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Griffani DS, Rognon P, Farquhar GD. The role of thermodiffusion in transpiration. THE NEW PHYTOLOGIST 2024; 243:1301-1311. [PMID: 38453691 DOI: 10.1111/nph.19642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 01/28/2024] [Indexed: 03/09/2024]
Abstract
Plant leaf temperatures can differ from ambient air temperatures. A temperature gradient in a gas mixture gives rise to a phenomenon known as thermodiffusion, which operates in addition to ordinary diffusion. Whilst transpiration is generally understood to be driven solely by the ordinary diffusion of water vapour along a concentration gradient, we consider the implications of thermodiffusion for transpiration. We develop a new modelling framework that introduces the effects of thermodiffusion on the transpiration rate, E. By applying this framework, we quantify the proportion of E attributable to thermodiffusion for a set of physiological and environmental conditions, varied over a wide range. Thermodiffusion is found to be most significant (in some cases > 30% of E) when a leaf-to-air temperature difference coincides with a relatively small water vapour concentration difference across the boundary layer; a boundary layer conductance that is large as compared to the stomatal conductance; or a relatively low transpiration rate. Thermodiffusion also alters the conditions required for the onset of reverse transpiration, and the rate at which this water vapour uptake occurs.
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Affiliation(s)
- Danielle S Griffani
- Faculty of Science and Engineering, Southern Cross University, East Lismore, NSW, 2480, Australia
| | - Pierre Rognon
- School of Civil Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Graham D Farquhar
- Research School of Biology, Australian National University, Acton, ACT, 2601, Australia
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2
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Araújo KC, Souza BC, Carvalho ECD, Freire RS, Teixeira AS, Muniz CR, Martins FR, Oliveira RS, Eller CB, Soares AA. The multiple roles of trichomes in two Croton species. PLANT, CELL & ENVIRONMENT 2024; 47:1685-1700. [PMID: 38282477 DOI: 10.1111/pce.14829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 01/30/2024]
Abstract
Trichomes are common in plants from dry environments, and despite their recognized role in protection and defense, little is known about their role as absorptive structures and in other aspects of leaf ecophysiology. We combine anatomical and ecophysiological data to evaluate how trichomes affect leaf gas exchange and water balance during drought. We studied two congeneric species with pubescent leaves which co-occur in Brazilian Caatinga: Croton blanchetianus (dense trichomes) and Croton adenocalyx (sparse trichomes). We found a novel foliar water uptake (FWU) pathway in C. blanchetianus composed of stellate trichomes and underlying epidermal cells and sclereids that interconnect the trichomes from both leaf surfaces. The water absorbed by these trichomes is redistributed laterally by pectin protuberances on mesophyll cell walls. This mechanism enables C. blanchetianus leaves to absorb water more efficiently than C. adenocalyx. Consequently, the exposure of C. blanchetianus to dew during drought improved its leaf gas exchange and water status more than C. adenocalyx. C. blanchetianus trichomes also increase their leaf capacity to reflect light and maintain lower temperatures during drought. Our results emphasize the multiple roles that trichomes might have on plant functioning and the importance of FWU for the ecophysiology of Caatinga plants during drought.
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Affiliation(s)
- Karina Crisóstomo Araújo
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Bruno Cruz Souza
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Ellen Cristina Dantas Carvalho
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Rosemeyre Souza Freire
- Centro de Ciências, Central Analítica, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Adunias Santos Teixeira
- Departament of Agricultural Engineering, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | - Fernando Roberto Martins
- Department of Plant Biology, Institute of Biology, CP6109, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Rafael Silva Oliveira
- Department of Plant Biology, Institute of Biology, CP6109, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Cleiton Breder Eller
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Arlete Aparecida Soares
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Ceará, Brazil
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Fradera-Soler M, Mravec J, Schulz A, Taboryski R, Jørgensen B, Grace OM. Revisiting an ecophysiological oddity: Hydathode-mediated foliar water uptake in Crassula species from southern Africa. PLANT, CELL & ENVIRONMENT 2024; 47:460-481. [PMID: 37876364 DOI: 10.1111/pce.14743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 10/10/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
Hydathodes are usually associated with water exudation in plants. However, foliar water uptake (FWU) through the hydathodes has long been suspected in the leaf-succulent genus Crassula (Crassulaceae), a highly diverse group in southern Africa, and, to our knowledge, no empirical observations exist in the literature that unequivocally link FWU to hydathodes in this genus. FWU is expected to be particularly beneficial on the arid western side of southern Africa, where up to 50% of Crassula species occur and where periodically high air humidity leads to fog and/or dew formation. To investigate if hydathode-mediated FWU is operational in different Crassula species, we used the apoplastic fluorescent tracer Lucifer Yellow in combination with different imaging techniques. Our images of dye-treated leaves confirm that hydathode-mediated FWU does indeed occur in Crassula and that it might be widespread across the genus. Hydathodes in Crassula serve as moisture-harvesting structures, besides their more common purpose of guttation, an adaptation that has likely played an important role in the evolutionary history of the genus. Our observations suggest that ability for FWU is independent of geographical distribution and not restricted to arid environments under fog influence, as FWU is also operational in Crassula species from the rather humid eastern side of southern Africa. Our observations point towards no apparent link between FWU ability and overall leaf surface wettability in Crassula. Instead, the hierarchically sculptured leaf surfaces of several Crassula species may facilitate FWU due to hydrophilic leaf surface microdomains, even in seemingly hydrophobic species. Overall, these results confirm the ecophysiological relevance of hydathode-mediated FWU in Crassula and reassert the importance of atmospheric humidity for some arid-adapted plant groups.
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Affiliation(s)
- Marc Fradera-Soler
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- Royal Botanic Gardens, Kew, Richmond, Surrey, UK
| | - Jozef Mravec
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Plant Science and Biodiversity Center, Nitra, Slovakia
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Rafael Taboryski
- National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark, Lyngby, Denmark
| | - Bodil Jørgensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Olwen M Grace
- Royal Botanic Gardens, Kew, Richmond, Surrey, UK
- Royal Botanic Garden Edinburgh, Edinburgh, UK
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4
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Brum M, Vadeboncoeur M, Asbjornsen H, Puma Vilca BL, Galiano D, Horwath AB, Metcalfe DB. Ecophysiological controls on water use of tropical cloud forest trees in response to experimental drought. TREE PHYSIOLOGY 2023; 43:1514-1532. [PMID: 37209136 DOI: 10.1093/treephys/tpad070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 05/03/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023]
Abstract
Tropical montane cloud forests (TMCFs) are expected to experience more frequent and prolonged droughts over the coming century, yet understanding of TCMF tree responses to moisture stress remains weak compared with the lowland tropics. We simulated a severe drought in a throughfall reduction experiment (TFR) for 2 years in a Peruvian TCMF and evaluated the physiological responses of several dominant species (Clusia flaviflora Engl., Weinmannia bangii (Rusby) Engl., Weinmannia crassifolia Ruiz & Pav. and Prunus integrifolia (C. Presl) Walp). Measurements were taken of (i) sap flow; (ii) diurnal cycles of stem shrinkage, stem moisture variation and water-use; and (iii) intrinsic water-use efficiency (iWUE) estimated from foliar δ13C. In W. bangii, we used dendrometers and volumetric water content (VWC) sensors to quantify daily cycles of stem water storage. In 2 years of sap flow (Js) data, we found a threshold response of water use to vapor pressure deficit vapor pressure deficit (VPD) > 1.07 kPa independent of treatment, though control trees used more soil water than the treatment trees. The daily decline in water use in the TFR trees was associated with a strong reduction in both morning and afternoon Js rates at a given VPD. Soil moisture also affected the hysteresis strength between Js and VPD. Reduced hysteresis under moisture stress implies that TMCFs are strongly dependent on shallow soil water. Additionally, we suggest that hysteresis can serve as a sensitive indicator of environmental constraints on plant function. Finally, 6 months into the experiment, the TFR treatment significantly increased iWUE in all study species. Our results highlight the conservative behavior of TMCF tree water use under severe soil drought and elucidate physiological thresholds related to VPD and its interaction with soil moisture. The observed strongly isohydric response likely incurs a cost to the carbon balance of the tree and reduces overall ecosystem carbon uptake.
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Affiliation(s)
- Mauro Brum
- Department of Natural Resources & the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
| | - Matthew Vadeboncoeur
- Earth Systems Research Center, University of New Hampshire, 8 College Rd, Durham, NH 03824, USA
| | - Heidi Asbjornsen
- Department of Natural Resources & the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
- Earth Systems Research Center, University of New Hampshire, 8 College Rd, Durham, NH 03824, USA
| | - Beisit L Puma Vilca
- Facultad de Ciencias Biológicas, Universidad Nacional de San Antonio Abad del Cusco, Av. de La Cultura 773, Cusco, Cusco Province 08000, Peru
- Asociación Civil Sin Fines De Lucro Para La Biodiversidad, Investigación Y Desarrollo Ambiental En Ecosistemas Tropicales (ABIDA), Urbanización Ucchullo Grande, Avenida Argentina F-9, Cusco, Perú
| | - Darcy Galiano
- Facultad de Ciencias Biológicas, Universidad Nacional de San Antonio Abad del Cusco, Av. de La Cultura 773, Cusco, Cusco Province 08000, Peru
- Asociación Civil Sin Fines De Lucro Para La Biodiversidad, Investigación Y Desarrollo Ambiental En Ecosistemas Tropicales (ABIDA), Urbanización Ucchullo Grande, Avenida Argentina F-9, Cusco, Perú
| | - Aline B Horwath
- Asociación Civil Sin Fines De Lucro Para La Biodiversidad, Investigación Y Desarrollo Ambiental En Ecosistemas Tropicales (ABIDA), Urbanización Ucchullo Grande, Avenida Argentina F-9, Cusco, Perú
| | - Daniel B Metcalfe
- Department of Ecology & Environmental Science, Umeå University, KBC-huset, Linnaeus väg 6, Umeå 901 87, Sweden
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Chin ARO, Guzmán-Delgado P, Görlich A, HilleRisLambers J. Towards multivariate functional trait syndromes: Predicting foliar water uptake in trees. Ecology 2023; 104:e4112. [PMID: 37252804 DOI: 10.1002/ecy.4112] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/10/2023] [Accepted: 05/18/2023] [Indexed: 06/01/2023]
Abstract
Analysis of functional traits is a cornerstone of ecology, yet individual traits seldom explain useful amounts of variation in species distribution or climatic tolerance, and their functional significance is rarely validated experimentally. Multivariate suites of interacting traits could build an understanding of ecological processes and improve our ability to make sound predictions of species success in our rapidly changing world. We use foliar water uptake capacity as a case study because it is increasingly considered to be a key functional trait in plant ecology due to its importance for stress-tolerance physiology. However, the traits behind the trait, that is, the features of leaves that determine variation in foliar water uptake rates, have not been assembled into a widely applicable framework for uptake prediction. Focusing on trees, we investigated relationships among 25 structural traits, leaf osmotic potential (a source of free energy to draw water into leaves), and foliar water uptake in 10 diverse angiosperm and conifer species. We identified consistent, multitrait "uptake syndromes" for both angiosperm and conifer trees, with differences in key traits revealing suspected differences in the water entry route between these two clades and an evolutionarily significant divergence in the function of homologous structures. A literature review of uptake-associated functional traits, which largely documents similar univariate relationships, provides additional support for our proposed "uptake syndrome." Importantly, more than half of shared traits had opposite-direction influences on the capacity of leaves to absorb water in angiosperms and conifers. Taxonomically targeted multivariate trait syndromes provide a useful tool for trait selection in ecological research, while highlighting the importance of micro-traits and the physiological verification of their function for advancing trait-based ecology.
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Affiliation(s)
- Alana R O Chin
- Plant Ecology Group, Institute of Integrative Biology, ETH-Zürich, Zürich, Switzerland
| | - Paula Guzmán-Delgado
- Department of Plant Sciences, University of California, Davis, Davis, California, USA
| | - Anna Görlich
- Plant Ecology Group, Institute of Integrative Biology, ETH-Zürich, Zürich, Switzerland
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6
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Losso A, Dämon B, Hacke U, Mayr S. High potential for foliar water uptake in early stages of leaf development of three woody angiosperms. PHYSIOLOGIA PLANTARUM 2023; 175:e13961. [PMID: 37341178 PMCID: PMC10953411 DOI: 10.1111/ppl.13961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/06/2023] [Accepted: 06/16/2023] [Indexed: 06/22/2023]
Abstract
Foliar water uptake (FWU) is a widespread mechanism that may help plants cope with drought stress in a wide range of ecosystems. FWU can be affected by various leaf traits, which change during leaf development. We exposed cut and dehydrated leaves to rainwater and measured FWU, changes in leaf water potential after 19 h of FWU (ΔΨ), minimum leaf conductance (gmin ), and leaf wettability (abaxial and adaxial) of leaves of Acer platanoides, Fagus sylvatica, and Sambucus nigra at three developmental stages: unfolding (2-5-day-old), young (1.5-week-old) and mature leaves (8-week-old). FWU and gmin were higher in younger leaves. ΔΨ corresponded to FWU and gmin in all cases but mature leaves of F. sylvatica, where ΔΨ was highest. Most leaves were highly wettable, and at least one leaf surface (adaxial or abaxial) showed a decrease in wettability from unfolding to mature leaves. Young leaves of all studied species showed FWU (unfolding leaves: 14.8 ± 1.1 μmol m-2 s-1 ), which may improve plant water status and thus counterbalance spring transpirational losses due to high gmin . The high wettability of young leaves probably supported FWU. We observed particularly high FWU and respective high ΔΨ in older leaves of F. sylvatica, possibly aided by trichomes.
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Affiliation(s)
- Adriano Losso
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - Birgit Dämon
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
| | - Uwe Hacke
- Department of Renewable ResourcesUniversity of AlbertaEdmontonAlbertaCanada
| | - Stefan Mayr
- Department of BotanyUniversity of InnsbruckInnsbruckAustria
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Li C, Mo Y, Wang N, Xing L, Qu Y, Chen Y, Yuan Z, Ali A, Qi J, Fernández V, Wang Y, Kopittke PM. The overlooked functions of trichomes: Water absorption and metal detoxication. PLANT, CELL & ENVIRONMENT 2023; 46:669-687. [PMID: 36581782 DOI: 10.1111/pce.14530] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
Trichomes are epidermal outgrowths on plant shoots. Their roles in protecting plants against herbivores and in the biosynthesis of specialized metabolites have long been recognized. Recently, studies are increasingly showing that trichomes also play important roles in water absorption and metal detoxication, with these roles having important implications for ecology, the environment, and agriculture. However, these two functions of trichomes have been largely overlooked and much remains unknown. In this review, we show that the trichomes of 37 plant species belonging to 14 plant families are involved in water absorption, while the trichomes of 33 species from 13 families are capable of sequestering metals within their trichomes. The ability of trichomes to absorb water results from their decreased hydrophobicity compared to the remainder of the leaf surface as well as the presence of special structures for collecting and absorbing water. In contrast, the metal detoxication function of trichomes results not only from the good connection of their basal cells to the underlying vascular tissues, but also from the presence of metal-chelating ligands and transporters within the trichomes themselves. Knowledge gaps and critical future research questions regarding these two trichome functions are highlighted. This review improves our understanding on trichomes.
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Affiliation(s)
- Cui Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Yingying Mo
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Nina Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Longyi Xing
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Yang Qu
- Baoji Academy of Agriculture Sciences, Baoji, China
| | - Yanlong Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Zuoqiang Yuan
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Arshad Ali
- College of Life Sciences, Hebei University, Hebei, China
| | - Jiyan Qi
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Victoria Fernández
- School of Forest Engineering, Technical University of Madrid, Madrid, Spain
| | - Yuheng Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Peter M Kopittke
- School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Queensland, Australia
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Wang H, Li Z, Ji S, Lv G. Response of water and photosynthetic physiological characteristics to leaf humidification in Calligonum ebinuricum. PLoS One 2023; 18:e0285130. [PMID: 37141258 PMCID: PMC10159122 DOI: 10.1371/journal.pone.0285130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 04/14/2023] [Indexed: 05/05/2023] Open
Abstract
Foliar water uptake (FWU) has increasingly been regarded as a common approach for plants to obtain water under water-limited conditions. At present, the research on FWU has mostly focused on short-term experiments; the long-term FWU plant response remains unclear; Methods: Through a field in-situ humidification control experiment, the leaves of Calligonum ebinuricum N. A. Ivanova ex Soskov were humidified, and the changes of leaf water potential, gas exchange parameters and fluorescence physiological parameters of plants after long-term and short-term FWU were discussed; The main results were as follows: (1) After short-term humidification, the water potential of Calligonum ebinuricum decreased, the non-photochemical quenching (NPQ) increased, and the plant produced photoinhibition phenomenon, indicating that short-term FWU could not alleviate drought stress. (2) After long-term humidification, the leaf water potential, chlorophyll fluorescence parameter and net photosynthetic rate (Pn) increased significantly. That is to say, after long-term FWU, the improvement of plant water status promoted the occurrence of light reaction and carbon reaction, and then increased the net photosynthetic rate (Pn); Therefore, long-term FWU is of great significance to alleviate drought stress and promote Calligonum ebinuricum growth. This study will be helpful to deepen our understanding of the drought-tolerant survival mechanism of plants in arid areas.
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Affiliation(s)
- Huimin Wang
- College of Ecology and the Environmental, Xinjiang University, Urumqi, China
| | - Zhoukang Li
- College of Ecology and the Environmental, Xinjiang University, Urumqi, China
| | - Suwan Ji
- College of Ecology and the Environmental, Xinjiang University, Urumqi, China
| | - Guanghui Lv
- College of Ecology and the Environmental, Xinjiang University, Urumqi, China
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Bahamonde HA, Aranda I, Peri PL, Gyenge J, Fernández V. Leaf wettability, anatomy and ultra-structure of Nothofagus antarctica and N. betuloides grown under a CO 2 enriched atmosphere. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 194:193-201. [PMID: 36427381 DOI: 10.1016/j.plaphy.2022.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/16/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Increasing CO2 air concentration may affect wettability, anatomy and ultra-structure of leaves of Patagonian forest species, evergreen and deciduous plants potentially responding differently to such CO2 increases. In this study, we analysed the wettability, anatomy and ultra-structure of leaves of Nothofagus antarctica (deciduous) and N. betuloides (evergreen) grown under high CO2 concentrations. Leaf wettability was affected by increasing CO2, in different directions depending on species and leaf side. In both species, soluble cuticular lipid concentrations per unit leaf area raised with higher CO2 levels. Stomatal parameters (density, size of guard cells and pores) showed different responses to CO2 increasing depending on the species examined. In both species, leaf tissues showed a general trend to diminish with higher CO2 concentration. Cuticle thickness was modified with higher CO2 concentration in N. betuloides, but not in N. antarctica leaves. In both species, chloroplasts were often damaged with the increase in CO2 concentration. Our results show that several surface and internal leaf parameters can be modified in association with an increase in atmospheric CO2 concentration which may very among plant species.
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Affiliation(s)
- Héctor A Bahamonde
- Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata (UNLP), Av. 60 y 119, La Plata, 1900, Buenos Aires, Argentina
| | - Ismael Aranda
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA CSIC), Centro de Investigación Forestal (ICIFOR), Carretera Coruña Km 7.5, E-28040, Madrid, Spain
| | - Pablo L Peri
- Instituto Nacional de Tecnología Agropecuaria (INTA), Universidad Nacional de la Patagonia Austral (UNPA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CC 332, Río Gallegos, 9400, Santa Cruz, Argentina
| | - Javier Gyenge
- Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, AER Tandil INTA, EEA Balcarce, B7620, Argentina
| | - Victoria Fernández
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
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10
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Kagawa A. Foliar water uptake as a source of hydrogen and oxygen in plant biomass. TREE PHYSIOLOGY 2022; 42:2153-2173. [PMID: 35554604 PMCID: PMC9652008 DOI: 10.1093/treephys/tpac055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/08/2022] [Indexed: 05/11/2023]
Abstract
Introductory biology lessons around the world typically teach that plants absorb water through their roots, but, unfortunately, absorption of water through leaves and subsequent transport and use of this water for biomass formation remains a field limited mostly to specialists. Recent studies have identified foliar water uptake as a significant net water source for terrestrial plants. The growing interest in the development of a new model that includes both foliar water uptake (in liquid form) and root water uptake to explain hydrogen and oxygen isotope ratios in leaf water and tree rings demands a method for distinguishing between these two water sources. Therefore, in this study, I have devised a new labelling method that utilizes two different water sources, one enriched in deuterium (HDO + D2O; δD = 7.0 × 10 4‰, δ18O = 4.1‰) and one enriched in oxygen-18 (H218O; δD = -85‰, δ18O = 1.1 × 104‰), to simultaneously label both foliar-absorbed and root-absorbed water and quantify their relative contributions to plant biomass. Using this new method, I here present evidence that, in the case of well-watered Cryptomeria japonica D. Don, hydrogen and oxygen incorporated into new leaf cellulose in the rainy season derives mostly from foliar-absorbed water (69% from foliar-absorbed water and 31% from root-absorbed water), while that of new root cellulose derives mostly from root-absorbed water (20% from foliar-absorbed water and 80% from root-absorbed water), and new branch xylem is somewhere in between (55% from foliar-absorbed water and 45% from root-absorbed water). The dual-labelling method first implemented in this study enables separate and simultaneous labelling of foliar-absorbed and root-absorbed water and offers a new tool to study the uptake, transport and assimilation processes of these waters in terrestrial plants.
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11
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Gimeno TE, Stangl ZR, Barbeta A, Saavedra N, Wingate L, Devert N, Marshall JD. Water taken up through the bark is detected in the transpiration stream in intact upper-canopy branches. PLANT, CELL & ENVIRONMENT 2022; 45:3219-3232. [PMID: 35922889 DOI: 10.1111/pce.14415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Alternative water uptake pathways through leaves and bark complement water supply with interception, fog or dew. Bark water-uptake contributes to embolism-repair, as demonstrated in cut branches. We tested whether bark water-uptake could also contribute to supplement xylem-water for transpiration. We applied bandages injected with 2 H-enriched water on intact upper-canopy branches of Pinus sylvestris and Fagus sylvatica in a boreal and in a temperate forest, in summer and winter, and monitored transpiration and online isotopic composition (δ2 H and δ18 O) of water vapour, before sampling for analyses of δ2 H and δ18 O in tissue waters. Xylem, bark and leaf waters from segments downstream from the bandages were 2 H-enriched whereas δ18 O was similar to controls. Transpiration was positively correlated with 2 H-enrichment. Isotopic compositions of transpiration and xylem water allowed us to calculate isotopic exchange through the bark via vapour exchange, which was negligible in comparison to estimated bark water-uptake, suggesting that water-uptake occurred via liquid phase. Results were consistent across species, forests and seasons, indicating that bark water-uptake may be more ubiquitous than previously considered. We suggest that water taken up through the bark could be incorporated into the transpiration stream, which could imply that sap-flow measurements underestimate transpiration when bark is wet.
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Affiliation(s)
- Teresa E Gimeno
- CREAF, 08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Basque Centre for Climate Change (BC3), Leioa, Spain
| | - Zsofia R Stangl
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
| | - Adrià Barbeta
- BEECA, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Noelia Saavedra
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
| | | | | | - John D Marshall
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, Sweden
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12
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Grünzweig JM, De Boeck HJ, Rey A, Santos MJ, Adam O, Bahn M, Belnap J, Deckmyn G, Dekker SC, Flores O, Gliksman D, Helman D, Hultine KR, Liu L, Meron E, Michael Y, Sheffer E, Throop HL, Tzuk O, Yakir D. Dryland mechanisms could widely control ecosystem functioning in a drier and warmer world. Nat Ecol Evol 2022; 6:1064-1076. [PMID: 35879539 DOI: 10.1038/s41559-022-01779-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/28/2022] [Indexed: 11/09/2022]
Abstract
Responses of terrestrial ecosystems to climate change have been explored in many regions worldwide. While continued drying and warming may alter process rates and deteriorate the state and performance of ecosystems, it could also lead to more fundamental changes in the mechanisms governing ecosystem functioning. Here we argue that climate change will induce unprecedented shifts in these mechanisms in historically wetter climatic zones, towards mechanisms currently prevalent in dry regions, which we refer to as 'dryland mechanisms'. We discuss 12 dryland mechanisms affecting multiple processes of ecosystem functioning, including vegetation development, water flow, energy budget, carbon and nutrient cycling, plant production and organic matter decomposition. We then examine mostly rare examples of the operation of these mechanisms in non-dryland regions where they have been considered irrelevant at present. Current and future climate trends could force microclimatic conditions across thresholds and lead to the emergence of dryland mechanisms and their increasing control over ecosystem functioning in many biomes on Earth.
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Affiliation(s)
- José M Grünzweig
- Institute of Plant Sciences and Genetics in Agriculture, the Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel.
| | - Hans J De Boeck
- Plants and Ecosystems, Department of Biology, Universiteit Antwerpen, Wilrijk, Belgium
| | - Ana Rey
- Department of Biogeography and Global Change, National Museum of Natural History, Spanish National Research Council (CSIC), Madrid, Spain
| | - Maria J Santos
- Department of Geography, University of Zurich, Zurich, Switzerland
| | - Ori Adam
- The Fredy and Nadine Herrmann Institute of Earth Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Jayne Belnap
- US Geological Survey, Southwest Biological Science Center, Moab, UT, USA
| | - Gaby Deckmyn
- Plants and Ecosystems, Department of Biology, Universiteit Antwerpen, Wilrijk, Belgium
| | - Stefan C Dekker
- Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, the Netherlands
| | - Omar Flores
- Plants and Ecosystems, Department of Biology, Universiteit Antwerpen, Wilrijk, Belgium.,Department of Biogeography and Global Change, National Museum of Natural History, Spanish National Research Council (CSIC), Madrid, Spain
| | - Daniel Gliksman
- Institute for Hydrology and Meteorology, Faculty of Environmental Sciences, Technische Universität Dresden, Tharandt, Germany.,Institute of Geography, Technische Universität Dresden, Dresden, Germany
| | - David Helman
- Institute of Environmental Sciences, the Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel.,Advanced School for Environmental Studies, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ, USA
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, China
| | - Ehud Meron
- Department of Physics, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Israel
| | - Yaron Michael
- Institute of Environmental Sciences, the Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel
| | - Efrat Sheffer
- Institute of Plant Sciences and Genetics in Agriculture, the Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot, Israel
| | - Heather L Throop
- School of Earth and Space Exploration, and School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Omer Tzuk
- Department of Physics, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Department of Industrial Engineering, Faculty of Engineering, Tel-Aviv University, Tel Aviv-Yafo, Israel
| | - Dan Yakir
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
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13
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Abstract
Foliar water uptake (FWU) is a mechanism that enables plants to acquire water from the atmosphere through their leaves. As mangroves live in a saline sediment water environment, the mechanism of FWU might be of vital importance to acquire freshwater and grow. The goal of this study was to assess the FWU capacity of six different mangrove species belonging to four genera using a series of submersion experiments in which the leaf mass increase was measured and expressed per unit leaf area. The foliar water uptake capacity differed between species with the highest and lowest average water uptake in Avicennia marina (Forssk.) Vierh. (1.52 ± 0.48 mg H2O cm−2) and Bruguiera gymnorhiza (L.) Lam. (0.13 ± 0.06 mg H2O cm−2), respectively. Salt-excreting species showed a higher FWU capacity than non-excreting species. Moreover, A. marina, a salt-excreting species, showed a distinct leaf anatomical trait, i.e., trichomes, which were not observed in the other species and might be involved in the water absorption process. The storage of leaves in moist Ziplock bags prior to measurement caused leaf water uptake to already occur during transport to the field station, which proportionately increased the leaf water potential (A. marina: −0.31 ± 0.13 MPa and B. gymnorhiza: −2.70 ± 0.27 MPa). This increase should be considered when performing best practice leaf water potential measurements but did not affect the quantification of FWU capacity because of the water potential gradient between a leaf and the surrounding water during submersion. Our results highlight the differences that exist in FWU capacity between species residing in the same area and growing under the same environmental conditions. This comparative study therefore enhances our understanding of mangrove species’ functioning.
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14
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Chin ARO, Guzmán‐Delgado P, Sillett SC, Orozco J, Kramer RD, Kerhoulas LP, Moore ZJ, Reed M, Zwieniecki MA. Shoot dimorphism enables Sequoia sempervirens to separate requirements for foliar water uptake and photosynthesis. AMERICAN JOURNAL OF BOTANY 2022; 109:564-579. [PMID: 35274309 PMCID: PMC9322557 DOI: 10.1002/ajb2.1841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 05/11/2023]
Abstract
PREMISE Trees in wet forests often have features that prevent water films from covering stomata and inhibiting gas exchange, while many trees in drier environments use foliar water uptake to reduce water stress. In forests with both wet and dry seasons, evergreen trees would benefit from producing leaves capable of balancing rainy-season photosynthesis with summertime water absorption. METHODS Using samples collected from across the vertical gradient in tall redwood (Sequoia sempervirens) crowns, we estimated tree-level foliar water uptake and employed physics-based causative modeling to identify key functional traits that determine uptake potential by setting hydraulic resistance. RESULTS We showed that Sequoia has two functionally distinct shoot morphotypes. While most shoots specialize in photosynthesis, the axial shoot type is capable of much greater foliar water uptake, and its within-crown distribution varies with latitude. A suite of leaf surface traits cause hydraulic resistance, leading to variation in uptake capacity among samples. CONCLUSIONS Shoot dimorphism gives tall Sequoia trees the capacity to absorb up to 48 kg H2 O h-1 during the first hour of leaf wetting, ameliorating water stress while presumably maintaining high photosynthetic capacity year round. Geographic variation in shoot dimorphism suggests that plasticity in shoot-type distribution and leaf surface traits helps Sequoia maintain a dominate presence in both wet and dry forests.
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Affiliation(s)
- Alana R. O. Chin
- Plant Sciences DepartmentUniversity of California DavisDavisCA95616USA
- Present address:
Alana R. O. Chin, D‐USYS, ETHZürich8092Switzerland
| | | | - Stephen C. Sillett
- Department of Forestry and Wildland ResourcesHumboldt State UniversityArcataCA95521USA
| | - Jessica Orozco
- Plant Sciences DepartmentUniversity of California DavisDavisCA95616USA
| | | | - Lucy P. Kerhoulas
- Department of Forestry and Wildland ResourcesHumboldt State UniversityArcataCA95521USA
| | - Zane J. Moore
- Plant Sciences DepartmentUniversity of California DavisDavisCA95616USA
| | - Marty Reed
- Department of Biological SciencesHumboldt State UniversityArcataCA95521USA
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15
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Binks O, Cernusak LA, Liddell M, Bradford M, Coughlin I, Carle H, Bryant C, Dunn E, Oliveira R, Mencuccini M, Meir P. Forest system hydraulic conductance: partitioning tree and soil components. THE NEW PHYTOLOGIST 2022; 233:1667-1681. [PMID: 34861052 DOI: 10.1111/nph.17895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/23/2021] [Indexed: 06/13/2023]
Abstract
Soil-leaf hydraulic conductance determines canopy-atmosphere coupling in vegetation models, but it is typically derived from ex-situ measurements of stem segments and soil samples. Using a novel approach, we derive robust in-situ estimates for whole-tree conductance (ktree ), 'functional' soil conductance (ksoil ), and 'system' conductance (ksystem , water table to canopy), at two climatically different tropical rainforest sites. Hydraulic 'functional rooting depth', determined for each tree using profiles of soil water potential (Ψsoil ) and sap flux data, enabled a robust determination of ktree and ksoil . ktree was compared across species, size classes, seasons, height above nearest drainage (HAND), two field sites, and to alternative representations of ktree ; ksoil was analysed with respect to variations in site, season and HAND. ktree was lower and changed seasonally at the site with higher vapour pressure deficit (VPD) and rainfall; ktree differed little across species but scaled with tree circumference; rsoil (1/ksoil ) ranged from 0 in the wet season to 10× less than rtree (1/ktree ) in the dry season. VPD and not rainfall may influence plot-level k; leaf water potentials and sap flux can be used to determine ktree , ksoil and ksystem ; Ψsoil profiles can provide mechanistic insights into ecosystem-level water fluxes.
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Affiliation(s)
- Oliver Binks
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Lucas A Cernusak
- Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Qld, 4878, Australia
| | - Michael Liddell
- Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Qld, 4878, Australia
| | - Matt Bradford
- CSIRO Land and Water, Atherton, Qld, 4883, Australia
| | - Ingrid Coughlin
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Hannah Carle
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Callum Bryant
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Elliot Dunn
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Rafael Oliveira
- Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, Sao Paulo, 13083-970, Brazil
| | | | - Patrick Meir
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3FF, UK
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16
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Bryant C, Fuenzalida TI, Zavafer A, Nguyen HT, Brothers N, Harris RJ, Beckett HAA, Holmlund HI, Binks O, Ball MC. Foliar water uptake via cork warts in mangroves of the Sonneratia genus. PLANT, CELL & ENVIRONMENT 2021; 44:2925-2937. [PMID: 34118083 DOI: 10.1111/pce.14129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 06/12/2023]
Abstract
Foliar water uptake (FWU) occurs in plants of diverse ecosystems; however, the diversity of pathways and their associated FWU kinetics remain poorly resolved. We characterized a novel FWU pathway in two mangrove species of the Sonneratia genus, S. alba and S. caseolaris. Further, we assessed the influence of leaf wetting duration, wet-dry seasonality and leaf dehydration on leaf conductance to surface water (Ksurf ). The symplastic tracer dye, disodium fluorescein, revealed living cells subtending and encircling leaf epidermal structures known as cork warts as a pathway of FWU entry into the leaf. Rehydration kinetics experiments revealed a novel mode of FWU, with slow and steady rates of water uptake persistent over a duration of 12 hr. Ksurf increased with longer durations of leaf wetting and was greater in leaves with more negative water potentials at the initiation of leaf wetting. Ksurf declined by 68% between wet and dry seasons. Our results suggest that FWU via cork warts in Sonneratia sp. may be rate limited and under active regulation. We conclude that FWU pathways in halophytes may require ion exclusion to avoid uptake of salt when inundated, paralleling the capacity of halophyte roots for ion selectivity during water acquisition.
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Affiliation(s)
- Callum Bryant
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Tomas I Fuenzalida
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Alonso Zavafer
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Hoa T Nguyen
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
- Vietnam National University of Agriculture, Trau Quy, Gia Lam, Ha Noi, Vietnam
| | - Nigel Brothers
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Rosalie J Harris
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Holly A A Beckett
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Helen I Holmlund
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
- Pepperdine University, Natural Science Division, Malibu, CA, 90263, USA
| | - Oliver Binks
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
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17
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Xu X, Konings AG, Longo M, Feldman A, Xu L, Saatchi S, Wu D, Wu J, Moorcroft P. Leaf surface water, not plant water stress, drives diurnal variation in tropical forest canopy water content. THE NEW PHYTOLOGIST 2021; 231:122-136. [PMID: 33539544 DOI: 10.1111/nph.17254] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/27/2021] [Indexed: 05/25/2023]
Abstract
Variation in canopy water content (CWC) that can be detected from microwave remote sensing of vegetation optical depth (VOD) has been proposed as an important measure of vegetation water stress. However, the contribution of leaf surface water (LWs ), arising from dew formation and rainfall interception, to CWC is largely unknown, particularly in tropical forests and other high-humidity ecosystems. We compared VOD data from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) and CWC predicted by a plant hydrodynamics model at four tropical sites in Brazil spanning a rainfall gradient. We assessed how LWs influenced the relationship between VOD and CWC. The analysis indicates that while CWC is strongly correlated with VOD (R2 = 0.62 across all sites), LWs accounts for 61-76% of the diurnal variation in CWC despite being < 10% of CWC. Ignoring LWs weakens the near-linear relationship between CWC and VOD and reduces the consistency in diurnal variation. The contribution of LWs to CWC variation, however, decreases at longer, seasonal to inter-annual, time scales. Our results demonstrate that diurnal patterns of dew formation and rainfall interception can be an important driver of diurnal variation in CWC and VOD over tropical ecosystems and therefore should be accounted for when inferring plant diurnal water stress from VOD measurements.
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Affiliation(s)
- Xiangtao Xu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| | - Alexandra G Konings
- Department of Earth System Science, Stanford University, Stanford, CA, 94305, USA
| | - Marcos Longo
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Andrew Feldman
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Liang Xu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Sassan Saatchi
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
- Institute of Environment and Sustainability, University of California, Los Angeles, CA, 90024, USA
| | - Donghai Wu
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| | - Jin Wu
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Paul Moorcroft
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
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18
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Hill AJ, Dawson TE, Dody A, Rachmilevitch S. Dew water-uptake pathways in Negev desert plants: a study using stable isotope tracers. Oecologia 2021; 196:353-361. [PMID: 34008141 DOI: 10.1007/s00442-021-04940-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 05/08/2021] [Indexed: 10/21/2022]
Abstract
Dew is an important water resource for plants in most deserts. The mechanism that allows desert plants to use dew water was studied using an isotopic water tracer approach. Most plants use water directly from the soil; the roots transfer the water to the rest of the plant, where it is required for all metabolic functions. However, many plants can also take up water into their leaves and stems. Examining the dew water uptake pathways in desert plants can lend insight on another all water-use pathways examination. We determined where and how dew water enters plants in the water limited Negev desert. Highly depleted isotopic water was sprayed on three different dominant plant species of the Negev desert-Artemesia sieberi, Salsola inermis and Haloxylon scoparium-and its entry into the plant was followed. Water was sprayed onto the soil only, or on the leaves/stems only (with soil covered to prevent water entry via root uptake). Thereafter, the isotopic composition of water in the roots and stems were measured at various time points. The results show that each plant species used the dew water to a different extent, and we obtained evidence of foliar uptake capacity of dew water that varied depending on the microenvironmental conditions. A. sieberi took up the greatest amount of dew water through both stems and roots, S. inermis took up dew water mainly from the roots, and H. scoparium showed the least dew capture overall.
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Affiliation(s)
- Amber J Hill
- The Jacob Blaustein Institutes for Desert Research, Sede Boqer Campus Midreshet Ben Gurion, Ben Gurion University of the Negev, 84990, Beersheba, Israel.
| | - Todd E Dawson
- Center for Stable Isotope Biogeochemistry and the Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
| | - Avraham Dody
- Geography and Environmental Developing Department, Ben Gurion University, BeerSheba, Israel
| | - Shimon Rachmilevitch
- The Jacob Blaustein Institutes for Desert Research, Sede Boqer Campus Midreshet Ben Gurion, Ben Gurion University of the Negev, 84990, Beersheba, Israel
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19
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Oliveira RS, Eller CB, Barros FDV, Hirota M, Brum M, Bittencourt P. Linking plant hydraulics and the fast-slow continuum to understand resilience to drought in tropical ecosystems. THE NEW PHYTOLOGIST 2021; 230:904-923. [PMID: 33570772 DOI: 10.1111/nph.17266] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 12/11/2020] [Indexed: 05/12/2023]
Abstract
Tropical ecosystems have the highest levels of biodiversity, cycle more water and absorb more carbon than any other terrestrial ecosystem on Earth. Consequently, these ecosystems are extremely important components of Earth's climatic system and biogeochemical cycles. Plant hydraulics is an essential discipline to understand and predict the dynamics of tropical vegetation in scenarios of changing water availability. Using published plant hydraulic data we show that the trade-off between drought avoidance (expressed as deep-rooting, deciduousness and capacitance) and hydraulic safety (P50 - the water potential when plants lose 50% of their maximum hydraulic conductivity) is a major axis of physiological variation across tropical ecosystems. We also propose a novel and independent axis of hydraulic trait variation linking vulnerability to hydraulic failure (expressed as the hydraulic safety margin (HSM)) and growth, where inherent fast-growing plants have lower HSM compared to slow-growing plants. We surmise that soil nutrients are fundamental drivers of tropical community assembly determining the distribution and abundance of the slow-safe/fast-risky strategies. We conclude showing that including either the growth-HSM or the resistance-avoidance trade-off in models can make simulated tropical rainforest communities substantially more vulnerable to drought than similar communities without the trade-off. These results suggest that vegetation models need to represent hydraulic trade-off axes to accurately project the functioning and distribution of tropical ecosystems.
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Affiliation(s)
- Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, Campinas, SP, 13083-970, Brazil
| | - Cleiton B Eller
- Department of Plant Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, Campinas, SP, 13083-970, Brazil
| | - Fernanda de V Barros
- Department of Plant Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, Campinas, SP, 13083-970, Brazil
- Department of Geography, University of Exeter, Exeter, EX4 4QE, UK
| | - Marina Hirota
- Department of Plant Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, Campinas, SP, 13083-970, Brazil
- Department of Physics, Federal University of Santa Catarina, Florianópolis, SC, 88040-900, Brazil
| | - Mauro Brum
- Department of Plant Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, Campinas, SP, 13083-970, Brazil
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Paulo Bittencourt
- Department of Plant Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, Campinas, SP, 13083-970, Brazil
- Department of Geography, University of Exeter, Exeter, EX4 4QE, UK
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20
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Li X, Zhang C, Zhang B, Wu D, Zhu D, Zhang W, Ye Q, Yan J, Fu J, Fang C, Ha D, Fu S. Nitrogen deposition and increased precipitation interact to affect fine root production and biomass in a temperate forest: Implications for carbon cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:144497. [PMID: 33418324 DOI: 10.1016/j.scitotenv.2020.144497] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/06/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Fine roots connect belowground and aboveground systems and help regulate the carbon balance of terrestrial ecosystems by providing nutrients and water for plants. To evaluate the effects of atmospheric nitrogen (N) deposition and increased precipitation on fine root production and standing biomass in a temperate deciduous forest in central China, we conducted a 6-year experiment. From 2013 to 2018, we applied N (25 kg N ha-1 yr-1) and water (336 mm, 30% of the ambient annual precipitation) above the forest canopy, and we quantified fine root production and biomass in 2017 and 2018. At 0-10 cm soil depth, the statistical interaction between addition of N and water was not significant in terms of fine root production or biomass. At 0-10 cm soil depth, N addition significantly increased fine root production by 18.1%, but did not affect fine root biomass. Water addition significantly increased fine root production and biomass by 13.6 and 17.0%, respectively. Both N and water addition had significant direct positive effects on fine root production, and water addition had indirect positive effects on fine root biomass through decreasing soil NO3- concentration. At 10-30 cm soil depth, the statistical interaction between N addition and water addition was significant in terms of both fine root production and biomass, i.e., the positive effect of N addition was reduced by water addition, and vice versa. These findings indicate that fine roots and therefore belowground carbon storage may have complex responses to increases in atmospheric N deposition and changes in precipitation predicted for the future. The findings also suggest that results obtained from experiments that consider only one independent variable (e.g., N input or water input) and only one soil depth should be interpreted with caution.
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Affiliation(s)
- Xiaowei Li
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China
| | - Chenlu Zhang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China.
| | - Beibei Zhang
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Di Wu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Dandan Zhu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China
| | - Wei Zhang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Juemin Fu
- Jigongshan National Nature Reserve, Xinyang 464039, China
| | | | - Denglong Ha
- Jigongshan National Nature Reserve, Xinyang 464039, China
| | - Shenglei Fu
- Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Environment and Planning, Henan University, Kaifeng 475004, China; Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security, Henan University, Kaifeng 475004, China
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21
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Britto de Assis Prado CH, de Brito Melo Trovão DM, Souza JP. A network model for determining decomposition, topology, and properties of the woody crown. J Theor Biol 2020; 499:110318. [DOI: 10.1016/j.jtbi.2020.110318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/17/2020] [Accepted: 05/04/2020] [Indexed: 11/24/2022]
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22
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Vega C, González G, Bahamonde HA, Valbuena-Carabaña M, Gil L, Fernández V. Effect of irradiation and canopy position on anatomical and physiological features of Fagus sylvatica and Quercus petraea leaves. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 152:232-242. [PMID: 32449682 DOI: 10.1016/j.plaphy.2020.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/07/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
Growing conditions at different tree canopy positions may significantly vary and lead to foliar changes even within the same tree. An assessment of foliar anatomy, including also epidermal features, can help us understand how plants respond to environmental factors. Working with two model tree species (i.e., Quercus petraea and Fagus sylvatica) grown at their southernmost European distribution area in Central Spain, the influence of irradiation and canopy height was examined by sampling lower canopy leaves and comparing them with fully irradiated, top canopy leaves and shaded top canopy leaves grown for months within a bag made of shade netting fabric before they sprouted. At the end of the summer, samples were collected, and several parameters were analysed. The results indicate that SLA (specific leaf area) differences are significant both between species and groups. Leaf and cuticle thickness differed significantly between groups while stomatal densities only between species. Regarding mineral concentrations, differences between species were significant for K, Mn, N and N: P ratios. It is concluded that leaf responses to environmental conditions may be variable both within the same tree and between species.
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Affiliation(s)
- Clara Vega
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Guillermo González
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Héctor A Bahamonde
- Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Diagonal 113 Nº 469, 1900, La Plata, Argentina
| | - María Valbuena-Carabaña
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Gil
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Victoria Fernández
- Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid (UPM), Ciudad Universitaria s/n, 28040, Madrid, Spain.
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23
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Bittencourt PRL, Oliveira RS, da Costa ACL, Giles AL, Coughlin I, Costa PB, Bartholomew DC, Ferreira LV, Vasconcelos SS, Barros FV, Junior JAS, Oliveira AAR, Mencuccini M, Meir P, Rowland L. Amazonia trees have limited capacity to acclimate plant hydraulic properties in response to long-term drought. GLOBAL CHANGE BIOLOGY 2020; 26:3569-3584. [PMID: 32061003 DOI: 10.1111/gcb.15040] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/30/2019] [Accepted: 02/02/2020] [Indexed: 05/29/2023]
Abstract
The fate of tropical forests under future climate change is dependent on the capacity of their trees to adjust to drier conditions. The capacity of trees to withstand drought is likely to be determined by traits associated with their hydraulic systems. However, data on whether tropical trees can adjust hydraulic traits when experiencing drought remain rare. We measured plant hydraulic traits (e.g. hydraulic conductivity and embolism resistance) and plant hydraulic system status (e.g. leaf water potential, native embolism and safety margin) on >150 trees from 12 genera (36 species) and spanning a stem size range from 14 to 68 cm diameter at breast height at the world's only long-running tropical forest drought experiment. Hydraulic traits showed no adjustment following 15 years of experimentally imposed moisture deficit. This failure to adjust resulted in these drought-stressed trees experiencing significantly lower leaf water potentials, and higher, but variable, levels of native embolism in the branches. This result suggests that hydraulic damage caused by elevated levels of embolism is likely to be one of the key drivers of drought-induced mortality following long-term soil moisture deficit. We demonstrate that some hydraulic traits changed with tree size, however, the direction and magnitude of the change was controlled by taxonomic identity. Our results suggest that Amazonian trees, both small and large, have limited capacity to acclimate their hydraulic systems to future droughts, potentially making them more at risk of drought-induced mortality.
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Affiliation(s)
- Paulo R L Bittencourt
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Rafael S Oliveira
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
- Biological Sciences, UWA, Perth, WA, Australia
| | | | - Andre L Giles
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Ingrid Coughlin
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Patricia B Costa
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
- Biological Sciences, UWA, Perth, WA, Australia
| | - David C Bartholomew
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | | | - Fernanda V Barros
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Joao A S Junior
- Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | | | | | - Patrick Meir
- Research School of Biology, Australian National University, Canberra, ACT, Australia
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Lucy Rowland
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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24
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Schreel JDM, Steppe K. Foliar Water Uptake in Trees: Negligible or Necessary? TRENDS IN PLANT SCIENCE 2020; 25:590-603. [PMID: 32407698 DOI: 10.1016/j.tplants.2020.01.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 01/06/2020] [Accepted: 01/15/2020] [Indexed: 06/11/2023]
Abstract
Foliar water uptake (FWU) has been identified as a mechanism commonly used by trees and other plants originating from various biomes. However, many questions regarding the pathways and the implications of FWU remain, including its ability to mitigate climate change-driven drought. Therefore, answering these questions is of primary importance to adequately address and comprehend drought stress responses and associated growth. In this review, we discuss the occurrence, pathways, and consequences of FWU, with a focus predominantly on tree species. Subsequently, we highlight the tight coupling between FWU and foliar fertilizer applications, discuss FWU in a changing climate, and conclude with the importance of including FWU in mechanistic vegetation models.
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Affiliation(s)
- Jeroen D M Schreel
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium.
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium.
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25
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Wu J, Serbin SP, Ely KS, Wolfe BT, Dickman LT, Grossiord C, Michaletz ST, Collins AD, Detto M, McDowell NG, Wright SJ, Rogers A. The response of stomatal conductance to seasonal drought in tropical forests. GLOBAL CHANGE BIOLOGY 2020; 26:823-839. [PMID: 31482618 DOI: 10.1111/gcb.14820] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 08/20/2019] [Indexed: 05/27/2023]
Abstract
Stomata regulate CO2 uptake for photosynthesis and water loss through transpiration. The approaches used to represent stomatal conductance (gs ) in models vary. In particular, current understanding of drivers of the variation in a key parameter in those models, the slope parameter (i.e. a measure of intrinsic plant water-use-efficiency), is still limited, particularly in the tropics. Here we collected diurnal measurements of leaf gas exchange and leaf water potential (Ψleaf ), and a suite of plant traits from the upper canopy of 15 tropical trees in two contrasting Panamanian forests throughout the dry season of the 2016 El Niño. The plant traits included wood density, leaf-mass-per-area (LMA), leaf carboxylation capacity (Vc,max ), leaf water content, the degree of isohydry, and predawn Ψleaf . We first investigated how the choice of four commonly used leaf-level gs models with and without the inclusion of Ψleaf as an additional predictor variable influence the ability to predict gs , and then explored the abiotic (i.e. month, site-month interaction) and biotic (i.e. tree-species-specific characteristics) drivers of slope parameter variation. Our results show that the inclusion of Ψleaf did not improve model performance and that the models that represent the response of gs to vapor pressure deficit performed better than corresponding models that respond to relative humidity. Within each gs model, we found large variation in the slope parameter, and this variation was attributable to the biotic driver, rather than abiotic drivers. We further investigated potential relationships between the slope parameter and the six available plant traits mentioned above, and found that only one trait, LMA, had a significant correlation with the slope parameter (R2 = 0.66, n = 15), highlighting a potential path towards improved model parameterization. This study advances understanding of gs dynamics over seasonal drought, and identifies a practical, trait-based approach to improve modeling of carbon and water exchange in tropical forests.
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Affiliation(s)
- Jin Wu
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong
| | - Shawn P Serbin
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Kim S Ely
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Brett T Wolfe
- Smithsonian Tropical Research Institute, Apartado, Panama
| | - L Turin Dickman
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Charlotte Grossiord
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Sean T Michaletz
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Adam D Collins
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Matteo Detto
- Smithsonian Tropical Research Institute, Apartado, Panama
- Ecology and Evolutionary Biology Department, Princeton University, Princeton, NJ, USA
| | - Nate G McDowell
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | | | - Alistair Rogers
- Environmental & Climate Sciences Department, Brookhaven National Laboratory, Upton, NY, USA
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