Tree physiology最新文献

{"title":"Adjustment in leaf water relations and the maintenance of mangrove seedling growth under increasing salinity.","authors":"Vanessa Negrão-Rodrigues, Mauro Brum, Karoline Chaves Silva, Grazielle Sales Teodoro","doi":"10.1093/treephys/tpaf091","DOIUrl":"https://doi.org/10.1093/treephys/tpaf091","url":null,"abstract":"<p><p>Mangroves are ecosystems of high ecological and economic importance, particularly due to their capacity to store high amounts of carbon and stabilize soil. However, climate change and rising sea levels are intensifying salinity levels, challenging the survival of plant mangrove species, especially seedlings. Here, we evaluated the effects of different salinity concentrations on the growth and leaf water relations of Avicennia germinans and Rhizophora racemosa seedlings. Specifically, we tested whether A. germinans, due to its broader distribution, higher salinity tolerance, and salt-excreting ability, would exhibit more pronounced adjustments and greater resilience to saline stress compared to R. racemosa. To this end, we conducted a greenhouse experiment, exposing 212 eleven-month-old seedlings (106 of each species) previously grown in freshwater to five salinity treatments over three months. These seedlings were analyzed for growth, embolism resistance, leaf water potential, osmotic parameters, and gas exchange. Our results showed that A. germinans exhibited greater osmotic adjustment and stomatal regulation, enabling it to maintain leaf hydration and reduce the risk of cavitation under high salinity. Conversely, R. racemosa adopted a more conservative strategy, with lower osmotic adjustment and stomatal regulation capacity but a higher hydraulic safety margin. Thus, we demonstrated that these species employ distinct strategies to cope with salinity, reflecting specific adaptations to their ecological distributions and salinity tolerance. These findings contribute to understanding the adaptive responses of mangrove seedlings to varying salinity conditions, with implications for the conservation of these ecosystems under predicted climate change scenarios.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leaf transpiration decreases similarly among five pine species as height increases over stand development.","authors":"Chainey A Boroski, Jean-Christophe Domec, Christopher Maier, Sari Palmroth, Yi Wang, Ram Oren","doi":"10.1093/treephys/tpaf093","DOIUrl":"https://doi.org/10.1093/treephys/tpaf093","url":null,"abstract":"<p><p>With increasing tree height, leaf transpiration (EL) is increasingly restricted by path-length resistance and gravity's discount to the driving force of xylem water flow. The effect of height on leaf transpiration is nearly always assessed using chronosequence data; however, in this long-term, dynamic study, we assessed increasing height's effects on EL using continuous monitoring of sap-flux for five Pinus species growing in a common-garden and experiencing a wide range of environmental conditions. We assessed how three drivers of EL-path-length (h), water-potential gradient (ΔΨ), and sapwood-to-leaf area ratio (AS:AL)-affect transpiration of the five Pinus species ranging five-fold in needle length by performing gas-exchange and water potential measurements, and monitoring tree biometrics, sap-flux, and soil and atmospheric conditions over five years at the Duke Forest, NC. With our methods controlling for all but the effect of tree hydraulics on transpiration, we found that EL, derived early in the study based on gas-exchange and later based on sap-flux measurements, were similar among species under both wet and dry soil moisture conditions. When soil moisture was not limiting, ΔΨ decreased across species with increasing needle length while whole-plant conductance (kplant) increased, leading to similar EL among species. Under soil drought, the trends with needle length of both variables became weaker as shorter-needle species showed a greater decrease in ΔΨ, while longer-needle species had a greater decline in kplant, again resulting in similar EL among species. Increasing h over time reduced EL similarly in all species, in part owing to similar annual minima of AS:AL among species and its invariance over a four-fold range in h. Controlling for non-hydraulic sources of variation showed that EL decreased with h similarly in five Pinus spp. of a wide range in leaf and crown characteristics.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coppice and high forest Eucalyptus stands show similar drought resistance on deep soils.","authors":"Jenickson R S Costa, Jhuan L M Maciel, Magali R Silva, Otávio C Campoe, Guerric Maire, Clayton A Alvares, Nicolas K Martin-Stpaul, Paulo Bittencourt, Luciano Pereira, Leticia B Cagnoni, Jean-Paul Laclau, Yann Nouvellon, Sonia M F Ustulin, Joannès Guillemot","doi":"10.1093/treephys/tpaf089","DOIUrl":"https://doi.org/10.1093/treephys/tpaf089","url":null,"abstract":"<p><p>Increasing drought under climate change is affecting forests worldwide, raising concerns about management strategies for sustainable wood production. Eucalyptus, the dominant genus in hardwood plantations, can be managed as either coppice or high forest stands, yet the effects of this silvicultural decision on water stress and drought resistance remains largely unexplored. If coppice trees experience reduced water stress during their early growth due to the surviving deep root apparatus from the previous rotation, they may exhibit traits that are less adapted to drought survival. Here, we measured structural stand features (leaf area index, LAI; standing biomass), dehydration-resistance traits (leaf turgor loss point, Ψtlp; xylem vulnerability to embolism, Ψ50), in situ water stress (minimum leaf water potential, Ψmin), and metrics of drought-mortality risk (hydraulic safety margins) to compare the drought resistance and productivity of 10 Eucalyptus clones growing in deep soils under both high forest and coppice silvicultural treatments in a common garden in southeastern Brazil. Biomass at mid-rotation (3 years after planting) was on average 15% greater in coppice stands, associated with a 32% greater LAI across Eucalyptus clones. Standing biomass of clones grown in coppice could not be predicted from that of high forests. Water stress, drought resistance traits, and drought-mortality risks were similar between silvicultural treatments. Some traits (LAI, Ψtlp, Ψ50, Ψtlp-based HSM) exhibited a consistent clonal ranking in both silvicultural treatments, while other traits (Ψmin, Ψmin-based HSM) did not. The hydraulic system of Eucalyptus trees does not plastically respond to coppicing, making coppice a viable option for Eucalyptus management under drought, if appropriate clonal selection is implemented. However, selecting drought-resistant and productive coppice clones based on high forest data should be considered with caution.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Douglas-fir raises xylem safety in response to a drier climate but also increases supported leaf area.","authors":"Leonie P Rudorff, Sharath S Paligi, Martyna M Kotowska, Fon Robinson Tezeh, Bernhard Schuldt, Christoph Leuschner","doi":"10.1093/treephys/tpaf094","DOIUrl":"https://doi.org/10.1093/treephys/tpaf094","url":null,"abstract":"<p><p>Phenotypic plasticity in traits related to plant water relations and hydraulics is fundamental for the adjustment of trees to rapid climate change. It is not fully understood how conifers can acclimatize their hydraulic system and foliage to a reduction in water availability. For the economically important species Douglas-fir (Pseudotsuga menziesii), we assessed the acclimation potential to a drier climate for mature trees of a common seed source by exploring the phenotypic plasticity of 15 hydraulic and water status-related traits across a steep precipitation gradient in the North German lowlands. Branch embolism resistance (P12, P50), turgor loss point (ΨTLP), hydraulic safety margin (HSM), Huber value (Hv), foliage area, needle lifespan, and leaf mass δ18O and δ13C were measured. Across the 10 study sites, precipitation explained a large proportion of the variance in P12, P50, ΨTLP, leaf δ18O and δ13C and Hv, while its influence on foliar traits was small. P12 and P50 became more resistant by ~0.2 MPa and ΨTLP decreased by ~0.1 MPa with a precipitation reduction by 310 mm yr-1, indicating a significant increase in HSM with increasing climatic aridity; however, the extent of adjustment was small. Contrary to expectation, needle lifespan and foliage area increased, while Hv decreased, with a reduction in precipitation, suggesting greater foliage drought exposure at drier sites. We found fairly high plasticity in hydraulic and foliar traits and enhanced embolism resistance in drier climates, which might distinguish Douglas-fir from other conifers. However, the Hv reduction with decreasing precipitation suggests drought vulnerability in drier lowland regions.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trees use exogenous sugars for growth, but excess triggers negative feedback reducing photosynthetic carbon gain.","authors":"Yan-Li Zhang, Arthur Gessler, Marco M Lehmann, Matthias Saurer, Haoyu Diao, Janneke Hille Ris Lambers, Marcus Schaub, Yi Zhu, Andreas Rigling, Mai-He Li","doi":"10.1093/treephys/tpaf092","DOIUrl":"https://doi.org/10.1093/treephys/tpaf092","url":null,"abstract":"<p><p>Plants' non-structural carbohydrates (NSCs) serve as their capital for growth, reproduction, defense, and survival. To increase the NSC availability of carbon-limited trees, a recent study revealed the possibility of adding exogenous soluble sugars to carbon-starved trees. This provides an opportunity to investigate carbon allocation between source and sink, as well as the growth and physiological responses to external sugars. Using this method, we infused 13C-labeled glucose solution into the stem xylem of sycamore maple (Acer pseudoplatanus L.) trees (Experiment 1) and immersed branch cuttings of various tree species in a 13C-labeled glucose solution (Experiment 2). Our aim was to study whether infused sugars contribute to structural growth and how they influence photosynthesis. Specifically, we focused on whether trees can transport and utilize exogenous sugars for growth, and if sugar addition might trigger negative feedback mechanisms on carbon gain. We then traced the 13C label in bulk tissue and cellulose, and measured tissue NSC concentrations and leaf photosynthesis. Glucose addition consistently increased leaf NSC concentrations (Experiments 1 and 2), and exogenous sugars added were transported and incorporated into biomass formation in Experiment 1. However, excessive sugar addition triggered a negative feedback response, leading to leaf senescence (Experiments 1 and 2) and reduced photosynthesis (Experiment 2). Our findings validate the recently developed sugar addition method but emphasize the importance of carefully controlling the amount and rate of sugar addition to avoid negative feedback responses. This study will contribute to carbon physiological research, particularly in understanding carbon balance and source-sink relationships at the whole-plant level.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cambial and phloem reactivation timing in relation to floral phenology in four co-occurring woody species.","authors":"Dustin M Ray, Andrew C Arthur, Jasmine Baerg, Elise W Mckeever, Jessica A Savage","doi":"10.1093/treephys/tpaf088","DOIUrl":"https://doi.org/10.1093/treephys/tpaf088","url":null,"abstract":"<p><p>The timing of spring floral production is crucial for plant reproduction and thus fitness. Floral production in spring is a carbon sink as is the construction of new cell walls for xylem and phloem, and leaf production. As carbon transport is necessary to support any growth in the spring, it is important to understand the timing of the production and resumption of phloem activity in the spring. Phloem and cambial reactivation have been studied in relation to leaf-out, but not in relation for floral phenology. We sampled the stems of three co-occurring temperate broad-leaved woody plants and one shrub to investigate the timing of phloem and cambial reactivation in relation to spring floral production and environmental factors. We find that cambial reactivation is primarily predicted by environmental factors. Wood porosity, also is tied to the timing of cambial reactivation. Phloem reactivation, however, was not influenced by environmental effects during the period of our study. We further present evidence that overwintering strategies could be inferred by tracking changes in phloem increment width during spring. Our results underscore the importance of cambial reactivation in supporting floral and foliar spring phenology.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond Proxies: Towards ecophysiological indicators of drought resistance for forest management.","authors":"Alice Copie, Caroline Scotti-Saintagne, François Lefèvre, Hervé Cochard, Sylvain Delzon, Arsène Druel, Pierre-Jean Dumas, Damien Gounelle, Stéphane Herbette, Florence Jean, Nicolas Mariotte, Maurizio Mencuccini, Ivan Scotti, Nicolas Martin-StPaul","doi":"10.1093/treephys/tpaf090","DOIUrl":"https://doi.org/10.1093/treephys/tpaf090","url":null,"abstract":"<p><p>As drought-induced mortality increases globally in forest biomes, it becomes necessary for foresters to have access to reliable predictors of species vulnerability to drought and mortality risk under different climatic scenarios. On the one hand, there exist several \"operational\" indicators of drought resistance, which are based on technical literature, observations, expert knowledge and species bioclimate. However they are not available for all species, reduce a species to a single value and have the same limitations as species distribution models. On the other hand, different traits can be measured to estimate mechanistically species' vulnerability to drought and in particular to hydraulic failure, a key process of tree mortality under drought. These traits typically include xylem vulnerability to cavitation, stomatal regulation, minimum leaf conductance and water storage capacity. However, the mechanistic approach, based on functional traits, has never been compared to the operational approach. In this study, we review if indicators commonly used by foresters provide information on Abies species' vulnerability to hydraulic failure. We measured a set of traits in a common garden experiment of closely related Mediterranean Abies species. These traits were used to configure and parametrise SurEau, a plant hydraulic model dedicated to simulate plant mortality risk due to hydraulic failure under extreme drought conditions. SurEau was then used to compute a single indicator of vulnerability (Time to Hydraulic Failure - THF) and to assess mortality risk in future climate. We found that among circum-Mediterranean firs, a high THF was largely driven by differences in minimum leaf water conductance. Some operational indicators are good proxies of THF but fail to distinguish between closely related Mediterranean Abies species. We argue that the mechanistic approach could help foresters in species selection and in estimating the risk faced by forest tree species in a changing climate. While accounting for the variability of traits, hydraulic models can be forced with different climatic scenarios allowing hydraulic failure risk assessment by the end of the century.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144733389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ontogenetic shift in biomass allocation and functional traits of leaves and seeds in a resprouting aridland shrub.","authors":"Guang-Qian Yao, Yu-Na Duan, Shun-Ping Han, Yan-Ru Li, Yi-Chen Li, Shi-Hua Qi, Feng-Ping Li, Min-Hui Bi, Xiang-Wen Fang","doi":"10.1093/treephys/tpaf086","DOIUrl":"https://doi.org/10.1093/treephys/tpaf086","url":null,"abstract":"<p><p>Ontogeny-driven variation in plant functional traits is considered the core component of a plant's life-history strategy. However, how vegetative and reproductive traits covary to mediate growth and reproduction throughout the life history of resprouts is largely unknown. Here, the leaf and seed biomass allocation, nutrient contents, and morphological and physiological traits of leaves and seeds were investigated during different life history stages of Caragana korshinskii resprouts aged 1 to 13 years in a common garden. The findings indicated that with increasing age, leaf traits shifted from an acquisitive strategy-characterized by high photosynthesis (An), stomatal conductance (gs), leaf nitrogen content (LNC) and leaf phosphorus content (LPC), along with low leaf mass per area (LMA) and water use efficiency (WUE)-to a conservative strategy characterized by low An, gs, LNC, LPC, high LMA and WUE, in combination with changes in leaf biomass allocation (LBA). Most notably, seed traits shifted from a K-strategy-characterized by high seed mass (SM), seed nitrogen content (SNC), seed phosphorus content (SPC) and seed germination rate (SGR), but low seed number (SN)-to an r-strategy with opposite traits, reflecting a trade-off with seed biomass allocation (SBA). These ontogeny-driven strategies shift from an acquisitive-K strategy that favours faster growth and competitive advantage in younger resprouts to a conservative-r strategy that improves vegetative adaptability and reproductive stability in older resprouts. Our results highlight that ontogeny-driven transitions in life history strategies and biomass allocation patterns jointly mediate vegetative and reproductive strategies in resprouts, providing new insights for understanding the dynamic balance between the growth and reproduction of resprouts.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144699645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing genetic adaptations and plastic stress responses within a transcontinental North American keystone species.","authors":"Roos Goessen, Nathalie Isabel, Christian Wehenkel, Eliana Gonzales-Vigil, Osmond Hui, Lyne Touchette, Justine Gagné, Mebarek Lamara, Jean Bousquet, Karen E Mock, Raju Soolanayakanahally, Ilga Porth","doi":"10.1093/treephys/tpaf087","DOIUrl":"https://doi.org/10.1093/treephys/tpaf087","url":null,"abstract":"<p><p>Local adaptation can lead to the intraspecific variation in a species' genetic makeup, shaping both its physiological and morphological traits as well as its molecular responses. In this study we assessed variation in key functional leaf traits, such as stomata density, carbon and nitrogen content, cuticular wax composition and leaf shapes, within the transcontinental North American Populus tremuloides Michx. (quaking aspen) by sampling individuals from its four major genetic lineages. We also performed a small-scale common garden experiment with imposed higher temperature and drought stress during which we sampled for transcriptomes using RNAseq and performed physiological measurements to obtain insights into the intraspecific responses among aspen lineages to such abiotic stressors. Our findings revealed several differences in functional traits indicative of local adaptation, such as variation in cuticular wax content, petiole lengths and 𝛿13C. Notably, stomatal density was significantly associated with mean annual precipitation. Moreover, genotypes from the most southern lineage (Mexico) exhibited the largest decline in net photosynthesis under drought, suggesting a more conservative water-use strategy. Gene expression analyses revealed numerous differentially expressed genes under different stress conditions and in different lineages, with overlaps with previous gene selection scans, confirming their possible roles in local adaptation. Weighted gene co-expression network analysis further identified 22 co-expressed gene modules, several of which strongly associated with temperature responses and geographic origin of genetic lineage. Our findings highlight substantial intraspecific variation in functional traits and gene expression patterns in P. tremuloides linked to geographical origin and local environmental conditions. Understanding such adaptive variation is crucial for predicting how forest trees may cope with and adapt to the challenges of climate change.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144675738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of drought on carbon-nitrogen dynamics in root exudates of Qinghai Spruce.","authors":"Weibin Li, Hongxia Zhang, Yingyi Pu, Fan Li","doi":"10.1093/treephys/tpaf085","DOIUrl":"https://doi.org/10.1093/treephys/tpaf085","url":null,"abstract":"<p><p>Root exudates play a critical role in plant adaptation and the regulation of soil carbon and nutrient cycling, especially under climate change conditions. Despite their importance, the dynamics of root exudation under drought, particularly during drought-induced tree mortality, remain poorly understood. Here, we investigate how drought affects root exudation dynamics, root morphology traits, and non-structural carbohydrate (NSC) concentrations in Qinghai spruce (Picea crassifolia Kom.) seedlings across the progression of drought-induced mortality. We conducted a two-stage drought manipulation experiment, beginning with moderate drought (50% irrigation reduction) followed by complete water cessation to induce lethal drought conditions. Our results reveal that drought significantly decreased the exudation rate of total organic carbon (C), while nitrogen (N) exudation rate remained unaffected, resulting in a lower C:N ratio in root exudates, indicative of a higher proportion of N-rich compounds. In addition, drought induced a shift in root morphological traits towards a more competitive strategy, marked by increased specific root length (SRL), specific root area (SRA), and branch intensity, and a reduction in root diameter (RD), root tissue density, and root NSC concentrations. Notably, root exudation rates were negatively correlated with competitive root traits (higher SRL, SRA, and branch intensity) and positively correlated with conservative traits (larger RD and root tissue density), suggesting that root exudation serves a more conservative function under drought conditions, prioritizing carbon storage and morphological adaptations over exudation. These findings provide valuable insights into the adaptive mechanisms of trees under drought stress, with implications for nutrient cycling, forest resilience, and ecosystem productivity in water-limited environments.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144675739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}