Significance Many plant species face increasing drought under climate change, making tolerance integral to predicting and ecosystem responses. physiology traits interact determine overall tolerance, but trait relationships have not been assessed for general patterns across global diversity. We analyzed stomatal, hydraulic, mesophyll 310 from ecosystems worldwide. evaluated the sequence of responses plants water stress, showed that coselection with environmental stress drives most...

Summary 1. Across plant species, drought tolerance and distributions with respect to water availability are strongly correlated two physiological traits, the leaf potential at wilting, that is, turgor loss point (π tlp ), cell solute full hydration, osmotic o ). We present methods determine these parameters 30 times more rapidly than standard pressure–volume (p–v) curve approach, making feasible community‐scale studies of tolerance. 2. optimized existing for measurements π using...

Leaf hydraulic supply is crucial to maintaining open stomata for CO2 capture and plant growth. During drought-induced dehydration, the leaf conductance (K leaf) declines, which contributes stomatal closure and, eventually, death. Previous studies have tended attribute decline of K embolism in vein xylem. We visualized at high resolution quantified experimentally vulnerability xylem outside-xylem pathways modeled their respective influences on water transport. Evidence from all approaches...

Summary Amazonian droughts are predicted to become increasingly frequent and intense, the vulnerability of trees has documented. However, little is known about physiological mechanisms diversity drought tolerance tropical due lack quantitative measurements. Leaf water potential at wilting or turgor loss point (π tlp ) a determinant leaves stress contributes plant‐level tolerance. Recently, it been demonstrated that leaf osmotic full hydration o tightly correlated with π . Estimating from...

Stomata, the microvalves on leaf surfaces, exert major influences across scales, from plant growth and productivity to global carbon water cycling. Stomatal opening enables photosynthesis, use, whereas survival of drought depends stomatal closure. Here we report that function is constrained by a safety-efficiency trade-off, such species with greater conductance under high availability (gmax) show sensitivity closure during dehydration, i.e., higher potential at which reduced 50% (Ψgs50). The...

Abstract The need for rigorous analyses of climate impacts has never been more crucial. Current textbooks state that directly influences ecosystem annual net primary productivity ( NPP ), emphasizing the urgent to monitor change. A recent paper challenged this consensus, arguing, based on an analysis 1247 woody plant communities across global gradients, temperature and precipitation have negligible direct effects only perhaps indirect by constraining total stand biomass M tot ) age a )....

The influence of the dynamics leaf hydraulic conductance (Kleaf) diurnally and during dehydration on stomatal photosynthesis remains unclear. Using model species Arabidopsis (Arabidopsis thaliana ecotype Columbia-0), we applied a multitiered approach including physiological measurements, high-resolution x-ray microcomputed tomography, modeling at range scales to characterize (1) Kleaf decline dehydration; (2) its basis in conductances xylem outside-xylem pathways (Kox); (3) dependence...

Tropical forest responses are an important feedback on global change, but changes in composition with projected increases CO2 and drought highly uncertain. Here we determine shifts the most competitive plant hydraulic strategy (the evolutionary stable or ESS) from frequency intensity. Hydraulic strategies were defined along a spectrum avoidance to tolerance by physiology traits. Drought impacted competition more than , elevated reducing not reversing drought-induced ESS towards tolerant...

Knowledge about physiological stress thresholds provides crucial information plant performance and survival under drought. In this study, we report on the triphasic nature of relationship between water potential (Ψ) at predawn midday describe a method that predicts Ψ stomatal closure turgor loss exclusively from curve (WP curve). The is based piecewise linear regression model was developed to predict boundaries (termed Θ1 Θ2) separating three phases corresponding slope values. tested for...

Abstract The application of functional traits to predict and explain plant species’ distributions vital rates has been a major direction in ecology for decades, yet numerous physiological have not incorporated into the approach. Using commonly measured such as leaf mass per area ( LMA ) wood density WD ), additional related water transport, gas exchange resource economics, including vein, stomatal wilting traits, we tested hypotheses Hawaiian wet montane lowland dry forests MWF LDF ,...

Abstract Plants are enormously diverse in their traits and ecological adaptation, even within given ecosystems, such as tropical rainforests. Accounting for this diversity vegetation models poses serious challenges. Global plant functional trait databases have highlighted general correlations across species that considerably advanced research program. However, it remains unclear whether found globally hold communities, they extend to drought tolerance traits. For 134 individual plants...

Abstract Eutypa lata is a fungal pathogen of grapevine that causes widespread economic damage and threatens vineyard longevity worldwide. This study was initiated to further understanding how grapevines resist E. infections, using an integrated approach combining inoculation assays in the greenhouse with physiological biochemical measurements. Resistant ‘Zinfandel’ susceptible ‘Syrah’ were subjected control treatments assessed for gas exchange, water status, photosynthetic biochemistry,...

Strong positive correlations between the maximum rate of canopy photosynthesis, canopy-averaged foliar nitrogen concentration, and albedo have been shown in previous studies. While leaf-level relationships photosynthetic capacity are well documented, it is not clear whether solar-weighted reflectance underlie canopy-scale patterns. Using an integrating sphere, we measured transmittance (350–2500 nm) both individual leaves multileaf stacks. Samples were collected from 12 broadleaf species at...

Salinity tolerance in plant species varies widely due to adaptation and acclimation processes at the cellular whole-plant scales. In mangroves, extreme substrate salinity induces hydraulic failure ion excess toxicity reduces growth survival, thus suggesting a potentially critical role for physiological salinity. We tested hypothesis that osmotic adjustment, key type of plasticity mitigates shock, would take place coordination with declines conductance common garden experiment using saplings...

Pan-tropically, liana density increases with decreasing rainfall and increasing seasonality. This pattern has led to the hypothesis that lianas display a growth advantage over trees under dry conditions. However, physiological mechanisms underpinning this remain elusive. A key trait influencing leaf plant drought tolerance is water potential at turgor loss point (π

Abstract. Extreme drought events in Amazon forests are expected to become more frequent and intense with climate change, threatening ecosystem function carbon balance. Yet large uncertainties exist on the resilience of this drought. A better quantification tree hydraulics mortality processes is needed anticipate future effects forests. Most state-of-the-art dynamic global vegetation models relatively poor their mechanistic description these complex processes. Here, we implement a plant...

Spatial patterns in trait variation reflect underlying community assembly processes, allowing us to test hypotheses about their and environmental drivers by identifying the strongest correlates of characteristic spatial patterns. For 43 evergreen tree species (> 1 cm dbh) a 20-ha seasonal tropical rainforest plot Xishuangbanna, China, we compared ability drought-tolerance traits, other physiological commonly measured functional traits predict expected from processes habitat associations,...

Abstract Water availability is a key determinant of forest ecosystem function and tree species distributions. While droughts are increasing in frequency many ecosystems, including the tropics, plant responses to water supply vary with drought intensity therefore difficult model. Based on physiological first principles, we hypothesized that trees lower turgor loss point ( π tlp ), is, more negative leaf potential at wilting, would maintain transport for longer into dry season. We measured...

Abstract Environmental filtering and dispersal limitation can both maintain diversity in plant communities by aggregating conspecifics, but parsing the contribution of each process has proven difficult empirically. Here, we assess to spatial aggregation patterns 456 tree species a hyperdiverse Amazonian forest find distinct functional trait correlates interspecific variation these processes. Spatial point model analysis revealed that mechanisms are important drivers intraspecific for...