A globally coherent fingerprint of climate change impacts across natural systems

Incipient Range Expansion of Green Turtles in the Mediterranean

In response to global climate change, numerous taxa are expanding their living ranges. In highly migratory species such as sea turtles, this expansion may be driven by individuals from nearby or distant areas. Recent nests outside the species' typical nesting range and reports of adult-sized individuals in the western Mediterranean suggest a green turtle (Chelonia mydas) range expansion into the central and western Mediterranean. To assess the green turtles' origin in these novel habitats, we built a genomic baseline using 2bRAD sequencing on five individuals from each of three Regional Management Units (RMUs): North Atlantic, South Atlantic and Mediterranean. We then compared this baseline with genotyped hatchlings from three nests laid in new central and eastern Mediterranean sites and four mature-sized green turtles tagged with satellite telemetry in the western Mediterranean. Our analyses revealed that the Tunisia nest originated from the South Atlantic RMU, while the Crete nests were produced by turtles from the Mediterranean RMU. Additionally, the three adult-sized turtles sampled in the southwestern Mediterranean were assigned to the South Atlantic RMU, while the mature-sized individual sampled in the northwestern Mediterranean belonged to the Mediterranean RMU. These results suggest a simultaneous incipient colonisation by two geographically distant RMUs. We propose that the range expansion of green turtles into the central and western Mediterranean is likely climate driven and these populations may become globally important as temperatures rise. Finally, our results highlight the essential role of the cost-effective RAD-Seq genomic assessment combined with tagging data to understand potential new colonisations.

Setting the limit: cold rather than hot temperatures limit intertidal distribution of a coastal foundation species

Long-lasting restoration success of foundation species requires understanding their responses to climate change. For species with broad distributions, lower latitudes may serve as a proxy for future warming at higher latitudes. Such space-for-time substitutions are a powerful tool for developing climate change predictions for species distributed along steep elevational gradients. To understand climate resilience of a key coastal foundation species, we examined the upper elevational limit of the native Olympia oyster (Ostrea lurida) along its entire range at 26 sites spanning 21° latitude, from British Columbia to Baja California. Counter to our expectations, high air temperatures did not affect variation in the upper limit of Olympia oysters. Indeed, Olympia oysters extended high into the intertidal zone at the warmer southern sites, and shading did not influence the upper limit. Our models indicated instead that extreme low temperatures set the upper limit for Olympia oysters at higher latitudes. In contrast, neither the Pacific oyster (Magallana gigas), a co-occurring global invader, nor barnacles exhibited clear latitudinal patterns. These findings suggest that Olympia oysters and restoration projects aimed at supporting their recovery will be resilient to increased temperatures projected by climate change models. Our results also illustrate the importance of testing the assumption that species on steep elevational gradients are living close to their upper thermal limits and will be negatively impacted by warming; for this foundation species, the assumption was false. Latitudinal studies enhance understanding of species response to climate stressors and are key to the design of climate-resilient conservation strategies.

The evolution of thermal performance curves in response to rising temperatures across the model genus yeast

The maintenance of biodiversity crucially depends on the evolutionary potential of populations to adapt to environmental change. Accelerating climate change and extreme temperature events urge us to better understand and forecast evolutionary responses. Here, we harnessed the power of experimental evolution with the microbial model system yeast (Saccharomyces spp.) to measure the evolutionary potential of populations to adapt to future warming, in real-time and across the entire phylogenetic diversity of the genus. We tracked the evolution of thermal performance curves (TPCs) in populations of eight genetically and ecologically diverse species under gradually increasing temperature conditions, from 25 to 40 °C, for up to 600 generations. We found that evolving toward higher critical thermal limits generally came at a cost, causing a decrease in both thermal tolerance and maximum growth performance. The evolution of TPCs varied significantly between species with strong genotype-by-environment interactions, revealing two main trajectories: i) Warm-tolerant species showed an increase in both optimum growth temperature and thermal tolerance, consistent with the "hotter is wider" hypothesis. ii) Cold-tolerant species on the other hand evolved larger thermal breadth and higher thermal limits, but suffered from reduced maximum performance overall, consistent with the generalist or "a jack of all temperatures is a master of none" hypothesis. In addition, cold-tolerant species never reached the warm-tolerant species' upper thermal limits. Our results show that adaptive strategies to increasing temperatures are complex, highlighting the need to consider both within and between species diversity when predicting and managing the impacts of climate change on populations.

Individual clown anemonefish shrink to survive heat stress and social conflict

Vertebrate growth is generally considered to be unidirectional, but challenging environmental conditions, such as heatwaves, may disrupt normal growth patterns and affect individual survival. Here, we investigate the growth of individual clown anemonefish, Amphiprion percula, during a marine heatwave. We measured the length of 134 wild clown anemonefish every month and monitored temperature at the scale of their anemone for five lunar months. Our results show that clown anemonefish shrink in response to heat stress and individuals that shrink also display relatively more catch-up growth. Further, shrinking is modulated by social rank and size, and individuals that shrink more often and in a coordinated fashion with their breeding partner have higher survival during the heat stress event. In conclusion, a plastic individual growth response to heat stress, constrained by the social environment, can lead to short-term survival benefits. If this plasticity were widespread in fishes, it may have marked consequences for populations and communities as heatwaves become more frequent.

Range size and abundance dynamics of Japanese breeding birds over 40 years suggest a potential crisis in warm areas

Understanding the current status of biodiversity is crucial to preventing its loss in a changing world. We examined changes in the geographical range size and abundance of 165 bird species breeding in Japan during the past 40 years, as well as temperature niche changes in the past 20 years. Higher temperatures were recorded within the ranges of non-native species than in those of native species, and we detected range-size expansion and increased abundance among non-native species. Although open-land species exhibited range reductions from the 1970s to the 1990s, many recovered and the ranges of only a few species declined after this period. Nevertheless, the abundance of open-land species did decline, despite range-size recovery; similar inconsistencies were detected for waterbirds and raptors. Analysis of long-term temperatures suggested that species left warmest areas within their distributions while maximum temperatures experienced by species during the survey years did not change systematically. Birds in warm regions may be facing a crisis, with attrition of native bird communities and expansion of non-native species. It is necessary to establish efficient measures to prevent further expansions of non-native species and conservation measures of native species within managed areas in warm regions with few intact habitats.

Phylogenetic relatedness and plant traits influenced flowering phenology change patterns in natural habitats in China (2003-2021)

BACKGROUND

Phenology research has provided important insights on the influence of climate change on ecosystems. Investigation of spatial and interspecific difference can help us to better understand the phenology change pattern. In this study, observational data for 190 species collected from 2003 to 2021 at eight ecological stations in China were assessed via linear regression to detect trends in first flowering date (FFD), air temperature, and precipitation. We then examined the relationship between FFD change patterns, air temperature and precipitation through redundancy analysis, calculated the relative importance of phylogenetic relatedness, climate change, site conditions and plant traits in explaining variations in FFD change intensity using boosted regression tree method.

RESULTS

We found that (1) FFDs of nearly 40% of the observed species changed significantly (p < 0.05), with species showing advanced and delayed FFDs accounting for half. (2) Air temperature increased at most stations, particularly in spring and summer, while precipitation decreased in humid and subhumid temperate zones and increased during most seasons in arid temperate and subtropical zones. (3) Spatial differences were observed in FFD trends. At stations in Northeast, North, and Southwest China, which are regions with increased temperature, the percentage of species with advanced FFD was higher than that of species with delayed FFD, with the mean trend ranging from - 2.4 to - 6.5 d decade- 1. Conversely, at stations distributed in Northwest and South China, which are regions with increased precipitation, the percentage of species with advanced FFD was lower than that of species with delayed FFD, with the mean trend ranging from 1.3 to 7.1 d decade- 1. (4) Air temperature and precipitation had a stronger influence on FFD change in the temperate zone than in the subtropical zone. Climate factors with the greatest influence on FFD change patterns varied with the observation site. Interspecific variations in FFD change intensity were mostly explained by phylogenetic relatedness, although plant traits, site conditions, and climate change also had a certain effect.

CONCLUSIONS

Our research found that the first flowering phenology of large percent of the observed plants changed significantly from 2003 to 2021, showing spatial and interspecific differences across observation sites. Our research also demonstrated the importance of plant phylogeny on interspecific differences in phenological changes, plant traits such as growth form, plant height, and flowering time influence flowering phenology to a certain extent. These findings will help us to better understand phenological responses to climate change on a national scale, and help us better predict the response of various plants to climate change in the future.

Multiple source locations and long-distance dispersal explain the rapid spread of a recent amphibian invasion

Rapid range expansions are characteristic for non-native invasive species when introduced outside their native range. Understanding the dynamics and mechanisms of expanding non-native invasive species is key for regional management. While population genetics and long-term occurrence records are often used in this context, each provides only partial insights, highlighting the need for a combined approach. We demonstrate this synergy using the American bullfrog (Lithobates catesbeianus) invasion in the Grote Nete river valley (Belgium) as a case study. It is commonly believed that this invasion constitutes a single metapopulation established by one primary introduction followed by downstream dispersal. However, recent evidence suggests a more complex scenario, involving introduction at multiple locations and bidirectional dispersal. To differentiate between both scenarios, we analysed nearly three decades of occurrence records and 8592 single nucleotide polymorphisms across 372 individuals from 31 localities, and determined the number of source locations, the range expansion rate, the population genetic structure, and the magnitude and direction of gene flow. We found that invasive spread originated from up to six source locations followed by bidirectional dispersal and downstream long-distance dispersal (LDD) events. Our results suggest that at least two source locations were founded by primary introductions, two from LDD events, while the remaining resulted from secondary introductions. A canal crossing the river was identified as a dispersal barrier, leading to different invasion dynamics on both sides. Our study shows how asynchronous introductions at multiple locations, dispersal barriers, and environmental heterogeneity can lead to distinct spread dynamics within a seemingly continuous and interconnected metapopulation.

Using Fitness Surfaces to Better Link Conservation Breeding Programmes With Wild Population Recovery

Fitness surfaces offer a valuable tool for bridging the gap between captive breeding programmes and wild populations. By quantifying the relationship between phenotypes and reproductive success in captive and wild settings, fitness surfaces can help identify the fitness consequences of phenotypic change in either environment. Measuring fitness surfaces in captive and wild populations from the same species would help us to predict the success of reintroduction efforts and help inform the selection of release candidates. Overall, the inclusion of fitness surface estimates into conservation breeding programmes increases the effectiveness of reintroduction efforts and should improve our understanding of evolution at the interface of human-managed and wild populations. Beyond conservation breeding, fitness surfaces may have applications for at-risk species such as predicting outcomes in range expansions, translocation or under changing environmental conditions.

Geometric Insights into evolutionary rescue dynamics in a two-deme model

Understanding evolutionary rescue mechanisms in fragmented populations is crucial in the context of rapidly changing environments. This study employs analytical derivations and simulations within a two-deme metapopulation model using Fisher's geometric model framework. We explore the impacts of abrupt environmental changes on two subpopulations that lead to distinct phenotypic optima. We determine the probability density of distances between these optima through analytical derivations. This enables us to calculate the intersection volume of the rescue domains of two subpopulations in the phenotypic space. This approach also allows us to assess the fixation probability of mutations that concurrently rescue both subpopulations and identify the domain of one-step rescue mutations. Our findings reveal that the likelihood of joint evolutionary rescue diminishes with increasing dimensionality of the phenotypic space, posing significant challenges for species with complex trait configurations. The study underscores the importance of genetic variation due to de novo mutations, local adaptation, and migration rates. These insights enhance our understanding of the factors that govern the adaptive potential of fragmented populations in response to severe environmental disturbances.

Reimagining species on the move across space and time

Climate change is already leaving a broad footprint of impacts on biodiversity, from an individual caterpillar emerging earlier in spring to dominant plant communities migrating poleward. Despite the various modes of how species are on the move, we primarily document shifting species along only one gradient (e.g., latitude or phenology) and along one dimension (space or time). In this opinion article we present a unifying framework for integrating the study of species on the move over space and time and from micro to macro scales. Future conservation planning and natural resource management will depend on our ability to use this framework to improve understanding, attribution, and prediction of species on the move.

Species Richness and Distribution of Calliphoridae Along an Elevation Gradient in Sicily (Italy) and Ecuador

Blow flies (Diptera: Calliphoridae) are among the first insects to arrive on a corpse, and so they are particularly important in forensic entomology. To use blow flies in forensic investigations, there must be information available on their species diversity, abundance, and distribution in the areas where investigations are conducted. Several factors can contribute to species distribution, and elevation is one of those factors. The purpose of this study was to document the distribution of Calliphoridae across four elevational gradients in Sicily and Ecuador, where little information is available. Baited traps were placed at elevations ranging from 20 m to 1552 m in Sicily (a major island and region of Italy and a distinct ecoregion) and 561 m to 3336 m in Ecuador. Species richness, relative abundance, and diversity were calculated, as well as the ratio of female to male blow flies and community assemblage. Twelve species were collected in Sicily, and seventeen species were collected in Ecuador. In Sicily, the most abundant species was Lucilia sericata (Meigen) (68.50% of the total capture), while in Ecuador, it was Compsomyiops verena (Walker) (51.67% of the total capture). In Sicily, significant differences were only observed in the relative abundance of L. sericata across elevations. In Ecuador, significant differences were observed in the relative abundance of Calliphora nigribasis (Macquart), Chrysomya albiceps (Wiedemann), C. verena, Hemilucilia semidiaphana (Rondani), Lucilia ibis (Shannon), L. purpurascens (Walker), and Paralucilia sp. across elevations. These data can help build a checklist of blow fly species in these two regions and can be instrumental in environmental and forensic investigations.

Strong genetic differentiation and low genetic diversity in a habitat-forming fucoid seaweed (Cystophora racemosa) across 850 km of its range

Temperate seaweed forests are among the most productive and widespread habitats in coastal waters. However, they are under threat from climate change and other anthropogenic stressors. To effectively conserve and manage these ecosystems under these rising pressures, an understanding of the genetic diversity and structure of habitat-forming seaweeds will be necessary. Australia's Great Southern Reef, a global hotspot of endemic diversity, is home to one of the world's most speciose habitat-forming seaweed genera, Cystophora (order Fucales). Despite severe declines in some species, genomic data on this genus remain limited. We used a reduced representation genomic approach (DaRTSeq) to investigate the genetic diversity and structure of Cystophora racemosa, a dominant canopy-forming species, across ~850 km of its range. Our sequencing captured 4741 high-quality single nucleotide polymorphisms (SNPs), and we distinguished neutral loci from those under natural selection (i.e., outlier loci). We identified strong population structure and high genetic differentiation for both neutral (mean FST = 0.404) and outlier loci (mean FST = 0.901). Across populations, genetic diversity was low (neutral: mean HE = 0.046; outlier: HE = 0.042), with high inferred inbreeding (neutral loci mean FIS = 0.531) and no evidence of isolation-by-distance. Several SNPs (n = 70) were observed to be putatively adaptive, with most (97%) correlated with annual maximum sea surface temperature (SST, °C), indicating local adaptation to this key ocean variable. Our results show that C. racemosa populations have low genetic diversity and high differentiation, both of which may increase the vulnerability of this important foundation species to global change.

Matching the green wave: growing season length determines embryonic diapause in roe deer

The roe deer (Capreolus capreolus) is Europe's most widespread ungulate, notable for its unique trait of embryonic diapause (delayed blastocyst implantation after mating) and an ongoing debate regarding how climate change affects its parturition timing. Given the relatively constant timing of the rut, roe deer could cope with advancing greening by adjusting its diapause end. Here, we bridge the gap on factors influencing roe deer's diapause by analysing 390 uteri from legally hunted roe deer females in Germany (2017-2020), which we macroscopically examined for the presence of visible embryonic tissue to retrospectively identify the diapause end date. By employing a marginal Cox proportional hazard model, we tested associations between female phenotypic attributes, environmental conditions and the probability of ending embryonic diapause prematurely. Our results confirmed that high-quality, well-conditioned and prime-aged females tend to terminate embryonic diapause earlier. We also demonstrated for the first time that on a population-averaged level, the growing season length in the year of conception significantly influences the diapause timing, even explaining the much-debated shifts in parturition dates in roe deer over the last seven decades. Increased knowledge of mechanisms involved in embryonic diapause may also help decipher embryo-maternal interactions in general, including in vitro fertilization.

Geographic Variation in Epigenetic Responses to Hypoxia in Deer Mice (Peromyscus maniculatus) Distributed Along an Elevational Gradient

Lowland and highland Peromyscus maniculatus populations display divergent, locally adapted physiological phenotypes shaped by altitudinal differences in oxygen availability. Many physiological responses to hypoxia seem to have evolved in lowland ancestors to offset episodic and localised bouts of low internal oxygen availability. However, upon chronic hypoxia exposure at high elevation, these responses can lead to physiological complications. Therefore, highland ancestry is often associated with evolved hypoxia responses, particularly traits promoting tolerance of constant hypoxia. Environmentally induced DNA methylation can dynamically alter gene expression patterns, providing a proximate basis for phenotypic plasticity. Given each population's differential reliance on plasticity for hypoxia tolerance, we hypothesised that lowland mice have a more robust epigenetic response to hypoxia exposure, driving trait plasticity, than highland mice. Using DNA methylation data of tissues from the heart's left ventricle, we show that upon hypoxia exposure, lowland mice chemically modulate the epigenetic landscape to a greater extent than highland mice, especially at key hypoxia-relevant genes such as Egln3. This gene is a regulator of the gene Epas1 that is frequently targeted for positive selection at high elevation. We find higher methylation among wild highland mice at gene Egln3 compared to wild lowland mice, suggesting a shared epigenetic ancestral response to episodic and chronic hypoxia. These findings highlight each population's distinct reliance on molecular plasticity driven by their unique evolutionary histories.

Shifts in vernalization and phenology at the rear edge hold insight into the adaptation of temperate plants to future milder winters

Temperate plants often regulate reproduction through winter cues, such as vernalization, that may decrease under climate change. Studies of rear-edge populations, glacial relicts that persist in environments that have warmed since the last glaciation, can provide insight into the adaptive potential to milder winters. We studied how rear-edge populations have adapted to shorter winters and compared them to the rest of the range in the herb Campanula americana. Using citizen science, climate data and experimental climate manipulation, we characterize variation in vernalization requirements and reproductive phenology across the range and their potential climatic drivers. Rear-edge populations experienced little to no vernalization in nature. In climate manipulation experiments, these populations also had a reduced vernalization requirement, a weaker response to changes in vernalization length and flowered later compared to the rest of the range. Our results suggest shifts in phenology and its underlying regulation at the rear edge to compensate for unreliable vernalization cues. Thus, future milder winters may be less detrimental to these populations than more northern ones. Furthermore, our results showcase strong adaptive shifts at the rear edge of temperate plants' ranges, highlighting the importance of these areas in studies of predicted future climates.

Shrinking body size under climate warming is not associated with selection for smaller individuals in a migratory bird

How species are responding to climate change is a key topic in evolutionary ecology. Increasing temperatures are expected to affect phenotypic traits involved in thermoregulation, thus decreasing body size and/or increasing body appendages associated with heat exchange, as predicted by Bergmann's and Allen's rules. Results from long-term studies of variation in morphology over time have generally provided results supporting these predictions. However, two outstanding questions are frequently raised in studies relating changes in phenotypes to increasing temperatures: (1) whether such changes involve a shift in animal shape through the non-proportional variation of different body parts; and (2) whether they result from adaptive evolutionary responses. Relying on capture-recapture histories of almost 9000 breeding individuals from a declining Italian population of an Afro-Palearctic migratory bird, the barn swallow (Hirundo rustica), we documented a decrease in some body size traits (body mass, keel and wing length) over a 31-year period (1993-2023), with body mass declining the most (up to 4.0% in males). However, this was not the case for bill and partly tarsus length. Intra-individual lifelong changes in morphological traits of sexually mature birds showed only a limited contribution to trends over time in phenotypically plastic morphological traits. Viability and fecundity selection analyses revealed that smaller individuals did not enjoy greater success compared to larger ones. For some traits, the opposite was actually the case. The shifts in body size and, partly, shape over time we observed were coherent with predictions deriving from Bergmann's and Allen's rules. Yet, natural selection did not consistently favour smaller individuals. We thus call for caution in interpreting recent decreases in body size as adaptive evolutionary responses to climate warming, as they may rather reflect phenotypically plastic responses to changing climatic/environmental conditions occurring during early ontogenetic stages.

Linking ringed seal foraging behaviour to environmental variability

BACKGROUND

Foraging rates directly influence animals' energetic intake and expenditure and are thus linked to body condition and the ability to survive and reproduce. Further, understanding the underlying processes driving a species' behaviour and habitat use is important as changes in behaviour could result from changes in environmental conditions.

METHODS

In this study, the dives of Saimaa ringed seals (Pusa hispida saimensis) were classified for the first time using hidden Markov models and telemetry data collected on individual dives, and the behavioural states of the diving seals were estimated. In addition, we used generalized additive mixed models on the foraging probability of the seals to identify environmental and temporal drivers of foraging behaviour.

RESULTS

We inferred three (in winter) or four (in summer) different dive types: sleeping/resting dives, shallow inactive dives, transiting dives and foraging dives, based on differences in dive metrics logged by or derived from data from telemetry tags. Long and relatively deep sleeping/resting dives were missing entirely in the winter, compensated by an increased proportion of time used for haul-out. We found profound differences in the behaviour of Saimaa ringed seals during the open water season compared to the ice-covered winter, with the greatest proportion of time allocated to foraging during the summer months (36%) and the lowest proportion in the winter (21%). The seals' foraging probability peaked in summer (July) and was highest during the daytime during both summer and winter months. Moreover, foraging probability was highest at lake depths of 7-30 m in the winter and at depths > 15 m in the summer. We also found some evidence of sex-specific foraging strategies that are adapted seasonally, with females preferring more sheltered water areas during winter.

CONCLUSIONS

We suggest that the foraging behaviour of Saimaa ringed seals is largely influenced by diel vertical movements and availability of fish, and that the seals optimize their energy acquisition while conserving energy, especially during the cold winter months. Further, the seals display some flexibility in foraging strategies, a feature that may help this endangered subspecies to cope with the ongoing climate change.

Timing mismatches, carryover effects, and the role of neuroendocrine mechanisms in determining birds' responses to environmental change

The neuroendocrine system plays a critical role in the synchronization of life cycle stages with variation in the environment, and in the coordination of life cycle stages with one another. When humans modify environments, these neuroendocrine mechanisms may impact how different individuals, populations, species, and even communities are affected. Here we conceptualize how endocrine mechanisms may influence the likelihood of: (1) timing mismatches between life cycle stages and environmental conditions, and (2) carryover effects within annual cycles. Timing mismatches can occur when an individual fails to synchronize a particular life cycle stage to the appropriate environmental conditions. Carryover effects occur when activities of one stage (including its timing) affect the performance in one or more subsequent stages. We suggest that there is a trade-off between timing adjustments within and across stages such that neuroendocrine mechanisms that reduce timing mismatches in temporally changing environments (e.g., strong neuroendocrine responsiveness to short-term cues, with resultant increased temporal flexibility to fine-tune the current stage to local conditions) may inherently increase the likelihood of carryover effects (e.g., through delay of a transition between stages), and vice versa. We use two examples-flexibility of the onset of photorefractoriness mediated by responsiveness to short-term cues, and sensitivity of molt to sex steroids-to illustrate these ideas, and suggest that future work should investigate the impacts of variation in these and potentially other seasonal timing mechanisms on carryover effects. The conceptual framework presented here suggests that there may be no single best set of tactics for coping with the effects of climate change; species with neuroendocrine mechanisms facilitating temporal flexibility may avoid some timing mismatches but set themselves up for deleterious carryover effects as they make temporal adjustments to environmental conditions modified by climate change.

Pronghorn movements and mortality during extreme weather highlight the critical importance of connectivity

Human disturbance and development are fragmenting landscapes, limiting the ability of organisms to freely move to meet their survival and reproductive needs. Simultaneously, extreme weather events-such as tropical cyclones, megafires, and heatwaves-pose a major threat to survival and may require animals to rapidly move to escape. As the dual forces of landscape fragmentation and extreme weather events continue to intensify, researchers urgently need to develop an understanding of the synergistic effects of these forces on animal mobility and survival. Here, we present a case study on pronghorn (Antilocapra americana) that undertook extraordinary long-distance movements (up to 399 km) to escape a once-in-two-decades extreme snowstorm in the Red Desert, WY, USA. Although Wyoming is a seemingly underdeveloped landscape, high fence density and two major highways in the region exposed pronghorn to novel barriers that delayed movement, restricted habitat access, and ultimately hindered their ability to escape extreme snow accumulation. The synergistic effects of movement barriers and extreme weather increased mortality rates by 3.7-fold such that over 50% of GPS-monitored pronghorn perished. These findings highlight the critical need to study escape movements and prioritize connectivity planning to curtail mass mortality events and ensure population persistence.

The global determinants of climate niche breadth in birds

Understanding why certain species occupy wider climate niches than others is a fundamental pursuit in ecology with important implications for conservation and management. However, existing synthesis on this topic has focused on the consequences rather than the causes of climate niche expansion, leading to significant gaps in our understanding of the possible evolutionary drivers of this important ecological property. Here we leverage species distribution models powered by millions of citizen science sightings of birds to determine how a comprehensive suite of parameters influences the breadth of climate niches. Our analyses show that migration and more central locations in climate space are directly associated with wider climate niches. Additionally, they indicate that larger brains, smaller bodies, and broader dietary requirements are indirectly associated with narrower niches, presumably because they enable the occupancy of geographically widespread habitats that occupy narrow areas in climate niche space. Through follow-up analyses we further clarify how the different factors considered in this study help shape niche breadth by affecting the colonization of more versus less frequently used habitats. Overall, our findings shed light on critical, yet highly underappreciated properties of climate niches, underscoring the complexity and interconnectivity of the factors that shaped their evolution among birds.

Anatomy of a range contraction: Flow-phenology mismatches threaten salmonid fishes near their trailing edge

Climate change is redistributing life on Earth, with profound impacts for ecosystems and human well-being. While repeat surveys separated by multidecadal intervals can determine whether observed shifts are in the expected direction (e.g., poleward or upslope due to climate change), they do not reveal their mechanisms or time scales: whether they were gradual responses to environmental trends or punctuated responses to disturbance events. Here, we document population reductions and temporary range contractions at multiple sites resulting from drought for three Pacific salmonids at their ranges' trailing edge. During California's 2012 to 2016 historic multiyear drought, the 2013 to 2014 winter stood apart because rainfall was both reduced and delayed. Extremely low river flows during the breeding season ("flow-phenology mismatch") reduced or precluded access to breeding habitat. While Chinook (Oncorhynchus tshawytscha) experienced a down-river range shift, entire cohorts failed in individual tributaries (steelhead trout, O. mykiss) and in entire watersheds (coho salmon, O. kisutch). Salmonids returned to impacted sites in subsequent years, rescued by reserves in the ocean, life history diversity, and, in one case, a conservation broodstock program. Large population losses can, however, leave trailing-edge populations vulnerable to extinction due to demographic stochasticity, making permanent range contraction more likely. When only a few large storms occur during high flow season, the timing of particular storms plays an outsized role in determining which migratory fish species are able to access their riverine breeding grounds and persist.

The Role of Intrinsic Factors in Explaining Range Shifts of European Breeding Birds: A Meta-Analysis

Species are shifting their distribution ranges in response to climate and land-use change. However, the observed range shift patterns are idiosyncratic in rate and direction. Species traits, such as ecological, life-history and movement traits, may play an important role in determining range shifts by influencing a species' capacity to shift successfully. Whilst several studies investigate the role of different species traits in driving range shifts, they generally consider few traits and range shift types. Range shift types such as abundance shift and centroid shift are generally not taken into account. Drivers of range shifts may, however, differ per range shift type. We conducted a meta-analysis to uncover the role of intrinsic factors (nine species functional traits and five spatial abundance characteristics) in explaining six contemporary range shift types (range size changes: expansion/contraction, relative change and rate of change; latitudinal shifts: abundance shift, centroid shift and range margin shift) in European breeding birds (n = 270). We found that the role of intrinsic factors in explaining contemporary range shifts in European breeding birds is indeed range shift type dependent. Natal dispersal distance and clutch size were, for instance, positively related to range size changes, while diet breadth and conservation status showed both negative and positive relationships depending on the range shift type. Acknowledging limitations regarding unevenness of data availability across the study region, the region of study was an important predictor for range size changes, suggesting a relative importance of local context and extrinsic drivers. Future trait-based analyses of range shifts would benefit from accounting for intraspecific variation in functional traits across time and space, the inclusion of additional traits like phenological traits, exposure to environmental pressures, and competitive ability, and should be investigated across multiple scales and for multiple types of range shifts.

A Picky Predator and Its Prey: How Snow Conditions and Ptarmigan Abundance Impact Gyrfalcon Feeding Behaviour and Breeding Success

Species interactions can be altered by climate change but can also mediate its effects. The gyrfalcon (Falco rusticolus) and the ptarmigan (Lagopus spp.) form a predator-prey couple that reflects the dynamics of boreal, tundra, and alpine ecosystems. To determine how climate change may impact the alpine food web, we investigated how ptarmigan abundance and local weather impact gyrfalcon diet and feeding behaviour, nest occupancy, and reproductive success. Using wildlife cameras, we monitored gyrfalcon nests throughout the nestling period to collect data on diet and feeding behaviour. We quantified the gyrfalcon's functional response by describing how ptarmigan kill rates relate to ptarmigan density. Additionally, we quantified the gyrfalcon's numerical demographic and aggregative response by describing how gyrfalcon reproductive success and nest occupancy, respectively, were related to ptarmigan density, using data from large-scale monitoring projects. Ptarmigan were the dominant prey species, representing 98% of the diet. The proportion of ptarmigan in the gyrfalcon diet and gyrfalcon breeding success increased in springs with more snow, but breeding success decreased with more snow during the nestling period. Gyrfalcon reproductive success was positively related to ptarmigan density, but gyrfalcon nest occupancy and the ptarmigan kill rate were not related to ptarmigan density. These results indicate that the effect of climate change is not straightforward, and investigating how (a)biotic factors impact both prey and predator is relevant in predicting how a predator will respond to climate change. Following current climate predictions, spring will occur earlier, which will change the food-web structure through prey availability and diversity and through interactions with other species. This requires adaptations from gyrfalcons and other predators. We emphasise that the impact of climate change on predators and other species can be more accurately evaluated on a multi-species level rather than individually.

Implications of summer breeding phenology on demography of monarch butterflies

Phenological changes have been widely documented in animal and plant responses to directional environmental change. However, predicting the consequences of these shifts for species interactions and population viability requires knowledge of vital rate responses to biotic and abiotic drivers. Here, we paired long-term phenology data documenting monarch butterfly abundance and occurrence of their milkweed hostplant with outdoor experiments in the central United States to ask how changes in spring arrival times to monarch breeding sites affect their development, survival, and within-season population growth. Monarch arrival times did not change across the 17 years of monitoring, but the peak abundance of monarchs, which occurred just prior to their fall migration, shifted 9 days later in 2019 as compared to 2003. Summer population growth declined from 2003 to 2019, significant in ~80% bootstrap calculations. Phenological changes in milkweed occurrence mirrored changes in monarch abundance, happening later through time. Our field experiment showed that early season larval survival was highest when the timing of hatching matched the average timing of the first natural monarch cohort; survival was lowest when egg hatching shifted 14 days earlier. The results of our study indicate that earlier arrival of adult monarchs to summer breeding habitat would be costly for monarchs-but field survey data show that arrival times have not changed to date. Instead, the local changes we observed in the timing of peak abundance occurred towards the end of the breeding season, not the onset. At present, we conclude that changes in early season phenology are not a threat to eastern North American monarchs living in the central United States, but drivers of breeding-season growth rates and changes in late-season phenology merit further study, both in the central United States and in other parts of the monarch's range.

Chasing the Niche: Escaping Climate Change Threats in Place, Time, and Space

Climate change is creating mismatches between species' current environments and their historical niches. Locations that once had the abiotic and biotic conditions to support the persistence of a species may now be too warm, too dry, or simply too different, to meet their niche requirements. Changes in behaviors, altered phenology, and range shifts are common responses to climate change. Though these responses are often studied in isolation by scientists from disparate subfields of ecology, they all represent variants of the same solution-strategies to realign the conditions populations experience with their niche. Here, we aim to (1) identify the physiological and ecological effects, and potential alignment, of these three ecological responses: shifts in behavior, phenology, or ranges, (2) determine the circumstances under which each type of response may be more or less effective at mitigating the effects of climate change, and (3) consider how these strategies might interact with each other. Each response has been previously reviewed, but efforts to consider relationships between ecological (or with evolutionary) responses have been limited. A synthetic perspective that considers the similarities among ecological responses and how they interact with each other and with evolutionary responses offers a more robust view on species' resilience to climate change.

Stomach Microbiome Simplification of a Coral Reef Fish at Its Novel Cold-Range Edge Under Climate Change

Climate-driven range extensions of animals into higher latitudes are often facilitated by phenotypic plasticity. Modifications to habitat preference, behaviour and diet can increase the persistence of range-extending species in novel high-latitude ecosystems. These strategies may be influenced by changes in their gut and stomach microbial communities that are critical to host fitness and potentially adaptive plasticity. Yet, it remains unknown if the gut and stomach microbiome of range-extending species is plastic in their novel ranges to help facilitate these modifications. Here, we categorised stomach microbiome communities of a prevalent range-extending coral reef fish along a 2000-km latitudinal gradient in a global warming hotspot, extending from their tropical core range to their temperate cold range edge. At their cold range edge, the coral reef fish's stomach microbiome showed a 59% decrease in bacterial diversity and a 164% increase in the relative abundance of opportunistic bacteria (Vibrio) compared to their core range. Microbiome diversity was unaffected by fish body size, water temperature, physiology (cellular defence and damage) and habitat type (turf, barren, oyster, kelp and coral) across their range. The observed shifts in microbiome composition suggest dysbiosis and low plasticity of tropical range-extending fishes to novel environmental conditions (e.g., temperate prey and lower seawater temperature) at their novel range edges, which may increase their susceptibility to disease in temperate ecosystems. We conclude that fishes extending their ranges to higher latitudes under ocean warming can experience a simplification (i.e., reduced diversity) of their stomach microbiome, which could restrict their current rate of range extensions or establishment in temperate ecosystems.

Climate, vegetation, people: disentangling the controls of fire at different timescales

Human activities have a major impact on fire regimes. Human activities that cause landscape fragmentation, such as creating roads and other infrastructure or converting areas to agriculture, tend to restrict, rather than promote, fire. The human influence is complex, however, and the impact of fragmentation on the fire regime depends on climate and vegetation conditions. Climate-induced changes in vegetation and fuel loads also affect the natural fire regime in ways independent of human influence. Disentangling the controls of fire regimes is challenging because of the multiple interactions between climate, vegetation, people and fire, and the different timescales over which they operate. We explore these relationships, drawing on statistical and modelling analyses of palaeoenvironmental, historical and recent observations at regional to global scales. We show how these relationships have changed through time and how they vary spatially as a function of environmental and biotic gradients. Specifically, we show that climate and climate-driven changes in vegetation have been the most important drivers of changing fire regimes at least until the Industrial Revolution. Statistical and modelling analyses show no discernible impact of hunter-gatherer communities, and even the time-transgressive introduction of agriculture during the Neolithic had no impact on fire regimes at a regional scale. The post-industrial expansion of agriculture was an important influence on fires, but since the late 19th century, the overwhelming influence of humans has been to reduce fire through progressive landscape fragmentation rather than through influencing ignitions. Model projections suggest that the reduction of fire through fragmentation will be outweighed by climatically driven increases by the end of the 21st century.This article is part of the theme issue 'Novel fire regimes under climate changes and human influences: impacts, ecosystem responses and feedbacks'.

Dynamics of Suitable Habitats for Typical Predators and Prey on the Qinghai-Tibet Plateau Driven by Climate Change: A Case Study of Tibetan Fox, Red Fox, and Plateau Pika

The Qinghai-Tibet Plateau (QTP) is a biodiversity hotspot highly sensitive to global climate change. The Tibetan fox (Vulpes ferrilata), red fox (V. vulpes), and plateau pika (Ochotona curzoniae) are key species of the plateau, serving as typical representatives of predators and prey among its diverse wildlife. To evaluate the impact of climate change, we employed the maximum entropy model with 1237 distribution points and various environmental variables to predict habitat suitability under three global climate models and four representative concentration pathways for the 2050s and 2070s. The results revealed that the suitable habitats for two predators were projected to decline, with reductions ranging from 0.23% to 5.64% and 4.12% to 6.63%, respectively, with most reductions occurring in the central-western and southern regions of the QTP. The decline was anticipated to be more pronounced in the 2070s compared to the 2050s. Conversely, the suitable habitat for prey species, plateau pikas, was expected to experience only a slight decrease (0.45%-0.98%) under scenarios of moderate greenhouse gas emissions. Habitat centroid analyses indicated a consistent northward migration of suitable areas for both predators and prey in response to climate change on the QTP. Furthermore, future overlap analysis between predator and prey habitats showed uncertain trends; however, the overlap between the Tibetan fox and Plateau pika habitats was notably lower compared to that of the red fox and plateau pika habitats. Regarding the current conservation efforts of both predators and prey, evaluation results highlighted the critical significant role of Sanjiangyuan National Park, China's first national park located in Qinghai Province, and Qiangtang Nature Reserve in Xizang as critical areas for the protection of these species on the QTP in China. The findings and methodologies of this research hold significant reference value for the conservation of predator and prey habitats in other global biodiversity hotspots.

Changes in community composition and functional diversity of European bats under climate change

Climate change is predicted to drive geographical range shifts that will result in changes in species diversity and functional composition and have potential repercussions for ecosystem functioning. However, the effect of these changes on species composition and functional diversity (FD) remains unclear, especially for mammals, specifically bats. We used species distribution models and a comprehensive ecological and morphometrical trait database to estimate how projected future climate and land-use changes could influence the distribution, composition, and FD of the European bat community. Future bat assemblages were predicted to undergo substantial shifts in geographic range and trait structure. Range suitability decreased substantially in southern Europe and increased in northern latitudes. Our findings highlight the potential for climate change to drive shifts in bat FD, which has implications for ecosystem function and resilience at a continental scale. It is important to incorporate FD in conservation strategies. These efforts should target species with key functional traits predicted to be lost and areas expected to experience losses in FD. Conservation strategies should include habitat and roost protection, enhancing landscape connectivity, and international monitoring to preserve bat populations and their ecosystem services.

Potential for bird-insect phenological mismatch in a tri-trophic system

Climate change is altering the seasonal timing of biological events across the tree of life. Phenological asynchrony has the potential to hasten population declines and disrupt ecosystem function. However, we lack broad comparisons of the degree of sensitivity to common phenological cues across multiple trophic levels. Overcoming the complexity of integrating data across trophic levels is essential for identifying spatial locations and species for which mismatches are most likely to occur. Here, we synthesized over 15 years of data across three trophic levels to estimate the timing of four interacting phenological events in eastern North America: the green-up of forest canopy trees, emergence of adult Lepidoptera and arrival and subsequent breeding of migratory birds. We next quantified the magnitude of phenological shift per one unit change of springtime temperature accumulation as measured by accumulated growing degree days (GDD). We expected trophic responses to spring temperature accumulation to be related to physiology, thus predicting a weaker response of birds to GDD than that of insects and plants. We found that insect and plant phenology indeed had similarly strong sensitivity to GDD, while bird phenology had lower sensitivity. We also found that vegetation green-up and bird arrival were more sensitive to GDD in higher latitudes, but the timing of bird breeding was less sensitive to GDD in higher latitudes. Migratory bird species with slow migration pace, early arrivals and more northerly wintering grounds shifted their arrival the most. Across Eastern Temperate Forests, the similar responses of vegetation green-up and Lepidoptera emergence to temperature shifts support the use of remotely sensed green-up to track how the timing of bird food resources is shifting in response to climate change. Our results indicate that, across our plant-insect-bird system, the bird-insect phenological link has a greater potential for phenological mismatch than the insect-plant link, with a higher risk of decoupling at higher latitudes.

Integrating ecological niche modeling and natural regeneration assessment to identify conservation priorities for Garcinia pedunculata in India

Garcinia pedunculata Roxb. ex-Buch. -Ham. (Clusiaceae) is a fruit-bearing tree species known for its frequent utilisation as an anti-obesity agent and to treat gastrointestinal disorders by the dwellers of the Indo-Myanmar Biodiversity Hotspot (IMBH) region. The nutritional profile of the phytocompounds found in fruits has been in high demand in pharmaceutics. Due to a lack of sustainable harvesting practices, the species population has been severely fragmented, leading to its limited genetic resources being vulnerable to the threat of climate change. This study was conducted in the northeastern states of India for 2 years between 2022 and 2024 to assess the regeneration fitness of G. pedunculata through sporadic population surveys and to predict its habitat suitability under current and future climatic scenarios using ecological niche modeling (ENM). The study incorporated 19 bioclimatic variables from WorldClim, along with physiographic (elevation, slope, hillshade), edaphic (soil pH, soil organic carbon), and biotic factors (land use, land cover). Species distribution was modelled using an ensemble of four machine learning algorithms-maxent, random forest, support vector machine, and boosted regression tree. Annual precipitation, precipitation of the coldest quarter, soil pH, and precipitation in the driest month were found to have the maximum contributions as key determinants of the species distribution. The ENM predictions of a substantial decline in suitable niches for the species toward projected climatic regimes in the year 2080 with significant model support (AUC = 0.96 and TSS = 0.87), and poor regeneration fitness of the species indicated an alarming situation for the conservation of the species and the development of its sustainable harvesting practices. Therefore, the findings of this study recommend taking immediate action to develop strict nature reserves, germplasm banks, and seed gene banks for the sustainable management of the species.

Genomics highlight an underestimation of phenology sensitivity to the urban heat island effect

The phenological timing of leaf out in temperate forests is a critical transition point each year that alters the global climate system, which in turn, feeds back to plants, driving leaf out to occur nearly 3 d earlier per decade as temperatures rise. To improve predictions of leaf out timing, urban heat islands (UHIs) or densely developed areas that are hotter than surrounding undeveloped regions are often used to approximate warming via space-for-time substitutions (i.e., rural-to-urban temperature gradients). However, more than just environment changes along these gradients-urban regions are highly managed systems with limited-to-no within species diversity. We demonstrate here that recent observations that UHI gradients underpredict leaf out response to temperature when compared to temperature gradients through time is likely because both genetics and environment are changing across rural-to-urban gradients, whereas only environment is changing through time. We tested this hypothesis using genomic, phenological, and temperature data of northern red oak (Quercus rubra) over several years between an urban and rural site. Across our gradient, models that included just temperature predicted moderate advancement of leaf out. However, if we account for the genetic diversity of our trees in our model, leaf out phenology is predicted to advance significantly more in response to temperature. We demonstrate that this stronger relationship between phenological timing and climate is because urban trees have reduced genetic diversity as they are planted from limited stock by humans and, moreover, are most closely related to individuals at the rural site that leaf out later on average.

Shortening migration by 4500 km does not affect nesting phenology or increase nest success for black brant (Branta bernicla nigricans) breeding in Arctic and subarctic Alaska

BACKGROUND

Since the 1980s, Pacific Black Brant (Branta bernicla nigricans, hereafter brant) have shifted their winter distribution northward from Mexico to Alaska (approximately 4500 km) with changes in climate. Alongside this shift, the primary breeding population of brant has declined. To understand the population-level implications of the changing migration strategy of brant, it is important to connect movement and demographic data. Our objectives were to calculate migratory connectivity, a measure of spatial and temporal overlap during the non-breeding period, for Arctic and subarctic breeding populations of brant, and to determine if variation in migration strategies affected nesting phenology and nest survival.

METHODS

We derived a migratory network using light-level geolocator migration tracks from an Arctic site (Colville River Delta) and a subarctic site (Tutakoke River) in Alaska. Using this network, we quantified the migratory connectivity of the two populations during the winter. We also compared nest success rates among brant that used different combinations of winter sites and breeding sites.

RESULTS

The two breeding populations were well mixed during the winter, as indicated by a migratory connectivity score close to 0 (- 0.06) at the primary wintering sites of Izembek Lagoon, Alaska (n = 11 brant) and Baja California, Mexico (n = 48). However, Arctic birds were more likely to migrate the shorter distance to Izembek (transition probability = 0.24) compared to subarctic birds (transition probability = 0.09). Nest survival for both breeding populations was relatively high (0.88-0.92), and we did not detect an effect of wintering site on nest success the following year.

CONCLUSIONS

Nest survival of brant did not differ among brant that used wintering sites despite a 4500 km difference in migration distances. Our results also suggested that the growing Arctic breeding population is unlikely to compensate for declines in the larger breeding population of brant in the subarctic. However, this study took place in 2011-2014 and wintering at Izembek Lagoon may have greater implications for reproductive success under future climate conditions.

Changes in cranberry phenology from 1958 to 2022: Implications for spring frost protection in Massachusetts, United States

Warmer temperatures associated with climate change have affected the phenology of most plants, but limited information exists for the American cranberry (Vaccinium macrocarpon Ait.), an important specialty crop. We examined long-term spatiotemporal trends in spring development of cranberry buds using field observations of cranberry bud stages over a 65-yr period, spanning from 1958-2022. A growing degree day (GDD) model was further used to interpret the observed trends in bud development over the study period. To assess spatial variability in cranberry bud development, the GDDs were computed using gridded weather data for four counties of Massachusetts, representing 85% of the state's cranberry acreage. A Theil-Sen linear regression model was implemented to determine trends in the occurrence of the bud stages. Field observations revealed significant temporal trends (p-value < 0.01) in the annual timing of white bud and cabbage head stages, occurring 18-20 days earlier in the spring than 65 years ago. This earlier bud development can increase the risk of frost damage, especially during late-spring freezes. GDDs accumulated at a faster rate towards the end of the study period due to rising air temperatures. Analysis of 65 years of gridded data revealed a significant trend of earlier development across the four counties. The rate of advancement in cabbage head stage ranged from -0.15 to -0.25 d yr -1 across the study area. These findings highlight the need for updated frost forecasting models that account for the changing growth schedule of cranberry.

Incorporating genetic load contributes to predicting Arabidopsis thaliana's response to climate change

Understanding how species respond to climate change can facilitate species conservation and crop breeding. Current prediction frameworks about population vulnerability focused on predicting range shifts or local adaptation but ignored genetic load, which is also crucial for adaptation. By analyzing 1115 globally distributed Arabidopsis thaliana natural accessions, we find that effective population size (Ne) is the major contributor of genetic load variation, both along genome and among populations, and can explain 74-94% genetic load variation in natural populations. Intriguingly, Ne affects genetic load by changing both effectiveness of purifying selection and GC biased gene conversion strength. In particular, by incorporating genetic load, genetic offset and species distribution models (SDM), we predict that, the populations at species' range edge are generally at higher risk. The populations at the eastern range perform poorer in all aspects, southern range have higher genetic offset and lower SDM suitability, while northern range have higher genetic load. Among the diverse natural populations, the Yangtze River basin population is the most vulnerable population under future climate change. Overall, here we deciphered the driving forces of genetic load in A. thaliana, and incorporated SDM, local adaptation and genetic load to predict the fate of populations under future climate change.

It's time to go-Drivers and plasticity of migration phenology in a short-distance migratory ungulate

Recurring events like migrations are an important part of the biological cycles of species. Understanding the factors influencing the timing of such events is crucial for determining how species face the pervasive consequences of climate change in highly seasonal environments. Relying on data from 406 GPS-collared Alpine ibex Capra ibex monitored across 17 populations, we investigated the environmental and individual drivers of short-distance migrations in this mountain ungulate. We found that vegetation phenology, including spring growth and autumn senescence, along with snow dynamics-snowmelt in spring, onset of snow cover in autumn-were the main drivers of the timing of migration. In spring, ibex migration timing was synchronized with the peak of vegetation green-up, but more in males than in females. Specifically, a peak of green-up occurring 10 days later delayed migration by 6.4 days for males and 2.7 days for females. This led to increased differences in migration timing between sexes when the peak of green-up occurred early or late in the season. In addition, ibex delayed migration timing when the length of the spring season was longer and when the date of snowmelt on ibex summer ranges occurred later. Similarly, in autumn, prolonged vegetation senescence and delayed onset of snow cover led to later migration. Overall, we observed a high degree of behavioural plasticity, with individuals responding to inter-annual variations in vegetation and snow phenology, even though the extent of these adjustments in migration dates was lower than the magnitude of the interannual changes in environmental conditions. Nonetheless, females could be less plastic than males in their timing of spring migration, likely due to the parturition period following migration forcing them to trade off foraging needs with predation risk. As the identified drivers of ibex migration are known to be and will continue to be largely impacted by climate change, the capacity of ibex to respond to such rapid changes could differ between sexes.

Population dynamics, threat assessment, and conservation strategies for critically endangered Meconopsis aculeata in alpine zone

BACKGROUND

The Himalayan alpine zone harbors a rich diversity of endemic medicinal plant species, such as Meconopsis aculeata, due to its habitat heterogeneity. Globally, alpine environments are most significantly affected by climate change, characterized by low temperatures and restricted growing seasons, offering essential services yet remaining most vulnerable. M. aculeata holds immense ecological significance in alpine ecosystems, while human disturbances and climate change pose serious threats to its long-term viability. The present study was conducted to explore population ecology, spatial distribution patterns, significant threats, diversity patterns along elevational gradients, and future conservation strategies for the dwindling populations of M. aculeata.

METHODS

Field sampling was carried out from 2022 to 2024 in various districts of Kashmir to examine the vegetation characteristics of M. aculeata populations, along with the geographic variables and threats impacting these populations. The quadrat method was used to investigate the vegetation characteristics across an extensive elevational gradient, ranging from 3000 m to 4600 m.

RESULTS

Healthier M. aculeata populations were found in the middle elevational range of 3700 m to 4100 m. The SIMPER analysis revealed an overall average dissimilarity of 80.08, indicating spatial variability in species composition across the studied sites. GIS analysis showed that M. aculeata was found on the north aspect, with steppe slope in rocky habitat. The average herb density was calculated to be 20.6/ha, while 60% of sampled sites experienced intense grazing. A total of 20 indicator species were identified as associated with M. aculeata populations. Mantel tests identified key species influencing the population structure of M. aculeata. Aconitum heterophyllum (R = 0.7954, P = 0.003) was found to be the most critical indicator species, followed by Anaphalis nepalensis (R = 0.6564, P = 0.034), and Bistorta affinis (R = 0.522, P = 0.044). CCA analysis identified NTFP extraction, grazing and fire as serious threats for the sustainability of M. aculeata populations. Alpha diversity results highlight significant altitudinal influences on the diversity metrics of M. aculeata populations. Beta diversity results indicate that Site 8 exhibited substantial differences in species composition compared to other sites, while Sites 1 and 9 highlighted the spatial heterogeneity within the M. aculeata populations. As this species is already classified as a critically endangered species, we recommend implementing effective conservation measures such as habitat restoration, sustainable harvesting practices, involving local communities, and promoting stewardship. These initiatives will encourage sustainable management of the species in the region.

CLINICAL TRIAL NUMBER

Not applicable.

Prediction of potential habitat of Verbena officinalis in China under climate change based on optimized MaxEnt model

Verbena officinalis is an important medicinal plant widely used in traditional Chinese medicine for the treatment of rheumatism, insomnia, and liver and gallbladder diseases. Its resources primarily rely on wild populations, which are insufficient to meet the increasing market demand. Furthermore, climate change exacerbates the uncertainty of its distribution range. This study employs an optimized MaxEnt model to predict the potential distribution of V. officinalis under current and future climate scenarios in China. Based on 445 effective occurrence records and 90 environmental variables (covering climatic, soil, and topographic factors), the study selected key variables influencing the distribution through correlation analysis and variable contribution rates, and optimized model parameters to improve prediction accuracy (AUC = 0.934). Results showed that, under current climate conditions, the total suitable habitat area of V. officinalis is 2.06 × 106 km2, accounting for 21.39% of China's land area, mainly distributed in central, eastern, and southern China. The minimum temperature of the coldest month (bio_6, contribution rate 72.8%) was identified as the key factor influencing distribution, while November precipitation (prec_11) and annual temperature range (bio_7) also played important roles. Under future climate change scenarios (SSP1-2.6 and SSP5-8.5), the total suitable habitat area shows an overall increasing trend, reaching a maximum in the 2070s under the high-emission scenario (an increase of 3.6 × 105 km2 compared to the current distribution). Expansion was primarily observed in northern high-latitude regions. The geometric centroid of suitable areas demonstrated a significant northward shift, reflecting the adaptive expansion potential of V. officinalis in response to warming climates. This study highlights the significant impact of temperature and precipitation on the distribution of V. officinalis and provides scientific evidence for its conservation, cultivation planning, and sustainable development in the context of climate change.

Evaluating Past Range Shifts and Niche Dynamics of Giant Pandas Since the Last Interglacial

Understanding the response of species to past climate change provides great opportunities to know their adaptive capacity for resilience under future climate change. Since the Late Pleistocene, dramatic climate fluctuations have significantly impacted the distribution of giant pandas (Ailuropoda melanoleuca). However, how the spatial distribution and climatic niche of giant pandas shifted in response to past climate change remain poorly understood. Based on the known distribution records (fossil and present day) and the most updated climate projections for the Last Interglacial (LIG; ~120 ka), Last Glacial Maximum (LGM; ~22 ka), Mid-Holocene (MH; ~6 ka), and the present day, we predicted and compared the distribution and climatic niche of giant pandas. The results show that giant pandas have undergone a considerable range contraction (a 28.27% reduction) followed by a marked range expansion (a 75.8% increase) during the LIG-LGM-MH period, while its climatic niche remained relatively stable. However, from the MH to the current, both the distribution area and climatic niche of giant pandas have undergone significant changes. Our findings suggest that the giant panda may adjust its distribution to track stable climatic niches in response to future climate change. Future conservation planning should designate accessible areas for giant pandas and adjust priority conservation areas as needed.

Forecasting the Impact of Climate Change on Apis dorsata (Fabricius, 1793) Habitat and Distribution in Pakistan

Climate change has led to global biodiversity loss, severely impacting all species, including essential pollinators like bees, which are highly sensitive to environmental changes. Like other bee species, A. dorsata is also not immune to climate change. This study evaluated the habitat suitability of A. dorsata under climate change in Pakistan by utilizing two years of occurrence and distribution data to develop a Maximum Entropy (MaxEnt) model for forecasting current and future habitat distribution. Future habitat projections for 2050 and 2070 were based on two shared socioeconomic pathways (SSP245 and SSP585) using the CNRM-CM6-1 and EPI-ESM1-2-HR-1 global circulation models. Eight bioclimatic variables (Bio1, Bio4, Bio5, Bio8, Bio10, Bio12, Bio18, and Bio19) were selected for modeling, and among the selected variables, the mean temperature of the wettest quarter (Bio8) and precipitation of the warmest quarter (Bio18) showed major contributions to the model building and strongest influence on habitat of A. dorsata. The model estimated 23% of our study area as a suitable habitat for A. dorsata under current climatic conditions, comprising 150,975 km2 of moderately suitable and 49,792 km2 of highly suitable regions. For future climatic scenarios, our model projected significant habitat loss for A. dorsata with a shrinkage and shift towards northern, higher-altitude regions, particularly in Khyber Pakhtunkhwa and the Himalayan foothills. Habitat projections under the extreme climatic scenario (SSP585) are particularly alarming, indicating a substantial loss of the suitable habitat for the A. dorsata of 40% under CNRM-CM6-1 and 79% for EPI-ESM1-2-HR-1 for the 2070 time period. This study emphasizes the critical need for conservation efforts to protect A. dorsata and highlights the species' role in pollination and supporting the apiculture industry in Pakistan.

Upslope plant species shifts in Mesoamerican cloud forests driven by climate and land use change

Global change drives biodiversity shifts worldwide, but these shifts are poorly understood in highly diverse tropical regions. In tropical mountains, plants are mostly expected to migrate upslope in response to warming. To assess this, we analyze shifts in elevation ranges of species in Mesoamerican cloud forests using three decades of species' occurrence records. Our findings reveal a mean upslope shift of 1.8 to 2.7 meters per year since 1979 driven by the upslope retreat of the less thermophilic montane species. These shifts are mostly accompanied by retreating lower and upper edges attributed to varying degrees of species' exposure to deforestation and climate change. Our results highlight the vulnerability of cloud forests under global change and the urgency to increase monitoring of species' responses.

The Relationship Between Phenological Characteristics and Life Forms Within Temperate Semi-Natural Grassland Ecosystems in the Central Himalaya Region of India

The seasonal phenological segregation observed among various species within a plant community can be interpreted as a form of niche differentiation that facilitates the coexistence of these species. In the present study, life forms and phenological attributes of dominant plant species in temperate semi-natural grasslands of Central Himalaya, India, were assessed between January 2022 and December 2022. This study was carried out in three sites in different forest zones, viz. oak, cypress and pine. In each site, plots measuring 0.5 hectares were established and phenological assessments were conducted within each of these plots. A total of 50, 36, and 49 herbaceous species were identified in the grasslands of oak, cypress and pine zones, respectively, with these species categorized into five distinct life form classes. In the grasslands of both oak and pine zones, hemicryptophytes emerged as the predominant life form, whereas in the cypress zone grasslands, it was found that chamaephytes take precedence. The differences observed in the classifications of life forms can be ascribed to the geographical distribution and the biotic interactions present in these sites. The three grasslands exhibit comparable climatic conditions and day lengths, resulting in no significant variations in soil temperature, light intensity or overall climatic factors. The majority of species commenced their flowering phase during the monsoon season, attributed to the favorable conditions characterized by warm, humid weather and adequate soil moisture. Various phenological events, including germination, growth, and senescence, are significantly affected by weather and climate, and their timing subsequently influences ecosystem processes in a reciprocal manner. This study provides valuable foundational data for ecological and environmental research, aiding in the comparison and distinction of plant compositions across the Himalayas and its ecosystems.

Phenological Shifts Since 1830 in 29 Native Plant Species of California and Their Responses to Historical Climate Change

Climate change is affecting Mediterranean climate regions, such as California. Retrospective phenological studies are a useful tool to track biological response to these impacts through the use of herbarium-preserved specimens. We used data from more than 12,000 herbarium specimens of 29 dominant native plant species that are characteristic of 12 broadly distributed vegetation types to investigate phenological patterns in response to climate change. We analyzed the trends of four phenophases: preflowering (FBF), flowering (F), fruiting (FS) and growth (DVG), over time (from 1830 to 2023) and through changes in climate variables (from 1896 to 2023). We also examined these trends within California's 10 ecoregions. Among the four phenophases, the strongest response was found in the timing of flowering, which showed an advance in 28 species. Furthermore, 21 species showed sequencing in the advance of two or more phenophases. We highlight the advances found over temperature variables: 10 in FBF, 28 in F, 17 in FS and 18 in DVG. Diverse and less-consistent results were found for water-related variables with 15 species advancing and 11 delaying various phenophases in response to decreasing precipitation and increasing evapotranspiration. Jepson ecoregions displayed a more pronounced advance in F related to time and mean annual temperature in the three of the southern regions compared to the northern ones. This study underscores the role of temperature in driving phenological change, demonstrating how rising temperatures have predominantly advanced phenophase timing. These findings highlight potential threats, including risks of climatic, ecological, and biological imbalances.

Adaptive Distribution and Priority Protection of Endangered Species Cycas balansae

As an endangered species, the habitat of Cycas balansae (C. balansae) is subject to a variety of impacts, including climate change and human activities, and exploring its adaptive distribution and conservation areas under such conditions is crucial to protecting the ecological security of endangered species. In this study, we used the MaxEnt model and Marxan v4.0.6 to systematically evaluate the adaptive distribution and priority protection areas of the endangered species C. balansae. The results showed that the endangered species C. balansae is concentrated in Xishuangbanna and its surrounding zones in the southern Yunnan Province. The main factors affecting the distribution of C. balansae were temperature seasonality, mean temperature of the coldest quarter, isothermality, and precipitation of the warmest quarter, among which temperature was the dominant factor. Under different climate scenarios in the future, the adaptive distribution area of C. balansae showed a slight decrease, and the adaptive distribution showed a northward migration trend. The future climate distribution pattern is closely related to temperature seasonality and the mean temperature of the coldest quarter. In addition, the influence of anthropogenic disturbances on the distribution of C. balansae cannot be ignored. Currently, there is a large range of conservation vacancies for C. balansae, and it is recommended that Simao City be used as a priority conservation area. This study provides new insights for determining the priority conservation areas and conservation strategies for the endangered species C. balansae.

Eco-Evolutionary Dynamics of Plant-Soil Feedbacks Explain the Spread Potential of a Plant Invader Under Climate Warming and Biocontrol Herbivory

Plant-soil feedbacks (PSFs) can contribute to the success of invasive plants. Despite strong evidence that plant genetic traits influence soil microbial communities and vice versa, empirical evidence exploring these feedbacks over evolutionary timescales, especially under climate change, remains limited. We conducted a 5-year field study of the annual invasive plant, Ambrosia artemisiifolia L., to examine how selection under climate warming and biocontrol insect herbivory shapes plant population genetics, soil properties, and microbial communities. After four generations under warming and herbivory, we collected seeds of the F4 plant populations together with their conditioned soil for a common garden PSF experiment to explore how resulting PSFs patterns are influencing the performance and spread potential of Ambrosia under changing environmental conditions. This is especially relevant because our recent predictions point to a northward spread of Ambrosia in Europe and Asia under climate change, outpacing the spread of its insect biocontrol agent. We discovered that warming and herbivory significantly but differentially altered plant genetic composition and its soil microbial communities, with less pronounced effects on soil physicochemical properties. Our results indicate that both herbivory and warming generated negative PSFs. These negative PSFs favored plant growth of the seeds from the persistent soil seed bank growing in the conditioned soil under insect herbivory, and by this maintaining the Ambrosia population genetic diversity. They also enhanced the spread potential of warming-selected plant offspring, especially from warmer (southern) to colder (northern) climates. This can be explained by the observed decrease in soil pathogens occurrence under insect herbivory and by the especially strong genetic changes in plant populations under climate warming. Our findings provide insights into how climate warming and biocontrol management affect eco-evolutionary interactions between invasive plant populations and their soil environments, which are critical for predicting invasion dynamics in the context of global change.

Differences in phenological term changes in field crops and wild plants - do they have the same response to climate change in Central Europe?

Phenological shifts in wild-growing plants and wild animal phenophases are well documented at many European sites. Less is known about phenological shifts in agricultural plants and how wild ecosystem phenology interacts with crop phenology. Here, we present long-term phenological observations (1961-2021) from the Czech Republic for wild plants and agricultural crops and how the timing of phenophases differs from each other. The phenology of wild-growing plants was observed at various experimental sites with no agriculture or forestry management within the Czech Hydrometeorological Institute observations. The phenological data of the crops were collected from small experimental plots at the Central Institute for Supervising and Testing in Agriculture. The data clearly show a tendency to shift to earlier times during the observation period. The data also show some asynchrony in phenological shifts. Compared with wild plants, agricultural crops showed more expressive shifts to the start of the season. Phenological trends for crop plants (Triticum aestivum) showed accelerated shifts of 4.1 and 5.1 days per decade at low and middle altitudes, respectively; on the other hand, the average phenological shift for wild plants showed smaller shifts of 2.7 and 2.9 days per decade at low and middle altitudes, respectively. The phenophase ´heading´ of T. aestivum showed the highest correlation with maximum temperatures (r = 0.9), followed by wild species (with r = 0.7-0.8) and two remaining phenophases of T. aestivum jointing and ripening (with r = 0.7 and 0.6). To better understand the impacts of climate on phenological changes, it is optimal to evaluate natural and unaffected plant responses in wild species since the phenology of field crops is most probably influenced not only by climate but also by agricultural management.

Gain of thermal tolerance through acclimation is quicker than the loss by de-acclimation in the freeze-tolerant potworm, Enchytraeus albidus

Environmental temperature variation, naturally occurring or induced by climate change, leads organisms to evolve behavioural and physiological responses to handle thermal fluctuations. Among them, phenotypic plasticity is considered a fundamental response to natural thermal variations. Nevertheless, we know little about the rate of thermal acclimation responses and the physiological mechanisms underpinning phenotypic plasticity in freeze-tolerant invertebrates. We assessed the temporal dynamics of heat and cold tolerance plasticity in the freeze-tolerant potworm Enchytraeus albidus following thermal acclimation. Acclimation responses were investigated in worms cultured at 5 or 20°C and acclimated for varying duration (hours to weeks) at the same temperature or relocated to the opposite temperature. The rate of phenotypic responses of thermal tolerance was evaluated by assessing survival after exposure to high and low stressful temperatures. Worms cultured at 5°C were more cold tolerant and less heat tolerant than worms cultured at 20°C. The plasticity of thermal tolerance in E. albidus varied in scope and response time according to both culture and acclimation temperatures: acclimation at 20°C of worms cultured at 5°C increased heat survival within 1 day and reduced cold tolerance in 5 days, while acclimation at 5°C of worms cultured at 20°C did not affect heat survival but considerably and quickly, within 1 day, increased cold tolerance. Effects of acclimation were also assessed on membrane phospholipid fatty acid (PLFA) composition and glycogen content of worms, and showed that improved tolerance was linked to changes in membrane PLFA desaturation and chain length.

Freshwater trematodes in Iceland and the surrounding north - current advances and questions

Iceland is an isolated, sub-Arctic, oceanic island of volcanic origin in the northern North Atlantic. With a limited faunal diversity and being the most northern point in the distributional range for some species, it is an intriguing model region to study parasite biodiversity and biogeography. Since 2006, there has been a history of intense biodiversity discoveries of freshwater trematodes (Trematoda, Digenea), thanks to the use of integrative taxonomic methods. The majority of digeneans (28 out of 41 known) were characterised with molecular genetic methods and morphological analyses, with some of their life-cycle stages and geographical distribution assessed. A surprising diversity has been discovered, comprising species of the families Allocreadiidae, Cyclocoeliidae, Diplostomidae, Echinostomatidae, Gorgoderidae, Plagiorchiidae, Notocotylidae, Schistosomatidae, and Strigeidae. Many of the recorded species complete their life cycles within Iceland, with three snail species (Ampullaceana balthica, Gyraulus parvus, Physa acuta) known as intermediate hosts. No trematodes endemic for Iceland were found; they appear to be generalists with wide geographical ranges dispersed mainly by migratory birds. Interestingly, fish trematodes recorded in Iceland were found in mainland Europe, indicating that they might be dispersed by anadromous fishes, by human activity, or by migratory birds carrying intermediate hosts. The trematode fauna is mainly Palaearctic, with few species recorded in North America. We highlight the ongoing need for precise species identification via integrative taxonomic methods, which is a baseline for any further ecological studies and adequate epidemiological and conservation measures. Also, there is still a need of obtaining well-preserved vouchers of adults for definite species delimitation.

High voltinism, late-emerging butterflies are sensitive to interannual variation in spring temperature in North Carolina

Climate change has been repeatedly linked to phenological shifts in many taxa, but the factors that drive variation in phenological sensitivity remain unclear. For example, relatively little is known about phenological responses in areas that have not exhibited a consistent warming trend, making it difficult to project phenological responses in response to future climate scenarios for these regions. We used an extensive community science dataset to examine changes in the adult flight onset dates of 38 butterfly species with interannual variation in spring temperatures in the Piedmont region of North Carolina, a region that did not experience a significant overall warming trend in the second half of the 20th century. We also explored whether voltinism, overwintering stage, and mean adult flight onset dates explain interspecific variation in phenological sensitivity to spring temperature. We found that 12 out of 38 species exhibited a significant advance in adult flight onset dates with higher spring temperatures. In comparison, none of the 38 species exhibited a significant advance with year. There was a significant interaction between mean onset flight date and voltinism, such that late-emerging, multivoltine species tended to be the most sensitive to spring temperature changes. We did not observe a significant correlation between phenological sensitivity and the overwintering stage. These results suggest that butterfly arrival dates may shift as temperatures are projected to rise in the southeastern United States, with late-emerging, multivoltine species potentially exhibiting the greatest shifts in adult flight onset dates.

Predicting climate-driven habitat dynamics of adjutants for implementing strategic conservation measures in South and Southeast Asian landscape

The storks (Ciconiiformes: Ciconiidae) are a fascinating group of birds known for their tall, wading stance, long legs, extended necks, and strong bills. The South and Southeast Asian region boasts the most diverse population of storks, necessitating immediate conservation efforts to protect their habitats and save them from the escalating threats of climate change. Within the genus Leptoptilos, three distinct species exist, two of which-the Greater Adjutant (Leptoptilos dubius) and the Lesser Adjutant (Leptoptilos javanicus)-have garnered attention as 'Near-Threatened' according to the IUCN Red List. However, the assessment overlooks the crucial aspects like ramifications of climatic shifts and anthropogenic-induced habitat fragmentation. Hence, this study endeavors to assess climatic impacts via an ensemble approach to species distribution modeling. The findings unveil alarming trends for both adjutants across South and Southeast Asia. The L. dubius is projected to undergo a severe decline of over 95% across all future scenarios (SSP245 and SSP585 in both time periods) from its current suitable extent of 38,686 km2, which represents only 5.91% of its total extent. On the contrary, the L. javanicus experiences a spatial relocation towards Southeast Asia under the SSP245 and SSP585 scenarios, resulting in a decline of over 20% from its present suitable range of 239,490 km2, which accounts 22.59% of its IUCN range. Furthermore, the resulting habitat fragmentation, propelled by climatic alterations, is severe, with the L. dubius losing numerous viable patches entirely and the L. javanicus experiencing discontinuity in its habitat. Furthermore, given the overlapping ranges of both adjutant species, the current scenario yields a niche overlap value of 0.370. Therefore, the present study advocates for the reassessment of both L. dubius andL. dubius, urging their IUCN assessment under threatened category. Furthermore, strategic conservation measures are proposed in this study, involving local communities, non-governmental organizations, and governmental entities, to safeguard these remarkable avian species.