Leaf turgor loss point (π_tlp) indicates the capacity of a plant to maintain cell turgor pressure during dehydration, which has been proven to be strongly predictive of the plant response to drought. In this study, we compiled a data set of π_tlp for 1752 woody plant individuals belonging to 389 species from nine major woody biomes in China, along with reduced sample size of hydraulic and leaf carbon economics data. We aimed to investigate the variation of π_tlp across biomes varying in water availability. We also tested two hypotheses: (i) π_tlp predicts leaf hydraulic safety margins and (ii) it is correlated with leaf carbon economics traits. Our results showed that there was a positive relationship between π_tlp and aridity index: biomes from humid regions had less negative values than those from arid regions. This supports the idea that π_tlp may reflect drought tolerance at the scale of woody biomes. As expected, π_tlp was significantly positively correlated with leaf hydraulic safety margins that varied significantly across biomes, indicating that this trait may be useful in modelling changes of forest components in response to increasing drought. Moreover, π_tlp was correlated with a suite of coordinated hydraulic and economics traits; therefore, it can be used to predict the position of a given species along the ‘fast–slow’ whole-plant economics spectrum. This study expands our understanding of the biological significance of π_tlp not only in drought tolerance, but also in the plant economics spectrum.

Water must be transported long distances in tall plants, resulting in increasing hydraulic resistance, which may place limitations on the maximum plant height (H_max) in a given habitat. However, the coordination of hydraulic traits with H_max and habitat aridity remains poorly understood. To explore whether H_max modifies the trade-off between hydraulic efficiency and safety or how water availability might influence the relationship between H_max and other hydraulic traits, we compiled a dataset including H_max and 11 hydraulic traits for 1281 woody species from 369 sites worldwide. We found that taller species from wet habitats exhibited greater xylem efficiency and lower hydraulic safety, wider conduits, lower conduit density, and lower sapwood density, which were all associated with habitat water availability. Plant height and hydraulic functioning appear to represent a single, coordinated axis of variation, aligned primarily with water availability, thus suggesting an important role for this axis in species sorting processes.

Quantifying the stomatal responses of plants to global change factors is crucial for modeling terrestrial carbon and water cycles. Here we synthesize worldwide experimental data to show that stomatal conductance (g_s) decreases with elevated carbon dioxide (CO₂), warming, decreased precipitation, and tropospheric ozone pollution, but increases with increased precipitation and nitrogen (N) deposition. These responses vary with treatment magnitude, plant attributes (ambient g_s, vegetation biomes, and plant functional types), and climate. All two-factor combinations (except warming + N deposition) significantly reduce g_s, and their individual effects are commonly additive but tend to be antagonistic as the effect sizes increased. We further show that rising CO₂ and warming would dominate the future change of plant g_s across biomes. The results of our meta-analysis provide a foundation for understanding and predicting plant g_s across biomes and guiding manipulative experiment designs in a real world where global change factors do not occur in isolation.

In the past decades, drought‐induced forest die‐off has been recorded on every forested biome, exerting great effects on biodiversity and ecosystem functions (Allen et al., 2010; Hartmann et al., 2018; Brodribb et al., 2020). A general understanding of forest vulnerability to damage due to climate is lacking, because of our limited understanding of the variation in lethal water potential (Ψ_lethal) of trees. Achieving this critical goal requires a reliable proxy for Ψ_lethal that can be used to characterize many species in a forest community.