Trait‐based approaches are widely used to understand variation in plant demographic performance, yet their predictive power is often limited by context dependence. In particular, trait–demography relationships may shift across life stages and be modulated by local abiotic and biotic conditions. However, few studies have simultaneously examined how ontogeny, soil fertility, and neighborhood trait composition jointly shape the outcomes of trait–performance relationships. Here, we integrate long‐term demographic data, functional traits, and soil variables from a 20‐ha warm temperate forest dynamics plot to evaluate how three key traits, specific leaf area (SLA), leaf dry matter content (LDMC), and wood density (WD), affect tree growth and survival across seedling, sapling, and adult stages. We also examine how these effects, including neighborhood interactions for trait dissimilarity, are modified by soil fertility. Our study showed that soil fertility modulated trait effects on tree performance, which varied across life stages. Direct trait effects were detected primarily at the adult stage, where adult survival increased with WD but decreased with LDMC. In contrast, at the seedling and sapling stages, trait effects on survival were largely contingent on soil nutrients. Increasing soil organic matter, moisture, and available potassium intensified the negative effects of conservative traits (LDMC and WD) on seedling and sapling survival, while alleviating the negative effects of acquisitive traits (SLA). Seedlings exhibited lower survival when surrounded by heterospecific neighbors with dissimilar SLA. The negative effect of SLA dissimilarity among neighboring seedlings on seedling survival was amplified in soils rich in organic matter, moisture, and available potassium, whereas between seedlings and neighboring trees it was alleviated under higher nitrogen and phosphorus availability. Our results demonstrate the importance of explicitly considering life stage, local abiotic conditions, and biotic neighborhood context. This multidimensional approach offers new insights into trait‐based mechanisms underlying forest community dynamics across life stages.

The structure and function of ecological communities emerge from interactions among populations within specific environmental contexts. Yet we still lack general principles that explain how communities assemble, which patterns we should expect, and when transitions occur across diverse settings. To address this challenge, I propose the feasibility principle in community ecology as a guide to assembly. Grounded in a synthesis of theoretical work and empirical studies, the principle is articulated through three hypotheses: 1) for a given interaction structure at a given time, each potential community has a feasibility domain – the range of environmental conditions under which it can persist; 2) during assembly, the communities most likely to be observed are those whose feasibility domains overlap most with local conditions; and 3) transitions among communities occur when environmental change or species gains and losses move the system across boundaries separating their feasibility domains, with the probability of a transition decreasing as the overlap between the corresponding domains becomes smaller. This framing focuses on feasibility domains and the boundaries that separate attainable communities, providing testable predictions for assembly and transitions without invoking a particular dynamical endpoint. I outline a quantitative framework to estimate feasibility domains and compare predictions with data across organisms and contexts. In the face of rapid climate change and habitat modification, I discuss how the feasibility principle can inform conservation and restoration by anticipating assembly pathways, likely transitions, and points of intervention.

Abstract Area‐restricted search (ARS) is one of the most influential and widely used concepts in foraging theory, capturing a simple rule by which animals intensify local search following a resource encounter. Because ARS performs well in many spatially structured environments, it serves as a basic model for interpreting movement patterns across taxa. Despite this prominence, there is no synthesis of when and why ARS is expected to fail, even when implemented correctly. Here, we develop a failure‐based framework that treats departures from ARS not as errors, but as informative consequences of mismatches between a local search rule and ecological reality. We identify multiple classes of failure, spanning informational, spatiotemporal, spatial, cognitive and normative dimensions. These include situations in which encounters are statistically uninformative, self‐generated movement creates misleading cues, environmental change outpaces the temporal horizon of the rule, movement is constrained or costly, or maximizing encounter rates conflicts with other fitness objectives. Many of these failures do not require abandoning ARS. Instead, they point to plausible refinements, such as decaying responses, state dependence, or limits on search duration, all of which preserve the simplicity of ARS while reducing its vulnerability to systematic mismatch.

Island area is widely known to affect taxonomic richness across different trophic levels. However, the impact of island size on taxonomic evenness, which quantifies the species abundance distribution, has yet to be explored, especially in tropical island ecosystems. In this study, twenty representative tropical islands with areas ranging from 2 ha to 406 ha and minimal human disturbance were selected. Then we measured the taxonomic evenness of aboveground plants, belowground soil bacterial and fungal communities, as well as a series of soil properties (i.e. pH, salinity, organic carbon, total nitrogen, total phosphorus, total potassium and carbon/nitrogen ratio). We found that, like the positive area‐richness relationship, the taxonomic evenness of the plant community also increased with island area, indicating more stable plant communities on the larger islands. However, the island area did not affect the taxonomic evenness of soil bacterial and fungal communities. Furthermore, the effects of island area on the taxonomic evenness of the plant and soil bacterial communities were mediated through soil factors (e.g. soil pH and salinity). Together, the contrasting area–evenness relationships among plant and soil microbe groups highlight the importance of dissecting potential mechanisms underlying community dynamics of different organisms.

As habitats change, the effectiveness of animal‐mediated seed dispersal increasingly depends on animal responses to altered structure and resources. With habitat loss and degradation accelerating across the tropics, understanding how dispersers' foraging behavior and movement influence seed removal and deposition is critical to promoting forest regeneration. In a tropical lowland landscape of southeastern Mexico with varying levels of human disturbance, we studied how black howler monkeys' Alouatta pigra foraging behavior influences the seed dispersal services they provide. Additionally, given the species' long gut transit time, we examined how their movement patterns across spatial and temporal scales directly and indirectly shape seed dispersal distance. We found that habitat disturbance significantly reduced food resource availability and frugivory levels, limiting the black howler monkeys' ability to support natural forest succession through seed dispersal. However, by dispersing seeds an average of 90.98 ± 59.59 m from the parent plant and 88.23 ± 47.55 m between samples, black howler monkeys may reduce mortality risks associated with distance‐ and density‐dependent effects. At the smallest spatiotemporal scale, relative turning angles best predicted seed dispersal distance, indicating that goal‐oriented movement can enhance animals' seed dispersal roles. For black howler monkeys, this may be a necessary compensatory strategy for navigating lower‐quality habitats, helping disperse seeds over longer distances. At broader scales, an increase in weekly activity areas – driven by low resource availability – was associated with greater seed dispersal distance. Ultimately, our results show that animal responses to habitat disturbance can influence seed dispersal, potentially affecting forest regeneration and ecosystem resilience. These findings emphasize the importance of understanding animal resilience dynamics to more accurately predict and manage the long‐term impacts of disturbance on biodiversity and ecosystem health.

Understanding plant competitive outcomes, driven by niche and fitness differences, requires exploring these differences across simultaneous changes in abiotic and biotic conditions, such as soil properties, mutualisms and natural enemies. Here, we combined coexistence theory with detailed field observations in an annual grassland over two consecutive years and in silico simulations to assess changes in competitive outcomes, from coexistence to competitive exclusion, and from exclusion to priority effects. Our analysis shows that competitive exclusion is the most common outcome but with marked changes in the identity of the superior competitor under abiotic and biotic variation, highlighting the potential for regional coexistence. Herbivores were identified as the factor with the largest effect on the sensitivity of species pairs to shifts between coexistence and exclusion, although the effect size reflects sensitivity rather than the direction of change. Additionally, herbivores strongly influence the identity of the superior competitor, which can promote coexistence at larger spatial scales. Local coexistence was rarely predicted in our system. Finally, priority effects were mostly observed in the absence of a deterministic driver, as expected. Overall, our results suggest that while local coexistence is limited, species diversity can be maintained across larger spatial scales through shifts in competitive dominance mediated by multiple abiotic and biotic drivers.

Droughts, increasingly frequent under human‐driven climate change, are expected to intensify globally. Both pulsed and prolonged droughts can strongly affect organismal survival and population dynamics, potentially altering terrestrial communities and ecosystems. Understanding how drought influences communities is therefore critical for predicting and mitigating its 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. By synthesizing experimental and observational studies across terrestrial ecosystems, we show that while drought consistently restructures community composition in ways that scale with severity and duration, its effects on species interactions are more heterogeneous and do not scale predictably, revealing a decoupling between community reorganization and interaction dynamics. In particular, we found negative effects on species richness, and on plant and arthropod community composition, and predation and decomposition were more likely to be negatively affected by drought. Drought's effects also varied among biomes: community composition was most altered in grasslands and boreal forests, whereas trophic interactions in forests consistently weakened under drought, reflected as reduced rates of predation, herbivore attack, and litter consumption. Although drought is expected to harm systems across taxa and biomes, we also identified cases where drought had no overall effect, suggesting the potential resilience of some communities and stability of certain trophic interactions. Overall, our meta‐analyses demonstrate that drought can disrupt ecological communities on a global scale and underscores the importance of targeted monitoring of drought effects in terrestrial ecosystems, particularly in regions of high risk.

Annual survival is a key demographic parameter driving population trends in wildlife populations. However, despite numerous species‐specific or regional studies, global reviews of the factors affecting the survival of declining taxa remain scarce. Here, we investigated annual survival of fledged immature and adult shorebirds, a globally‐distributed and substantially‐declining avian taxon exhibiting diverse life‐history and migration strategies. We compiled 796 estimates of annual survival from 436 populations of 105 species, spanning 133 years from 1891–2023. Next, we investigated temporal and spatial trends and the impact of different life‐history traits on survival in a phylogenetic and spatial framework on a robust subset of 418 estimates from 1980 to the present. As expected, annual survival of adults was higher than immatures, and increased with body mass. Survival declined with longer migration distance, and marginally with breeding latitude. Additionally, annual survival significantly declined since 1980, especially among adult shorebirds. In contrast to previous analyses, neither insularity nor flyway type affected annual survival, and with small differences among continents. We concluded that annual survival did not show clear spatial patterns, but has declined substantially over recent decades. Some characteristics, including migratory behaviour, might make some populations of shorebirds more vulnerable than others. However, poor data coverage in some regions and methodological limitations might still mask local temporal and spatial patterns in the survival rates. The continuing collection of standardised data for population‐specific demographic parameters of wild animals is essential for a better understanding of their population dynamics, as well as for the improvement of conservation strategies.

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 109 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 ecological 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 woody plants exposed to drought conditions or elevated temperatures, but not on non‐woody plants. Sucking insects performed worse on plants exposed to elevated CO 2 , while chewing insect performance did not appear to differ between plants exposed to ambient or elevated CO 2 . 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 insects with slower life history strategies appeared to be less vulnerable to climate change, while plants with slower life history strategies appeared to be more vulnerable. 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.

Phenological shifts caused by climate change are increasingly documented in wild populations. These events may be inferred by examining changes in population abundance and age structure throughout the breeding season, often using citizen science. However, several gaps still limit optimal use of such data. First, the link between the proportion of juveniles sampled over time and the underlying distribution of breeding times and reproductive success remains unclear. Second, such observations necessarily concern individuals that survived to fledge, thus potentially reflecting selection on reproductive timing. Third, the effect of sampling design on estimating breeding parameters needs careful assessment. In this study, we address these three concerns, taking the example of bird monitoring. We first propose an analytical model relating the proportion of juveniles in counts (e.g. mist‐net captures) to fledging date distribution and mean reproductive success. We then show how the estimated fledging parameters relate to the underlying laying date distribution, accounting for a possible influence of selection, and use simulations to assess how sampling design affects the inference of fledging and breeding parameters. Our analytical results show that mean fledging time lags behind the inflection point in juvenile proportions, especially when laying date variance and reproductive success are high. Selection for earlier breeding advances the inferred mean laying date, but this bias can be corrected if independent information on selection strength is available. Our simulations show that our approach is able to recover the true mean and variance of fledging dates under unlimited sampling effort. A more realistic multi‐site approach reveals that accurate estimates can be reached with only a few sampling sessions per site, although increasing the number of capture sessions and capture sites improves precision. Our results hold promise to improve the accuracy of phenological estimates from population monitoring, and the interpretation of climate‐driven changes in wild populations.