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

Animal-mediated seed dispersal is a key process in plant population dynamics, species distribution and ecosystem functioning. As long-distance dispersal agents, ungulates help to maintain native plant populations facing abiotic changes in their habitat and habitat fragmentation or habitat loss. However, they also contribute to the spread of exotic species. Most ungulates live in groups, whose dynamics depend on the social status, personality, sex, age and body size of its different members. But how ungulate sociality affects zoochory remains largely unknown. We designed our experiment with sheep to test the effect of age composition on epizoochorous dispersal. Ewe lambs have stronger social links and respond more strongly to stress than adult ewes, therefore showing higher group cohesion. First, we expected that the more frequent interactions among ewe-lambs would shorten diaspore retention times and dispersal distances as ewe-lamb proportion increases. Second, diaspore exchange should be higher with increasing ewe-lamb proportion. We monitored groups of six domestic sheep (Ovis aries, Romane breed) individuals with different age ratios, replicated four times: respectively, 0/6, 2/4, 4/2 and 6/0 adult ewes to ewe lambs. We attached five cocklebur (Xanthium strumarium) diaspores, colour-coded for each animal, to the fur on each individual flank, 10 in total. We traced each diaspore fate during six-hour sessions where we recorded movements, physical interactions among individuals and individual behaviour resulting in diaspore detachment or exchange. As expected, we found shorter retention times and dispersal distances and more diaspore exchanges as the proportion of ewe-lamb increases in the groups. Shaking, then scratching were the main behaviours leading to diaspore loss. Non-intentional contacts between individuals were the most frequent interactions associated with diaspore exchange. We encourage further research on the effect of group living, be it group size or composition, on the different phases of epizoochorous dispersal.

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.

The export of emergent aquatic insects is a critical energy subsidy for terrestrial food webs. While urbanization is known to alter stream communities, its effects on the size structure of these insect subsidies and the subsequent consequences for riparian predators remain poorly understood. Yet, body size, a key dimension of subsidy quality, can strongly shape resource use by terrestrial predators, given their size-dependent foraging. Here, we investigated how land impervious cover affects the body-size distribution of emergent insects and riparian spider communities along the entire length of two urban streams. We sampled and analyzed emergent insect community composition, three size-structure metrics (i.e., size-spectrum slopes, mean body size and size range) and used stable isotopes to assess spider reliance on aquatic prey. Impervious cover was the strongest driver of the emergent community structure, overriding effects of longitudinal position. Increasing impervious surface cover was associated with community homogenization, a pronounced shift toward smaller individuals, steeper size-spectrum slopes and a contraction of body-size range. Notably, total exported biomass did not change significantly, indicating that the influence of surface imperviousness manifests primarily in qualitative rather than quantitative terms. Those changes led to higher reliance on aquatic prey from riparian spiders. Our work highlights that the homogenization of aquatic prey size distribution is a powerful driver of change within riparian food webs and underscore the importance of integrating body-size composition into assessments of land

Landscape heterogeneity is widely recognized as a driver of biodiversity, yet its ecological consequences for insect communities under active grassland management remain underexplored. Patch-burn grazing (PBG), which rotates fire across patches within a grazed landscape, is designed to promote spatial and temporal heterogeneity by creating a shifting mosaic of successional stages. In contrast, annual burning and grazing (ABG) imposes uniform disturbance. We tested how these contrasting strategies shape aboveground invertebrate communities across three years (2021-2023) in tallgrass prairie at the Konza Prairie Biological Station in Manhattan, Kansas. Using vacuum sampling, we quantified family-level richness, evenness, abundance, functional group composition of aboveground invertebrates, and herbivory across PBG and ABG units. Contrary to expectations, PBG did not consistently enhance local (alpha) or beta-diversity. Insect richness was higher in ABG in one year, while evenness was greater in PBG in another. Total abundances and functional group distributions were broadly similar, with only limited treatment differences. However, PBG significantly altered invertebrate community composition in two of three years, suggesting that heterogeneity influenced community structuring, even when richness was unchanged. Herbivory rates did not differ between treatments. Our findings reveal that using PBG to manage spatial heterogeneity leads to complex responses in insect communities but may lead to distinct community compositions across the landscape. This decoupling of richness from composition highlights the importance of considering multiple biodiversity metrics when evaluating ecological outcomes. By fostering compositional variability without inflating herbivore pressure, PBG has potential as a heterogeneity-based strategy for managing grasslands.

Droughts, increasingly frequent under human-driven climate change, are expected to intensify globally. Both pulsed and prolonged droughts can have pronounced effects on organismal survival and population dynamics, potentially altering terrestrial communities and ecosystems. Understanding the impacts of drought on communities is important to make predictions and mitigate these impacts. Here, we conducted two meta-analyses that evaluate two components of communities: community composition and species interactions, revealing overall negative effects of drought in both analyses. In particular, we found negative impacts on the richness of species, and plant and arthropod community composition, and predation and decomposition were more likely to be negatively impacted. Additionally, we found differences in the effect of droughts in different biomes, with community composition mainly impacted in grasslands and boreal forests, whereas species interaction was negatively affected in forests. Our meta-analyses highlight the potential for drought to disrupt ecological communities on a global scale. These findings underscore the importance of monitoring drought effects in terrestrial ecosystems, particularly in regions of high risk.

As habitats change, animal-mediated seed dispersal increasingly depends on how animals respond to altered habitat structure and resource availability. With habitat loss and degradation accelerating across the tropics, understanding how animal movement influences distance- and density-dependent seed mortality is key to promoting forest regeneration. Across a gradient of anthropogenic disturbance in a tropical lowland landscape of southeast Mexico, we assessed how the movement patterns of black howler monkeys (Alouatta pigra) influence their seed dispersal services through GPS tracking, behavioral observations, and seed sampling. Given the species’ long gut transit time, we employed a path analysis to examine how movement patterns across spatiotemporal scales directly and indirectly shape seed dispersal distance. By dispersing seeds away from the parent plant at an average distance of 99.5 ± 64.4 m, black howler monkeys likely reduce mortality risks associated with distance- and density-dependent effects. At the smallest scale, step lengths and relative turning angles emerged as key predictors of seed dispersal distance, revealing that goal-oriented movement strategies may enhance their ecological role as seed dispersers. At broader scales, variability in weekly core area size, driven by resource availability, strongly influenced seed dispersal distance. However, low availability of fruiting trees in disturbed areas may limit the black howlers’ ability to support natural forest succession. Ultimately, our findings show that animal responses to human habitat disturbance can influence key processes like seed dispersal, potentially affecting forest regeneration and ecosystem resilience, highlighting the need to understand these dynamics to predict and manage long-term impacts of disturbance on biodiversity and ecosystem function.

Climate change is expected to disrupt many trophic interactions, including those between insect herbivores and their host plants, which could have detrimental effects at the ecosystem level. However, the response of insect herbivory to climate change can vary widely across species, and an understanding of the mechanisms underlying this variation is lacking. Here we examine whether functional traits of insect herbivores and their host plants influence how climate change affects herbivore performance. Information on sixteen functional traits across 86 insect and 93 plant species were collated from values in literature and combined with a dataset of 102 climate manipulation studies measuring herbivore performance. We identified clusters within both plant and insect functional trait values which aligned closely with the fast-slow continuum of life history strategies (woody, perennial plants and chewing insects were larger and had greater longevity/slow development, while non-woody, annual plants and sucking insects were smaller and had shorter longevity/fast development). We found that herbivores performed better on drought-stressed woody plants but not on non-woody plants. Sucking insects performed worse on plants exposed to elevated CO2, while chewing insect performance improved but only on annuals when both plants and insects were exposed to elevated CO2. When insects were exposed to elevated temperatures, we found that both chewing and sucking insects performed better, but when both plants and insects were exposed to elevated temperatures, sucking insects performed worse and chewing insects performed better. Generally, we found the slower life history strategies appeared to be less vulnerable to climate change, except in the case of woody vs. non-woody plants exposed to drought or elevated temperature. This research identifies key functional trait relationships that could enhance our ability to predict the vulnerability of plant-insect interactions to projected climate change and guide conservation efforts.

Many mechanisms can lead to successful plant invasion, but their importance is often context dependent. One such mechanism is allelopathy: chemical inhibition of neighbouring plants. The importance of allelopathy may be mediated by soil microbiota and environmental conditions, and depend upon the species or functional group affected. To better understand how these factors alter allelopathy and competition, we conducted a combined field and greenhouse experiment focusing on absinthe (Artemisia absinthium). We experimentally introduced absinthe into native grassland via disturbances and collected soil from beneath these plants after three years. We then tested how invaded versus uninvaded field soil, within burned or unburned grassland, affected the performance of absinthe, two forbs (Achillea millefolium and Medicago sativa), and two grasses (Bromus inermis and Elymus lanceolatus) in a greenhouse competition experiment. We included activated carbon and soil sterilization treatments to test for allelopathic and microbial effects. Microbial inhibition, rather than allelopathy, drove competitive interactions. In uninvaded, unburned soil all species were inhibited and absinthe had no competitive effect. However, when absinthe was released from microbial inhibition by soil sterilization or prescribed fire, it suppressed other species. Microbial inhibition was also reduced for all species in invaded soil, suggesting suppression of pathogens by absinthe. Responses also varied between functional groups, with grasses being more vulnerable to microbial inhibition. Our findings highlight the complexity of invasion effects on soils and the potential for feedbacks on invasion outcomes. They also suggest that disturbance may facilitate invasion via effects on both plants and soil microbes.

Seed dispersal by large, mobile vertebrates plays a key role in shaping plant spatial dynamics and community structure. However, how variation in animal population size influences the magnitude and spatial scale of seed-dispersal remains poorly understood. We used and agent based modeling approach to simulate stomatochoric seed dispersal by the endangered Lear’s Macaw (Anodorhynchus leari) to evaluate how changes in population size affect the seed-dispersal function it provides for the licuri palm (Syagrus coronata), a keystone species in the Caatinga dry forests of Brazil. By simulating macaw movements under different population scenarios, we show that both the frequency and distance of seed dispersal events increase disproportionately with population size. Small populations result in highly localized seed deposition, whereas larger populations promote a considerable expansion in the frequency and length of long-distance dispersal (LDD). These findings suggest that the ongoing recovery and reintroduction of A. leari may not only benefit the macaws themselves but also enhance the regeneration and connectivity of S. coronata populations. More broadly, our results emphasize the potential for population recovery of large frugivores to restore lost ecological functions and reveal stomatochory by parrots as an overlooked but functionally significant dispersal mechanism for large-seeded plants.

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.

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.