21 results on '"Danielle Creek"'
Search Results
2. Physiological trait networks enhance understanding of crop growth and water use in contrasting environments
- Author
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Sean M. Gleason, Dave M. Barnard, Timothy R. Green, Scott Mackay, Diane R. Wang, Elizabeth A. Ainsworth, Jon Altenhofen, Timothy J. Brodribb, Hervé Cochard, Louise H. Comas, Mark Cooper, Danielle Creek, Kendall C. DeJonge, Sylvain Delzon, Felix B. Fritschi, Graeme Hammer, Cameron Hunter, Danica Lombardozzi, Carlos D. Messina, Troy Ocheltree, Bo Maxwell Stevens, Jared J. Stewart, Vincent Vadez, Joshua Wenz, Ian J. Wright, Kevin Yemoto, Huihui Zhang, Water Management and Systems Research (WMSR), United States Department of Agriculture (USDA), University at Buffalo [SUNY] (SUNY Buffalo), State University of New York (SUNY), Purdue University [West Lafayette], University of Tasmania [Hobart, Australia] (UTAS), Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant (PIAF), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA), Queensland Alliance for Agriculture and Food Innovation (QAAFI), University of Queensland [Brisbane], Biodiversité, Gènes & Communautés (BioGeCo), Université de Bordeaux (UB)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Missouri [Columbia] (Mizzou), University of Missouri System, Colorado State University [Fort Collins] (CSU), National Center for Atmospheric Research [Boulder] (NCAR), University of Florida [Gainesville] (UF), International Crops Research Institute for the Semi-Arid Tropics [Inde] (ICRISAT), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), and Macquarie University
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photosynthesis ,Physiology ,stomata ,Water ,food and beverages ,Plant Science ,plant growth ,xylem ,maize ,process simulation ,crop improvement ,Droughts ,Plant Leaves ,Soil ,breeding ,Plant Stomata ,hydraulic traits ,[SDE]Environmental Sciences ,water potential ,Edible Grain ,Ecosystem - Abstract
Plant function arises from a complex network of structural and physiological traits. Explicit representation of these traits, as well as their connections with other biophysical processes, is required to advance our understanding of plant-soil-climate interactions. We used the Terrestrial Regional Ecosystem Exchange Simulator (TREES) to evaluate physiological trait networks in maize. Net primary productivity (NPP) and grain yield were simulated across five contrasting climate scenarios. Simulations achieving high NPP and grain yield in high precipitation environments featured trait networks conferring high water use strategies: deep roots, high stomatal conductance at low water potential (“risky” stomatal regulation), high xylem hydraulic conductivity, and high maximal leaf area index. In contrast, high NPP and grain yield was achieved in dry environments with low late-season precipitation via water conserving trait networks: deep roots, high embolism resistance, and low stomatal conductance at low leaf water potential (“conservative” stomatal regulation). We suggest that our approach, which allows for the simultaneous evaluation of physiological traits and their interactions (i.e., networks), has potential to improve crop growth predictions in different environments. In contrast, evaluating single traits in isolation of other coordinated traits does not appear to be an effective strategy for predicting plant performance.Summary statementOur process-based model uncovered two beneficial but contrasting trait networks for maize which can be understood by their integrated effect on water use/conservation. Modification of multiple, physiologically aligned, traits were required to bring about meaningful improvements in NPP and yield.
- Published
- 2022
3. Acclimation of leaf respiration temperature responses across thermally contrasting biomes
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Patrick Meir, Lasantha K. Weerasinghe, Kevin L. Griffin, Danielle Creek, Mark G. Tjoelker, John J. G. Egerton, Lingling Zhu, Shinichi Asao, Keith J. Bloomfield, Vaughan Hurry, Michael J. Liddell, Matthew H. Turnbull, Lucy Hayes, Owen K. Atkin, Australia's national university, Western Sydney University, Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant (PIAF), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA), Columbia University [New York], Swedish University of Agricultural Sciences (SLU), James Cook University (JCU), University of Kent [Canterbury], Australian Research Council / DP0986823, DP130101252, and CE140100008Australian Government
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0106 biological sciences ,0301 basic medicine ,Physiology ,[SDV]Life Sciences [q-bio] ,Acclimatization ,Biome ,Irradiance ,Plant Science ,Rainforest ,Solar irradiance ,01 natural sciences ,phenotypic plasticity ,thermal tolerance ,03 medical and health sciences ,respiration modelling ,Respiration ,Climate change ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Ecosystem ,Phenotypic plasticity ,Thermal acclimation ,Temperature ,15. Life on land ,Evergreen ,Plant Leaves ,Horticulture ,030104 developmental biology ,13. Climate action ,Environmental science ,metabolism ,010606 plant biology & botany - Abstract
International audience; Short-term temperature response curves of leaf dark respiration (R-T) provide insights into a critical process that influences plant net carbon exchange. This includes how respiratory traits acclimate to sustained changes in the environment. Our study analysed 860 high-resolutionR-T(10-70 degrees C range) curves for: (a) 62 evergreen species measured in two contrasting seasons across several field sites/biomes; and (b) 21 species (subset of those sampled in the field) grown in glasshouses at 20 degrees C : 15 degrees C, 25 degrees C : 20 degrees C and 30 degrees C : 25 degrees C, day : night. In the field, across all sites/seasons, variations inR(25)(measured at 25 degrees C) and the leafTwhereRreached its maximum (T-max) were explained by growthT(mean air-Tof 30-d before measurement), solar irradiance and vapour pressure deficit, with growthThaving the strongest influence.R(25)decreased andT(max)increased with rising growthTacross all sites and seasons with the single exception of winter at the cool-temperate rainforest site where irradiance was low. The glasshouse study confirmed thatR(25)andT(max)thermally acclimated. Collectively, the results suggest: (1) thermal acclimation of leafRis common in most biomes; and (2) the highTthreshold of respiration dynamically adjusts upward when plants are challenged with warmer and hotter climates.
- Published
- 2020
4. Coordination between leaf, stem, and root hydraulics and gas exchange in three arid-zone angiosperms during severe drought and recovery
- Author
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David T. Tissue, Timothy J. Brodribb, Brendan Choat, Danielle Creek, and Chris J. Blackman
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0106 biological sciences ,0301 basic medicine ,Canopy ,Stomatal conductance ,Resistance (ecology) ,Physiology ,Drought tolerance ,Plant physiology ,Plant Science ,Evergreen ,Biology ,Photosynthesis ,01 natural sciences ,03 medical and health sciences ,030104 developmental biology ,Agronomy ,010606 plant biology & botany ,Transpiration - Abstract
The ability to resist hydraulic dysfunction in leaves, stems, and roots strongly influences whether plants survive and recover from drought. However, the coordination of hydraulic function among different organs within species and their links to gas exchange during drought and recovery remains understudied. Here, we examine the interaction between gas exchange and hydraulic function in the leaves, stems, and roots of three semiarid evergreen species exposed to a cycle of severe water stress (associated with substantial cavitation) and recovery. In all species, stomatal closure occurred at water potentials well before 50% loss of stem hydraulic conductance, while in two species, leaves and/or roots were more vulnerable than stems. Following soil rewetting, leaf‐level photosynthesis (Anet) returned to prestress levels within 2–4 weeks, whereas stomatal conductance and canopy transpiration were slower to recover. The recovery of Anet was decoupled from the recovery of leaf, stem, and root hydraulics, which remained impaired throughout the recovery period. Our results suggest that in addition to high embolism resistance, early stomatal closure and hydraulic vulnerability segmentation confers drought tolerance in these arid zone species. The lack of substantial embolism refilling within all major organs suggests that vulnerability of the vascular system to drought‐induced dysfunction is a defining trait for predicting postdrought recovery.
- Published
- 2018
5. Stomatal and non-stomatal limitations of photosynthesis for four tree species under drought: A comparison of model formulations
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Sally A. Power, Danielle Creek, Michael J. Aspinwall, Remko A. Duursma, Sebastian Pfautsch, Chelsea Maier, John E. Drake, Derek Eamus, Mark G. Tjoelker, Renee Smith, Belinda E. Medlyn, Brendan Choat, and David T. Tissue
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0106 biological sciences ,Atmospheric Science ,Global and Planetary Change ,Stomatal conductance ,010504 meteorology & atmospheric sciences ,Empirical modelling ,Forestry ,Biology ,Rainout ,Photosynthesis ,Atmospheric sciences ,01 natural sciences ,Photosynthetic capacity ,Botany ,Soil water ,Ecosystem ,Water-use efficiency ,Agronomy and Crop Science ,010606 plant biology & botany ,0105 earth and related environmental sciences - Abstract
Drought strongly influences terrestrial C cycling via its effects on plant H2O and CO2 exchange. However, the treatment of photosynthetic physiology under drought by many ecosystem and earth system models remains poorly constrained by data. We measured the drought response of four tree species and evaluated alternative model formulations for drought effects on photosynthesis (A). We implemented a series of soil drying and rewetting events (i.e. multiple droughts) with four contrasting tree species in large pots (75 L) placed in the field under rainout shelters. We measured leaf-level gas exchange, predawn and midday leaf water potential (Ψpd and Ψmd), and leaf isotopic composition (δ13C) and calculated discrimination relative to the atmosphere (Δ). We then evaluated eight modeling frameworks that simulate the effects of drought in different ways. With moderate reductions in volumetric soil water content (θ), all species reduced stomatal conductance (gs), leading to an equivalent increase in water use efficiency across species inferred from both leaf gas exchange and Δ, despite a small reduction in photosynthetic capacity. With severe reductions in θ, all species strongly reduced gs along with a coincident reduction in photosynthetic capacity, illustrating the joint importance of stomatal and non-stomatal limitations of photosynthesis under strong drought conditions. Simple empirical models as well as complex mechanistic model formulations were equally successful at capturing the measured variation in A and gs, as long as the predictor variables were available from direct measurements (θ, Ψpd, and Ψmd). However, models based on leaf water potential face an additional challenge, as we found that Ψpd was substantially different from Ψsoil predicted by standard approaches based on θ. Modeling frameworks that combine gas exchange and hydraulic traits have the advantage of mechanistic realism, but sacrificed parsimony without an improvement in predictive power in this comparison. Model choice depends on the desired balance between simple empiricism and mechanistic realism. We suggest that empirical models implementing stomatal and non-stomatal limitations based on θ are highly predictive simple models. Mechanistic models that incorporate hydraulic traits have excellent potential, but several challenges currently limit their widespread implementation.
- Published
- 2017
6. Water availability affects seasonal <scp>CO</scp> 2 ‐induced photosynthetic enhancement in herbaceous species in a periodically dry woodland
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David S. Ellsworth, Danielle Creek, Oula Ghannoum, Kristine Y. Crous, Julia Cooke, and Varsha S. Pathare
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0106 biological sciences ,2. Zero hunger ,Global and Planetary Change ,Stomatal conductance ,010504 meteorology & atmospheric sciences ,Ecology ,Woodland ,Understory ,15. Life on land ,Herbaceous plant ,Biology ,Photosynthesis ,01 natural sciences ,Eucalyptus ,Agronomy ,13. Climate action ,Soil water ,Environmental Chemistry ,Ecosystem ,010606 plant biology & botany ,0105 earth and related environmental sciences ,General Environmental Science - Abstract
Elevated atmospheric CO2 (eCO2) is expected to reduce the impacts of drought and increase photosynthetic rates via two key mechanisms: first, through decreased stomatal conductance (gs) and increased soil water content (VSWC) and second, through increased leaf internal CO2 (Ci) and decreased stomatal limitations (Slim>). It is unclear if such findings from temperate grassland studies similarly pertain to warmer ecosystems with periodic water deficits. We tested these mechanisms in three important C3 herbaceous species in a periodically dry Eucalyptus woodland and investigated how eCO2-induced photosynthetic enhancement varied with seasonal water availability, over a 3 year period. Leaf photosynthesis increased by 10%–50% with a 150 μmol mol-1 increase in atmospheric CO2 across seasons. This eCO2-induced increase in photosynthesis was a function of seasonal water availability, given by recent precipitation and mean daily VSWC. The highest photosynthetic enhancement by eCO2 (>30%) was observed during the most water-limited period, for example, with VSWC 2 there was neither a significant decrease in gs in the three herbaceous species, nor increases in VSWC, indicating no “water-savings effect” of eCO2. Periods of low VSWC showed lower gs (less than ≈ 0.12 mol m-2 s-1), higher relative Slim (>30%) and decreased Ci under the ambient CO2 concentration (aCO2), with leaf photosynthesis strongly carboxylation-limited. The alleviation of Slim by eCO2 was facilitated by increasing Ci, thus yielding a larger photosynthetic enhancement during dry periods. We demonstrated that water availability, but not eCO2, controls gs and hence the magnitude of photosynthetic enhancement in the understory herbaceous plants. Thus, eCO2 has the potential to alter vegetation functioning in a periodically dry woodland understory through changes in stomatal limitation to photosynthesis, not by the “water-savings effect” usually invoked in grasslands.
- Published
- 2017
7. Strong thermal acclimation of photosynthesis in tropical and temperate wet‐forest tree species: the importance of altered Rubisco content
- Author
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Danielle Creek, Peter B. Reich, Shuang Xiang, Owen K. Atkin, John R. Evans, Benedict M. Long, Andrew P. Scafaro, Lasantha K. Weerasinghe, and Nur H. A. Bahar
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0106 biological sciences ,0301 basic medicine ,Acclimatization ,Ribulose-Bisphosphate Carboxylase ,Forests ,Photosynthesis ,01 natural sciences ,Trees ,03 medical and health sciences ,chemistry.chemical_compound ,Abundance (ecology) ,Botany ,Temperate climate ,Environmental Chemistry ,General Environmental Science ,Global and Planetary Change ,Ecology ,biology ,RuBisCO ,Carbon Dioxide ,15. Life on land ,Photosynthetic capacity ,Plant Leaves ,030104 developmental biology ,chemistry ,Chlorophyll ,biology.protein ,Temperate rainforest ,010606 plant biology & botany - Abstract
Understanding of the extent of acclimation of light-saturated net photosynthesis (An) to temperature (T), and associated underlying mechanisms, remains limited. This is a key knowledge gap given the importance of thermal acclimation for plant functioning, both under current and future higher temperatures, limiting the accuracy and realism of Earth System Model (ESM) predictions. Given this, we analysed and modelled T-dependent changes in photosynthetic capacity in 10 wet-forest tree species; six from temperate forests and four from tropical forests. Temperate and tropical species were each acclimated to three daytime growth temperatures (Tgrowth): temperate - 15, 20 and 25°C; tropical - 25, 30 and 35°C. CO2 response curves of An were used to model maximal rates of RuBP (ribulose-1,5-bisphosphate) carboxylation (Vcmax) and electron transport (Jmax) at each treatment's respective Tgrowth, and at a common measurement T (25°C). SDS-PAGE gels were used to determine abundance of the CO2-fixing enzyme, Rubisco. Leaf chlorophyll, nitrogen (N) and mass per unit leaf area (LMA) were also determined. For all species and Tgrowth, An at current atmospheric CO2 partial pressure was Rubisco-limited. Across all species, LMA decreased with increasing Tgrowth. Similarly, area-based rates of Vcmax at a measurement T of 25°C (Vcmax25) linearly declined with increasing Tgrowth, linked to a concomitant decline in total leaf protein per unit leaf area and Rubisco as a percentage of leaf N. The decline in Rubisco constrained Vcmax and An for leaves developed at higher Tgrowth and resulted in poor predictions of photosynthesis by currently widely used models that do not account for Tgrowth-mediated changes in Rubisco abundance that underpin the thermal acclimation response of photosynthesis in wet-forest tree species. A new model is proposed that accounts for the effect of Tgrowth-mediated declines in Vcmax25 on An, complementing current photosynthetic thermal acclimation models that do not account for T-sensitivity of Vcmax25. This article is protected by copyright. All rights reserved.
- Published
- 2017
8. Xylem embolism in leaves does not occur with open stomata: evidence from direct observations using the optical visualisation technique
- Author
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Danielle Creek, Camille Parise, José M. Torres-Ruiz, Régis Burlett, Sylvain Delzon, David T. Tissue, Laurent J. Lamarque, Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant - Clermont Auvergne (PIAF), Institut National de la Recherche Agronomique (INRA)-Université Clermont Auvergne (UCA), Biodiversité, Gènes et Communautés, Institut National de la Recherche Agronomique (INRA), Western Sydney University (UWS), Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant (PIAF), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de la Recherche Agronomique (INRA), Biodiversité, Gènes & Communautés (BioGeCo), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB), Western Sydney University, Università di Padova. ITA., ProdInra, Archive Ouverte, Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), IdEx Bordeaux International Post-doctoral ProgramAustralian Government Hawkesbury Institute for the Environment Research Exchange Program, and Université de Bordeaux (UB)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
- Subjects
0106 biological sciences ,0301 basic medicine ,Plant growth ,Physiology ,[SDV]Life Sciences [q-bio] ,Embolism ,Hydraulics ,Plant Science ,drought ,Biology ,01 natural sciences ,03 medical and health sciences ,Magnoliopsida ,water stress ,Hydraulic conductivity ,Xylem ,medicine ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,[SDV.BV] Life Sciences [q-bio]/Vegetal Biology ,sécheresse ,Abiotic component ,optical visualization ,Water stress ,Optical Imaging ,fungi ,Water ,food and beverages ,15. Life on land ,medicine.disease ,stomatal closure ,Horticulture ,030104 developmental biology ,Plant Stomata ,stress hydrique ,Literature survey ,Tree species ,010606 plant biology & botany - Abstract
Drought represents a major abiotic constraint to plant growth and survival. On the one hand, plants keep stomata open for efficient carbon assimilation while, on the other hand, they close them to prevent permanent hydraulic impairment from xylem embolism. The order of occurrence of these two processes (stomatal closure and the onset of leaf embolism) during plant dehydration has remained controversial, largely due to methodological limitations. However, the newly developed optical visualization method now allows concurrent monitoring of stomatal behaviour and leaf embolism formation in intact plants. We used this new approach directly by dehydrating intact saplings of three contrasting tree species and indirectly by conducting a literature survey across a greater range of plant taxa. Our results indicate that increasing water stress generates the onset of leaf embolism consistently after stomatal closure, and that the lag time between these processes (i.e. the safety margin) rises with increasing embolism resistance. This suggests that during water stress, embolism-mediated declines in leaf hydraulic conductivity are unlikely to act as a signal for stomatal down-regulation. Instead, these species converge towards a strategy of closing stomata early to prevent water loss and delay catastrophic xylem dysfunction.
- Published
- 2019
9. Non-invasive imaging shows no evidence of embolism repair after drought in tree species of two genera
- Author
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Jennifer M. R. Peters, Timothy J. Brodribb, Markus Nolf, Brendan Choat, Rosana López, Madeline R Carins-Murphy, Danielle Creek, Western Sydney University (UWS), Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant - Clermont Auvergne (PIAF), Institut National de la Recherche Agronomique (INRA)-Université Clermont Auvergne (UCA), University of Tasmania (UTAS), Western Sydney University, Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant (PIAF), Institut National de la Recherche Agronomique (INRA)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), University of Tasmania [Hobart, Australia] (UTAS), and Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de la Recherche Agronomique (INRA)
- Subjects
0106 biological sciences ,0301 basic medicine ,Drought stress ,Physiology ,Plant Science ,xylem ,micro-ct ,01 natural sciences ,Trees ,Quercus ,refilling ,laurus-nobilis ,Eucalyptus ,biology ,xylème ,food and beverages ,Forestry ,vessel-associated cells ,Droughts ,x-ray microtomography ,leaf gas-exchange ,Tree species ,Woody plant ,Noninvasive imaging ,embolism ,xylem hydraulic conductivity ,water-status ,03 medical and health sciences ,recovery ,cavitation ,medicine ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Quercus palustris ,Botánica ,fungi ,Xylem ,Water ,15. Life on land ,negative-pressure ,biology.organism_classification ,medicine.disease ,diffuse-porous trees ,030104 developmental biology ,Agronomy ,Embolism ,embolisme ,repair ,010606 plant biology & botany - Abstract
Drought stress can result in significant impairment of the plant hydraulic system via blockage of xylem conduits by gas emboli. Recovery after drought stress is an essential component of plant survival but is still a poorly understood process. In this study, we examined the capacity of woody species from two genera (Eucalyptus and Quercus) to refill embolized xylem vessels during a cycle of drought and recovery. Observations were made on intact plants of Eucalyptus calmudulensis, E. grandis, E. saligna and Quercus palustris using X-ray microtomography. We found no evidence of an effective xylem refilling mechanism in any of the plant species. Despite rehydration and recovery of plant water potential to near pre-drought levels, embolized vessels were not refilled up to 72 h after rewatering. In E. saligna, water droplets accumulated in previously air-filled vessels for a very small percentage of vessels. However, no instances of complete refilling that would restore embolized vessels to hydraulic function were observed. Our observations suggest that rapid refilling of embolized vessels after drought may not be a wide spread mechanism in woody plants and that embolism formed during drought represents long term cost to the plant hydraulic system.
- Published
- 2019
10. Drought response strategies and hydraulic traits contribute to mechanistic understanding of plant dry-down to hydraulic failure
- Author
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Michael J. Aspinwall, John E. Drake, Belinda E. Medlyn, Sebastian Pfautsch, Chris J. Blackman, Chelsea Maier, Brendan Choat, Danielle Creek, David T. Tissue, Sylvain Delzon, Anthony P. O'Grady, Hawkesbury Institute for the Environment, Western Sydney University, University of North Florida [Jacksonville] (UNF), Forest and Natural Resources Management, Partenaires INRAE, Land and Water, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Biodiversité, Gènes & Communautés (BioGeCo), and Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB)
- Subjects
0106 biological sciences ,Stomatal conductance ,pinus ,Physiology ,Range (biology) ,[SDV]Life Sciences [q-bio] ,Drought tolerance ,hydraulics ,Plant Science ,drought ,Biology ,01 natural sciences ,Trees ,03 medical and health sciences ,recovery ,Magnoliopsida ,Stress, Physiological ,rainfall exclusion ,rainout shelter ,030304 developmental biology ,0303 health sciences ,Biomass (ecology) ,Eucalyptus ,Plant Stems ,Water stress ,fungi ,Xylem ,food and beverages ,NSCs ,15. Life on land ,mortality ,Droughts ,Plant Leaves ,Agronomy ,Plant Stomata ,010606 plant biology & botany ,Woody plant - Abstract
Drought-induced tree mortality alters forest structure and function, yet our ability to predict when and how different species die during drought remains limited. Here, we explore how stomatal control and drought tolerance traits influence the duration of drought stress leading to critical levels of hydraulic failure. We examined the growth and physiological responses of four woody plant species (three angiosperms and one conifer) representing a range of water-use and drought tolerance traits over the course of two controlled drought–recovery cycles followed by an extended dry-down. At the end of the final dry-down phase, we measured changes in biomass ratios and leaf carbohydrates. During the first and second drought phases, plants of all species closed their stomata in response to decreasing water potential, but only the conifer species avoided water potentials associated with xylem embolism as a result of early stomatal closure relative to thresholds of hydraulic dysfunction. The time it took plants to reach critical levels of water stress during the final dry-down was similar among the angiosperms (ranging from 39 to 57 days to stemP88) and longer in the conifer (156 days to stemP50). Plant dry-down time was influenced by a number of factors including species stomatal-hydraulic safety margin (gsP90 – stemP50), as well as leaf succulence and minimum stomatal conductance. Leaf carbohydrate reserves (starch) were not depleted at the end of the final dry-down in any species, irrespective of the duration of drought. These findings highlight the need to consider multiple structural and functional traits when predicting the timing of hydraulic failure in plants.
- Published
- 2019
11. Coordination between leaf, stem, and root hydraulics and gas exchange in three arid-zone angiosperms during severe drought and recovery
- Author
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Danielle, Creek, Chris J, Blackman, Timothy J, Brodribb, Brendan, Choat, and David T, Tissue
- Subjects
Plant Leaves ,Eucalyptus ,Dehydration ,Plant Stems ,Acacia ,Water ,Plant Transpiration ,Plant Roots - Abstract
The ability to resist hydraulic dysfunction in leaves, stems, and roots strongly influences whether plants survive and recover from drought. However, the coordination of hydraulic function among different organs within species and their links to gas exchange during drought and recovery remains understudied. Here, we examine the interaction between gas exchange and hydraulic function in the leaves, stems, and roots of three semiarid evergreen species exposed to a cycle of severe water stress (associated with substantial cavitation) and recovery. In all species, stomatal closure occurred at water potentials well before 50% loss of stem hydraulic conductance, while in two species, leaves and/or roots were more vulnerable than stems. Following soil rewetting, leaf-level photosynthesis (A
- Published
- 2018
12. Stem and leaf hydraulic properties are finely coordinated in three tropical rain forest tree species
- Author
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Stefan Mayr, Joseph A. M. Holtum, Brendan Choat, Danielle Creek, Markus Nolf, and Remko A. Duursma
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Physiology ,Hydraulics ,ved/biology ,fungi ,Biome ,ved/biology.organism_classification_rank.species ,food and beverages ,Xylem ,Plant Science ,Rainforest ,Arid ,law.invention ,Agronomy ,Hydraulic conductivity ,law ,Terrestrial plant ,Threatened species ,Botany ,Environmental science - Abstract
Coordination of stem and leaf hydraulic traits allows terrestrial plants to maintain safe water status under limited water supply. Tropical rain forests, one of the world's most productive biomes, are vulnerable to drought and potentially threatened by increased aridity due to global climate change. However, the relationship of stem and leaf traits within the plant hydraulic continuum remains understudied, particularly in tropical species. We studied within-plant hydraulic coordination between stems and leaves in three tropical lowland rain forest tree species by analyses of hydraulic vulnerability [hydraulic methods and ultrasonic emission (UE) analysis], pressure-volume relations and in situ pre-dawn and midday water potentials (Ψ). We found finely coordinated stem and leaf hydraulic features, with a strategy of sacrificing leaves in favour of stems. Fifty percent of hydraulic conductivity (P50) was lost at −2.1 to −3.1 MPa in stems and at −1.7 to −2.2 MPa in leaves. UE analysis corresponded to hydraulic measurements. Safety margins (leaf P50 – stem P50) were very narrow at −0.4 to −1.4 MPa. Pressure-volume analysis and in situ Ψ indicated safe water status in stems but risk of hydraulic failure in leaves. Our study shows that stem and leaf hydraulics were finely tuned to avoid embolism formation in the xylem.
- Published
- 2015
13. Macromolecular rate theory (MMRT) provides a thermodynamics rationale to underpin the convergent temperature response in plant leaf respiration
- Author
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Mary A. Heskel, Danielle Creek, Vickery L. Arcus, John J. G. Egerton, Mark G. Tjoelker, Liyin L. Liang, Lasantha K. Weerasinghe, Louis A. Schipper, Odhran S. O'Sullivan, and Owen K. Atkin
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0106 biological sciences ,0301 basic medicine ,Hot Temperature ,Climate ,Thermodynamics ,Flux ,01 natural sciences ,Heat capacity ,Models, Biological ,03 medical and health sciences ,symbols.namesake ,Transition state theory ,Oxygen Consumption ,Exponential growth ,Respiration ,Environmental Chemistry ,Ecosystem ,General Environmental Science ,Arrhenius equation ,Global and Planetary Change ,Ecology ,Chemistry ,Temperature ,Plants ,Plant Leaves ,030104 developmental biology ,symbols ,Respiration rate ,010606 plant biology & botany - Abstract
Temperature is a crucial factor in determining the rates of ecosystem processes, for example, leaf respiration (R) - the flux of plant respired CO2 from leaves to the atmosphere. Generally, R increases exponentially with temperature and formulations such as the Arrhenius equation are widely used in earth system models. However, experimental observations have shown a consequential and consistent departure from an exponential increase in R. What are the principles that underlie these observed patterns? Here, we demonstrate that macromolecular rate theory (MMRT), based on transition state theory (TST) for enzyme-catalyzed kinetics, provides a thermodynamic explanation for the observed departure and the convergent temperature response of R using a global database. Three meaningful parameters emerge from MMRT analysis: the temperature at which the rate of respiration would theoretically reach a maximum (the optimum temperature, Topt ), the temperature at which the respiration rate is most sensitive to changes in temperature (the inflection temperature, Tinf ) and the overall curvature of the log(rate) versus temperature plot (the change in heat capacity for the system, ΔCP‡). On average, the highest potential enzyme-catalyzed rates of respiratory enzymes for R are predicted to occur at 67.0 ± 1.2°C and the maximum temperature sensitivity at 41.4 ± 0.7°C from MMRT. The average curvature (average negative ΔCP‡) was -1.2 ± 0.1 kJ mol-1 K-1 . Interestingly, Topt , Tinf and ΔCP‡ appear insignificantly different across biomes and plant functional types, suggesting that thermal response of respiratory enzymes in leaves could be conserved. The derived parameters from MMRT can serve as thermal traits for plant leaves that represent the collective temperature response of metabolic respiratory enzymes and could be useful to understand regulations of R under a warmer climate. MMRT extends the classic TST to enzyme-catalyzed reactions and provides an accurate and mechanistic model for the short-term temperature response of R around the globe.
- Published
- 2017
14. Species climate range influences hydraulic and stomatal traits in Eucalyptus species
- Author
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David S. Ellsworth, Jennifer M. R. Peters, Aimee E. Bourne, Danielle Creek, and Brendan Choat
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0106 biological sciences ,Range (biology) ,Climate ,Turgor pressure ,Species distribution ,Plant Science ,Biology ,010603 evolutionary biology ,01 natural sciences ,Trees ,Xylem ,Eucalyptus ,Tissue water ,Ecology ,fungi ,food and beverages ,Climatic variables ,Water ,Original Articles ,Droughts ,Vessel diameter ,Plant Leaves ,Plant Stomata ,010606 plant biology & botany - Abstract
Background and Aims Plant hydraulic traits influence the capacity of species to grow and survive in water-limited environments, but their comparative study at a common site has been limited. The primary aim of this study was to determine whether selective pressures on species originating in drought-prone environments constrain hydraulic traits among related species grown under common conditions. Methods Leaf tissue water relations, xylem anatomy, stomatal behaviour and vulnerability to drought-induced embolism were measured on six Eucalyptus species growing in a common garden to determine whether these traits were related to current species climate range and to understand linkages between the traits. Key Results Hydraulically weighted xylem vessel diameter, leaf turgor loss point, the water potential at stomatal closure and vulnerability to drought-induced embolism were significantly ( P < 0·05) correlated with climate parameters from the species range. There was a co-ordination between stem and leaf parameters with the water potential at turgor loss, 12 % loss of conductivity and the point of stomatal closure significantly correlated. Conclusions The correlation of hydraulic, stomatal and anatomical traits with climate variables from the species' original ranges suggests that these traits are genetically constrained. The conservative nature of xylem traits in Eucalyptus trees has important implications for the limits of species responses to changing environmental conditions and thus for species survival and distribution into the future, and yields new information for physiological models.
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- 2017
15. Reply to Adams et al.: Empirical versus process-based approaches to modeling temperature responses of leaf respiration
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Patrick Meir, Chris Huntingford, Mary A. Heskel, Zsofia R. Stangl, Alberto Martínez-de la Torre, Aurore Penillard, Keith J. Bloomfield, Danielle Creek, Felipe Sinca, Odhran S. O'Sullivan, Mark G. Tjoelker, Owen K. Atkin, John J. G. Egerton, Peter B. Reich, Vaughan Hurry, Jen Xiang, K. W. Lasantha K Weerasinghe, Matthew H. Turnbull, and Kevin L. Griffin
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0106 biological sciences ,0301 basic medicine ,Multidisciplinary ,Ecology ,Cellular respiration ,fungi ,food and beverages ,Biology ,Photosynthesis ,01 natural sciences ,carbohydrates (lipids) ,03 medical and health sciences ,030104 developmental biology ,Scientific method ,Botany ,Respiration ,010606 plant biology & botany - Abstract
Reply to Adams et al. : Empirical versus process-based approaches to modeling temperature responses of leaf respiration
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- 2016
16. Water availability affects seasonal CO
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Varsha S, Pathare, Kristine Y, Crous, Julia, Cooke, Danielle, Creek, Oula, Ghannoum, and David S, Ellsworth
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Plant Leaves ,Eucalyptus ,Soil ,Rain ,Water ,Seasons ,Asteraceae ,Carbon Dioxide ,Forests ,Photosynthesis ,Droughts - Abstract
Elevated atmospheric CO
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- 2016
17. Convergence in the temperature response of leaf respiration across biomes and plant functional types
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Danielle Creek, Keith J. Bloomfield, Felipe Sinca, Chris Huntingford, Alberto Martínez-de la Torre, Patrick Meir, Aurore Penillard, Mark G. Tjoelker, Odhran S. O'Sullivan, Jen Xiang, Peter B. Reich, John J. G. Egerton, Zsofia R. Stangl, Lasantha K. Weerasinghe, Owen K. Atkin, Mary A. Heskel, Matthew H. Turnbull, Kevin L. Griffin, and Vaughan Hurry
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0106 biological sciences ,Hot Temperature ,010504 meteorology & atmospheric sciences ,Cellular respiration ,Acclimatization ,Climate Change ,Cell Respiration ,Biome ,Climate change ,Biology ,Atmospheric sciences ,01 natural sciences ,Carbon Cycle ,Trees ,Carbon cycle ,Atmosphere ,Respiration ,Letters ,Ecosystem ,0105 earth and related environmental sciences ,Multidisciplinary ,food and beverages ,Biosphere ,Vegetation ,Carbon Dioxide ,15. Life on land ,Biological Sciences ,Plant Leaves ,13. Climate action ,Climatology ,Energy Metabolism ,010606 plant biology & botany - Abstract
Plant respiration constitutes a massive carbon flux to the atmosphere, and a major control on the evolution of the global carbon cycle. It therefore has the potential to modulate levels of climate change due to the human burning of fossil fuels. Neither current physiological nor terrestrial biosphere models adequately describe its short-term temperature response, and even minor differences in the shape of the response curve can significantly impact estimates of ecosystem carbon release and/or storage. Given this, it is critical to establish whether there are predictable patterns in the shape of the respiration-temperature response curve, and thus in the intrinsic temperature sensitivity of respiration across the globe. Analyzing measurements in a comprehensive database for 231 species spanning 7 biomes, we demonstrate that temperature-dependent increases in leaf respiration do not follow a commonly used exponential function. Instead, we find a decelerating function as leaves warm, reflecting a declining sensitivity to higher temperatures that is remarkably uniform across all biomes and plant functional types. Such convergence in the temperature sensitivity of leaf respiration suggests that there are universally applicable controls on the temperature response of plant energy metabolism, such that a single new function can predict the temperature dependence of leaf respiration for global vegetation. This simple function enables straightforward description of plant respiration in the land-surface components of coupled earth system models. Our cross-biome analyses shows significant implications for such fluxes in cold climates, generally projecting lower values compared with previous estimates.
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- 2016
18. Thermal limits of leaf metabolism across biomes
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Peter B. Reich, Keith J. Bloomfield, Owen K. Atkin, Patrick Meir, Vaughan Hurry, John J. G. Egerton, Kevin L. Griffin, Danielle Creek, K. W. Lasantha K Weerasinghe, Mary A. Heskel, Lingling Zhu, Mark G. Tjoelker, Odhran S. O'Sullivan, Nur H. A. Bahar, Aurore Penillard, and Matthew H. Turnbull
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0106 biological sciences ,Canopy ,Chlorophyll ,Acclimatization ,Climate Change ,Biome ,Climate change ,Rainforest ,Biology ,Atmospheric sciences ,010603 evolutionary biology ,01 natural sciences ,Environmental Chemistry ,Animals ,Respiratory function ,General Environmental Science ,Global and Planetary Change ,Ecology ,Arctic Regions ,Chlorophyll A ,Global warming ,Temperature ,15. Life on land ,Plant Leaves ,Arctic ,13. Climate action ,010606 plant biology & botany - Abstract
High-temperature tolerance in plants is important in a warming world, with extreme heat-waves predicted to increase in frequency and duration, potentially leading to lethal heating of leaves. Global patterns of high-temperature tolerance are documented in animals, but generally not plants, limiting our ability to assess risks associated with climate warming. To assess whether there are global patterns in high-temperature tolerance of leaf metabolism, we quantified Tcrit (high temperature where minimal chlorophyll a fluorescence rises rapidly, and thus where photosystem II is disrupted) and Tmax (temperature where leaf respiration in darkness is maximal, beyond which respiratory function rapidly declines) in upper-canopy leaves of 218 plant species spanning seven biomes. Mean site-based Tcrit values ranged from 41.5 °C in the Alaskan arctic to 50.8 °C in lowland tropical rainforests of Peruvian Amazon. For Tmax, the equivalent values were 51.0 and 60.6 °C in the Arctic and Amazon, respectively. Tcrit and Tmax followed similar biogeographic patterns, increasing linearly (~8 °C) from polar to equatorial regions. Such increases in high temperature tolerance are much less than expected based on the 20 °C span in high temperature extremes across the globe. Moreover, with only modest high-temperature tolerance despite high summer temperature extremes, species in mid-latitude (~20°-50°) regions have the narrowest thermal safety margins in upper-canopy leaves; these regions are at the greatest risk of damage due to extreme heat-wave events, especially under conditions when leaf temperatures are further elevated by a lack of transpirational cooling. Using predicted heat-wave events for 2050 and accounting for possible thermal acclimation of Tcrit and Tmax, we also found that these safety margins could shrink in a warmer world, as rising temperatures are likely to exceed thermal tolerance limits. Thus, increasing numbers of species in many biomes may be at risk as heat-wave events become more severe with climate change.
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- 2016
19. Stem and leaf hydraulic properties are finely coordinated in three tropical rain forest tree species
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Markus, Nolf, Danielle, Creek, Remko, Duursma, Joseph, Holtum, Stefan, Mayr, and Brendan, Choat
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Plant Leaves ,Tropical Climate ,Rainforest ,Plant Stems ,Xylem ,Elaeocarpaceae ,Syzygium ,Australia ,Temperature ,Water ,Plant Transpiration ,Meliaceae ,Trees - Abstract
Coordination of stem and leaf hydraulic traits allows terrestrial plants to maintain safe water status under limited water supply. Tropical rain forests, one of the world's most productive biomes, are vulnerable to drought and potentially threatened by increased aridity due to global climate change. However, the relationship of stem and leaf traits within the plant hydraulic continuum remains understudied, particularly in tropical species. We studied within-plant hydraulic coordination between stems and leaves in three tropical lowland rain forest tree species by analyses of hydraulic vulnerability [hydraulic methods and ultrasonic emission (UE) analysis], pressure-volume relations and in situ pre-dawn and midday water potentials (Ψ). We found finely coordinated stem and leaf hydraulic features, with a strategy of sacrificing leaves in favour of stems. Fifty percent of hydraulic conductivity (P50 ) was lost at -2.1 to -3.1 MPa in stems and at -1.7 to -2.2 MPa in leaves. UE analysis corresponded to hydraulic measurements. Safety margins (leaf P50 - stem P50 ) were very narrow at -0.4 to -1.4 MPa. Pressure-volume analysis and in situ Ψ indicated safe water status in stems but risk of hydraulic failure in leaves. Our study shows that stem and leaf hydraulics were finely tuned to avoid embolism formation in the xylem.
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- 2014
20. Canopy position affects the relationships between leaf respiration and associated traits in a tropical rainforest in Far North Queensland
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Kristine Y. Crous, Shuang Xiang, Michael J. Liddell, Matthew H. Turnbull, Lasantha K. Weerasinghe, Danielle Creek, and Owen K. Atkin
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Canopy ,Rainforest ,Light ,Physiology ,ved/biology.organism_classification_rank.species ,Cell Respiration ,chemistry.chemical_element ,Plant Science ,Biology ,Photosynthesis ,Shrub ,Trees ,Dry weight ,Botany ,ved/biology ,Phosphorus ,Temperature ,Understory ,Plant Leaves ,Horticulture ,Phenotype ,chemistry ,Queensland ,Tropical rainforest - Abstract
We explored the impact of canopy position on leaf respiration (R) and associated traits in tree and shrub species growing in a lowland tropical rainforest in Far North Queensland, Australia. The range of traits quantified included: leaf R in darkness (R-D) and in the light (R-L; estimated using the Kok method); the temperature (T)-sensitivity of R-D; light-saturated photosynthesis (A(sat)); leaf dry mass per unit area (LMA); and concentrations of leaf nitrogen (N), phosphorus (P), soluble sugars and starch. We found that LMA, and area-based N, P, sugars and starch concentrations were all higher in sun-exposed/upper canopy leaves, compared with their shaded/lower canopy and deep-shade/understory counterparts; similarly, area-based rates of R-D, R-L and A(sat) (at 28aEuro...A degrees C) were all higher in the upper canopy leaves, indicating higher metabolic capacity in the upper canopy. The extent to which light inhibited R did not differ significantly between upper and lower canopy leaves, with the overall average inhibition being 32% across both canopy levels. Log-log R-D-A(sat) relationships differed between upper and lower canopy leaves, with upper canopy leaves exhibiting higher rates of R-D for a given A(sat) (both on an area and mass basis), as well as higher mass-based rates of R-D for a given [N] and [P]. Over the 25-45aEuro...A degrees C range, the T-sensitivity of R-D was similar in upper and lower canopy leaves, with both canopy positions exhibiting Q(10) values near 2.0 (i.e., doubling for every 10aEuro...A degrees C rise in T) and T-max values near 60aEuro...A degrees C (i.e., T where R-D reached maximal values). Thus, while rates of R-D at 28aEuro...A degrees C decreased with increasing depth in the canopy, the T-dependence of R-D remained constant; these findings have important implications for vegetation-climate models that seek to predict carbon fluxes between tropical lowland rainforests and the atmosphere.
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- 2014
21. Global variability in leaf respiration in relation to climate, plant functional types and leaf traits
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Shuang Xiang, Trofim C. Maximov, Lucy Rowland, Stephen Sitch, Keith J. Bloomfield, Emanuel Gloor, Christopher H. Lusk, Danielle Creek, Nicholas Mirotchnick, Ülo Niinemets, Michael G. Ryan, Peter B. Reich, Jon Lloyd, Fernando Valladares, Joana Zaragoza-Castells, Mary A. Heskel, John J. G. Egerton, Matthew H. Turnbull, Erik J. Veneklaas, John R. Evans, Roberta E. Martin, Jens Kattge, Françoise Yoko Ishida, Kevin L. Griffin, Gerhard Bönisch, Norma Salinas, Michael J. Liddell, Desmond Ng, Jeffrey S. Dukes, Martijn Slot, Hans Lambers, Lina M. Mercado, Pieter Poot, Mark C. Vanderwel, Kirk R. Wythers, Ian J. Wright, Nicholas G. Smith, Lasantha K. Weerasinghe, Rossella Guerrieri, Chris Huntingford, Jen Xiang, Teresa E. Gimeno, Yadvinder Malhi, Paul P. G. Gauthier, Patrick Meir, Eric G. Cosio, Odhran S. O'Sullivan, Gregory P. Asner, Mark G. Tjoelker, Damien Bonal, Lucas A. Cernusak, Graham D. Farquhar, Christian Wirth, Lourens Poorter, Matt Bradford, I. Colin Prentice, Oliver L. Phillips, Tomas F. Domingues, Belinda E. Medlyn, Nikolaos M. Fyllas, Owen K. Atkin, Kristine Y. Crous, Ayal P. Maksimov, Atkin O.K., Bloomfield K.J., Reich P.B., Tjoelker M.G., Asner G.P., Bonal D., Bonisch G., Bradford M.G., Cernusak L.A., Cosio E.G., Creek D., Crous K.Y., Domingues T.F., Dukes J.S., Egerton J.J.G., Evans J.R., Farquhar G.D., Fyllas N.M., Gauthier P.P.G., Gloor E., Gimeno T.E., Griffin K.L., Guerrieri R., Heskel M.A., Huntingford C., Ishida F.Y., Kattge J., Lambers H., Liddell M.J., Lloyd J., Lusk C.H., Martin R.E., Maksimov A.P., Maximov T.C., Malhi Y., Medlyn B.E., Meir P., Mercado L.M., Mirotchnick N., Ng D., Niinemets U., O'Sullivan O.S., Phillips O.L., Poorter L., Poot P., Prentice I.C., Salinas N., Rowland L.M., Ryan M.G., Sitch S., Slot M., Smith N.G., Turnbull M.H., Vanderwel M.C., Valladares F., Veneklaas E.J., Weerasinghe L.K., Wirth C., Wright I.J., Wythers K.R., Xiang J., Xiang S., Zaragoza-Castells J., Australian National University (ANU), Hawkesbury Institute for the Environment [Richmond] (HIE), Western Sydney University, University of Minnesota [Twin Cities] (UMN), University of Minnesota System, Carnegie Institution for Science [Washington], Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Max-Planck-Institut für Biogeochemie (MPI-BGC), CSIRO Land and Water, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), James Cook University (JCU), Pontificia Universidad Católica del Perú (PUCP), Universidade de São Paulo (USP), Purdue University [West Lafayette], National and Kapodistrian University of Athens (NKUA), Department of Geosciences [Princeton], Princeton University, School of Geography [Leeds], University of Leeds, Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], School of Geosciences [Edinburgh], University of Edinburgh, University of New Hampshire (UNH), Centre for Ecology and Hydrology [Wallingford] (CEH), Natural Environment Research Council (NERC), School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia, The University of Western Australia (UWA), Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, UK, University of Waikato [Hamilton], Institute of Biological Problems of the Cryolithozone, Russian Academy of Sciences [Moscow] (RAS), School of Geography and the Environment [Oxford] (SoGE), University of Oxford [Oxford], Macquarie University, College of Life and Environmental Sciences, University of Exeter, Department of Ecology and Evolutionary Biology [University of Toronto] (EEB), University of Toronto, Wageningen University and Research [Wageningen] (WUR), School of Biological Sciences, University of Canterbury, Colorado State University [Fort Collins] (CSU), Department of Biology [Gainesville] (UF|Biology), University of Florida [Gainesville] (UF), Smithsonian Tropical Research Institute, University of Regina (UR), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), University of Peradeniya, Universität Leipzig [Leipzig], Chinese Academy of Sciences [Beijing] (CAS), Western Sydney University (UWS), University of Minnesota [Twin Cities], National and Kapodistrian University of Athens = University of Athens (NKUA | UoA), School of Geography and the Environment [Oxford], Estonian University of Life Sciences, Wageningen University and Research Centre [Wageningen] (WUR), Department of Biology (University of Florida), University of Florida [Gainesville], Smithsonian Tropical Research Institute, Panama City, Republic of Panama., Consejo Superior de Investigaciones Científicas [Spain] (CSIC), and AXA Research Fund
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temperature sensitivity ,Physiology ,[SDV]Life Sciences [q-bio] ,Acclimatization ,Climate ,Plant Science ,Photosynthesis ,Aridity ,Temperatures ,Ecology ,Respiration ,Temperature ,Biosphere ,Plants ,PE&RC ,Phenotype ,nitrogen concentration ,Leaf nitrogen (N) ,Plant Leave ,Life Sciences & Biomedicine ,Woody plant ,terrestrial carbon-cycle ,thermal-acclimation ,Nitrogen ,Plant Biology & Botany ,Cell Respiration ,Climate change ,Biology ,FOTOSSÍNTESE ,Climate model ,Ecology and Environment ,tropical rain-forests ,Carbon cycle ,Climate models ,Carbon Cycle ,Photosynthesi ,07 Agricultural and Veterinary Sciences ,Bosecologie en Bosbeheer ,Plant functional types (PFTs) ,elevated atmospheric co2 ,photosynthetic capacity ,Science & Technology ,Plant Sciences ,Tropics ,scaling relationships ,Plant ,15. Life on land ,Herbaceous plant ,06 Biological Sciences ,Carbon Dioxide ,Models, Theoretical ,vegetation models ,Photosynthetic capacity ,Arid ,Forest Ecology and Forest Management ,Plant Leaves ,Biology and Microbiology ,13. Climate action ,dark respiration ,Acclimation - Abstract
Owen K. Atkin [et al.].- Received: 8 July 2014, Accepted: 29 November 2014, Leaf dark respiration (Rdark) is an important yet poorly quantified component of the global carbon cycle. Given this, we analyzed a new global database of Rdark and associated leaf traits., Data for 899 species were compiled from 100 sites (from the Arctic to the tropics). Several woody and nonwoody plant functional types (PFTs) were represented. Mixed-effects models were used to disentangle sources of variation in Rdark., Area-based Rdark at the prevailing average daily growth temperature (T) of each site increased only twofold from the Arctic to the tropics, despite a 20°C increase in growing T (8–28°C). By contrast, Rdark at a standard T (25°C, Rdark25) was threefold higher in the Arctic than in the tropics, and twofold higher at arid than at mesic sites. Species and PFTs at cold sites exhibited higher Rdark25 at a given photosynthetic capacity (Vcmax25) or leaf nitrogen concentration ([N]) than species at warmer sites. Rdark25 values at any given Vcmax25 or [N] were higher in herbs than in woody plants., The results highlight variation in Rdark among species and across global gradients in T and aridity. In addition to their ecological significance, the results provide a framework for improving representation of Rdark in terrestrial biosphere models (TBMs) and associated land-surface components of Earth system models (ESMs).
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