Why is Tree Drought Mortality so Hard to Predict?

Trends in Ecology & Evolution, Год журнала: 2021, Номер 36(6), С. 520 - 532

Опубликована: Март 2, 2021

Язык: Английский

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Functional xylem characteristics associated with drought‐induced embolism in angiosperms

New Phytologist, Год журнала: 2022, Номер 236(6), С. 2019 - 2036

Опубликована: Авг. 30, 2022

Hydraulic failure resulting from drought-induced embolism in the xylem of plants is a key determinant reduced productivity and mortality. Methods to assess this vulnerability are difficult achieve at scale, leading alternative metrics correlations with more easily measured traits. These efforts have led longstanding pervasive assumed mechanistic link between vessel diameter angiosperms. However, there least two problems assumption that requires critical re-evaluation: (1) our current understanding does not provide explanation why increased width should lead greater vulnerability, (2) most recent advancements nanoscale processes suggest direct driver. Here, we review data physiological comparative wood anatomy studies, highlighting potential anatomical physicochemical drivers formation spread. We then put forward knowledge gaps, emphasising what known, unknown speculation. A meaningful evaluation diameter-vulnerability will require better biophysical level determine spread, which turn accurate predictions how water transport affected by drought.

Язык: Английский

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Tamm review: Drought-induced Scots pine mortality – trends, contributing factors, and mechanisms

Forest Ecology and Management, Год журнала: 2024, Номер 561, С. 121873 - 121873

Опубликована: Апрель 3, 2024

A recent increase in the intensity and frequency of climate extremes under global warming is likely to continue cause unprecedented rates forest dieback different habitats around world. As one most widely distributed tree species, Scots pine (Pinus sylvestris L.) has experienced widespread mortality over past two decades many those forests transitioned broadleaved dominance inducing massive changes ecosystem functioning services. Here, we synthesize factors processes underlying drought-induced mortality. Our review identifies agreement across studies on impact drought, prevalence crown defoliation prior mortality, influence stand density ecological growth memory, as well presence biotic agents, such insects mistletoes. Studies generally agree that drought triggered self-thinning plays an important role. The post-mortality seems far below comparable pre-drought numbers trees per hectare, which indicates a significant reduction productivity stands. Most surprisingly, show while early-2000 s occurred at species' arid distribution limits, high are now also reported from climatic optimum where conditions used be more beneficial. Extreme droughts 2003, 2015 2018 causing this observed pattern, may indicate extreme could challenge growing climatically favorable areas. level acclimation strategies lowering leaf area enhancing water-use efficiency stand-level adjustments including apparently not sufficient prevent induced by frequent associated agents (insects mistletoes). However, still lack clear understanding linking functional species local variation fully understand capabilities grow survive future climate.

Язык: Английский

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Climate and functional traits jointly mediate tree water‐use strategies

New Phytologist, Год журнала: 2021, Номер 231(2), С. 617 - 630

Опубликована: Апрель 24, 2021

Tree water use is central to plant function and ecosystem fluxes. However, it still unknown how organ-level water-relations traits are coordinated determine whole-tree water-use strategies in response drought, whether this coordination depends on climate. Here we used a global sap flow database (SAPFLUXNET) study the of use, terms canopy conductance (G), vapour pressure deficit (VPD) soil content (SWC) for 142 tree species. We investigated individual effect six (vulnerability embolism, Huber value, hydraulic conductivity, turgor-loss point, rooting depth leaf size) parameters, also accounting height climate (mean annual precipitation, MAP). Reference G its sensitivity VPD were tightly with rather than MAP. Species efficient xylem transport had higher but VPD. Moreover, found that angiosperms reference did gymnosperms. Our results highlight need consider trait integration reveal complications challenges defining single, whole-plant resource spectrum ranging from 'acquisitive' 'conservative'.

Язык: Английский

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Opportunities, challenges and pitfalls in characterizing plant water‐use strategies

Functional Ecology, Год журнала: 2021, Номер 36(1), С. 24 - 37

Опубликована: Окт. 13, 2021

Abstract Classifying the diverse ways that plants respond to hydrologic stress into generalizable ‘water‐use strategies’ has long been an eco‐physiological research goal. While many schemes for describing water‐use strategies have proven be quite useful, they are also associated with uncertainties regarding their theoretical basis and connection plant carbon water relations. In this review, we discuss factors shape responses assess approaches used classify a plant's strategy, paying particular attention popular but controversial concept of continuum from isohydry anisohydry. A predictive framework assessing historically elusive, yet recent advances in physiology hydraulics provide field way past these obstacles. Specifically, promote idea metrics quantify highly dynamic emergent interaction between traits environmental conditions, complexity hindered development strategy framework. This is explored using model identify: (a) distinct temporal phases hydraulic regulation during drought underpin responses, (b) how variation both forcings can significantly alter common characterize strategies. modelling exercise bridge divide various conceptualizations targeted hypotheses advance understanding quantification status across spatial scales. Finally, describe frontiers necessary improve capacity concept, including further investigation below‐ground determinants relations, data collection efforts potential scale concepts individuals whole regions. free Plain Language Summary found within Supporting Information article.

Язык: Английский

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One Stomatal Model to Rule Them All? Toward Improved Representation of Carbon and Water Exchange in Global Models

Journal of Advances in Modeling Earth Systems, Год журнала: 2022, Номер 14(4)

Опубликована: Фев. 3, 2022

Abstract Stomatal conductance schemes that optimize with respect to photosynthetic and hydraulic functions have been proposed address biases in land‐surface model (LSM) simulations during drought. However, systematic evaluations of both optimality‐based alternative empirical formulations for coupling carbon water fluxes are lacking. Here, we embed 12 optimization approaches within a LSM framework. We use theoretical experiments explore parameter identifiability understand how behaviors differ response abiotic changes. also evaluate the models against leaf‐level observations gas‐exchange variables, from xeric wet forest/woody species spanning mean annual precipitation range 361–3,286 mm yr −1 . find easily parameterized they are, due to: (a) poorly constrained optimality criteria (i.e., resulting multiple solutions), (b) low influence parameters, (c) sensitivities environmental drivers. In idealized compared observations, variability drivers do not agree among models. Marked differences arise soil moisture (soil potential) vapor pressure deficit. For example, stomatal closure rates at high deficit between −45% +70% those observed. Although over half new generation perform similar standard leaf‐gas exchange, two so through large simulated leaf potential (up 11 MPa). Our results provide guidance development, by highlighting key areas need additional experimentation theory, constraining currently viable hypotheses.

Язык: Английский

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Plant hydraulics at the heart of plant, crops and ecosystem functions in the face of climate change

New Phytologist, Год журнала: 2023, Номер 241(3), С. 984 - 999

Опубликована: Дек. 14, 2023

Summary Plant hydraulics is crucial for assessing the plants' capacity to extract and transport water from soil up their aerial organs. Along with exchange between plant compartments regulate evaporation, hydraulic properties determine relations, status susceptibility pathogen attacks. Consequently, any variation in characteristics of plants likely significantly impact various mechanisms processes related growth, survival production, as well risk biotic attacks forest fire behaviour. However, integration traits into disciplines such pathology, entomology, ecology or agriculture can be improved. This review examines how provide new insights our understanding these processes, including modelling vegetation dynamics, illuminating numerous perspectives consequences climate change on agronomic systems, addressing unanswered questions across multiple areas knowledge.

Язык: Английский

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Tree mortality response to drought‐density interactions suggests opportunities to enhance drought resistance

Journal of Applied Ecology, Год журнала: 2021, Номер 59(2), С. 549 - 559

Опубликована: Ноя. 1, 2021

Abstract The future of dry forests around the world is uncertain given predictions that rising temperatures and enhanced aridity will increase drought‐induced tree mortality. Using forest management ecological restoration to reduce density competition for water offers one few pathways managers can potentially minimize Competition during drought leads elevated mortality in dense stands, although influence on heat‐induced stress durations hot or conditions most impact remain unclear. Understanding how interacts with hot‐drought essential recognize how, where much reducing help sustain a rapidly changing world. Here, we integrated repeat measurements 28,881 ponderosa pine trees across western US (2000–2017) soil moisture estimates from balance model examine annual responds competition, temperature conditions. Tree responded strongly basal area, was places high mean temperatures, unusually 7‐year anomalies, 8‐year low anomalies. Mortality also lower experienced wet 3‐year anomalies between measurements. Importantly, found area moisture, exacerbating times imposed by moisture. Synthesis applications . Our results imply 50% reduction could drought‐driven 20%–80%. largest impacts are seen areas current experience and/or severe multiyear droughts. These interactions critical understand past patterns context climate change, provide information resource seeking enhance resistance.

Язык: Английский

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SurEau-Ecos v2.0: a trait-based plant hydraulics model for simulations of plant water status and drought-induced mortality at the ecosystem level

Geoscientific model development, Год журнала: 2022, Номер 15(14), С. 5593 - 5626

Опубликована: Июль 21, 2022

Abstract. A widespread increase in tree mortality has been observed around the globe, and this trend is likely to continue because of ongoing climate-induced increases drought frequency intensity. This raises need identify regions ecosystems that are experience most frequent significant damage. We present SurEau-Ecos, a trait-based, plant hydraulic model designed predict desiccation at scales from stand region. SurEau-Ecos draws on general principles SurEau but introduces simplified representation architecture alternative numerical schemes. Both additions were made facilitate parameterization large-scale applications. In water fluxes soil atmosphere represented through two organs (a leaf stem, which includes volume trunk, roots branches) as product an interface conductance difference between potentials. Each organ described by its symplasmic apoplasmic compartments. The dynamics plant's status beyond point stomatal closure explicitly via residual transpiration flow, cavitation solicitation plants' reservoirs. addition “explicit” scheme SurEau, we implemented “semi-implicit” “implicit” scheme. schemes led substantial gain computing time compared explicit (>10 000 times), implicit was accurate. also similar slight disparities infra-daily variations potentials, attributed differences models. global model's sensitivity analysis revealed factors controlling rates differ depending whether potential below or above closure. Total available for plant, area index 50 % mostly drove needed reach Once stomata closed, resistance cavitation, cuticular stocks determined failure. Finally, illustrated simulate regional drought-induced over France. promising tool perform regional-scale predictions failure, determine vulnerable areas drying conditions, assess forest flammability.

Язык: Английский

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Do stomata optimize turgor‐driven growth? A new framework for integrating stomata response with whole‐plant hydraulics and carbon balance

New Phytologist, Год журнала: 2022, Номер 238(2), С. 506 - 528

Опубликована: Ноя. 15, 2022

Every existing optimal stomatal model uses photosynthetic carbon assimilation as a proxy for plant evolutionary fitness. However, and growth are often decoupled, making less ideal representing fitness when optimizing conductance to water vapor dioxide. Instead, should be considered closer We hypothesize stomata have evolved maximize turgor-driven growth, instead of assimilation, over entire plants' lifetimes, improving their abilities compete reproduce. develop that dynamically maximizes whole-stem following principles from models. Stomata open assimilate carbohydrates supply osmotically generate turgor, while close prevent losses turgor due negative potentials. In steady state, the optimization captures realistic stomatal, carbohydrate responses environmental cues, reconciles conflicting interpretations within theories, explains patterns storage xylem observed during after drought. Our hypothesis introduces new paradigm models, elevates role whole-plant use in functioning, has potential simultaneously predict gross productivity, net mortality through single, consistent modeling framework.

Язык: Английский

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