Abstract Climate warming is redistributing insects, but species‐level projections alone rarely show which functional strategies are most exposed or how traits are linked to climatic niche structure. We developed a trait‐anchored framework connecting projected range change, functional trait‐space occupancy and climatic niche geometry in global butterflies. We compiled functional traits and georeferenced occurrences for 12,448 butterfly species across six families. Species distribution models estimated current suitable area (A now ) and mid‐century suitable area under SSP5‐8.5 (A 2050 ), from which we derived an expansion index, E = (A 2050 − A now )/A now . Current suitable cells were projected into a two‐axis climatic harshness space to quantify climatic niche breadth and niche position. We then constructed a global functional trait space, estimated family‐level trait‐space occupancy with trait probability density surfaces, mapped the SDM‐derived expansion index with generalised additive models and tested trait–niche associations with structural equation models. Butterfly functional strategies formed a pronounced core–edge structure. Family core fractions (A50/A99) ranged from 17% to 33%, and standardised total trait‐space extent (A99) varied from 0.12 to 0.85. Projected range change formed a nonlinear, contraction‐dominated trait‐space response surface: mean predicted expansion rates were negative in both functional cores and edges across all families, although contraction intensity and the probability of weakly positive fitted values differed among families. In the pooled SEM, Seasonality was negatively associated with climatic niche breadth ( β = −0.14), whereas Environmental affinity ( β = 0.21) and Diapause timing ( β = 0.13) were positively associated with niche position. Projected climate‐change responses were structured across combinations of functional traits rather than along single traits alone. By linking SDM‐derived range change to functional trait‐space occupancy and climatic niche geometry, this framework shifts vulnerability assessment from species counts toward functional strategy coverage and identifies trait–niche pathways that warrant targeted validation. Read the free Plain Language Summary for this article on the Journal blog.
Abstract This Special Feature examines how macrosystems ecology advances understanding of ecological patterns and processes that operate across nested spatial, temporal, and organizational scales, from microsite to continent. This Special Feature synthesizes 10 contributions spanning freshwater and terrestrial systems, plants and animals, and methods development through empirical synthesis, showing that continental observational networks (e.g., NEON, USA‐NPN) and coordinated citizen science enable questions no single team or dataset could address alone. These studies reveal that ecological patterns are strongly scale‐ and assemblage‐dependent, that trait‐based and intraspecific approaches increasingly complement species‐level descriptions, and that open software tools and shared leadership models are as essential as the data themselves. Collectively, the papers highlight three lessons: cross‐scale linkages are the unit of analysis in macrosystems ecology; trait distributions provide a natural currency for cross‐scale and cross‐continent comparison; and the data revolution is inseparable from a parallel revolution in how teams collaborate, communicate, and engage the public. The collection calls for cross‐network synthesis across continents, operationalization of CARE principles alongside FAIR norms, translation of continental‐scale findings into actionable science, and structural investment in the next generation of macrosystems ecologists. Read the free Plain Language Summary for this article on the Journal blog.
Abstract Ecosystem productivity stability is a key indicator of ecosystem functioning under climate change, but the role of cooling periods in increasingly variable climates remains poorly resolved. Using a 17‐year reciprocal transplant experiment along an elevational gradient in alpine grasslands, we examined the asymmetric effects of temperature fluctuations, including warming and cooling, on the above‐ground net primary productivity (ANPP) temporal stability. Warming significantly decreased ANPP temporal stability, whereas cooling had no net effect. These asymmetric responses were primarily governed by phenological dynamics. The decline in ANPP temporal stability under warming was primarily driven by advanced leaf‐out phenology. Under cooling, delayed leaf‐out and reduced plant size promoted temporal stability of ANPP, but these effects were offset by direct cooling‐induced suppression and delayed flowering. Our findings indicate that periods of cooling are unlikely to mitigate instability driven by warming, highlighting the necessity to incorporate temperature asymmetry and phenological regulation into predictions of ecosystem stability under increasing climate variability. Read the free Plain Language Summary for this article on the Journal blog.
Abstract Limited plant establishment creates demographic bottlenecks that can alter vegetation trajectories in changing environments, yet it is unclear how common eco‐evolutionary indicators of plant strategy shape early response to key stressors. We evaluated how early functional traits, phylogeny, and adult climate niche jointly explain seedling drought and freezing tolerance across 49 semi‐arid rangeland species. The best models explained 36% of variation in freezing tolerance (traits only) and 45% of variation in drought tolerance (traits, phylogeny, and climate), identifying both shared and unique indicators of different stress responses. Drought tolerance was explained by rapid root elongation and large seed size, while phylogeny captured additional tolerance within the grass family. Seedling freezing tolerance was linked to rapid root elongation and colder thresholds for root growth, though traits shared some explanatory power with adult climate niche (cold temperature distribution). While stress resistance can be shaped by phylogeny and adaptations to long‐term climate regimes, our results elucidate early traits with clearer direct links to establishment capacity under drought and freezing stress, across species. Additional research is needed to understand how variation in stress response strategies across multiple demographic stages (e.g., seeds, seedlings, mature plant) and ecological scales (e.g., within and across species' climate distributions) could affect vegetation distributions and trajectories in changing environments. Read the free Plain Language Summary for this article on the Journal blog.
Abstract Phosphorus (P) is an essential but often limiting nutrient for sustaining grassland ecosystem functions. Its soil dynamics are highly sensitive to land management practices and may vary across soil aggregate sizes due to differences in biotic and abiotic factors. However, the mechanisms affecting P fractions within aggregates remain largely unexplored. Here, we conducted an eight‐year field study in a meadow steppe to investigate how the addition of nitrogen (N) and P, alone and in combination, along with mowing, influences soil P dynamics in macroaggregates and microaggregates. In macroaggregates, nutrient addition and mowing stimulated the transformation of moderately labile P to resin P, likely reflecting enhanced recycling of microbial biomass P (MBP) and desorption via acidification. In contrast, lower P availability in microaggregates resulted from mobilization‐refixing processes between moderately labile P and occluded P fractions, mainly driven by increased activity of alkaline phosphatase (ALP) enzymes. Our results suggest that under nutrient addition and mowing, P is transferred from moderately labile forms to more available forms in macroaggregates, but to more stable forms in microaggregates. This study emphasizes the crucial role of macroaggregates in maintaining P availability and provides a mechanistic foundation for understanding how changes in soil aggregate affect nutrient cycling under land management interventions. Read the free Plain Language Summary for this article on the Journal blog.
Abstract The continuous rise in atmospheric CO 2 concentration has profoundly altered vegetation structure and function across terrestrial ecosystems. Among various indicators, vegetation phenology is conventionally considered an early warning indicator of changes in other ecosystem processes. However, the relationship between vegetation phenology and elevated CO 2 (eCO 2 ) remains highly elusive. Here, we conducted a comprehensive meta‐analysis of 624 experimental records from 39 published studies to evaluate eCO 2 effects on vegetation phenology and quantify the relative importance of climate variables, soil factors, eCO 2 magnitude and experimental duration. The findings showed that eCO 2 significantly advanced overall vegetation phenology by 2.50 days (−1.99%), with leaf‐out advancing by 3.00 days (−2.38%) and maturity by 4.09 days (−3.24%). Elevated CO 2 exerted a negligible overall effect on plant growing season length. Importantly, model selection showed that plant functional groups were not essential predictors of phenological shifts. Instead, phenological shifts were primarily predicted by mean annual temperature (MAT) and eCO 2 magnitude. These results provide new insights into the mechanisms linking atmospheric change with plant developmental timing and highlight the need to explicitly incorporate CO 2 ‐driven phenological responses into ecosystem and Earth system models. Read the free Plain Language Summary for this article on the Journal blog.
Abstract Urbanization from expanding human development has radically altered the structure, ecology and microclimate of landscapes worldwide. These dramatic environmental alterations subject organisms to novel ecological conditions and may select for distinct ecophysiological traits. Here, we investigate the effects of urbanization on cutaneous evaporative water loss (CEWL) in the Aegean Wall Lizard ( Podarcis erhardii ) and explore the potential environmental factors impacting physiology. In this Mediterranean setting, urban microhabitats were cooler and wetter, and urban lizards displayed higher CEWL than nonurban lizards. Increased urban lizard CEWL is a potential response to relaxed pressure for water conservation in areas with increased water availability from human activities, such as irrigation and ornamental water features. Our findings demonstrate that urbanization may shift microclimates and thus alter ectotherm ecophysiology. Quantifying these changes advances our understanding of how urbanization shapes organismal responses to novel environments and offers insights into adaptation and persistence in human‐modified landscapes. Read the free Plain Language Summary for this article on the Journal blog.
Abstract The biogeography of ectotherms is greatly influenced by their thermal tolerance, which is expected to be tightly coupled to aerobic performance. However, preferred temperatures of ectotherms often deviate substantially from aerobic performance optima. This suggests that alternate physiological mechanisms may constrain their thermal niche. Physiological breakpoints can indicate thermal thresholds, which can manifest at the cellular level before impacting organismal performance. Therefore, we tested whether cellular rather than organismal temperature thresholds aligned with thermal habitat use in a stenothermal fish. We reared eggs from a wild, montane population of bull trout ( Salvelinus confluentus ), a cold‐water species vulnerable to climate‐induced warming. Juveniles were then acclimated to ecologically relevant temperatures (6, 9, 12, 15, 18, or 21°C) for 3 weeks. We conducted behavioural trials to determine preferred temperatures. We used custom OpenArray qPCR chips to quantify the expression of 56 genes in gill, liver and muscle to estimate tissue‐specific transcriptional breakpoint temperatures. Metabolic rates were measured to determine the temperature at which aerobic performance peaks. We found that the interquartile range of the temperature preference of juveniles was 9.3 to 14.3°C, a range that aligned with tissue‐specific transcriptional breakpoint temperatures of genes in certain functional categories. When temperatures exceeded transcriptional breakpoints, pathways associated with the cellular stress response were upregulated, whereas genes related to growth and metabolism were downregulated. Aerobic performance increased beyond preferred temperatures and peaked at 20.6°C. Our findings suggest that although juvenile bull trout have the metabolic flexibility to exploit warmer habitats for short periods, they preferred temperatures that avoided the activation of cellular stress responses to potentially invest in the molecular machinery required to promote growth. Our results highlight the connection between thermoregulatory behaviour and cellular thermal thresholds, which has important implications for understanding the mechanistic basis of biogeography in ectotherms as climate change continues to reshape their thermal landscapes. Read the free Plain Language Summary for this article on the Journal blog.
Abstract As species distributions shift due to climate change, functional alterations may also occur within marine communities, potentially leading to ecosystem‐wide transformations. With Mediterranean marine ecosystems projected to undergo tropicalization, it is crucial to understand how climate change will impact not only species distributions but also the functional traits of marine organisms. This study evaluated the potential effects of climate change on functional patterns in shallow reef fish communities in the northeastern Mediterranean. Using random forest models, we projected current and future abundances of the most common reef fish and estimated community‐weighted mean traits under mid‐ and long‐term climate scenarios. Our findings indicate a shift toward fish communities dominated by species with shorter lifespans, smaller maximum sizes and earlier maturity, along with increased growth rates and fecundity. Long‐term scenarios suggest functional homogenization, with reduced trait diversity due to environmental filtering, potentially leading to communities with higher functional redundancy. This study provides initial insights into how climate‐driven changes could reshape functional patterns in northeastern Mediterranean reef fish communities, with significant implications for ecosystem services and resilience. Read the free Plain Language Summary for this article on the Journal blog.
Abstract Climate change is increasing the frequency and severity of heatwaves with potential consequences for host–parasite dynamics. While the acute heat tolerance of free‐living organisms has been intensively studied, much less is known about it for parasites and their life cycle stages. We investigated critical thermal maxima (CT max ) in two closely related marine invasive parasitic copepods ( Mytilicola orientalis and Mytilicola intestinalis ) that infect bivalves in the European Wadden Sea, using temperature ramping assays across life cycle stages (free‐living larvae and parasitic adult females) that mimicked rapid warming periods during heatwaves occurring in the spring and summer. CT max values of both life cycle stages of the two parasite species were relatively high (36°C–46°C), considering local environmental temperatures and typical CT max values of free‐living copepods. The values differed by species and life cycle stage, with ontogenic differences partially depending on the acclimation temperature (spring 14°C or summer 20°C). Overall, M. orientalis exhibited significantly higher CT max than M. intestinalis , both for the adult and the larval stages (6.6°C–6.8°C and 3.9°C–4.2°C higher, respectively) at both acclimation temperatures. Within M. orientalis , larvae had 2.6°C–4.8°C lower CT max than adults at both acclimation temperatures, while M. intestinalis showed a stage‐specific variation of 2.2°C only when acclimated to 14°C. Larval stages of both species had 2.8°C–3.1°C higher CT max values when acclimated to 20°C compared to 14°C, whereas no effect of acclimation temperature was seen among adults of either species. Our results suggest that parasitic copepods have a high acute heat tolerance that depends on the species, life cycle stage and seasonal temperature acclimation, with implications for heatwave tolerance. While current summer heatwaves do not exceed the CT max of parasites acclimated to summer temperatures, the lower CT max values when acclimated to spring temperatures may indicate negative effects of spring heatwaves on larval stages. Beyond our study, the CT max approach may be a practical tool to investigate the acute heat tolerance of parasites. Read the free Plain Language Summary for this article on the Journal blog.
1. Permafrost thaw is reshaping nutrient dynamics in boreal forests, but its impacts on tree nutrient limitation and functional strategies remain poorly understood. Clarifying these responses is crucial for predicting the response of boreal forests to climate change. 2. We investigated the stoichiometric and functional traits of Dahurian larch at the southern edge of the Eurasian permafrost zone. We compared uplands (active layer thickness, ALT >100 cm, dry) and lowland swamps (ALT <60 cm, wet) to examine variations in tree and soil nutrient status, and assessed the relative importance of climate and local soil factors in driving tree nutrient variations. 3. Our results showed that upland larches had higher phosphorus (P) and potassium (K) concentrations, lower carbon to phosphorus (C:P) and nitrogen to phosphorus (N:P) ratios, and similar N contents compared with lowland trees. Upland soils exhibited lower C and N contents but higher K content than swamps, whereas P levels did not differ significantly (p > 0.05). Climate and soil variables explained 34.2% and 26.6% of the variation in larch stoichiometry, respectively, and their interaction accounted for 4.4% of the variation. Upland larches with deeper ALT displayed more acquisitive functional traits, as they tended to have higher leaf P content, greater specific leaf area, and lower leaf dry matter content than in lowland swamps. 4. Our findings suggest that instead of N, deeper permafrost thaw and drier soil on uplands can increase the availability of P and K, promoting acquisitive strategies in upland larches. Our findings illustrate how permafrost and landscape factors alter nutrient limitation and boreal tree strategies in the rapidly changing climate.
Plant functional traits play critical roles in responding to environmental heterogeneity and provide a theoretical basis for understanding species' adaptive strategies. Pinus yunnanensis var. pygmaea, a highly resilient species endemic to the fire-prone regions of southwestern China, exhibits significant intraspecific variation in numerous functional traits, including serotiny. However, how these functional traits evolved to form an adaptive strategy in response to heterogeneous fire regimes has not been fully explored. We investigated intraspecific variation in 25 functional traits across 14 P. yunnanensis var. pygmaea populations. The functional traits significantly associated with serotiny were identified, and a fire-embracing index was developed based on the trade-offs among them. Subsequently, the environmental factors potentially driving variation in the fire-embracing index were explored. Populations with higher serotiny levels exhibited a more pronounced fire-embracing strategy, characterized by lower leaf nitrogen concentrations, a shorter stature and higher cone crude fat content. These populations tended to occur in areas characterized by larger burned areas and more nutrient-poor soils. Our results revealed clear trade-offs between serotiny and other functional traits of P. yunnanensis var. pygmaea and provided new insights into the evolutionary mechanisms of its fire-embracing strategy. These findings helped clarify how plants develop adaptive strategies in fire-prone ecosystems.Read the free for this article on the Journal blog.
In ecological communities, some taxa contribute to ecosystem functioning in highly similar ways. When numerous taxa within a community contribute similarly, this might suggest a degree of functional redundancy, where the loss of one species may not impair ecosystem functioning, providing other functionally similar species can compensate for the loss. Multidimensional ordination is commonly used to analyse patterns in ecological communities over space and time, being most intuitively visualised using multidimensional scaling techniques. The patterns produced by these techniques can therefore be thought of as a community's structure. Research has shown that it is typical for multiple taxa in a community to contribute to this structure interchangeably, representing a different form of redundancy, structural redundancy, where only a small subset of taxa is required to recreate the overall community pattern. Further to this, there can be multiple mutually exclusive subsets of taxa within a community that can reproduce the full-community pattern. In this study, we examine the proposed method to quantify structural redundancy within ecological communities. The intention behind the development of this method was to explore any potential link between the statistical concept of structural redundancy and concepts of ecosystem function, such as functional redundancy and compensation. Notionally, a high degree of structural redundancy within a community data set might be indicative of the potential for functional redundancy. We perform a series of tests on multiple freshwater macroinvertebrate community data sets to discover what, if any, characteristics of a community strongly influence the amount of structural redundancy present. Our tests ultimately determined that the method is extremely sensitive to sample size. As such, we demonstrate that this approach is unable to provide reliable information regarding the potential for functional redundancy in ecological communities. This was an unexpected result, which motivated a further preliminary simulation revealing that the underlying correlation procedure is also subject to the same sensitivity. This analytical technique is widely used in community ecology, especially in the analysis of biota-environment relationships, and is implemented in major statistical software packages.Read the free for this article on the Journal blog.
Nitrogen fertilization is commonly applied to increase crop yields in agroecosystems. Beyond its direct benefits, nitrogen fertilization may also influence crop production indirectly by altering crop-weed competition. Moreover, nitrogen fertilization can simultaneously threaten the biodiversity of both natural and managed communities, including weed diversity in wheat fields. Such diversity losses may weaken resistance to antagonists (e.g. pests and pathogens), compromising agroecosystem health and crop productivity. However, how nitrogen fertiliation affects crop-weed coexistence in agroecosystems, and the mechanisms underlying these effects, remain unclear. Here, we conducted a competition experiment between wheat and two dominant weeds (i.e. Avena fatua L. and Echinochloa crus-galli (L.) P. Beauv.) by growing a total of 2490 individuals in a response-surface design with and without nitrogen fertilization. At the end of growing season after 8 months, we harvested one-third individuals to measure individual seed production to parametrize competitive population models, allowing to quantify niche and fitness differences and to predict competitive outcomes. We then measured various functional traits at individual level on the remaining two-thirds at their peak growth, including plant height, three leaf traits (e.g. leaf area, specific leaf area), five root traits (root area, specific root area) with and without nitrogen fertilization. We found that nitrogen fertilization facilitated coexistence between wheat and weeds, but the underlying processes differed for the two weed species with distinct functional strategies. Specifically, fertilization increased the niche differences between wheat and E. crus-galli, resulting from amplified root area and length differences between them. In contrast, nitrogen addition reduced the competitive advantage of wheat over A. fatua and increased the likelihood of their coexistence by increasing A. fatua's seed mass, specific root area, and length while reducing wheat height. Synthesis. These findings demonstrate that nitrogen addition can affect coexistence through both niche and fitness difference-related processes and reveal the effect of nitrogen fertilization on plant coexistence is highly species-specific. Our study highlights the importance of trait plasticity for mediating coexistence under varying nutrient conditions and offers practical recommendations for selecting wheat varieties that support sustainable weed management under varying fertilization regimes to balance crop production and biodiversity conservation.Read the free for this article on the Journal blog.
Plant diversity affects both ecosystem functioning and the functional and taxonomic diversity of multiple trophic levels. However, in the literature, it is unclear if this pattern is driven by species richness per se or by the functional diversity or composition (e.g. resource-use strategy) of the community. Here, we use a novel Hawaiian lowland restoration experiment where plots were planted with the same number of plant species (n = 10), but different functional diversities and different resource-use strategies. The different plant combinations created a range of trait values with species placed in trait space according to their life history traits under the fast-slow plant economics spectrum. Because resource quality varied for detritivores, we were able to test how litter mixtures influenced litter decomposition rates and ground-dwelling arthropod taxonomic and functional diversity and abundance at high (predators) and low (detritivores, fungivores) trophic levels. Using Structural Equation Models, we found that plant functional diversity (measured using functional dispersion and Rao's Q indices) but not resource-use strategy increased both litter decomposition rates and low trophic level arthropod richness and functional diversity. Arthropod abundance increased arthropod taxonomic richness at the two trophic levels but decreased functional diversity at the low level. Finally, we also found indirect bottom-up effects of plant functional diversity on arthropod functional diversity at the high trophic level. Our findings demonstrate that interactions between food webs and plant functional diversity jointly shape biodiversity-productivity relationships, emphasizing the need to adopt a multi-trophic perspective when studying biodiversity and ecosystem function relationships and designing restoration strategies.Read the free for this article on the Journal blog.
Abstract This Special Focus examines how linking functional traits with phenology improves our understanding of how organisms respond to environmental change. It synthesizes studies across global gradients, field observations, experiments and conceptual work, showing that phenology–trait relationships are strongly scale‐ and context‐dependent. These relationships are shaped by understudied trait dimensions, such as genome size, below‐ground storage organs, internal carbon dynamics, winter activity and early life stages. Collectively, the studies highlight the importance of integrating observational networks, experiments and models to capture the dynamic coupling between traits, phenology and environmental change. The collection calls for research that links phenology and traits in taxonomic groups beyond vascular plants, explicitly considers biotic interactions and assesses the direct implications of phenological change for ecosystem functioning. Such approaches are still rare but essential for fully integrating the processes that drive ecosystem functions. Read the free Plain Language Summary for this article on the Journal blog.
Xylem anatomy underpins the capacity of trees to transport water while avoiding hydraulic failure, shaping species performance and resilience to climate change. However, the specific ways anatomical traits underpin hydraulic trade-offs in tropical forests remain debated. We investigated relationships between branch wood anatomical traits and their hydraulic properties across 78 individual trees, encompassing 13 species, in an aseasonal wet tropical forest in Puerto Rico. We combined metrics of vessel size, vessel grouping, and tissue fractions with key hydraulic traits, including theoretical hydraulic conductivity (Kth), embolism resistance (Psi 50) and stem capacitance at full turgor (Cft). This allowed us to address two questions. First, we tested whether species in an aseasonal wet forest exhibit a trade-off between xylem safety and efficiency. Second, we examined which anatomical traits are associated with hydraulic safety strategies, from drought tolerance to drought avoidance. We found a high diversity of hydraulic strategies across species, with strong evidence of a trade-off between safety and efficiency: individuals with higher Kth and higher Cft were more vulnerable to embolism (less negative Psi 50). Contrary to the vessel diameter hypothesis, vessel size was not significantly related to embolism resistance. Instead, vessel connectivity emerged as a key determinant: species with a higher proportion of solitary vessels were significantly more vulnerable to embolism, supporting the vessel network hypothesis. Multivariate combinations of vessel traits also explained variation in Psi 50, whereas tissue fractions, including total parenchyma and pith, did not predict variation in Cft. These findings reveal that drought tolerance (low Psi 50) and drought avoidance (high Cft) are coordinated with water transport efficiency (Kth), indicating that tropical tree species balance hydraulic strategies along complementary axes of safety-efficiency. Together, this work advances understanding of the xylem structure-function link in tropical forests and emphasizes the importance of vessel network properties for predicting patterns of species co-existence and forest resilience under intensifying climatic extremes.Read the free for this article on the Journal blog. La anatom & iacute;a del xilema sustenta la capacidad de los & aacute;rboles para transportar agua, evitando fallas hidr & aacute;ulicas, lo que determina el desempe & ntilde;o y la resiliencia de las especies frente al cambio clim & aacute;tico. Sin embargo, los mecanismos espec & iacute;ficos mediante los cuales los rasgos anat & oacute;micos soportan los intercambios hidr & aacute;ulicos en los bosques tropicales siguen siendo objeto de debate En este proyecto investigamos las relaciones entre la anatom & iacute;a de la madera de ramas y sus propiedades hidr & aacute;ulicas en 78 individuos de 13 especies en un bosque tropical h & uacute;medo no estacional de Puerto Rico. Al integrar m & eacute;tricas del tama & ntilde;o y del agrupamiento de los haces vasculares y de las fracciones de tejido con la conductividad hidr & aacute;ulica te & oacute;rica (Kth), la resistencia a la embolia (Psi 50) y la capacidad del tallo para la turgencia completa (Cft), abordamos dos preguntas. Primero, evaluamos si las especies de un bosque h & uacute;medo no estacional presentan un compromiso entre la seguridad y la eficiencia hidr & aacute;ulica. Segundo, examinamos qu & eacute; rasgos anat & oacute;micos se asocian con estrategias de seguridad hidr & aacute;ulica, desde la tolerancia hasta la evitaci & oacute;n de la sequ & iacute;a. Encontramos una alta diversidad de estrategias hidr & aacute;ulicas entre especies, con evidencia clara de un compromiso entre seguridad y eficiencia: los individuos con mayores Kth y Cft fueron m & aacute;s vulnerables a la embolia (Psi 50 menos negativo). En contraste con la hip & oacute;tesis del di & aacute;metro de los haces vasculares, el tama & ntilde;o de estos no se relacion & oacute; de manera significativa con la resistencia a la embolia. En cambio, la conectividad de los haces vasculares emergi & oacute; como un determinante clave: las especies con una mayor proporci & oacute;n de vasos solitarios resultaron significativamente m & aacute;s vulnerables a la embolia, lo que respalda la hip & oacute;tesis de la red vascular. Las combinaciones multivariadas de rasgos de los vasos tambi & eacute;n explicaron la variaci & oacute;n en Psi 50, mientras que las fracciones de tejido, incluidas el par & eacute;nquima total y la m & eacute;dula, no predijeron la variaci & oacute;n en Cft. Estos resultados revelan que la tolerancia a la sequ & iacute;a (Psi 50 bajo) y la evitaci & oacute;n de la sequ & iacute;a (Cft alto) est & aacute;n coordinadas con la eficiencia en el transporte de agua (Kth), lo que indica que las especies arb & oacute;reas tropicales equilibran estrategias hidr & aacute;ulicas a lo largo de ejes complementarios. En conjunto, este trabajo mejora la comprensi & oacute;n de la relaci & oacute;n entre la estructura y la funci & oacute;n del xilema en los bosques tropicales y resalta la importancia de las propiedades de la red de haces vasculares para predecir la coexistencia de especies y la resiliencia de los bosques frente a la intensificaci & oacute;n de los extremos clim & aacute;ticos
Abstract Seed dispersal allows plants to seek favourable conditions or spread the risk of unfavourable conditions through space and time. While theory predicts a trade‐off between spatial and temporal dispersal, empirical tests have been stymied by the difficulty of measuring dispersal directly and limited data on seed traits beyond mass. Using hidden Markov models and 20 years of plant community data, we estimated spatial and temporal dispersal probabilities for 60 native and non‐native annual plants and linked them to extensive seed trait measurements. We found a clear spatial–temporal dispersal trade‐off: non‐native grasses showed high spatial dispersal, native forbs high temporal dispersal and non‐native forbs spanned the spectrum. Importantly, the traits underlying these strategies differed by group. For native forbs, spatial dispersal increased with large, elongated seeds, while small, round seeds favoured temporal dispersal. In non‐native forbs, spatial dispersal declined with size, and temporal dispersal was linked to coat thickness and nitrogen content. Seed mass showed little association with either spatial or temporal dispersal. Our results provide empirical support for the spatial–temporal dispersal trade‐off while revealing that multiple distinct trait combinations can achieve similar dispersal strategies, underscoring the need to move beyond seed mass to understand plant life‐history strategies. Read the free Plain Language Summary for this article on the Journal blog.
