Understanding the ecological drivers of abundance is essential for assessing how environmental changes affect distributions. Gaining deeper insights into these drivers can also help explain global biodiversity patterns. Birds offer an exceptional opportunity to explore these patterns given their extensive spatial data coverage. In this study we used abundance data for 2,182 bird species to identify main drivers of intraspecific variation in abundance. We explored the relative impact of macroclimatic, biotic and anthropogenic drivers and distance to range centroid. We then applied phylogenetic comparative analyses to assess how morphological, geographical and ecological traits mediate species' responses to these drivers. We found that macroclimatic drivers were the most important predictors of abundance. We further found support for the abundant centre hypothesis. Trait analyses reveal that range size, hand-wing index and migratory behaviour are good predictors of how species respond to various environmental gradients. Our findings highlight a prominent role of the climate in explaining relative abundances of birds, but also that species traits can explain part of the complexity of abundance distributions. To this end, our results can help better predict how different species might respond to ongoing environmental changes.

Climate change is rapidly reshaping how insects interact with their environment, potentially disrupting ecosystem complexity and essential functioning. While functional homogenisation has been extensively investigated for charismatic insect taxa, particularly pollinators, the response of parasitoids remains largely overlooked. Parasitoid insects exhibit drastically distinct life stages, with parasitic larvae and free-living (often nectarivore) adults, meaning that global change can have differential impacts on their functional diversity depending on the life stage. Here, we estimate multiple metrics of functional diversity for European bristle flies (Diptera: Tachinidae), a widespread parasitoid group, using traits measured in both larval and adult stages. We test how functional diversity metrics of larvae and adults vary through time and elevation, to uncover the extent and breadth of functional homogenisation. Our results show a progressive reduction in functional specialisation at high altitudes, for both larval and adult stages, revealing a decreased uniqueness of mountaintop biota. This pattern emerges from the upshift of generalist species, which dilute specialist species from mountaintops and make these areas functionally similar to lower elevational bands. This process determines a temporary increase in functional richness at high elevation, but may anticipate the loss of specialised ecosystem functions if generalists will eventually outcompete specialists. This can have remarkable effects on ecosystem stability, affecting parasitoids’ ability to control herbivore insects and pollinate flowers. Our results offer insights into the complexity of climate-driven change in functional diversity patterns, with increased functional richness in parasitoid assemblages associated with an overall trend of functional homogenisation.

In metacommunity theory, which has primarily addressed horizontal processes, vertical connectivity has received little attention despite being a primary driver of biodiversity in spatially structured environments. This conceptual blind spot limits our understanding of community assembly in marine environments, where vertical processes are fundamental. Here, we used marine cave sessile communities as a model system to develop and test the first mechanistic framework to explicitly incorporate vertical connectivity, which we applied across hierarchical spatial scales. Based on a two-year dataset including nine marine caves in the Canary Islands, we partitioned community variance, examined spatial patterns of beta diversity, and analysed autocorrelation. Three-dimensional bathymetric analysis quantified connectivity to deep-water habitats, and mixed-effects models tested its influence on community diversity and thermal affinities. Cave-scale variance exceeded island-scale variance, a pattern consistent with a pronounced “cave individuality”. Species turnover drove beta diversity, and distance decay was weak — a pattern inconsistent with horizontal dispersal models. Bathymetric connectivity was a key predictor of diversity: caves more connected to deep-water habitats supported richer assemblages. These patterns reflect shifts in thermal structure, with well-connected caves exhibiting greater thermal diversity and stronger cold-water affinities. We propose the Environmental Patch Dynamics (EPD) framework, a mechanistic extension of metacommunity theory integrating species sorting and patch dynamics across four hierarchical stages. Vertical recruitment from depth-stratified external propagule pools, mediated by episodic upwelling, primarily structures these communities. By incorporating vertical connectivity and benthic–pelagic coupling, the EPD framework provides a transferable architecture for understanding community assembly in other vertically-structured ecosystems and reveals clear implications for their conservation under a warming ocean.

Understanding whether current macroecological biodiversity patterns are driven by shared evolutionary history remains a central question in biogeography. Here, we examine whether species’ geographic range sizes and abundance–distance relationships (ADRs) exhibit phylogenetic signal across terrestrial taxa, and what this reveals about their evolutionary structuring. We compiled published ADRs together with global range size data and phylogenetic information for 2,545 species, including 1,685 birds, 647 plants, and 213 mammals. Variation in ADRs and range sizes was quantified across taxonomic levels and across clades of increasing phylogenetic distance, and compared with random dispersion null expectations. Phylogenetic signal was evaluated with Bloomberg’s K and Moran’s I, and alternative evolutionary models were compared to assess which processes best described the distribution of ADRs and range sizes across phylogenies. We also examined whether any detected phylogenetic structure remained after accounting for dispersal-related traits, including plant height, seed mass, and body size. We found that range size showed consistent phylogenetic clustering across most taxonomic and phylogenetic levels, indicating that closely related species tend to have similar geographic extents. Contrastingly, ADRs exhibited limited phylogenetic structure, with weak under-dispersion detected only among plant species at intermediate phylogenetic depths. Trait evolution for both ADRs and range sizes was most consistent with an Ornstein–Uhlenbeck model, suggesting convergence toward optimal values rather than unrestricted divergence. After accounting for dispersal-related traits, range size retained significant phylogenetic signal, whereas ADRs did not differ from random expectations. Together, these findings indicate that geographic range sizes, but not ADRs, are strongly structured by phylogenetic relatedness across birds, plants, and mammals. Our findings suggest that broad-scale patterns of species’ range size are more evolutionarily conserved than ADRs, implying a fundamental decoupling between macroecological and population-level processes.

Predator-prey interactions can trigger behavioural responses in ungulates, influencing their space-use and foraging behaviour and, in turn, indirectly affecting browsing pressure. Changes in browsing pressure can affect plant recruitment and species composition, shaping forest regeneration through predator-mediated trophic cascades. Despite ecological significance, the extent to which predators indirectly affect browsing remains debated, particularly in anthropogenic landscapes where human impacts can interact with predator effects. In this study, we investigated interactions across trophic guilds and their consequences for ungulate browsing pressure while accounting for human activities. Human disturbance was quantified using surveys of recreational activities and hunting locations. Wolf space-use and kill-sites density were mapped from GPS telemetry; lynx and red and roe deer density was modelled from camera trap data. To monitor vegetation change, browsing pressure was assessed through landscape-scale field surveys in two years: before and after wolf establishment. All datasets were modelled to evaluate tri-trophic interactions in the Bavarian Forest National Park (Germany). On a landscape-scale, browsing pressure was lower in the core of wolf territories and areas with higher human recreation intensity, whereas deer presence was not lower in these areas. In contrast, browsing pressure was greater in areas with higher lynx activity and higher wolf kill-sites density. Here also red deer presence was higher. Comparison of browsing data between before and after wolf establishment indicated that wolf recolonization locally altered deer browsing patterns but not overall browsing intensity. Overall browsing intensity increased across the park but declined within high wolf utilisation density areas. By analysing tri-trophic interactions incorporating human activities, this study provides field-based insights into trophic interactions in a temperate forest ecosystem. Results indicate that returning predators can resume their ecological functions within anthropogenic landscapes, with wolf effects on lower trophic levels comparable in strength to those of humans in shaping ungulate browsing patterns.

Biodiversity databases increasingly function as the default substrate for species distribution mapping. Many processes can decouple archived occurrences from field reality, but one of the most consequential yet structurally omitted is documented local extinction—evidence that a population of a particular taxon previously recorded at a locality has since disappeared. We argue that local extinction is not simply absence but a directional, high-information transition (presence → loss) that, in database terms, requires data extirpation—something most biodiversity infrastructures cannot represent natively. The result is systematic temporal inflation: contemporary range products retain legacy presences, obscuring real-time decline and propagating error into conservation assessment, species distribution modelling, and invasion inference. To make biodiversity mapping time-aware without replacing occurrence backbones, we propose treating documented loss as a first-class record via a minimal, standardisable loss_event linked to historically occupied localities, with traceable provenance and (where available) a lightweight cause field. We anchor the proposal in an operational implementation using European crayfish extinctions, demonstrating that even fragmentary loss documentation produces measurable inflation in IUCN range metrics and revealing practical design constraints for spatial matching rules. This structural change—small in implementation but fundamental in effect—becomes essential as biodiversity informatics scales toward automated synthesis and AI-driven decision pipelines.

Mycorrhizal symbioses influence woody species diversity, but whether this association shifts with forest stand development remains underexplored. Using forest inventory data across subtropical and tropical forests in Taiwan, we found that woody species diversity was lower in ectomycorrhizal (EM)-dominated than in arbuscular mycorrhiza (AM)-dominated forests, while forests with mixed mycorrhizal strategies supported the highest woody species diversity. However, these differences were strongest in early development stands and tended to converge towards high diversity in late development stands independent of mycorrhizal strategies. The negative association between EM dominance and woody species diversity was more pronounced in cold regions, while the diversity peak in mixed AM–EM forests strongly emerged in median climates and diminished towards warm and cold climates. In addition, forests with mixed mycorrhizal strategies promoted equal species abundances more persistently than high species richness. These findings highlight that associations between mycorrhizal strategies and woody species diversity depend on forest developmental stage, underpinning new understanding of subtropical and tropical forest recovery under global change.

Continental scale metagenomics revealsMicrocystis-induced synchrony between aquatic taxa is exacerbated by trophic cascadesRunning title: Microcystis synchronizes taxa in food webs

The delineation of biogeographical regions is fundamental to conservation planning, yet it remains debated whether these regions represent discrete ecological entities or merely heuristic simplifications of continuous variation. While classical regionalization relies on expert judgment or abiotic proxies, the explosion of citizen-science data offers a unique opportunity to derive regions directly from empirical species turnover. In this study, a reproducible, data-driven workflow is developed to delineate biogeographical regions in Sweden using over 115 million species records. A spatially stratified focal-associate species filtering protocol was applied to enhance ecological signals and performed Leiden clustering on Hellinger-transformed community data across three ecological strata: grasslands, forests, and a general multi-taxon dataset. The analysis consistently recovered a robust latitudinal divide near 60°N, aligning closely with the established boreal–temperate ecotone. However, beyond this major transition, clustering solutions were unstable at higher resolutions, and community distinctiveness was low. Furthermore, beta-diversity was overwhelmingly driven by turnover rather than nestedness. These findings suggest that aside from the primary boreal transition, Swedish biodiversity is structured by continuous compositional gradients rather than sharp boundaries. While data-driven methods can validate macroecological patterns, the pursuit of fine-scale discrete bioregions is ecologically unsupported in this system. Instead, bioregions should be viewed as practical tools for conservation planning imposed upon a fundamentally Gleasonian continuum.

Insects are the most diverse terrestrial organisms, yet they are underrepresented in large-scale conservation assessments. To address this gap, the California Insect Barcoding Initiative is developing a publicly accessible, statewide DNA-barcode reference library for California insects to support scalable surveys, establish baseline biodiversity measurements, and generate potential distribution maps that inform conservation planning. Specimens are collected with a hybrid strategy that combines standardized Malaise trapping, to enable replicable sampling, and opportunistic collecting, to maximize taxonomic coverage. To date, we have barcoded over one million specimens; preliminary completeness analyses suggest that current sampling captures roughly 65–69% of the fauna, implying a conservative minimum of circa 61,000 insect species in California. Using all sequenced specimen records, we generated rule-based spatial range interpolations constrained by ecoregion and vegetation type, and used these to infer spatial patterns in insect species richness across the state. We identify areas of both high and low potential species richness, with current peaks in the Southern California Mountains ecoregion and the Mojave Basin and Range ecoregion. Our species richness estimates and spatial patterns are explicitly provisional and are expected to evolve as sampling gaps are addressed. Finally, we make all sequence data, specimen images, and occurrence records publicly available via the Barcode of Life Datasystem. This ongoing effort constitutes the first large-scale DNA barcode-based survey for California insects, providing an expandable foundation for tracking temporal change, testing drivers of insect diversity, and prioritizing regions for conservation and targeted inventory.

Understanding community assembly processes across spatiotemporal scales represents a central challenge in ecology. Short-term assembly studies reveal key mechanisms but are inadequate for reconstructing the dynamics of assembly processes or separate natural and anthropogenic states, underscoring the importance of long-term studies. Here, we investigated algal assembly processes over the past two centuries in two natural lakes and two human-impacted lakes using sediment DNA and multiple approaches including null models and joint species distribution models. We revealed that, overall, stochastic processes have dominated algal assembly in these relatively remote lakes over the past two centuries. Interestingly, in recent decades, deterministic processes, particularly environmental filtering, increased temporal homogenization across communities in both lake types. Mechanistically, environmental filtering enhanced network interactions and niche overlap, driving homogenization that ultimately reduced community resilience. This study provides long-term insights into algal assembly processes under multifaceted environmental pressures. Crucially, we reveal a potential loss of resilience even in natural lakes in the Anthropocene, forewarning a pervasive crisis under global change.

The Amazon River Plume (ARP) functions as a dynamic and porous biogeographic barrier whose permeability to larval dispersal depends on the interplay between species’ biological traits and oceanographic processes. Using biophysical modeling combined with a dual analytical framework a Multivariate Regression Tree (MRT) and a Generalized Additive Model (GAM) this study quantifies the factors regulating this permeability for eggs and larvae in the Western Tropical Atlantic. Our results reveal a clear hierarchy of controls. Planktonic Larval Duration (PLD) emerged as the primary determinant, explaining most of the variation in dispersal distances (58%). Diel Vertical Migration (DVM) was the second biologic key factor (11%), modulating whether larvae were locally retained (with DVM) or exported to distant regions (without DVM). Seasonality and the geographic context of spawning habitats further shaped larval interactions with the plume, reinforcing the spatial and temporal complexity of this system. Overall, the ARP acts not as an absolute barrier but as a continuum of permeability a selective filter that restricts dispersal of coastal species with short PLDs and low physiological tolerance, yet facilitates exchange for communities with greater dispersal capacity and behavioral plasticity.

Global biodiversity is rapidly declining under the influence of human-induced environmental change, but our understanding of what is driving change at the local scale is often incomplete. Global datasets such as the Living Planet Database (LPD) provide invaluable site-based time-series data on wildlife populations but often lack detailed information on the local threats affecting these. Here, we test whether threat impact probability maps for species can predict the presence of threats recorded in the LPD for terrestrial birds and mammals. We tested several logistic regression models, ranging from those based solely on the mapped threat probabilities to those that incorporate species-level threat data, biogeographic realm, species richness, and the Human Footprint Index. Our results show that threat impact probabilities used in combination with contextual information, particularly biogeographic realm, can provide significant improvements in predictive power compared with models without them. In contrast, the Human Footprint Index contributed little to model performance. These findings underscore the importance of incorporating ecological and regional context into threat assessments and provide a promising start to increasing our understanding of threats at a population-level.

Equilibrium theories propose that ungulate populations are regulated by the balance between predation and resource competition. However, many real-world ecosystems deviate from these equilibriums due to external abiotic and biotic factors. While prior research in Trans-Himalayan ecosystems has emphasized the adverse effects of livestock herding on wild ungulates, these studies often overlooked the simultaneous roles of resource limitation, predation, and climate variability. Our study fills this gap by examining a snow leopard Panthera uncia–bharal Pseudois nayaur–alpine meadow system under livestock grazing pressure in the Sanjiangyuan region (360,000 km²). Employing household censuses, transect surveys, and camera trapping along a livestock grazing gradient, we quantified how predation, resource competition, and climate jointly influence bharal density and recruitment. We found that while bottom-up forces such as forage availability and livestock competition primarily limited bharal birth rate and density, top-down predation by snow leopards significantly reduced recruitment after the first winter. Winter climate further affected both birth and recruitment rates, highlighting the complex interplay of biotic and abiotic drivers. Building on previous research emphasizing livestock as a major constraint, our findings reveal substantial and previously underestimated effects of predator activity and climate variability in shaping population dynamics. Our results emphasize the importance of integrating biotic and abiotic drivers to fully understand herbivore dynamics, offering critical insights for conservation and management in vulnerable alpine ecosystems worldwide.

Studies on the role of latitudinal gradients in shaping the structure of trophic networks have shown contrasting results, indicating that the effects of latitude at the community scale are still unclear. Our main goal was to evaluate the influence of the latitudinal gradient on the structure (i.e. connectance, nestedness, and modularity) of snake-prey interaction networks. Snake assemblages show considerable diversity in diet and hunting strategies, which, combined with the group’s robust natural and evolutionary history data, represent an attractive study model to test hypotheses about network patterns observed in other groups of predators. We studied 24 networks from the Americas, Africa, and Europe and used path analysis to investigate the association between latitude, with body mass, taxonomic diversity, species richness, and network structure of local communities. Our results showed that the snake-prey networks were generally nested, moderately connected, and non-modular. Latitude negatively affected body mass, which, together with richness, positively affected nestedness. Networks from tropical regions were more nested and had more specialist snakes than those from temperate regions. Frogs, lizards or small mammals represented the main food resources, being consumed, on average, by 64% of the snakes. In summary, our results indicated that despite the great variation in composition, richness, and resource use, network patterns were generally consistent, indicating that snake-prey interactions were only partially affected by the latitudinal gradient, potentially representing stable community components worldwide.

Understanding how deterministic and stochastic processes influence the shape of microorganism community assembly across different spatial scales is essential for disentangling biodiversity patterns. Mires are nutrient-poor and heterogeneous wetlands that form isolated habitats supporting highly diverse diatom assemblages, particularly in mountainous areas, allowing the evaluation of dispersal and species sorting forces. Diatoms are known as ubiquitous microalgae that disperse passively and whose community can endure changing environmental conditions. While their diversity is well documented, the mechanisms driving diatom community assembly across spatial scales remain unclear. Here, we quantified the influence of ecological drift, environmental selection, and dispersal following a null-modelling procedure based on phylogenetic (βNTI) and compositional turnover (RCBray) from diatom communities in 19 mountain mires across four Iberian National parks using a hierarchical spatial design; local (within mire): ~2 km, landscape (National park): ~15–40 km, and regional (Iberian Peninsula): ~700 km. Our results reveal a spatial continuum in community organization, shifting from a predominance of homogenizing dispersal at local scales (explaining up to 44.8 ± 28.5% of community variation) to ecological drift (36.2 ± 22.0%) and heterogeneous selection (environmental filtering) (14.7 ± 12.7%) at landscape and regional scales. These findings shed light on the scale-dependent interplay of community assembly processes in shaping diatom biodiversity in aquatic ecosystems, highlighting how the balance between stochastic and deterministic processes shifts across multiple spatial scales.

Circadian rhythms are highly conserved across the tree of life, with light serving as the primary cue for the circadian timer. Photoperiod variation follows a latitudinal gradient, reflecting fluctuations in seasonality that increases towards the poles. As photoperiod variability intensifies at higher latitudes, organisms must develop mechanisms to maintain circadian timing during prolonged periods of light or darkness. Consequently, latitudinal gradients in photic sensitivity occur, as populations in northern latitudes have physiologically adapted to significant seasonal variations in day length. However, the rise of urbanization has introduced artificial light on a global scale, creating new photoperiods for organisms to navigate. This artificial extension of the natural photoperiod is now interacting with evolutionarily established circadian rhythms. Because photic sensitivity follows a latitudinal gradient, this may also inform biogeographic patterns of vulnerability to light pollution. We introduce the term "circadian histories" to describe an organism's evolutionary history of circadian entrainment, which may influence its response to novel light pollution.

Feedbacks are the basic linkages of living systems. In living organisms, feedbacks regulate the processes of growth and homeostasis, as well as their interactions with their world. Feedbacks are equally important in ecological systems, which is why ‘feedback in ecology’ gets more than 2 million hits on Google. The ecological literature is rich in papers dealing with the role of feedback in various phenomena. However, attempts to embrace the subject of feedbacks as a whole in ecology are rare. Pichon et al. (in press) has done that, with skill and comprehensiveness. The paper succeeds in bringing the array of different types of feedbacks into a manageable order that makes this a valuable synthesis of the subject.