the wider ecosystem. We illustrate ecosystem-level consequences of climate-driven changes in spatial predator-prey overlap, from restructuring food webs to altering socio-ecological interactions. It remains unclear how predator-prey overlap at the landscape scale relates to prey encounter and consumption rates at local scales, or how the spatial reorganization of food webs affects ecosystem function. We identify key research directions necessary to resolve the scale of ecological impacts caused by species redistribution under climate change.

Projected loss of brown macroalgae and seagrasses with global environmental change

Although many studies predict extensive future biodiversity loss and redistribution in the terrestrial realm, future changes in marine biodiversity remain relatively unexplored. In this work, we model global shifts in one of the most important marine functional groups-ecosystem-structuring macrophytes-and predict substantial end-of-century change. By modelling the future distribution of 207 brown macroalgae and seagrass species at high temporal and spatial resolution under different climate-change projections, we estimate that by 2100, local macrophyte diversity will decline by 3-4% on average, with 17 to 22% of localities losing at least 10% of their macrophyte species. The current range of macrophytes will be eroded by 5-6%, and highly suitable macrophyte habitat will be substantially reduced globally (78-96%). Global macrophyte habitat will shift among marine regions, with a high potential for expansion in polar regions.

Distribution and extent of suitable habitats of Ruspoli's Turaco (Tauraco ruspolii) and White-cheeked Turaco (Tauraco leucotis) under a changing climate in Ethiopia

BACKGROUND

Understanding the distribution pattern of species and their suitable habitat is key to focus conservation efforts. Climate change has had notable impact on the distribution and extent of suitable habitats, and the long-term survival of various species. We aim to determine the distribution and extent of suitable habitats for Tauraco ruspolii and T. leucotis in Ethiopia and predict their range in the 2050s and 2070s using MaxEnt algorithm. We used 25 and 29 rarified occurrence points for T. ruspolii and T. leucotis, respectively, and 13 environmental variables. Three regularization multipliers and two cut-off thresholds were used to map the potential suitable habitats for each species under current and future climates. Maps were assembled from these techniques to produce final composite tertiary maps and investigated the habitat suitability overlap between the two species using the UNION tool in the geographical information system.

RESULT

All model run performances were highly accurate for both species. Precipitation of the driest month and vegetation cover are the most influential variables for the habitat suitability of T. ruspolii. The habitat suitability of T. leucotis is also mainly influenced by mean temperature of the driest quarter and vegetation cover. Under the current climate, the suitable habitat predicted for T. ruspolii covered about 24,639.19 km2, but its range size change shows a gain and increase by 156.00% and 142.68% in 2050 and 2070, respectively. The T. leucotis's current suitable habitat ranges about 204,397.62 km², but this is reduced by 40.84% and 68.67% in 2050 and 2070, respectively. Our modeling also showed that there was suitable habitat overlap between them at the margin of their respective habitat types in time series.

CONCLUSION

We concluded that there is a direct or indirect impact of climate change on the suitable habitat range expansion for T. ruspolii and contraction for T. leucotis as well as overlapping of these turaco species in different regions of Ethiopia. Therefore, understanding the distribution of current and future suitable habitats of the two turaco species can provide valuable information to implement conservation practices for the species and the regions as well.

Temporal variability of sea surface temperature affects marine macrophytes range retractions as well as gradual warming

Record mean sea surface temperatures (SST) during the past decades and marine heatwaves have been identified as responsible for severe impacts on marine ecosystems, but the role of changes in the patterns of temporal variability under global warming has been much less studied. We compare descriptors of two time series of SST, encompassing extirpations (i.e. local extinctions) of six cold-temperate macroalgae species at their trailing range edge. We decompose the effects of gradual warming, extreme events and intrinsic variability (e.g. seasonality). We also relate the main factors determining macroalgae range shifts with their life cycles characteristics and thermal tolerance. We found extirpations of macroalgae were related to stretches of coast where autumn SST underwent warming, increased temperature seasonality, and decreased skewness over time. Regardless of the species, the persisting populations shared a common environmental domain, which was clearly differentiated from those experiencing local extinction. However, macroalgae species responded to temperature components in different ways, showing dissimilar resilience. Consideration of multiple thermal manifestations of climate change is needed to better understand local extinctions of habitat-forming species. Our study provides a framework for the incorporation of unused measures of environmental variability while analyzing the distributions of coastal species.

Tree of life metabarcoding can serve as a biotic benchmark for shifting baselines in urbanized estuaries

Urbanization of estuaries drastically changed existing shorelines and bathymetric contours, in turn modifying habitat for marine foundational species that host critical biodiversity. And yet we lack approaches to characterize a significant fraction of the biota that inhabit these ecosystems on time scales that align with rates of urbanization. Environmental DNA (or eDNA) metabarcoding that combines multiple assays targeting a broad range of taxonomic groups can provide a solution, but we need to determine whether the biological communities it detects ally with different habitats in these changing aquatic environments. In this study, we tested whether tree of life metabarcoding (ToL-metabarcoding) data extracted from filtered seawater samples correlated with four known geomorphic habitat zones across a heavily urbanized estuary (Sydney Harbour, Australia). Using this method, we substantially expanded our knowledge on the composition and spatial distribution of marine biodiversity across the tree of life in Sydney Harbour, particularly for organisms where existing records are sparse. Excluding terrestrial DNA inputs, we identified significant effects of both distance from the mouth of Sydney Harbour and geomorphic zone on biological community structure in the ToL-metabarcoding dataset (entire community), as well as in each of the taxonomic subgroups that we considered (fish, macroinvertebrates, algae and aquatic plants, bacteria). This effect appeared to be driven by taxa as a collective versus a few individual taxa, with each taxon explaining no more than 0.62% of the variation between geomorphic zones. Similarly, taxonomic richness was significantly higher within geomorphic zones with large sample sizes, but also decreased by 1% with each additional kilometer from the estuary mouth, a result consistent with a reduction in tidal inputs and available habitat in upper catchments. Based on these results, we suggest that ToL-metabarcoding can be used to benchmark biological monitoring in other urbanized estuaries globally, and in Sydney Harbour at future time points based on detection of bioindicators across the tree of life. We also suggest that robust biotic snapshots can be archived following extensive curation of taxonomic assignments that incorporates ecological affinities, supported by records from relevant and regional biodiversity repositories.

Conservation and Evolution of Wildlife in the Context of Climate Change and Human Population Growth

Global climate change results in variations in morphological traits, resource competition, species diversity, physiological activity, genetic diversity, habitat use, distributional range, and conservation status in organisms [...].

How modularity and heterotrophy complicate the understanding of the causes of thermal performance curves: the case of feeding rate in a filter-feeding animal

Warming global temperatures have consequences for biological rates. Feeding rates reflect the intake of energy that fuels survival, growth and reproduction. However, temperature can also affect food abundance and quality, as well as feeding behavior, which all affect feeding rate, making it challenging to understand the pathways by which temperature affects the intake of energy. Therefore, we experimentally assessed how clearance rate varied across a thermal gradient in a filter-feeding colonial marine invertebrate (the bryozoan Bugula neritina). We also assessed how temperature affects phytoplankton as a food source, and zooid states within a colony that affect energy budgets and feeding behavior. Clearance rate increased linearly from 18°C to 32°C, a temperature range that the population experiences most of the year. However, temperature increased algal cell size, and decreased the proportion of feeding zooids, suggesting indirect effects of temperature on clearance rates. Temperature increased polypide regression, possibly as a stress response because satiation occurred quicker, or because phytoplankton quality declined. Temperature had a greater effect on clearance rate per feeding zooid than it did per total zooids. Together, these results suggest that the effect of temperature on clearance rate at the colony level is not just the outcome of individual zooids feeding more in direct response to temperature but also emerges from temperature increasing polypide regression and the remaining zooids increasing their feeding rates in response. Our study highlights some of the challenges for understanding why temperature affects feeding rates, especially for understudied, yet ecologically important, marine colonial organisms.

Predicting the distribution pattern changes of dye plant habitats caused by climate change

Climate change has accelerated the habitat loss and fragmentation of wildlife. Dye plants of "Fengxiang dyeing" are important indigenous natural resources for traditional printing and dyeing craft in southwest China, is of practical and cultural importance for dozens of ethnic minorities. However, lack of the spatial distribution information of these plants has hampered holistic and efficient conservation management measures. We analyzed the potentially suitable areas of four dye plants (Liquidambar formosana, Strobilanthes cusia, Persicaria tinctoria and Indigofera tinctoria) necessary for "Fengxiang dyeing" based on their geographical distribution sites under different climatic situations using the maximum entropy (MaxEnt) model. The results showed that temperature, precipitation and elevation were the most important factors affecting the suitable geographical areas of the four dye plants. Under the current climate conditions, the overlapping suitable habitat areas of the four plants were mainly in the four southern provinces of China, including Guizhou, Guangxi, Guangdong and Hainan. L. formosana was used as the base plant for combination with the other three plants under the two future climate scenarios (SSP126 and SSP585), and the overlapping suitable habitat areas of the obtained seven combination patterns were considered suitable for potential craft development. Five patterns showed an increase, while two patterns showed a decreasing trend with the increasing carbon emission. The prediction results showed that the overlapping suitable habitat center of the four plants will gradually move to the northeast, indicating that the overlapping suitable habitat area and craft distribution area will be changed. These results provide the basis for understanding the spatial distribution pattern changes of dye plants caused by climate change and establishing measures for protecting and developing printing and dyeing craft.

Patterns and correlates of potential range shifts of bat species in China in the context of climate change

Climate change may diminish biodiversity; thus, it is urgent to predict how species' ranges may shift in the future by integrating multiple factors involving more taxa. Bats are particularly sensitive to climate change due to their high surface-to-volume ratio. However, few studies have considered geographic variables associated with roost availability and even fewer have linked the distributions of bats to their thermoregulation and energy regulation traits. We used species distribution models to predict the potential distributions of 12 bat species in China under current and future greenhouse gas emission scenarios (SSP1-2.6 and SSP5-8.5) and examined factors that could affect species' range shifts, including climatic, geographic, habitat, and human activity variables and wing surface-to-mass ratio (S-MR). The results suggest that Ia io, Rhinolophus ferrumequinum, and Rhinolophus rex should be given the highest priority for conservation in future climate conservation strategies. Most species were predicted to move northward, except for I. io and R. rex, which moved southward. Temperature seasonality, distance to forest, and distance to karst or cave were the main environmental factors affecting the potential distributions of bats. We found significant relationships between S-MR and geographic distribution, current potential distribution, and future potential distribution in the 2050s. Our work highlights the importance of analyzing range shifts of species with multifactorial approaches, especially for species traits related to thermoregulation and energy regulation, to provide targeted conservation strategies.

Ecological Niche Differentiation and Response to Climate Change of the African Endemic Family Myrothamnaceae

Studying the ecological niches of species and their responses to climate change can provide better conservation strategies for these species. Myrothamnaceae is endemic to Africa, comprising only two species that belong to Myrothamnus (M. flabellifolius and M. moschatus). These closely related species exhibit allopatric distributions, positioning them as ideal materials for studying the species ecological adaptation. This study explores the ecological niche differentiation between M. flabellifolius and M. moschatus and their response capabilities to future climate change. The results indicate that M. flabellifolius and M. moschatus have undergone niche differentiation. The main drivers of niche differences are the minimum temperature of the coldest month (Bio6) for M. flabellifolius, precipitation of the driest month (Bio14), and precipitation of the coldest quarter (Bio19) for M. moschatus. M. flabellifolius demonstrated a stronger adaptation to environments characterized by lower precipitation, relatively lower temperatures, and greater annual temperature variations compared to M. moschatus. Under future climate scenarios (SSP5-8.5, 2081-2100 years), the results show that approximately 85% of the total suitable habitat for M. flabellifolius will be lost, with an 85% reduction in high-suitability areas and almost complete loss of the original mid-low suitability areas. Concurrently, about 29% of the total suitable habitat for M. moschatus will be lost, with a 34% reduction in high suitability areas and roughly 60% of the original mid-low suitability areas becoming unsuitable. This suggests that M. flabellifolius will face greater threats under future climate change. This study contributes novel insight into niche differentiation in Myrothamnaceae and provides useful information for the conservation of this distinctive African lineage.

Can large-scale tree planting in China compensate for the loss of climate connectivity due to deforestation?

Extensive deforestation has been a major reason for the loss of forest connectivity, impeding species range shifts under current climate change. Over the past decades, the Chinese government launched a series of afforestation and reforestation projects to increase forest cover, yet whether the new forests can compensate for the loss of connectivity due to deforestation-and where future tree planting would be most effective-remains largely unknown. Here, we evaluate changes in climate connectivity across China's forests between 2015 and 2019. We find that China's large-scale tree planting alleviated the negative impacts of forest loss on climate connectivity, improving the extent and probability of climate connectivity by 0-0.2 °C and 0-0.03, respectively. The improvements were particularly obvious for species with short dispersal distances (i.e., 3 km and 10 km). Nevertheless, only ~55 % of the trees planted in this period could serve as stepping stones for species movement. This indicates that focusing solely on the quantitative target of forest coverage without considering the connectivity of forests may miss opportunities in tree planting to facilitate climate-induced range shifts. More attention should be paid to the spatial arrangement of tree plantations and their potential as stepping stones. We then identify priority areas for future tree planting to create effective stepping stones. Our study highlights the potential of large-scale tree planting to facilitate range shifts. Future tree-planting efforts should incorporate the need for species range shifts to achieve more biodiversity conservation benefits under climate change.

Kelp holdfast microclimates buffer invertebrate inhabitants from extreme temperatures

Climate change is altering environmental conditions, with microclimates providing small-scale refuges within otherwise challenging environments. Durvillaea (southern bull kelp; rimurapa) is a genus of large intertidal fucoid algae, and some species harbour diverse invertebrate communities in their holdfasts. We hypothesised that animal-excavated Durvillaea holdfasts provide a thermal refuge for epibiont species, and tested this hypothesis using the exemplar species D. poha. Using a southern Aotearoa New Zealand population as a case-study, we found extreme temperatures outside the holdfast were 4.4 °C higher in summer and 6.9 °C lower in winter than inside the holdfast. A microclimate model of the holdfasts was built and used to forecast microclimates under 2100 conditions. Temperatures are predicted to increase by 2-3 °C, which may exceed the tolerances of D. poha. However, if D. poha or a similar congeneric persists, temperatures inside holdfasts will remain less extreme than the external environment. The thermal tolerances of two Durvillaea-associated invertebrates, the trochid gastropod Cantharidus antipodum and the amphipod Parawaldeckia kidderi, were also assessed; C. antipodum, but not P. kidderi, displayed metabolic depression at temperatures above and below those inside holdfasts, suggesting that they would be vulnerable outside the holdfast and with future warming. Microclimates, such as those within D. poha holdfasts or holdfasts of similar species, will therefore be important refuges for the survival of species both at the northern (retreating edge) and southern (expanding edge) limits of their distributions.

Long-term changes in autumn-winter harvest distributions vary among duck species, months, and subpopulations

Our aim was to describe shifts in autumn and winter harvest distributions of three species of dabbling ducks (blue-winged teal [Spatula discors], mallard [Anas platyrhynchos], and northern pintail [Anas acuta]) in the Central and Mississippi flyways of North America during 1960-2019. We measured shifts in band recovery distributions corrected for changes in hunting season dates and zones by using kernel density estimators to calculate 10 distributional metrics. We then assessed interannual and intraspecific variation by comparing species-specific changes in distributional metrics for 4 months (October-January) and three geographically based subpopulations. During 1960-2019, band recovery distributions shifted west- and southwards (blue-winged teal) or east- and northwards (mallard and northern pintail) by one hundred to several hundred kilometers. For all three species, the broad (95% isopleth) and core distributions (50% isopleth) showed widespread decreases in overlap and increases in relative area compared to a 1960-1979 baseline period. Shifts in band recovery distributions varied by month, with southward shifts for blue-winged teal most pronounced in October and northward shifts for mallard and northern pintail greatest during December and January. Finally, distributional metric response varied considerably among mallard subpopulations, including 2-4-fold differences in longitude, latitude, and overlap, whereas differences among subpopulations were minimal for blue-winged teal and northern pintail. Our findings support the popular notion that winter (December-January) distributions of duck species have shifted north; however, the extent and direction of distributional changes vary among species and subpopulations. Long-term distributional changes are therefore complex and summarizing shifts across species, months, or subpopulations could mask underlying finer-scale patterns that are important to habitat conservation and population management. A detailed understanding of how species distributions have changed over time will help quantify important drivers of species occurrence, identify habitat management options, and could inform decisions on where to focus conservation or restoration efforts.

Spatial and temporal variations of zooplankton assemblage in Chiffa Wadi (North Algeria)

The spatial and temporal variations in the distribution, abundance, and assemblage structure of zooplankton were examined in the Chiffa Wadi River, north central Algeria. Samples were taken seasonally from autumn 2020 to summer 2022. Nine physical and chemical variables were recorded, and their relationship with the density of 39 zooplankton species was established using canonical correspondence analysis. In order to study the structure of the zooplankton, Shannon-Wiener diversity indices (H'), Margalef richness index (Dmg), Pielou evenness (E), and abundance were calculated. During the analysis, rotifera was the dominant group in the zooplankton community, represented by 27 taxa, followed by Cladocera (9 taxa) and Copepoda (3 taxa). The diversity index indicated the higher richness, abundance, and evenness of zooplankton at a eutrophic site (S2) compared with other sites. The canonical correspondence analysis (CCA) showed that the structure of zooplankton is influenced by local environmental factors. The present study demonstrates that anthropogenic activities including urban discharge and the construction of Algeria's Medea-Chiffa highway, which increased the nutrient load in the aquatic system, disrupted water quality. Consequently, the distribution and quantity of zooplankton were dramatically impacted by these changes in water quality.

Conservation genomics assessment of Tharp's bluestar (Amsonia tharpii) with comparisons to widespread (A. longilora) and narrowly endemic (A. fugatei) congeners

Land-use change and habitat fragmentation are threats to biodiversity. The decrease in available habitat, increase in isolation, and mating within populations can lead to elevated inbreeding, lower genetic diversity, and poor fitness. Here we investigate the genetics of two rare and threatened plant species, Amsonia tharpii and A. fugatei, and we compare them to a widespread congener A. longiflora. We also report the first phylogenetic study of the genus Amsonia (Apocynaceae), including 10 of the 17 taxa and multiple sampling locations, to understand species relationships. We used a double digest restriction-site associated DNA sequencing (ddRADseq) approach to investigate the genetic diversity and gene flow of each species and to create a maximum likelihood phylogeny. The ddRADseq data was mapped to a reference genome to separate out the chloroplast and nuclear markers for population genetic analysis. Our results show that genetic diversity and inbreeding were low across all three species. The chloroplast and nuclear dataset in A. tharpii were highly structured, whereas they showed no structure for A. fugatei, while A. longiflora lacked structure for nuclear data but not chloroplast. Phylogenetic results revealed that A. tharpii is distinct and sister to A. fugatei, and together they are distantly related to A. longiflora. Our results demonstrated that evolutionary history and contemporary ecological processes largely influences genetic diversity within Amsonia. Interestingly, we show that in A. tharpii there was significant structure despite being pollinated by large, bodied hawkmoths that are known to be able to carry pollen long distances, suggesting that other factors are contributing to the structure observed among A. tharpii populations. Conservation efforts should focus on protecting all of the A. tharpii populations, as they contain unique genetic diversity, and a protection plan for A. fugatei needs to be established due to its limited distribution.

Legacies of millennial-scale climate oscillations in contemporary biodiversity in eastern North America

The Atlantic meridional overturning circulation (AMOC) has caused significant climate changes over the past 90 000 years. Prior work has hypothesized that these millennial-scale climate variations effected past and contemporary biodiversity, but the effects are understudied. Moreover, few biogeographic models have accounted for uncertainties in palaeoclimatic simulations of millennial-scale variability. We examine whether refuges from millennial-scale climate oscillations have left detectable legacies in the patterns of contemporary species richness in eastern North America. We analyse 13 palaeoclimate estimates from climate simulations and proxy-based reconstructions as predictors for the contemporary richness of amphibians, passerine birds, mammals, reptiles and trees. Results suggest that past climate changes owing to AMOC variations have left weak but detectable imprints on the contemporary richness of mammals and trees. High temperature stability, precipitation increase, and an apparent climate fulcrum in the southeastern United States across millennial-scale climate oscillations aligns with high biodiversity in the region. These findings support the hypothesis that the southeastern United States may have acted as a biodiversity refuge. However, for some taxa, the strength and direction of palaeoclimate-richness relationships varies among different palaeoclimate estimates, pointing to the importance of palaeoclimatic ensembles and the need for caution when basing biogeographic interpretations on individual palaeoclimate simulations. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

Future changes in society and climate may strongly shape wild large-herbivore faunas across Europe

Restoring wild communities of large herbivores is critical for the conservation of biodiverse ecosystems, but environmental changes in the twenty-first century could drastically affect the availability of habitats. We projected future habitat dynamics for 18 wild large herbivores in Europe and the relative future potential patterns of species richness and assemblage mean body weight considering four alternative scenarios of socioeconomic development in human society and greenhouse gas emissions (SSP1-RCP2.6, SSP2-RCP4.5, SSP3-RCP7.0, SSP5-RCP8.5). Under SSP1-RCP2.6, corresponding to a transition towards sustainable development, we found stable habitat suitability for most species and overall stable assemblage mean body weight compared to the present, with an average increase in species richness (in 2100: 3.03 ± 1.55 compared to today's 2.25 ± 1.31 species/area). The other scenarios are generally unfavourable for the conservation of wild large herbivores, although under the SSP5-RCP8.5 scenario there would be increase in species richness and assemblage mean body weight in some southern regions (e.g. + 62.86 kg mean body weight in Balkans/Greece). Our results suggest that a shift towards a sustainable socioeconomic development would overall provide the best prospect of our maintaining or even increasing the diversity of wild herbivore assemblages in Europe, thereby promoting trophic complexity and the potential to restore functioning and self-regulating ecosystems. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

Range and climate niche shifts in European and North American breeding birds

Species respond dynamically to climate change and exhibit time lags. Consequently, species may not occupy their full climatic niche during range shifting. Here, we assessed climate niche tracking during recent range shifts of European and United States (US) birds. Using data from two European bird atlases and from the North American Breeding Bird Survey between the 1980s and 2010s, we analysed range overlap and climate niche overlap based on kernel density estimation. Phylogenetic multiple regression was used to assess the effect of species morphological, ecological and biogeographic traits on range and niche metrics. European birds shifted their ranges north and north-eastwards, US birds westwards. Range unfilling was lower than expected by null models, and niche expansion was more common than niche unfilling. Also, climate niche tracking was generally lower in US birds and poorly explained by species traits. Overall, our results suggest that dispersal limitations were minor in range shifting birds in Europe and the USA while delayed extinctions from unfavourable areas seem more important. Regional differences could be related to differences in land use history and monitoring schemes. Comparative analyses of range and niche shifts provide a useful screening approach for identifying the importance of transient dynamics and time-lagged responses to climate change. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

Limits on the evolutionary rates of biological traits

This paper focuses on the maximum speed at which biological evolution can occur. I derive inequalities that limit the rate of evolutionary processes driven by natural selection, mutations, or genetic drift. These rate limits link the variability in a population to evolutionary rates. In particular, high variances in the fitness of a population and of a quantitative trait allow for fast changes in the trait's average. In contrast, low variability makes a trait less susceptible to random changes due to genetic drift. The results in this article generalize Fisher's fundamental theorem of natural selection to dynamics that allow for mutations and genetic drift, via trade-off relations that constrain the evolutionary rates of arbitrary traits. The rate limits can be used to probe questions in various evolutionary biology and ecology settings. They apply, for instance, to trait dynamics within or across species or to the evolution of bacteria strains. They apply to any quantitative trait, e.g., from species' weights to the lengths of DNA strands.

Microrefugia and microclimate: Unraveling decoupling potential and resistance to heatwaves

Microrefugia, defined as small areas maintaining populations of species outside their range margins during environmental extremes, are increasingly recognized for their role in conserving species in the face of climate change. Understanding their microclimatic dynamics becomes crucial with global warming leading to severe temperature and precipitation changes. This study investigates the phenomenon of short-term climatic decoupling within microrefugia and its implications for plant persistence in the Mediterranean region of southeastern France. We focus on microrefugia's ability to climatically disconnect from macroclimatic trends, examining temperature and Vapor Pressure Deficit (VPD) dynamics in microrefugia, adjacent control plots, and weather stations. Our study encompasses both "normal" conditions and heatwave episodes to explore the role of microrefugia as thermal and moisture insulators during extreme events. Landscape attributes such as relative elevation, solar radiation, distance to streams, and vegetation height are investigated for their contribution to short-term decoupling. Our results demonstrate that microrefugia exhibit notable decoupling from macroclimatic trends. This effect is maintained during heatwaves, underscoring microrefugia's vital role in responding to climatic extremes. Importantly, microrefugia maintain lower VPD levels than their surroundings outside and during heatwaves, potentially mitigating water stress for plants. This study advances our understanding of microclimate dynamics within microrefugia and underscores their ecological importance for plant persistence in a changing climate. As heatwaves become more frequent and severe, our findings provide insights into the role of microrefugia in buffering but also decoupling against extreme climatic events and, more generally, against climate warming. This knowledge emphasizes the need to detect and protect existing microrefugia, as they can be integrated into conservation strategies and climate change adaptation plans.

Modeling a hot, dry future: Substantial range reductions in suitable environment projected under climate change for a semiarid riparian predator guild

An understanding of species-environmental relationships is invaluable for effective conservation and management under anthropogenic climate change, especially for biodiversity hotspots such as riparian habitats. Species distribution models (SDMs) assess present species-environmental relationships which can project potential suitable environments through space and time. An understanding of environmental factors associated with distributions can guide conservation management strategies under a changing climate. We generated 260 ensemble SDMs for five species of Thamnophis gartersnakes (n = 347)-an important riparian predator guild-in a semiarid and biogeographically diverse region under impact from climate change (Arizona, United States). We modeled present species-environmental relationships and projected changes to suitable environment under 12 future climate scenarios per species, including the most and least optimistic greenhouse gas emission pathways, through 2100. We found that Thamnophis likely advanced northward since the turn of the 20th century and overwinter temperature and seasonal precipitation best explained present distributions. Future ranges of suitable environment for Thamnophis are projected to decrease by ca. -37.1% on average. We found that species already threatened with extinction or those with warm trailing-edge populations likely face the greatest loss of suitable environment, including near or complete loss of suitable environment. Future climate scenarios suggest an upward advance of suitable environment around montane areas for some low to mid-elevation species, which may create pressures to ascend. The most suitable environmental areas projected here can be used to identify potential safe zones to prioritize conservation refuges, including applicable critical habitat designations. By bounding the climate pathway extremes to, we reduce SDM uncertainties and provide valuable information to help conservation practitioners mitigate climate-induced threats to species. Implementing informed conservation actions is paramount for sustaining biodiversity in important aridland riparian systems as the climate warms and dries.

Research on aquatic microcosm: Bibliometric analysis, toxicity comparison and model prediction

Recently, aquatic microcosms have attracted considerable attention because they can be used to simulate natural aquatic ecosystems. First, to evaluate the development of trends, hotspots, and national cooperation networks in the field, bibliometric analysis was performed based on 1841 articles on aquatic microcosm (1962-2022). The results of the bibliometric analysis can be categorized as follows: (1) Aquatic microcosm research can be summarized in two sections, with the first part focusing on the ecological processes and services of aquatic ecosystems, and the second focusing on the toxicity and degradation of pollutants. (2) The United States (number of publications: 541, proportion: 29.5%) and China (248, 13.5%) are the two most active countries. Second, to determine whether there is a difference between single-species and microcosm tests, that is, to perform different-tier assessments, the recommended aquatic safety thresholds in risk assessment [i.e., the community-level no effect concentration (NOECcommunity), hazardous concentrations for 5% of species (HC5) and predicted no effect concentration (PNEC)] were compared based on these tests. There was a significant difference between the NOECcommunity and HC5 (P < 0.05). Moreover, regression models predicting microcosm toxicity values were constructed to provide a reference for ecological systemic risk assessments based on aquatic microcosms.

Deciphering mycobiota and its functional dynamics in root hairs of Rhododendron campanulatum D. Don through Next-gen sequencing

The Himalayas provide unique opportunities for the extension of shrubs beyond the upper limit of the tree. However, little is known about the limitation of the biotic factors belowground of shrub growth at these cruising altitudes. To fill this gap, the present study deals with the documentation of root-associated microbiota with their predicted functional profiles and interactions in the host Rhododendron campanulatum, a krummholz species. While processing 12 root samples of R. campanulatum from the sites using Omics we could identify 134 root-associated fungal species belonging to 104 genera, 74 families, 39 orders, 17 classes, and 5 phyla. The root-associated microbiota members of Ascomycota were unambiguously dominant followed by Basidiomycota. Using FUNGuild, we reported that symbiotroph and pathotroph as abundant trophic modes. Furthermore, FUNGuild revealed the dominant prevalence of the saptroptroph guild followed by plant pathogens and wood saprotrophs. Alpha diversity was significantly different at the sites. The heatmap dendrogram showed the correlation between various soil nutrients and some fungal species. The study paves the way for a more in-depth exploration of unidentified root fungal symbionts, their interactions and their probable functional roles, which may serve as an important factor for the growth and conservation of these high-altitude ericaceous plants.

Projected habitat preferences of commercial fish under different scenarios of climate change

The challenges of commercial species with the threats of climate change make it necessary to predict the changes in the distributional shifts and habitat preferences of the species under possible future scenarios. We aim to demonstrate how future climatic changes will affect the habitat suitability of three species of commercial fish using the predictive technique MaxEnt. The dataset used to extract geographical records included OBIS (54%), GBIF (1%), and literature (45%). The output of the model indicated accurate projections of MaxEnt (AUC above 0.9). Temperature was the main descriptor responsible for the main effects on the distribution of commercial fish. With increasing RCP from 2.5 to 8.5, the species would prefer saltier, higher temperatures and deeper waters in the future. We observed different percentages of suitable habitats between species during RCPs showing distinct sensitivity of each fish in facing climate changes. Negative effects from climate change on the distribution patterns of commercial fish were predicted to lead to varying degrees of reduction and changes of suitable habitats and movement of species towards higher latitudes. The finding emphasizes to implement adaptive management measures to preserve the stocks of these commercial fish considering that the intensification of the effects of climate change on subtropical areas and overexploited species is predicted.

Selective sweep probabilities in spatially expanding populations

Evolution during range expansions shapes biological systems from microbial communities and tumours up to invasive species. A fundamental question is whether, when a beneficial mutation arises during a range expansion, it will evade clonal interference and sweep through the population to fixation. However, most theoretical investigations of range expansions have been confined to regimes in which selective sweeps are effectively impossible, while studies of selective sweeps have either assumed constant population size or have ignored spatial structure. Here we use mathematical modelling and analysis to investigate selective sweep probabilities in the alternative yet biologically relevant scenario in which mutants can outcompete and displace a slowly spreading wildtype. Assuming constant radial expansion speed, we derive probability distributions for the arrival time and location of the first surviving mutant and hence find surprisingly simple approximate and exact expressions for selective sweep probabilities in one, two and three dimensions, which are independent of mutation rate. Namely, the selective sweep probability is approximately 1 - c w t / c m d , where c w t and c m are the wildtype and mutant radial expansion speeds, and d the spatial dimension. Using agent-based simulations, we show that our analytical results accurately predict selective sweep frequencies in the two-dimensional spatial Moran process. We further compare our results with those obtained for alternative growth laws. Parameterizing our model for human tumours, we find that selective sweeps are predicted to be rare except during very early solid tumour growth, thus providing a general, pan-cancer explanation for findings from recent sequencing studies.

Multiple scale assessment of habitat, landscape, and geographic-specific attributes driving decapod assemblages in Posidonia oceanica seagrass meadows

Seagrass meadows are biodiversity hotspots for invertebrate species including decapods. Understanding the drivers of species abundance, richness and diversity of decapod assemblages is crucial for the conservation of such hotspots, but how drivers act across multiple spatial scales remains unexplored. Here we describe the decapod assemblages of Posidonia oceanica seagrass meadows and assess the influence of attributes from three increasing spatial scales (habitat, landscape, and geographical levels) on the assemblages' structure and composition, as well as the variability partitioning among each one of these levels. Overall, geographical level attributes (i.e., inlet aperture, confinement) affected the most the decapod assemblages, while we only found a modest contribution from habitat (e.g., detritus biomass, sediment organic matter) and landscape attributes (e.g., fragmentation). We suggest that decapod assemblages are driven by the interaction of multiple processes occurring at different scales and other highly stochastic phenomena such as larval dispersion and recruitment.

Vrba was right: Historical climate fragmentation, and not current climate, explains mammal biogeography

Climate plays a crucial role in shaping species distribution and evolution over time. Dr Vrba's Resource-Use hypothesis posited that zones at the extremes of temperature and precipitation conditions should host a greater number of climate specialist species than other zones because of higher historical fragmentation. Here, we tested this hypothesis by examining climate-induced fragmentation over the past 5 million years. Our findings revealed that, as stated by Vrba, the number of climate specialist species increases with historical regional climate fragmentation, whereas climate generalist species richness decreases. This relationship is approximately 40% stronger than the correlation between current climate and species richness for climate specialist species and 77% stronger for generalist species. These evidences suggest that the effect of climate historical fragmentation is more significant than that of current climate conditions in explaining mammal biogeography. These results provide empirical support for the role of historical climate fragmentation and physiography in shaping the distribution and evolution of life on Earth.

Bringing genomics to the field: An integrative approach to seed sourcing for forest restoration

Premise

Global anthropogenic change threatens the health and productivity of forest ecosystems. Assisted migration and reforestation are tools to help mitigate these impacts. However, questions remain about how to approach sourcing seeds to ensure high establishment and future adaptability.

Methods

Using exome-capture sequencing, we demonstrate a computational approach to finding the best n-sets from a candidate list of seed sources that collectively achieve high genetic diversity (GD) and minimal genetic load (GL), while also increasing evolvability in quantitative traits. The benefits of this three-part strategy (diversity-load-evolvability) are to increase near-term establishment success while also boosting evolutionary potential to respond to future stressors. Members of The Nature Conservancy and the Central Appalachian Spruce Restoration Initiative planted 58,000 seedlings across 255 acres. A subset of seedlings was monitored for establishment success and variation in growth.

Results

The results show gains in GD relative to GL and increases in quantitative genetic variation in seedling growth for pooled vs. single-source restoration. No single "super source" was observed across planting sites; rather, monitoring results demonstrate that pooling of multiple sources helps achieve higher GD:GL and evolvability.

Discussion

Our study shows the potential for integrating genomics into local-scale restoration and the importance of building partnerships between academic researchers and applied conservation managers.

Leopard subspecies conservation under climate and land-use change

Predicting the effects of global environmental changes on species distribution is a top conservation priority, particularly for large carnivores, that contribute to regulating and maintaining ecosystems. As the most widespread and adaptable large felid, ranging across Africa and Asia, leopards are crucial to many ecosystems as both keystone and umbrella species, yet they are threatened across their ranges. We used intraspecific species distribution models (SDMs) to predict changes in range suitability for leopards under future climate and land-use change and identify conservation gaps and opportunities. We generated intraspecific SDMs for the three western leopard subspecies, the African, Panthera pardus pardus; Arabian, Panthera pardus nimr; and Persian, Panthera pardus tulliana, leopards, and overlapped predictions with protected areas (PAs) coverage. We show that leopard subspecies differ in their environmental associations and vulnerability to future changes. The African and Arabian leopards are predicted to lose ~25% and ~14% of their currently suitable range, respectively, while the Persian leopard is predicted to experience ~12% range gains. We found that most areas predicted to be suitable were not protected, with only 4%-16% of the subspecies' ranges falling inside PAs, and that these proportions will decrease in the future. The highly variable responses we found between leopard subspecies highlight the importance of considering intraspecific variation when modelling vulnerability to climate and land-use changes. The predicted decrease in proportion of suitable ranges falling inside PAs threatens global capacity to effectively conserve leopards because survival rates are substantially lower outside PAs due to persecution. Hence, it is important to work with local communities to address negative human-wildlife interactions and to restore habitats to retain landscape connectivity where PA coverage is low. On the other hand, the predicted increase in range suitability across southern Europe presents opportunities for expansion outside of their contemporary range, capitalising on European rewilding schemes.

Marine fishes experiencing high-velocity range shifts may not be climate change winners

Climate change is driving the global redistribution of species. A common assumption is that rapid range shifts occur in tandem with overall stable or positive abundance trends throughout the range and thus these species may be considered as climate change 'winners'. However, although establishing the link between range shift velocities and population trends is crucial for predicting climate change impacts it has not been empirically tested. Using 2,572 estimates of changes in marine fish abundance spread across the world's oceans, we show that poleward range shifts are not necessarily associated with positive population trends. Species experiencing high-velocity range shifts seem to experience local population declines irrespective of the position throughout the species range. High range shift velocities of 17 km yr-1 are associated with a 50% decrease in population sizes over a period of 10 yr, which is dramatic compared to the overall stable population trends in non-shifting species. This pattern, however, mostly occurs in populations located in the poleward, colder, portion of the species range. The lack of a positive association between poleward range shift velocities and population trends at the coldest portion of the range contrasts with the view that rapid range shifts safeguard against local population declines. Instead, our work suggests that marine fishes experiencing rapid range shifts could be more vulnerable to climatic change and therefore should be carefully assessed for conservation status.

Aquatic connectivity: challenges and solutions in a changing climate

The challenge of managing aquatic connectivity in a changing climate is exacerbated in the presence of additional anthropogenic stressors, social factors, and economic drivers. Here we discuss these issues in the context of structural and functional connectivity for aquatic biodiversity, specifically fish, in both the freshwater and marine realms. We posit that adaptive management strategies that consider shifting baselines and the socio-ecological implications of climate change will be required to achieve management objectives. The role of renewable energy expansion, particularly hydropower, is critically examined for its impact on connectivity. We advocate for strategic spatial planning that incorporates nature-positive solutions, ensuring climate mitigation efforts are harmonized with biodiversity conservation. We underscore the urgency of integrating robust scientific modelling with stakeholder values to define clear, adaptive management objectives. Finally, we call for innovative monitoring and predictive decision-making tools to navigate the uncertainties inherent in a changing climate, with the goal of ensuring the resilience and sustainability of aquatic ecosystems.

Regional reef fish assemblage maps provide baseline biogeography for tropicalization monitoring

The Anthropocene rise in global temperatures is facilitating the expansion of tropical species into historically non-native subtropical locales, including coral reef fish. This redistribution of species, known as tropicalization, has serious consequences for economic development, livelihoods, food security, human health, and culture. Measuring the tropicalization of subtropical reef fish assemblages is difficult due to expansive species ranges, temporal distribution shifts with the movement of isotherms, and many dynamic density-dependent factors affecting occurrence and density. Therefore, in locales where tropical and subtropical species co-occur, detecting tropicalization changes relies on regional analyses of the relative densities and occurrence of species. This study provides a baseline for monitoring reef fish tropicalization by utilizing extensive monitoring data from a pivotal location in southeast Florida along a known transition between tropical and subtropical ecotones to define regional reef fish assemblages and use benthic habitat maps to spatially represent their zoogeography. Assemblages varied significantly by ecoregion, habitat depth, habitat type, and topographic relief. Generally, the southern assemblages had higher occurrences and densities of tropical species, whereas the northern assemblages had a higher occurrence and density of subtropical species. A total of 108 species were exclusive to regions south of the Bahamas Fracture Zone (BFZ) (South Palm Beach, Deerfield, Broward-Miami) and 35 were exclusive to the north (North Palm Beach, Martin), supporting the BFZ as a pivotal location that affects the coastal biogeographic extent of tropical marine species in eastern North America. Future tropicalization of reef fish assemblages are expected to be evident in temporal deviance of percent occurrence and/or relative species densities between baseline assemblages, where the poleward expansion of tropical species is expected to show the homogenization of assemblage regions as adjacent regions become more similar or the regional boundaries expand poleward. Ecoregions, habitat depth, habitat type, and relief should be incorporated into the stratification and analyses of reef fish surveys to statistically determine assemblage differences across the seascape, including those from tropicalization.