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• Leaf venation networks evolved along several functional axes, including resource transport, damage resistance, mechanical strength, and construction cost. Because functions may depend on architectural features at different scales, network architecture may vary across spatial scales to satisfy functional tradeoffs. • We develop a framework for quantifying network architecture with multiscale statistics describing elongation ratios, circularity ratios, vein density, and minimum spanning tree ratios. We quantify vein networks for leaves of 260 southeast Asian tree species in samples of up to 2 cm², pairing multiscale statistics with traits representing axes of resource transport, damage resistance, mechanical strength, and cost. • We show that these multiscale statistics clearly differentiate species’ architecture and delineate a phenotype space that shifts at larger scales; functional linkages vary with scale and are weak, with vein density, minimum spanning tree ratio, and circularity ratio linked to mechanical strength (measured by force to punch) and elongation ratio and circularity ratio linked to damage resistance (measured by tannins); and phylogenetic conservatism of network architecture is low but scale-dependent. • This work provides tools to quantify the function and evolution of venation networks. Future studies including primary and secondary veins may uncover additional insights.

Leaf wetness is an important characteristic linked to a plant's strategies for water acquisition, use and redistribution. A trade-off between leaf water retention (LWR) and hydrophobicity (LWH) may be expected, since a higher LWH/lower LWR may enhance photosynthesis, while the opposite combination may increase the leaf water uptake (LWU). However, the validation of the ecological meaning of both traits and the influence of droplet volume when measuring them have been largely neglected. To address these questions, LWR and LWH of 14 species were measured using droplets of between 5 and 50 μL. Furthermore, the ability of those species to perform LWU was evaluated through leaf submergence in water. The droplet-volume effect on absolute values and on species ranking for LWR and LWH was tested, as well as the influence of water droplet volume on the relationship between leaf wetness traits and LWU. Variations in droplet volume significantly affected the absolute values and the species ranking for both LWR and LWH. The expected negative correlation between leaf wetness traits was not observed, and they were not validated as a proxy for LWU. The water droplet volume does matter when measuring leaf wetness traits. Therefore, it is necessary to standardize the methodological approach used to measure them. The use of a standard 5 μL droplet for LWH and a 50 μL droplet for LWR is proposed. It is cautioned that the validation of both traits is also needed before using them as proxies to describe responses and effects in functional approaches.

As a result of climate and land‐use changes, grasslands have been subjected to intensifying drought regimes. Extreme droughts could interfere in the positive feedbacks between grasses and soil water content, pushing grasslands across critical thresholds of productivity and leading them to collapse. If this happens, systems may show hysteresis and costly management interventions might be necessary to restore predrought productivity. Thus, neglecting critical transitions may lead to mismanagement of grasslands and to irreversible loss of ecosystem services. Rainfall manipulation experiments constitute a powerful approach to investigate the risk of such critical transitions. However, experiments performed to date have rarely applied extreme droughts and have used resilience indices that disregard the existence of hysteresis. Here, we suggest how to incorporate critical transitions when designing rainfall manipulation experiments on grasslands and when measuring their resilience to drought. The ideas presented here have the potential to trigger a perspective shift among experimental researchers, into a new state where the existence of critical transitions will be discussed, experimentally tested, and largely considered when assessing and managing vegetation resilience to global changes. We suggest two different approaches of how rainfall manipulation experiments in grasslands can be carried out to investigate critical transitions of productivity. We aim to trigger a perspective shift and guide researchers along the trajectory to a new state, where the existence of critical transitions will be discussed, experimentally tested, and largely considered when assessing and managing vegetation resilience to global changes.

Aims Amidst the Campos de Altitude (Highland Grasslands) in the Brazilian Atlantic Forest, woody communities grow either clustered in tree islands or interspersed within the herbaceous matrix. The functional ecology, diversity, and biotic processes shaping these plant communities are largely unstudied. We characterized the functional assembly and diversity of these tropical montane woody communities and investigated how they fit within Grime's CSR (C—competitor, S—stress‐tolerant, R—ruderal) scheme, what functional trade‐offs they exhibit, and how traits and functional diversity vary in response to bamboo presence/absence. Methods To characterize the functional composition of the community, we sampled five leaf traits and wood density along transects covering the woody communities both inside tree islands and outside (i.e., isolated woody plants in the grasslands community). Then, we used Mann–Whitney test, t test, and variation partitioning to determine the effects of inside versus outside tree island and bamboo presence on community‐weighted means, woody species diversity, and functional diversity. Results We found a general SC/S strategy with drought‐related functional trade‐offs. Woody plants in tree islands had more acquisitive traits than those within the grasslands. Trait variation was mostly taxonomically than spatially driven, and species composition varied between inside and outside tree islands. Leaf thickness, wood density, and foliar water uptake were unrelated to CSR strategies, suggesting independent trait dimensions and multiple drought‐coping strategies within the predominant S strategy. Islands with bamboo presence showed lower Simpson diversity, lower functional dispersion, lower foliar water uptake, and greater leaf thickness than in tree islands without bamboo. Conclusions The observed functional assembly hints toward large‐scale environmental abiotic filtering shaping a stress‐tolerant community strategy, and small‐scale biotic interactions driving small‐scale trait variation. We recommend experimental studies with fire, facilitation treatments, ecophysiological and recruitment traits to elucidate on future tree island expansion and community response to climate change. We assessed functional traits of woody communities in tree islands and grasslands in the montane Atlantic forest. The woody communities are stress‐tolerant and respond to facilitation and bamboo‐encroached tree islands show reduced diversity. This has implications for tree island expansion and their vulnerability to climate change.

A recent paper by de Bello et al. (2015) reviewed the problems of imposing phylogenetic corrections in functional ecology irrespective of the research question. Although we agree with them, we do believe that the scenarios where phylogenetic corrections would be unnecessary deserve a specific look on two aspects: scale and traits. Our intention is to show that the decision to use phylogenetic corrections is not that straightforward and that a more integrative approach yields a bigger picture of processes shaping communities. Firstly, patterns at local scales may depend on regional-scale processes, which are described by biogeographical processes and thus phylogeny. Secondly, de Bello et al. suggested that if traits are conserved, phytogeny may be used as a proxy for unmeasured traits; however, the importance of phylogenetic signals of traits must be taken into account when these vary across a spectrum rather than presenting a dichotomy between conserved and convergent traits. Additionally, there may be overdispersed and underdispersed patterns of traits within the same species pool, farther reinforcing that using phytogeny for unmeasured traits might lead to inaccurate predictions. Depending on the question, as discussed by de Bello et al. (2015), evaluating changes in functional trait values along environmental gradients does not preclude the use of phylogenetic corrections. However, previous studies have demonstrated that combined approaches are beneficial in reaching a more accurate precise picture of processes shaping communities species responses.

• Land surface models (LSMs) typically use empirical functions to represent vegetation responses to soil drought. These functions largely neglect recent advances in plant ecophysiology that link xylem hydraulic functioning with stomatal responses to climate. • We developed an analytical stomatal optimization model based on xylem hydraulics (SOX) to predict plant responses to drought. Coupling SOX to the Joint UK Land Environment Simulator (JULES) LSM, we conducted a global evaluation of SOX against leaf- and ecosystem-level observations. • SOX simulates leaf stomatal conductance responses to climate for woody plants more accurately and parsimoniously than the existing JULES stomatal conductance model. An ecosystem-level evaluation at 70 eddy flux sites shows that SOX decreases the sensitivity of gross primary productivity (GPP) to soil moisture, which improves the model agreement with observations and increases the predicted annual GPP by 30% in relation to JULES. SOX decreases JULES root-mean-square error in GPP by up to 45% in evergreen tropical forests, and can simulate realistic patterns of canopy water potential and soil water dynamics at the studied sites. • SOX provides a parsimonious way to incorporate recent advances in plant hydraulics and optimality theory into LSMs, and an alternative to empirical stress factors.

Premise Leaf venation network architecture can provide insights into plant evolution, ecology, and physiology. Venation networks are typically assessed through histological methods, but existing protocols provide limited guidance on processing large or challenging leaves. Methods and results We present an illustrated protocol for visualizing whole leaf venation networks, including sample preparation, clearing, staining, mounting, imaging, and archiving steps. The protocol also includes supply lists, troubleshooting procedures, safety considerations, and examples of successful and unsuccessful outcomes. The protocol is suitable for a wide range of leaf sizes and morphologies and has been used with all major plant groups. Conclusion We provide a workflow for obtaining high‐quality mounts and images of venation networks of a wide range of species, using readily available materials.

Background: Consumability, a component of flammability, describes how well plants burn and may be influenced by species traits and climate change. However, knowledge gaps remain regarding how species mixtures interact and whether non-additive effects are mediated by functional traits and diversity. Aims: This study examined the consumability of species mixtures in Brazil’s tropical montane grasslands (campos de altitude), focusing on traits and species interactions. Methods: Laboratory tests measured remaining biomass (a proxy for consumability) in monospecific and three-species mixtures for seven species. Traits like specific leaf area (SLA), leaf dry matter content (LDMC), fuel moisture at ignition (FMCig) and maximum combustion rate (MCR) were assessed, along with functional diversity, to understand their influence on consumability. Results: Consumability in species mixtures differed from predictions based on individual species values, indicating non-additive effects. Leptostelma maximum, Pleroma hospita and Chusquea pinifolia, despite low or medium individual consumability, contributed most to mixture consumability. Higher SLA reduced consumability, whereas higher MCR, LDMC and functional index FRich increased it. Conclusions: Our results suggest that low-consumability species like L. maximum may reduce fire severity, offering opportunities for fire management in the campos de altitude. Implications These findings highlight the importance of considering species interactions in mixtures and identifying traits that shape plant community flammability.

The Arctic is warming at a rate four times the global average, while also being exposed to other global environmental changes, resulting in widespread vegetation and ecosystem change. Integrating functional trait-based approaches with multi-level vegetation, ecosystem, and landscape data enables a holistic understanding of the drivers and consequences of these changes. In two High Arctic study systems near Longyearbyen, Svalbard, a 20-year ITEX warming experiment and elevational gradients with and without nutrient input from nesting seabirds, we collected data on vegetation composition and structure, plant functional traits, ecosystem fluxes, multispectral remote sensing, and microclimate. The dataset contains 1,962 plant records and 16,160 trait measurements from 34 vascular plant taxa, for 9 of which these are the first published trait data. By integrating these comprehensive data, we bridge knowledge gaps and expand trait data coverage, including on intraspecific trait variation. These data can offer insights into ecosystem functioning and provide baselines to assess climate and environmental change impacts. Such knowledge is crucial for effective conservation and management in these vulnerable regions.

The state of Sergipe has suffered extreme reduction of its Atlantic Forest area in the last decades. The objective of this study is to present an inventory of the Mata do Crasto flora, the largest Atlantic Forest Remnant in Sergipe (approximately 1,000 ha), located in the Municipality of Santa Luzia do Itanhy. An intensive survey was undertaken with monthly plant collections in the study area, for four years (1995 to 1999). Additionally, collections deposited in herbaria were consulted to complete the species list. A total of 324 species were found, belonging to 84 families and 193 genera. This study adds an additional 29 genera and 96 species to the Sergipe flora as new occurrences. The four most speciose families were the Fabaceae (33 species), Rubiaceae (24 species), Myrtaceae (23 species) and Melastomataceae (15 species), that accounted for ca. 30% of the total species. The taxonomic distinction of the area is very similar to three other lowland forests in Northeastern Brazil, although its species composition is quite distinct.