Leaf functional traits are informative of plant fitness and functions in ecosystems. These functional traits and their variation across geographic extents is much studied but less is known about their temporal variation, especially how phenology affects functional trait variation over a growing season. Here, we provide an analysis of the seasonal variation in six leaf functional traits of 11 sub-Arctic vascular plant species in northern Finland, highlighting significant temporal dynamics over a growing season. Our findings reveal that functional traits, including specific leaf area, leaf dry matter content, leaf area, leaf dry mass, brightness index, and greenness index, exhibit considerable variation across the 15-week growing season. These temporal variations are influenced by plant growth forms, with distinct patterns observed among forbs, deciduous shrubs, and evergreen shrubs. Our analyses show that the rank of species is rather well preserved through the growing season in the most commonly used traits, and for this reason, the timing of sampling has a rather minor impact on the relative trait differences across species. However, if different species are measured at different times of the year, the seasonal effect can be notable. The growth forms often followed roughly similar temporal dynamics, and therefore, the error can be especially strong when comparing species across different growth forms.

Frugivorous animals are key in plant communities, by dispersing seeds of fleshy-fruited plants and being involved in regeneration dynamics. Avian frugivorous forage on several, locally co-occurring fleshy-fruited plant . They co-disseminate seeds, setting the initial spatial template on which subsequent ecological processes operate. Despite this commitment, it remains unknown whether co-disseminated plant species maintain their co-occurrence along plant demographic cycle, reflecting the lasting signal of these interactions with avian frugivores in the plant community. We investigated whether plant species that share bird seed dispersers also co-occur spatially across different life stages, from seed rain to adult individuals. We combined data on seed-rain from nine fleshy-fruited species dispersed by 21 bird species, with spatial co-occurrence patterns among these plant species at sapling and adult stages. We built pairwise matrices showing: the number of frugivorous bird species shared between each pair of plant species, and their spatial co-occurrence at different life stages; seeds (seed–seed), saplings (sapling–sapling and sapling–adult), and adults (adult–adult). We then used structural equation modelling to test whether the level of shared avian frugivores predicts the spatial co-occurrence among adult plants, also assessing the indirect effects of processes occurring at intermediate demographic stages. Our results revealed these effects of frugivore-species sharing during the fruit-removal and seed-dissemination stage on the spatial assembly of adult species. Higher levels of shared avian frugivore increased the co-occurrence among plant species in seed rain, facilitation and adult community, but not within the sapling-sapling interactions. Frugivorous birds drive the co-occurrence among fleshy-fruited plant species, from seed to adult stages, although their influence decreases as plant demographic cycle advances. However, the co-occurrence at adult stages is achieved when adults facilitate saplings. This reinforces the key role of the facilitation in Mediterranean systems, and the role of mutualistic avian frugivores as drivers of plant commmuties

Global warming is altering the structure and dynamics of ecological communities, with significant consequences for soil food webs. Rising temperatures are expected to accelerate metabolic rates, rates in organisms, potentially altering species interactions, and the structure and energetics of food webs. However, most studies assessing warming impacts on soil invertebrates have been short-term, taxonomically narrow, or confounded by large-scale variability. We investigated how long-term warming affects soil invertebrate community structure across trophic levels. We sampled soil invertebrate along natural temperature gradients (17°C to 40°C) of geothermal surface features of New Zealand, and we analysed community composition and population densities in relation to soil temperature, pH, water content, and microbial biomass. We found that the invertebrate community composition was significantly influenced by temperature and associated environmental variables. Total invertebrate density increased with warming, primarily driven by decomposers. In contrast, omnivores exhibited increased species richness, while predators declined in richness but showed higher evenness. Our results highlight that warming effects are trophic-level specific and environmentally context-dependent. This suggests that long-term warming may disrupt key ecosystem functions – such as decomposition, predator-prey interactions, and top-down control by reshaping community composition and inducing the loss of predatory taxa. Such alterations could compromise soil food web stability and the resilience of those communities to disturbance events in a changing climate.

Host–parasite interactions are strongly influenced by the dispersal behaviour of both partners, yet direct evidence of parasite-driven active suppression of host dispersal has been lacking. Here, we provide evidence that the parasitic nematode Sphaerularia bombi manipulates its hosts, bumble bee queens (Bombus spp.), to limit their dispersal. We conducted genetic analyses of S. bombi and its hosts in Japan and the Netherlands, and found pronounced genetic differentiation among local S. bombi populations, despite minimal structure among host populations, indicating that infected queens exhibit severely restricted movement. Mark–recapture experiments further confirmed that infected queens tend to remain near their hibernation sites. We also identified cryptic species within S. bombi, based on concordance between mitochondrial haplotypes and nuclear clades, suggesting weak host specificity. Our findings provide the first empirical demonstration that a parasite can actively constrain host dispersal—a strategy likely enhancing mating opportunities and local transmission at the cost of broader range expansion. Parasite populations are probably established through rare, accidental transport of infected hosts, leading to strong founder effects and rapid cryptic speciation. This work highlights a novel mechanism by which parasites can shape host movement ecology and drive their own evolutionary trajectories.

Accurate functional trait data are critical for assessing ecosystem services and processes in fragmented landscapes. We evaluated whether the global EltonTraits 1.0 database adequately represents the functional structure of mammal communities in forest fragments and restoration sites in a highly fragmented Atlantic Forest landscape. We compared the local data on the frequency of occurrence of 30 mammal species (recorded via camera traps) and their locally compiled trait values (from 118 studies) with those from the global trait database. We focused on three key traits (diet, foraging stratum, and activity cycle), and tested the associations between local and global trait sets using species-level functional uniqueness (¯K_i), community-weighted means (CWM), functional diversity (Rao’s Q), and community-level functional uniqueness (U). Compared to global trait datasets, we found: (i) 85% of species in fragments and 77% in restoration forests showed higher ¯K_i with local traits; (ii) CWM values differed significantly between local and global datasets, particularly for crepuscular activity, scansorial/ground-aquatic foraging, and several dietary components, with local data capturing a broader range of ecological strategies across habitats; (iii) global data underestimated Rao’s Q and U in both habitats, suggesting trait convergence in global datasets masking local-scale variation. These gaps arise because the EltonTraits 1.0 database likely aggregates many trait values from pristine ecosystems, inflating niche space, while local communities face multiple effects of environmental filtering. Additionally, species with wide geographic distributions may exhibit greater intraspecific trait variation, which is often averaged in global datasets, potentially contributing to mismatches. Our findings indicate that depending on global data can risk underestimating the roles of specialized species in fragmented ecosystems, emphasizing the necessity for conservation strategies adapted to local-scale data in tropical landscapes. Our results also highlight the importance of integrating local trait information into functional ecology metrics to avoid biased assessments of community structure.

Extreme, variable heatwaves are predicted to increase in frequency under global warming, leading to thermal stress that can be damaging to biodiversity. Recently, it has been shown that exposure to heatwaves is detrimental for adult reproduction, reducing population viability. However, relatively little is known about how oviposited insect eggs, one of the early stages post-fertilisation, are affected by heatwaves. Here, we explore the impact of short- and longer-term thermal stress from experimental heatwaves in an economically important insect model, the red flour beetle (Tribolium castaneum). We uncovered that even short-term exposures (of 2 and 5 hours) (30°C, 40°C, 42°C, 44°C, 46°C, 48°C and 50°C) resulted in a drastic decline in the survival of oviposited eggs, a trend that was also observed when eggs experienced longer durations (1, 3 and 5 days at 42°C). Experiments were run independently across two labs, with results found to be reproducible, reinforcing confidence in our findings. Collectively, our results suggest that oviposited eggs (early embryos) may be particularly vulnerable to heatwaves, even when the exposures are brief.

Understanding the intricate ecological implications of species coexistence through trophic network analysis is crucial for biodiversity studies and for deciphering the environmental drivers of ecosystem dynamics. This study examines, in detail, the complexity, structure, and potential responses of the Strait of Magellan’s trophic network to both environmental and anthropogenic disturbances. Based on an extensive dataset of prey-predator interactions, we characterized the network’s topology and its theoretical resilience using a complex network methodology, analyzing the system at both the network-wide (holistic) and species-specific (reductionist) levels. Our analysis of 140 trophic species and 438 interactions reveals a network with low connectivity (0.022) and an asymmetrical distribution of links, where a few species disproportionately perform most interactions. The network exhibits a ”small-world” architecture, with high clustering and short path lengths, suggesting a rapid propagation of local disturbances. A significant proportion (over 50%) of species are omnivorous, a trait likely contributing to ecosystem stability amidst fluctuating prey availability. Key taxa – polychaetes, Fuegian sprat (Sprattus fuegensis) “sardina”, squat lobster (Grimothea gregaria) “langostino”, and Patagonian blenny (Eleginops maclovinus) “róbalo” – emerge as central conduits for matter and energy flow, effectively linking benthic and pelagic primary productivity to higher trophic levels and significantly underpinning ecosystem function. While the network shows potential robustness to general fluctuations, its concentrated interaction structure makes it vulnerable to the loss or migration of these pivotal species. These findings highlight the importance of understanding trophic relationships to inform effective conservation and ecosystem management strategies in this sensitive Sub-Antarctic marine region. This study provides a foundational understanding of the Strait of Magellan’s marine trophic architecture.

Two basic patterns describe local plant community assembly and functioning: the species abundance distribution (SAD) and the distribution of species functional traits (TAD). These patterns have been extensively studied for dominant and rare plants, while subordinates, the species of intermediate abundance in a community, have received less research attention although this group is most species rich and important for community functioning. Here, we study the functional role of subordinate species (those covering the intermediate 50% of abundance ranks) using a large data set of Palearctic dry and semi-dry grassland plant communities and data on specific leaf area, seed mass and plant height. Theory predicts that dominant and subordinate plants should be functionally complementary. However, our findings indicate that species rank orders of SADs and TADs tend to be negatively correlated, causing the TAD to have higher evenness than the associated SAD. Subordinate species represented on average less than 15% of total plant abundance and trait space. Functional diversity of subordinates was lower than expected by a null model that assumed an equiprobable random distribution of trait values among plant species. Climate seasonality in combination with elevation, appeared to be the most important drivers of subordinate abundance and functional diversity. We conclude that subordinates differ from dominants in trait composition, leading to partial functional complementarity. We hypothesise that both groups are assembled through different processes and habitat filtering, partly triggered by local climatic conditions.

Climate disruption threatens the persistence of temperature-sensitive species in many regions. Some species may be able to moderate hyperthermia risk by using cooler subsurface microclimates, a strategy that could afford some level of population resilience. However, such behavioral responses may interact with environmental factors, making it challenging to determine vulnerability. Here we assessed the extent to which collared pikas (Ochotona collaris), a temperature-sensitive boreal lagomorph, use below-talus microclimates as thermal refuges and whether environmental factors influence the plasticity of these responses, in order to assess the species’ vulnerability to regional warming. We monitored pika activity in Denali National Park and Preserve, Alaska, USA, with camera traps and temperature loggers (above and below ground), finding that pikas adjusted their activity in response to temperature, with peak activity at 13.9oC. Activity levels appeared driven by surface rather than subsurface temperatures, highlighting that regional warming could influence the species in ways that are not buffered by below ground thermal refugia. However, we also detected an interaction between patch quality and surface temperature, such that pikas were more active at cooler temperatures in talus patches with more vegetation. This suggests that pikas in better habitat could be more resilient to warming as they are afforded more flexibility in their diel activity patterns before reaching the upper limits of thermal tolerance. Overall, our results highlight that behavior and environment can interact to influence species’ resilience to climate change.

The current decline in pollinator abundance and diversity poses a significant threat to the natural world and the food and economic security of human societies. A major challenge faced by the scientific community in pollinator conservation is the lack of sufficient data. Citizen science has emerged as a promising avenue for addressing this issue. In this article, we present the global perspective of citizen science projects focused on pollinator monitoring. Our analysis reveals a notable underrepresentation of developing and tropical countries in citizen science-driven data generation efforts. More than 70% of the listed studies are conducted in North America (n:64), followed by Europe (n:22). Together, Europe and North America account for ~ 97% (n:86) of all the projects listed. Thirty-three percent of the projects are hosted on iNaturalist. The majority of projects focus on insects as pollinators, with only 52% recording the pollinated species. We classified these projects into structured, semi-structured, and unstructured categories based on their methodologies. Linear regression analysis was performed to evaluate the influence of various factors on the potential for generating outputs. The regression model explained 82% of the variance in document production (Adjusted R-squared = 0.766, F(10, 33) = 15.06, p < 0.001). Structured projects significantly contributed to document output (Estimate = 12.44, p < 0.001), as did the inclusion of training (Estimate = 6.89, p < 0.001). Fisher’s Exact Test for Count Data also revealed a significant association for outputs generated with the structured methodology (p < 0.001). Additionally, we discuss the merits and drawbacks of different approaches and propose recommendations for subsequent research.

Plants can have a facilitative effect on co-occurring neighbours by moderating microclimate conditions. In forested areas, vegetation buffers microclimates against macroclimate extremes compared to open areas, yet the neighbourhood characteristics that contribute to this buffering effect, particularly during early stand development, remain unclear. Here, we examined how the local neighbourhood affects aboveground temperature and relative humidity in 76 mapped neighbourhood plots in an 8-year-old experimental forest in Tasmania, Australia. We assessed which aspects of the neighbourhood – species identity, density, summed basal area and spatial arrangement – best described the microclimatic conditions over a year-long period, and examined how seasonal and extreme climatic conditions influenced the strength of neighbourhood effects on microclimate. Microclimate conditions varied substantially across neighbourhoods, with a significant proportion explained by neighbourhood metrics. Daytime temperature and relative humidity (RH) were strongly associated with the community neighbourhood index (NI), which reflects the number, size, and proximity of neighbouring trees rather than their species identity. Higher NI values – indicating more, larger, or closer neighbours – led to cooler, moister microclimates, especially in summer, explaining 57% of variation in temperature and 33% in RH. Although nighttime microclimate relationships with neighbourhood metrics were generally weaker, they were positively associated with the number and size of neighbours (summed basal area). The buffering effect of high NI and basal area neighbourhoods was most evident under extreme climatic conditions, with temperatures 3.5℃ cooler on the hottest recorded day and 1.2℃ warmer during the coldest. The amelioration in microclimatic conditions due to neighbouring plants has important implications for tree performance and forest regeneration, particularly in projected hotter and drier conditions.

Scavenging is a foraging strategy widely used across the animal kingdom and apex predators provide a large amount of energy in a food web. In the harsh environmental conditions of the Arctic, apex predators such as polar bears (Ursus maritimus) can provide scavenging opportunities for many species. Carrion can act as a buffer when food resources are low, and some terrestrial species use the marine environment for cross-ecosystem resource subsidies. We present an overview of scavenging as a foraging strategy in the Arctic marine environment and examine the contribution of prey provided by polar bears to the Arctic scavenging assemblage. As obligate predators of seals, polar bears contribute a substantial amount of carrion to the marine ecosystem, particularly to the sea ice surface where it is accessible for seasonal scavenging opportunities. We estimated that each adult polar bear kills an average of 1,001 kg of marine mammal biomass annually, and given preferential feeding of blubber and abandonment of carcasses, we estimate that 30% of the biomass is left as usable carrion. Consequently, polar bears provision approximately 7.0 x 106 kg/year of usable carrion biomass for scavengers across their range, equivalent to 1.55 x 108 MJ of energy. Eleven vertebrate species are known to scavenge polar bear kills, and an additional 7 are potential scavengers. While foraging associations with polar bear kills for some species are better understood, others are scarce or undocumented. We provide an overview of what is known about the role of polar bears as carrion providers, the network of scavenging species on the sea ice, and the possible consequences of trophic downgrading in this ecosystem and recipient ecosystems.

According to the ‘nest protection hypothesis’, some passerines incorporate fresh aromatic plants into their nests to reduce pathogens that can negatively affect nestlings. We experimentally evaluated the effect of five aromatic plant species on the nest bacterial microbiota of Corsican blue tits (Cyanistes caeruleus). The experimental addition of aromatic plants decreased bacterial diversity in nests collected post-hatching. We also detected a weak effect of aromatic plants on nest bacterial composition. In the observational approach, we tested the effect of these plants on the bacterial microbiota diversity and composition of eggshells and nests, and on nestling condition and behavior. Bacterial diversity decreased with the quantity of aromatic plants in nests containing nestlings and on eggshells during incubation, but only in one of the three studied populations. Again, there was a weak effect of aromatic plants on bacterial composition in nests and no effect on eggshell bacterial composition. Finally, nests with a high quantity of aromatic plants tended to have bigger and taller nestlings in two out of three populations. In the other population, the quantity of aromatic plants was associated negatively with speed of feather development and positively with handling aggression. Our results support the ‘nest protection hypothesis’, while highlighting differences in the effect of aromatic plants among populations. To our knowledge, our study is the first to reveal a correlation between the presence of aromatic plants and the bacterial diversity of nests and eggshells in a natural population, and to demonstrate experimentally that it results from a direct effect of five aromatic plant species on bacterial diversity in nest material.

Animals must constantly balance the need to find resources with the risk of predation. Not only avoiding direct encounters with predators but also assessing the overall risk of their environment using cues, social information or habitat traits at multiple spatial and temporal scales. Although such multiscale understanding of the landscape of fear has been recognized, few studies have concomitantly measured how habitat traits at different scales affect risk perception (direct or indirect). Here, we conducted a set of field-based giving-up density experiments to study risk perception on white-naped jays living in semi-arid thorn forests in northeastern Brazil. We recorded data from 23 groups of jays, ranging from 2 to 15 individuals per group, exposed to simulated predators in areas with varying habitat complexity at both local and landscape scales. Overall, our findings support the hypotheses of risky times and habitat complexity risk mediation. White-naped jays exhibited reduced food consumption in the presence of a predator and displayed increased vigilance while consuming less food in more complex habitat patches with dense canopy cover in regenerated forest areas. Finaly, we found no evidence supporting the many-eyes hypothesis; larger groups of white-naped jays did not reduce vigilance. Instead, vigilance was influenced by habitat characteristics like canopy cover and the differences between managed and regenerated forests. These findings underscore the dependency of risk perception on habitat complexity across various scales, indicating that simplifying habitats may create a less fearful environment, thereby increasing prey vulnerability by diminishing antipredator behaviours.

Closely-related species living in sympatry are often partitioned into divergent ecological niches. Such specialization can be enabled by the evolution of divergent traits enhancing adaptation to different niches. In this study, we investigate the partitioning of closely-related butterfly species into different forest strata and daily activity time and test the effects of such spatio-temporal niches on the evolution of thermal traits. First, using experiments in the field in Amazonia, we precisely characterized the daily activity patterns of nine species of Morpho butterflies, therefore documenting extensive temporal segregation among species and observing significant variations in temperature between their respective niches. Using controlled experiments in the lab, we then tested the thermal tolerance of wild individuals to both hot and cold conditions. The vertical distribution of species (understory vs. canopy micro-habitats) had a significant effect on several thermal traits, even when controlling for the phylogenetic distances between species, suggesting that forest stratification may shaped thermal adaptation in these tropical butterflies. However, butterfly activity time did not correlate with any thermal traits measured. The extensive temporal segregation observed between these sympatric species might thus stem from ecological interactions observed between species rather than thermal factors.

Seasonality in temperate ecosystems shapes species phenology, influencing interactions and food web structure. Variations in species richness and biomass affect trophic interaction strength, a crucial factor for community stability, which can be assessed through energy fluxes—an essential indicator of ecosystem function. Yet, we still have limited understanding on how energy fluxes and food web structure vary overtime and how the seasonal dynamics influence stability. We examined how the structure, energy fluxes and stability of a highly resolved multitrophic lake food web change across seasons over three successive years. Two estimates representing different facets of stability were considered: resilience and reactivity. We found a strong seasonal pattern in food web structure, with higher complexity observed in summer and autumn. In addition, we found that more complex food webs are more reactive to perturbations, and consequently, less stable than simpler ones over short time-scale. This was influenced by a lower proportion of strong energy fluxes. Resilience was unaffected by seasonality, food web structure and energy fluxes, highlighting the need to account for multifaceted nature of stability. The seasonal variability of stability suggests that food webs may vary temporally in their vulnerability to environmental perturbations, which has important implications for ecosystem management.

Functional trait similarity in metacommunities, important for community assembly and ecological resilience in the face of environmental changes on landscapes, is structured by niche and stochastic processes. Yet, uncertainties about the importance of these processes remain because opposing responses of different species to environmental variables can obscure the detection of niche patterns related to environmental variation. To counter this, we propose examining metacommunity assembly patterns detected within clusters of species that share similar functional traits. We focused on groups of crustacean zooplankton species in boreal lake metacommunities that are similar in body size, feeding guild, and phylogenetic distance. The crustacean zooplankton species composition of lake metacommunities in three regions of Quebec, Canada (Saguenay, Côte-Nord and Schefferville) were surveyed using organismal bulk sample cytochrome oxidase I (COI) metabarcoding. Species were clustered according to their similarity using the three traits, and redundancy analysis and variation partitioning were applied to parse the relative influences of niche processes (environmental variables) and stochastic processes (spatial vectors) in the structuring of the communities within-cluster, between-clusters, and unclustered. We found that stochastic processes were the main source of influence in all three regions, but especially in Schefferville, the northernmost region. Cladocerans were more strongly influenced by niche processes than copepods. Finally, we found that analyzing the community assembly processes for all zooplankton species together offered less explanatory power and missed environmental variables that were key in the structuring of the different groups of ecologically similar species.

The dynamics of reproductive allocation (RA) in herbaceous plant communities, particularly in response to varying environmental conditions such as drought stress and competitive interactions, remain underexplored. This study aims to fill this gap by hypothesising that both belowground resource limitation and the presence of dominant species significantly influence RA strategies within plant communities, leading to different patterns of reproductive synchrony. We also expected different effects of resource limitations on intraspecific synchrony in RA compared to interspecific synchrony. We conducted a mesocosm experiment in an experimental garden over five years, exposing wetland plant communities (one dominant species and three subordinate species) to different drought stress regimes and a dominant removal treatment. The results suggested that belowground resource limitation and aboveground competition critically influence RA synchrony, with increased synchrony under reduced competition and increased stress. The competitively dominant species require more belowground resources for seed reproduction, while competitively weaker subordinate species can reproduce at lower resource levels. Furthermore, our findings highlighted contrasting responses in intra- and interspecific flowering synchrony to the resource limitations, which may reflect the different importance of evolutionary synchronising factors and competitive and facilitative effects between conspecifics and between species within the community. Individuals of species synchronised flowering mainly at their favourable sites where generative reproduction is more efficient, i.e. dominant species at wet sites, whereas subordinate species at drought stress treatments with reduced competition. This research provides empirical evidence for the multiple resource limitation model and highlights the strategies of plants in resource-limited environments, as well as the ecological importance of reproductive synchrony within herbaceous plant communities.