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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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Wang HC, Huang CY. Cross-scale assessments of the impacts and resilience of subtropical montane cloud forests to chronic seasonal droughts and episodic typhoons. GLOBAL CHANGE BIOLOGY 2024; 30:e17000. [PMID: 37905471 DOI: 10.1111/gcb.17000] [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: 05/25/2023] [Revised: 09/28/2023] [Accepted: 10/02/2023] [Indexed: 11/02/2023]
Abstract
Montane cloud forests (MCFs) are ecosystems frequently immersed in fog and are vital for the terrestrial hydrological cycle and biodiversity hotspots. However, the potential impacts of climate change, particularly intensified droughts and typhoons, on the persistence of ecosystems remain unclear. Our study conducted cross-scale assessments using 6-year (2016-2021) ground litterfall and 21-year (2001-2021) satellite greenness data (the Enhanced Vegetation Index [EVI] and the EVI anomaly change [ΔEVI% ]), gross primary productivity anomaly change (ΔGPP% ), and meteorological variables (the standardized precipitation index [SPI] and wind speed). We found a positive correlation between summer EVI and ΔGPP% with the SPI-3 (3-month time scale), while winter litterfall showed a negative correlation. Maximum typhoon daily wind speed was negatively correlated with summer and the monthly ΔEVI% and ΔGPP% . These findings suggest vegetation damage and productivity loss were related to drought and typhoon intensities. Furthermore, our analysis highlighted that chronic seasonal droughts had more pronounced impacts on MCFs than severe typhoons, implying that high precipitation and frequent fog immersion do not necessarily mitigate the ramifications of water deficit on MCFs but might render MCFs more sensitive and vulnerable to drought. A significant negative correlation between the summer and winter ΔEVI% and ΔGPP% of the same year, suggesting disturbance severity during summer may facilitate vegetation regrowth and carbon accumulation in the subsequent winter. This finding may be attributed to the ecological resilience of MCFs, which enables them to recover from the previous summer. In the long-term, our results indicated an increase in vegetation resilience over two decades in MCFs, likely driven by rising temperatures and elevated carbon dioxide levels. However, the enhancement of resilience might be overshadowed by the potential intensified droughts and typhoons in the future, potentially causing severe damage and insufficient recovery times for MCFs, thus raising concerns about uncertainties regarding their sustained resilience.
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Affiliation(s)
- Hsueh-Ching Wang
- Department of Earth and Life Science, University of Taipei, Taipei, Taiwan
| | - Cho-Ying Huang
- Department of Geography, National Taiwan University, Taipei, Taiwan
- Research Center for Future Earth, National Taiwan University, Taipei, Taiwan
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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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Bravo-Avila CH, Feeley KJ. Variation in the Drought Tolerance of Tropical Understory Plant Communities across an Extreme Elevation and Precipitation Gradient. PLANTS (BASEL, SWITZERLAND) 2023; 12:2957. [PMID: 37631168 PMCID: PMC10459884 DOI: 10.3390/plants12162957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/20/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023]
Abstract
Little is known about how differences in water availability within the "super humid" tropics can influence the physiology of understory plant species and the composition of understory plant communities. We investigated the variation in the physiological drought tolerances of hundreds of understory plants in dozens of plant communities across an extreme elevation and precipitation gradient. Specifically, we established 58 understory plots along a gradient of 400-3600 m asl elevation and 1000-6000 mm yr-1 rainfall in and around Manu National Park in southeastern Peru. Within the plots, we sampled all understory woody plants and measured three metrics of physiological leaf drought tolerance-turgor loss point (TLP), cuticular conductance (Gmin), and solute leakage (SL)-and assessed how the community-level means of these three traits related to the mean annual precipitation (MAP) and elevation (along the study gradient, the temperature decreases linearly, and the vapor pressure deficit increases monotonically with elevation). We did not find any correlations between the three metrics of leaf drought tolerance, suggesting that they represent independent strategies for coping with a low water availability. Despite being widely used metrics of leaf drought tolerance, neither the TLP nor Gmin showed any significant relationships with elevation or the MAP. In contrast, SL, which has only recently been developed for use in ecological field studies, increased significantly at higher precipitations and at lower elevations (i.e., plants in colder and drier habitats have a lower average SL, indicating greater drought tolerances). Our results illustrate that differences in water availability may affect the physiology of tropical montane plants and thus play a strong role in structuring plant communities even in the super humid tropics. Our results also highlight the potential for SL assays to be efficient and effective tools for measuring drought tolerances in the field.
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Affiliation(s)
| | - Kenneth J. Feeley
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
- Fairchild Tropical Botanical Garden, Coral Gables, FL 33156, USA
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Mata-Guel EO, Soh MCK, Butler CW, Morris RJ, Razgour O, Peh KSH. Impacts of anthropogenic climate change on tropical montane forests: an appraisal of the evidence. Biol Rev Camb Philos Soc 2023; 98:1200-1224. [PMID: 36990691 DOI: 10.1111/brv.12950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/31/2023]
Abstract
In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects. Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.
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Affiliation(s)
- Erik O Mata-Guel
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Malcolm C K Soh
- National Park Boards, 1 Cluny Road, Singapore, 259569, Singapore
| | - Connor W Butler
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Rebecca J Morris
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Orly Razgour
- Biosciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Kelvin S-H Peh
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
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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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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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Fan X, Hao X, Zhang S, Zhao Z, Zhang J, Li Y. Populus euphratica counteracts drought stress through the dew coupling and root hydraulic redistribution processes. ANNALS OF BOTANY 2023; 131:451-461. [PMID: 36624896 PMCID: PMC10072085 DOI: 10.1093/aob/mcac159] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND In arid and semi-arid areas, plants can directly absorb and use dew through their leaves, and some plants have the ability for hydraulic redistribution of their roots. Therefore, in arid areas, plants may redistribute dew to the soil, using the soil as a reservoir for short-term dry seasons, i.e. dew may participate in the hydraulic redistribution process of plants. This process plays an important role in plant survival and community stability. METHODS To verify this hypothesis, we investigated the water use mechanism of Populus euphratica through a comprehensive observation of sap flow, water potential and soil water content using a heavy water tracer experiment under in situ field conditions. RESULTS AND DISCUSSION Dewdrops contributed 28.3 % of soil moisture near the roots, and applying dew on leaves for several days significantly improved soil moisture status. Hydraulic redistribution in the roots mainly occurred from 2200 h at night to 800 h the following day and mainly occurred in the 20- to 80-cm soil layer. Water storage in the trunk is the intermediate link in the coupling process of foliar water uptake and hydraulic redistribution; water storage in the trunk is mainly replenished from May to July and consumed throughout the rest of the year. In conclusion, dew redistributes water into soil through the coupling process of foliar water uptake and hydraulic redistribution. Populus euphratica uses the trunk and soil for water storage to cope with water stress during short-term drought periods. Our findings provide a scientific basis for the restoration of different species in water-deficient areas, which is conducive to maintaining vegetation ecosystem stability in areas of desertification and improving the soil water balance.
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Affiliation(s)
- Xue Fan
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Akesu National Station of Observation and Research for Oasis Agro-ecosystem, Akesu 843017, Xinjiang, China
| | - Xingming Hao
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- Akesu National Station of Observation and Research for Oasis Agro-ecosystem, Akesu 843017, Xinjiang, China
| | - Sen Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Akesu National Station of Observation and Research for Oasis Agro-ecosystem, Akesu 843017, Xinjiang, China
| | - Zhuoyi Zhao
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Akesu National Station of Observation and Research for Oasis Agro-ecosystem, Akesu 843017, Xinjiang, China
| | - Jingjing Zhang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Akesu National Station of Observation and Research for Oasis Agro-ecosystem, Akesu 843017, Xinjiang, China
| | - Yuanhang Li
- College of Life Sciences, Xinjiang Normal University, Urumqi 830054, China
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10
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Lima JF, Boanares D, Costa VE, Moreira ASFP. Do photosynthetic metabolism and habitat influence foliar water uptake in orchids? PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:257-267. [PMID: 36546714 DOI: 10.1111/plb.13499] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
Epiphytic and rupicolous plants inhabit environments with limited water resources. Such plants commonly use Crassulacean Acid Metabolism (CAM), a photosynthetic pathway that accumulates organic acids in cell vacuoles at night, so reducing their leaf water potential and favouring water absorption. Foliar water uptake (FWU) aids plant survival during drought events in environments with high water deficits. We hypothesized that FWU represents a strategy employed by epiphytic and rupicolous orchids for water acquisition and that CAM will favour increased water absorption. We examined 6 epiphyte, 4 terrestrial and 6 rupicolous orchids that use C3 (n = 9) or CAM (n = 7) pathways. Five individuals per species were used to evaluate FWU, structural characteristics and leaf water balance. Rupicolous species with C3 metabolism had higher FWU than other species. FWU (Cmax and k) could be related to succulence, SLM and leaf RWC. The results indicated that high orchid leaf densities favoured FWU, as area available for water storage increases with leaf density. Structural characteristics linked to water storage (e.g. high RWC, succulence), on the other hand, could limit leaf water absorption by favouring high internal leaf water potentials. Epiphytic, rupicolous and terrestrial orchids showed FWU. Rupicolous species had high levels of FWU, probably through absorption from mist. However, succulence in plants with CAM appears to mitigate FWU.
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Affiliation(s)
- J F Lima
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlândia, Brazil
| | - D Boanares
- Instituto Tecnológico Vale, Desenvolvimento Sustentável, Belém, Brazil
| | - V E Costa
- Instituto de Biociências, Centro de Isótopos Estáveis Prof. Dr. Carlos Ducatti, Botucatu, Brazil
| | - A S F P Moreira
- Instituto de Biologia, Universidade Federal de Uberlândia, Uberlândia, Brazil
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11
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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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12
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Hu T, Liu WY, Wen HD, Song L, Zhang TT, Chen Q, Liu S. Vascular epiphyte populations with higher leaf nutrient concentrations showed weaker resilience to an extreme drought in a montane cloud forest. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:215-225. [PMID: 36208062 DOI: 10.1111/plb.13474] [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: 06/22/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Leaf stoichiometry can characterize plant ecological strategies and correlate with plant responses to climate change. The role of vascular epiphytes in the ecosystem processes of tropical and subtropical forest ecosystems cannot be ignored. Vascular epiphytes are very vulnerable to climate change, however, the relationship between the response of epiphytes to climate change and leaf stoichiometry is not well understood. We present data for 19 vascular epiphyte species that were collected during four consecutive censuses (in 2005, 2010, 2015, and 2020) over 15 years in a subtropical montane cloud forest. We assessed the relationships between the population dynamics and leaf stoichiometry of these vascular epiphytes. Experiencing an extreme drought, 14 of the 19 epiphyte species showed an obvious decrease in the number of individuals, and all species showed negative growth in the number of populations. Subsequently, the total number of individuals gradually recovered, increasing from 7,195 in 2010 to 10,121 in 2015, then to 13,667 in 2020. The increase in the number of vascular epiphyte individuals from 2010 to 2015 was significantly negatively correlated with leaf nitrogen and phosphorus concentration, and was significantly positively correlated with the leaf carbon-nitrogen ratio. Vascular epiphyte populations with higher leaf nutrient concentrations exhibited weaker resilience to the extreme drought, which demonstrated that a resource-conservative strategy was advantageous for the recovery of epiphyte populations. Our findings suggest that ecological stoichiometry can be a useful framework for forecasting the dynamics of vascular epiphyte populations in response to climate change.
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Affiliation(s)
- T Hu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - W Y Liu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China
- Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Xishuangbanna, China
| | - H D Wen
- National Field Scientific Observation and Research Station of Forest Ecosystem in Ailao Mountain, Yunnan, China
| | - L Song
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China
- Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Xishuangbanna, China
| | - T T Zhang
- Henna University of Urban Construction, Pingdingshan, China
| | - Q Chen
- Life Sciences Institute, Guangxi Medical University, Nanning, China
| | - S Liu
- College of Life Sciences, Anhui Normal University, Wuhu, China
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13
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Tredenick EC, Stuart-Williams H, Enge TG. Materials on Plant Leaf Surfaces Are Deliquescent in a Variety of Environments. FRONTIERS IN PLANT SCIENCE 2022; 13:722710. [PMID: 35903227 PMCID: PMC9315345 DOI: 10.3389/fpls.2022.722710] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Materials on plant leaf surfaces that attract water impact penetration of foliar-applied agrochemicals, foliar water uptake, gas exchange, and stomatal density. Few studies are available on the nature of these substances, and we quantify the hygroscopicity of these materials. Water vapor sorption experiments on twelve leaf washes of sample leaves were conducted and analyzed with inductively coupled plasma-optical emission spectroscopy (ICP-OES) and X-ray diffraction. All leaf surface materials studied were hygroscopic. Oils were found on the surface of the Eucalyptus studied. For mangroves that excrete salt to the leaf surfaces, significant sorption occurred at high humidity of a total of 316 mg (~0.3 ml) over 6-10 leaves and fitted a Guggenheim, Anderson, and de Böer sorption isotherm. Materials on the plant leaf surface can deliquesce and form an aqueous solution in a variety of environments where plants grow, including glasshouses and by the ocean, which is an important factor when considering plant-atmosphere relations.
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Affiliation(s)
- E. C. Tredenick
- Division of Plant Sciences, ARC Centre of Excellence in Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - H. Stuart-Williams
- Division of Plant Sciences, ARC Centre of Excellence in Translational Photosynthesis, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - T. G. Enge
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
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14
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The Morpho-Physio-Biochemical Attributes of Urban Trees for Resilience in Regional Ecosystems in Cities: A Mini-Review. URBAN SCIENCE 2022. [DOI: 10.3390/urbansci6020037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Increased urbanization means human beings become the dominant species and reduction in canopy cover. Globally, urban trees grow under challenging and complex circumstances with urbanization trends of increasing anthropogenic carbon dioxide (CO2) emissions, high temperature and drought stress. This study aims to provide a better understanding of urban trees’ morpho-physio-biochemical attributes that can support sustainable urban greening programs and urban climate change mitigation policies. Globally, urban dwellers’ population is on the rise and spreading to suburban areas over time with an increase in domestic CO2 emissions. Uncertainty and less information on urban tree diversification and resistance to abiotic stress may create deterioration of ecosystem resilience over time. This review uses general parameters for urban tree physiology studies and employs three approaches for evaluating ecosystem resilience based on urban stress resistance in relation to trees’ morphological, physiological and biochemical attributes. Due to the lack of a research model of ecosystem resilience and urban stress resistance of trees, this review demonstrates that the model concept supports future urban tree physiology research needs. In particular, it is necessary to develop integral methodologies and an urban tree research concept to assess how main and combined effects of drought and/or climate changes affect indigenous and exotic trees that are commonly grown in cities.
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15
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Barros FDV, Bittencourt PL, Eller CB, Signori‐Müller C, Meireles LD, Oliveira RS. Phytogeographic origin determines Tropical Montane Cloud Forest hydraulic trait composition. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fernanda de V. Barros
- Programa de Pós Graduação em Ecologia Institute of Biology University of Campinas Brazil
- Department of Geography College of Life and Environmental Sciences University of Exeter EX4 4RJ Exeter UK
| | - Paulo L. Bittencourt
- Programa de Pós Graduação em Ecologia Institute of Biology University of Campinas Brazil
- Department of Geography College of Life and Environmental Sciences University of Exeter EX4 4RJ Exeter UK
| | - Cleiton B. Eller
- Programa de Pós Graduação em Ecologia Institute of Biology University of Campinas Brazil
| | - Caroline Signori‐Müller
- Department of Geography College of Life and Environmental Sciences University of Exeter EX4 4RJ Exeter UK
- Programa de Pós Graduação em Biologia Vegetal Institute of Biology University of Campinas Brazil
| | - Leonardo D. Meireles
- Environmental Management Course School of Art, Science, and Humanities University of São Paulo – USP 03828‐000 São Paulo SP Brazil
| | - Rafael S. Oliveira
- Departmento de Biologia Vegetal Institute of Biology, CP 6109, University of Campinas – UNICAMP 13083‐970 Campinas SP Brazil
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16
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Christmann T, Menor IO. A synthesis and future research directions for tropical mountain ecosystem restoration. Sci Rep 2021; 11:23948. [PMID: 34907235 PMCID: PMC8671388 DOI: 10.1038/s41598-021-03205-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 10/22/2021] [Indexed: 11/09/2022] Open
Abstract
Many tropical mountain ecosystems (TME) are severely disturbed, requiring ecological restoration to recover biodiversity and ecosystem functions. However, the extent of restoration efforts across TMEs is not known due to the lack of syntheses on ecological restoration research. Here, based on a systematic review, we identify geographical and thematic research gaps, compare restoration interventions, and consolidate enabling factors and barriers of restoration success. We find that restoration research outside Latin-America, in non-forested ecosystems, and on socio-ecological questions is scarce. For most restoration interventions success is mixed and generally limited by dispersal and microhabitat conditions. Finally, we propose five directions for future research on tropical mountain restoration in the UN decade of restoration, ranging from scaling up restoration across mountain ranges, investigating restoration in mountain grasslands, to incorporating socio-economic and technological dimensions.
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Affiliation(s)
- Tina Christmann
- School of Geography and the Environment, Environmental Change Institute, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK. .,Worcester College, 1 Walton Street, Oxford, OX12HB, UK.
| | - Imma Oliveras Menor
- School of Geography and the Environment, Environmental Change Institute, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK
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17
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Leaf Vein Morphological Variation in Four Endangered Neotropical Magnolia Species along an Elevation Gradient in the Mexican Tropical Montane Cloud Forests. PLANTS 2021; 10:plants10122595. [PMID: 34961066 PMCID: PMC8703730 DOI: 10.3390/plants10122595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022]
Abstract
Climatic variations influence the adaptive capacity of trees within tropical montane cloud forests species. Phenology studies have dominated current studies on tree species. Leaf vein morphology has been related to specific climatic oscillations and varies within species along altitudinal gradients. We tested that certain Neotropical broad leaf Magnolia species might be more vulnerable to leaf vein adaptation to moisture than others, as they would be more resilient to the hydric deficit. We assessed that leaf vein trait variations (vein density, primary vein size, vein length, and leaf base angle) among four Magnolia species (Magnolia nuevoleonensis, M. alejandrae, M. rzedowskiana, and Magnolia vovidesii) through the Mexican Tropical montane cloud forest with different elevation gradient and specific climatic factors. The temperature, precipitation, and potential evaporation differed significantly among Magnolia species. We detected that M. rzedowskiana and M. vovidesii with longer leaves at higher altitude sites are adapted to higher humidity conditions, and that M. nuevoleonensis and M. alejandrae inhabiting lower altitude sites are better adjusted to the hydric deficit. Our results advance efforts to identify the Magnolia species most vulnerable to climate change effects, which must focus priorities for conservation of this ecosystem, particularly in the Mexican tropical montane cloud forests.
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18
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Boanares D, Bueno A, de Souza AX, Kozovits AR, Sousa HC, Pimenta LPS, Isaias RMDS, França MGC. Cuticular wax composition contributes to different strategies of foliar water uptake in six plant species from foggy rupestrian grassland in tropical mountains. PHYTOCHEMISTRY 2021; 190:112894. [PMID: 34364088 DOI: 10.1016/j.phytochem.2021.112894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/21/2021] [Accepted: 07/31/2021] [Indexed: 06/13/2023]
Abstract
The cuticle is the outermost region of the epidermal cell wall of plant aerial organs. The cuticle acts as a two-way lipid barrier for water diffusion; therefore, it plays a vital role in foliar water uptake (FWU). We hypothesised that the chemical composition of the cuticular waxes influences the FWU strategy that plants adopt in a foggy tropical ecosystem. We analysed the leaf cuticular waxes of six plant species known by their different FWU strategies, in both qualitative and quantitative approaches, to test this hypothesis. We also investigated the fine structure of the plant cuticle by scanning electron microscopy. Neither the total wax loads nor the amounts of single wax compound classes correlated to the FWU. In contrast, the qualitative chemical composition of the cuticular waxes was related to the water absorption speed but not to the maximum water absorbed. The presence of wax crystals might interfere with the FWU. Our findings suggest that a complex three-dimensional network of the cuticular compounds contributes to different strategies of FWU in six plant species from foggy tropical mountaintops.
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Affiliation(s)
- Daniela Boanares
- Departamento de Botânica, Universidade Federal de Minas Gerais, Minas Gerais, Brazil.
| | - Amauri Bueno
- University of Würzburg, Julius-von-Sachs Institute of Biological Sciences, Chair of Botany II - Ecophysiology and Vegetation Ecology, Würzburg, Germany.
| | - Aline Xavier de Souza
- University of Würzburg, Julius-von-Sachs Institute of Biological Sciences, Chair of Botany II - Ecophysiology and Vegetation Ecology, Würzburg, Germany
| | | | - Hildeberto Caldas Sousa
- Departamento de Biodiversidade, Evolução e Meio Ambiente, Universidade Federal de Ouro Preto, Minas Gerais, Brazil
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19
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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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20
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Zhang B, Xu Q, Gao D, Wang T, Sui M, Huang J, Gu B, Liu F, Jiang J. Soil capacity of intercepting different rainfalls across subtropical plantation: Distinct effects of plant and soil properties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 784:147120. [PMID: 34088041 DOI: 10.1016/j.scitotenv.2021.147120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Forest management practices play an important role in soil water conservation. However, the soil water-holding capacity and associated drivers under different management practices remain uncertain, especially when the precipitation varies substantially at the regional scale. Here, we used hydrogen stable isotope to explore the contribution of rainfall to soil water (CRSW) under light, moderate and heavy precipitation in Pinus massoniana plantations with multiple management practices (pure stand, mixed stand, understory removal, light-intensity thinning and high-intensity thinning) in subtropical China. We further used variation partitioning analysis and structural equation modeling to identify the dominant driver affecting CRSW. Our results showed that after light rainfall, the highest CRSW (28.7%) was found in the high-intensity thinning plantation. However, after heavy rainfall, the high-intensity thinning plantation received the lowest CRSW (43.3%), while the mixed stand showed the highest CRSW (67.1%). These results demonstrated that the mixed stand of P. massoniana had a stronger capacity for soil water conservation, whereas high-intensity thinning showed poorer capacity. Furthermore, our results revealed that plant properties (i.e., tree, root and litter biomass) were the dominant controls of the CRSW under light rainfall, while soil properties (i.e., bulk density, total porosity, field capacity) were the primary drivers under moderate and heavy rainfall, indicating that the determinants influencing plantation capacity for intercepting rainfall vary with different levels of precipitation. These results highlight the importance of the level of precipitation in determining the dominant driver of CRSW. More importantly, these results suggest that the mixed stand, rather than high-intensity thinning, was better forest management since the former has a higher capacity for intercepting heavy rainfall.
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Affiliation(s)
- Beibei Zhang
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China
| | - Qing Xu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.
| | - Deqiang Gao
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China
| | - Ting Wang
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China
| | - Mingzhen Sui
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China
| | - Jin Huang
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Binhe Gu
- Soil and Water Sciences Department, University of Florida, Gainesville, FL 32603, USA
| | - Futing Liu
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Jing Jiang
- University of Calgary, Calgary T2N1N4, Canada
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21
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Christmann T, Rosado BHP, Delhaye G, Matos IS, Drummond JS, Roland HL, Moraes YC, Oliveras Menor I. Functional assembly of tropical montane tree islands in the Atlantic Forest is shaped by stress tolerance, bamboo presence, and facilitation. Ecol Evol 2021; 11:10164-10177. [PMID: 34367567 PMCID: PMC8328411 DOI: 10.1002/ece3.7824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/02/2021] [Accepted: 06/06/2021] [Indexed: 11/18/2022] Open
Abstract
AIMS Amidst the Campos de Altitude (Highland Grasslands) in the Brazilian Atlantic Forest, woody communities grow either clustered in tree islands or interspersed within the herbaceous matrix. The functional ecology, diversity, and biotic processes shaping these plant communities are largely unstudied. We characterized the functional assembly and diversity of these tropical montane woody communities and investigated how they fit within Grime's CSR (C-competitor, S-stress-tolerant, R-ruderal) scheme, what functional trade-offs they exhibit, and how traits and functional diversity vary in response to bamboo presence/absence. METHODS To characterize the functional composition of the community, we sampled five leaf traits and wood density along transects covering the woody communities both inside tree islands and outside (i.e., isolated woody plants in the grasslands community). Then, we used Mann-Whitney test, t test, and variation partitioning to determine the effects of inside versus outside tree island and bamboo presence on community-weighted means, woody species diversity, and functional diversity. RESULTS We found a general SC/S strategy with drought-related functional trade-offs. Woody plants in tree islands had more acquisitive traits than those within the grasslands. Trait variation was mostly taxonomically than spatially driven, and species composition varied between inside and outside tree islands. Leaf thickness, wood density, and foliar water uptake were unrelated to CSR strategies, suggesting independent trait dimensions and multiple drought-coping strategies within the predominant S strategy. Islands with bamboo presence showed lower Simpson diversity, lower functional dispersion, lower foliar water uptake, and greater leaf thickness than in tree islands without bamboo. CONCLUSIONS The observed functional assembly hints toward large-scale environmental abiotic filtering shaping a stress-tolerant community strategy, and small-scale biotic interactions driving small-scale trait variation. We recommend experimental studies with fire, facilitation treatments, ecophysiological and recruitment traits to elucidate on future tree island expansion and community response to climate change.
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Affiliation(s)
- Tina Christmann
- School of Geography and the EnvironmentUniversity of OxfordOxfordUK
| | - Bruno H. P. Rosado
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
| | | | - Ilaíne S. Matos
- Macrosystems Ecology LaboratoryUniversity of California BerkeleyBerkeleyCAUSA
| | - Julia S. Drummond
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
| | - Helena L. Roland
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
| | - Yan C. Moraes
- Laboratório de Ecologia VegetalDepartment of EcologyUniversidade do Estado do Rio de JaneiroRio de JaneiroBrazil
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22
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Guzmán-Delgado P, Laca E, Zwieniecki MA. Unravelling foliar water uptake pathways: The contribution of stomata and the cuticle. PLANT, CELL & ENVIRONMENT 2021; 44:1728-1740. [PMID: 33665817 DOI: 10.1111/pce.14041] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Plants can absorb water through their leaf surfaces, a phenomenon commonly referred to as foliar water uptake (FWU). Despite the physiological importance of FWU, the pathways and mechanisms underlying the process are not well known. Using a novel experimental approach, we parsed out the contribution of the stomata and the cuticle to FWU in two species with Mediterranean (Prunus dulcis) and temperate (Pyrus communis) origin. The hydraulic parameters of FWU were derived by analysing mass and water potential changes of leaves placed in a fog chamber. Leaves were previously treated with abscisic acid to force stomata to remain closed, with fusicoccin to remain open, and with water (control). Leaves with open stomata rehydrated two times faster than leaves with closed stomata and attained approximately three times higher maximum fluxes and hydraulic conductance. Based on FWU rates, we propose that rehydration through stomata occurs primarily via diffusion of water vapour rather than in liquid form even when leaf surfaces are covered with a water film. We discuss the potential mechanisms of FWU and the significance of both stomatal and cuticular pathways for plant productivity and survival.
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Affiliation(s)
- Paula Guzmán-Delgado
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | - Emilio Laca
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | - Maciej A Zwieniecki
- Department of Plant Sciences, University of California Davis, Davis, California, USA
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23
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Waseem M, Nie ZF, Yao GQ, Hasan M, Xiang Y, Fang XW. Dew absorption by leaf trichomes in Caragana korshinskii: An alternative water acquisition strategy for withstanding drought in arid environments. PHYSIOLOGIA PLANTARUM 2021; 172:528-539. [PMID: 33452683 DOI: 10.1111/ppl.13334] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 12/23/2020] [Accepted: 01/11/2021] [Indexed: 05/25/2023]
Abstract
Investigating plant morphological traits can provide insights into plant drought tolerance. To date, many papers have focused on plant hydraulic responses to drought during dehydration, but atmospheric water absorption by trichomes to mitigate drought stress by influencing leaf hydraulics in plant species that inhabit arid environments has been largely ignored. The experiment in this study was designed to assess how dew absorbed by leaf trichomes helps Caragana korshinskii withstand drought. The results showed that under a drought stress and dew (DS & D) treatment, C. korshinskii displayed a strong capacity to absorb dew with trichomes; exhibited slow decreases in leaf water potential (Ψleaf ), leaf hydraulic conductivity (Kleaf ), and gas exchange; experienced 50% Kleaf and gas exchange losses at lower relative soil water content levels than plants treated with drought stress and no dew (DS & ND); and experienced 50% Kleaf loss (Kleaf P50 ) at similar Ψleaf levels as DS & ND plants. Its congener C. sinica, which does not have leaf trichomes, displayed little ability to absorb dew under drought stress and did not show any remarkable improvement in the above parameters under the DS & D treatment. Our results indicated that leaf trichomes are important epidermal dew-uptake structures that assist in partially sustaining the leaf hydraulic assimilation system, mitigate the adverse effects of drought stress and contribute to the distribution of C. korshinskii in arid environments.
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Affiliation(s)
- Muhammad Waseem
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Zheng-Fei Nie
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Guang-Qian Yao
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Mahadi Hasan
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xiang-Wen Fang
- State Key Laboratory of Grassland Agro-ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China
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Losada JM, Díaz M, Holbrook NM. Idioblasts and peltate hairs as distribution networks for water absorbed by xerophilous leaves. PLANT, CELL & ENVIRONMENT 2021; 44:1346-1360. [PMID: 33347627 DOI: 10.1111/pce.13985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/11/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
Capparis odoratissima is a tree species native to semi-arid environments of South America where low soil water availability coexists with frequent night-time fog. A previous study showed that water applied to leaf surfaces enhanced leaf hydration, photosynthesis and growth, but the mechanisms of foliar water uptake are unknown. Here, we combine detailed anatomical evaluations with water and dye uptake experiments in the laboratory, and use immunolocalization of pectin and arabinogalactan protein epitopes to characterize water uptake pathways in leaves. Abaxially, the leaves of C. odoratissima are covered with peltate hairs, while the adaxial surfaces are glabrous. Both surfaces are able to absorb condensed water, but the abaxial surface has higher rates of water uptake. Thousands of idioblasts per cm2 , a higher density than stomata, connect the adaxial leaf surface and the abaxial peltate hairs, both of which contain hygroscopic substances such as arabinogalactan proteins and pectins. The highly specialized anatomy of the leaves of C odoratissima fulfils the dual function of minimizing water loss when stomata are closed, while maintaining the ability to absorb liquid water. Cell-wall related hygroscopic compounds in the peltate hairs and idioblasts create a network of microchannels that maintain leaf hydration and promote water uptake.
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Affiliation(s)
- Juan M Losada
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Málaga, Spain
- Department of Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA
- Arnold Arboretum of Harvard University, Boston, Massachusetts, USA
| | - Miriam Díaz
- Centro de Investigaciones en Ecología y Zonas Áridas (CIEZA), Universidad Nacional Experimental Francisco de Miranda, Coro, Venezuela
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA
- Arnold Arboretum of Harvard University, Boston, Massachusetts, USA
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25
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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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Boanares D, Lemos-Filho JP, Isaias RMS, França MGC. Photosynthetic heat tolerance in plants with different foliar water -uptake strategies. AMERICAN JOURNAL OF BOTANY 2021; 108:811-819. [PMID: 33891308 DOI: 10.1002/ajb2.1648] [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: 08/10/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
PREMISE The distribution and even the survival of plant species are influenced by temperature. In an old climatically buffered infertile landscape (OCBIL) in Brazil, we previously characterized different strategies for foliar water uptake (FWU). It is possible that photosystem II tolerance to heat and excessive light intensity varies among species with different FWU capacities. METHODS The relationship between FWU, photoinhibition, and thermotolerance was investigated in seven species from this ecosystem. RESULTS The species with slow water absorption and high water absorption are those that presented less photoinhibition. Contrastingly, the species that have fast and low water absorption presented greater thermotolerance when their leaves are totally hydrated. However, when there is greater leaf dehydration, the most thermotolerant species were those with slow but high water absorption. CONCLUSIONS Foliar water uptake is an important trait for plants to tolerate excessive light intensity and higher temperatures. Plants in this OCBIL may be differentially affected by future global warming, and the best strategy to deal with this expected climate change is with slow and high absorption of water.
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Affiliation(s)
- Daniela Boanares
- Departamento de Botânica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais, CEP 31270-901, Brasil
| | - José P Lemos-Filho
- Departamento de Botânica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais, CEP 31270-901, Brasil
| | - Rosy M S Isaias
- Departamento de Botânica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais, CEP 31270-901, Brasil
| | - Marcel G C França
- Departamento de Botânica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais, CEP 31270-901, Brasil
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Araújo EA, Kunz SH, Dias HM, Zorzanelli JPF, Callegaro RM. Vascular plant checklist in an area of extreme biological importance: filling gaps in the Caparaó National Park-ES, Brazil. BIOTA NEOTROPICA 2021. [DOI: 10.1590/1676-0611-bn-2020-1024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract Regional floristic lists are essential for defining biodiversity conservation strategies and are key to assist in filling knowledge gaps. They aim to provide a data source for applying tools to reduce extinction rates and to conserve ecosystems. Herein we present the results of an inventory of vascular plants in a rainforest in the Caparaó National Park (CNP) and approach their implications for conservation and management of this protected area and the surrounding communities. We conducted botanical expeditions between the years 2012 and 2017 in a montane and upper-montane forest of the CNP. We found 361 species distributed in 78 families and 181 genera. The study area is home to new species for science that have recently been described in other publications outside that location, and 4 new records for Espírito Santo State; also 43 species listed in different extinction threat categories (VU, EN and CR) and another 190 categorized with lesser concerns (LC and NT). The families with the highest species richness were: Melastomataceae (41 spp.), Lauraceae and Myrtaceae (30), Orchidaceae (26), Rubiaceae (24), and Asteraceae (20). Our results contribute to greater knowledge of the CNP flora, of the montane environments in Brazil and the vegetation of Espírito Santo state, in addition to demonstrate the importance of this protected area to the conservation Atlantic Forest biodiversity.
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Santos MGMD, Sousa ADS, Neves SPS, Rossatto DR, Miranda LDPD, Funch LS. Drought responses and phenotypic plasticity of Maprounea guianensis populations in humid and dry tropical forests. RODRIGUÉSIA 2021. [DOI: 10.1590/2175-7860202172077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract The wide distribution of Maprounea guianensis populations in contrasting environments (dry and humid forests) in the Chapada Diamantina, northeastern Brazil, can indicate the phenotypic plasticity of this species in relation to seasonal rainfall, drought regimes, and soil characteristics at different sites. Functional traits were measured in five individuals in each vegetation types. Water potential, succulence, thickness and density leaf, were evaluated during the dry and rainy periods; wood density and the saturated water content of the wood were evaluated in rainy period. Rainfall was monitored monthly for two years. The functional traits and the phenotypic plasticity indices (PPI) were submitted to analysis of variance. Our results demonstrated seasonal and spatial variations in plant functional traits. We found a low capacity for storing water in leaves and woody tissues, associated with soil properties and the seasonal rainfall/drought regimes, conditioning water potential variations that were greatest during the rainy season. Local environmental parameters influenced variations in the functional traits of M. guianensis populations, reflecting phenotypic plasticity. We highlight the connections between drought regimes and plant responses, demonstrating the importance of functional traits associated with water availability (especially water potential). Our study evidences the factors associated with the wide distribution of M. guianensis.
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29
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Griffiths AR, Silman MR, Farfán Rios W, Feeley KJ, García Cabrera K, Meir P, Salinas N, Dexter KG. Evolutionary heritage shapes tree distributions along an Amazon‐to‐Andes elevation gradient. Biotropica 2020. [DOI: 10.1111/btp.12843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
| | - Miles R. Silman
- Biology Department and Center for Energy, Environment and Sustainability Wake Forest University Winston‐Salem NC USA
| | - William Farfán Rios
- Living Earth Collaborative Washington University in Saint Louis St. Louis MO USA
- Center for Conservation and Sustainable Development Missouri Botanical Garden St. Louis MO USA
- Herbario Vargas (CUZ), Escuela Profesional de Biología Universidad Nacional de San Antonio Abad del Cusco Cusco Peru
| | - Kenneth J. Feeley
- Department of Biology University of Miami Coral Gables FL USA
- Fairchild Tropical Botanic Garden Coral Gables FL USA
| | - Karina García Cabrera
- Biology Department and Center for Energy, Environment and Sustainability Wake Forest University Winston‐Salem NC USA
| | - Patrick Meir
- School of Geosciences University of Edinburgh Edinburgh UK
- Research School of Biology Australian National University Canberra ACT Australia
| | - Norma Salinas
- Instituto de Ciencias de la Naturaleza, Territorio y Energías Renovables Pontificia Universidad Católica del Peru Lima Peru
| | - Kyle G. Dexter
- School of Geosciences University of Edinburgh Edinburgh UK
- Royal Botanic Garden Edinburgh Edinburgh UK
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30
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Jura-Morawiec J, Marcinkiewicz J. Wettability, water absorption and water storage in rosette leaves of the dragon tree (Dracaena draco L.). PLANTA 2020; 252:30. [PMID: 32725269 PMCID: PMC7387376 DOI: 10.1007/s00425-020-03433-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Leaf surfaces of Dracaena draco are wettable and can absorb water. The thick, basal leaf part could act as a water reservoir that changes in volume with plant hydration. Rosettes of leaves of Dracaena draco play an important role in directing fog water through leaf axils into the stem tissues, where it can be stored for further use. However, how water is intercepted and collected by the leaves remains unclear, especially since leaf blade surfaces are considered hydrophobic. Based on the observations of D. draco individuals growing in Spain and in glasshouse conditions in Poland, we hypothesised that their long leaves (~ 70 cm) are able to absorb water along the whole leaf blade, but leaf age affects this process. We used water droplet contact angle measurements, anatomical analyses of leaf cross sections along the age gradient and dye tracer experiments to test this hypothesis. The data showed that the leaf surfaces of D. draco are wettable. In general, the mature leaves of the rosette are more wettable than the young ones. Water can be absorbed both through the adaxial and abaxial surfaces. The hydrenchyma is not uniformly distributed along the leaf, it is especially abundant towards the leaf base where it forms a massive water reservoir, which changes in volume depending on plant water status. The results of these studies shed light on the role of rosettes in water absorption by D. draco, and broaden our understanding of the functioning of this vulnerable species.
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Affiliation(s)
- Joanna Jura-Morawiec
- Polish Academy of Sciences Botanical Garden-Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland.
| | - Jan Marcinkiewicz
- Polish Academy of Sciences Botanical Garden-Centre for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973, Warsaw, Poland
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31
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Schreel JDM, Leroux O, Goossens W, Brodersen C, Rubinstein A, Steppe K. Identifying the pathways for foliar water uptake in beech (Fagus sylvatica L.): a major role for trichomes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:769-780. [PMID: 32279362 DOI: 10.1111/tpj.14770] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/20/2020] [Accepted: 03/27/2020] [Indexed: 05/27/2023]
Abstract
Foliar water uptake (FWU), the direct uptake of water into leaves, is a global phenomenon, having been observed in an increasing number of plant species. Despite the growing recognition of its functional relevance, our understanding of how FWU occurs and which foliar surface structures are implicated, is limited. In the present study, fluorescent and ionic tracers, as well as microcomputed tomography, were used to assess potential pathways for water entry in leaves of beech, a widely distributed tree species from European temperate regions. Although none of the tracers entered the leaf through the stomatal pores, small amounts of silver precipitation were observed in some epidermal cells, indicating moderate cuticular uptake. Trichomes, however, were shown to absorb and redistribute considerable amounts of ionic and fluorescent tracers. Moreover, microcomputed tomography indicated that 72% of empty trichomes refilled during leaf surface wetting and microscopic investigations revealed that trichomes do not have a cuticle but are covered with a pectin-rich cell wall layer. Taken together, our findings demonstrate that foliar trichomes, which exhibit strong hygroscopic properties as a result of their structural and chemical design, constitute a major FWU pathway in beech.
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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, Ghent, Belgium
| | - Olivier Leroux
- Department of Biology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Willem Goossens
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium
| | - Craig Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, 06511, USA
| | - Adriana Rubinstein
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, 06511, USA
| | - Kathy Steppe
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000, Ghent, Belgium
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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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33
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Binks O, Coughlin I, Mencuccini M, Meir P. Equivalence of foliar water uptake and stomatal conductance? PLANT, CELL & ENVIRONMENT 2020; 43:524-528. [PMID: 31677188 DOI: 10.1111/pce.13663] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/29/2019] [Accepted: 10/08/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Oliver Binks
- Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
| | - Ingrid Coughlin
- Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
| | | | - Patrick Meir
- Research School of Biology, The Australian National University, Canberra, 2601, Australian Capital Territory, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, EH9 3FF, UK
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Fuenzalida TI, Bryant CJ, Ovington LI, Yoon HJ, Oliveira RS, Sack L, Ball MC. Shoot surface water uptake enables leaf hydraulic recovery in Avicennia marina. THE NEW PHYTOLOGIST 2019; 224:1504-1511. [PMID: 31419324 DOI: 10.1111/nph.16126] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/11/2019] [Indexed: 05/08/2023]
Abstract
The significance of shoot surface water uptake (SSWU) has been debated, and it would depend on the range of conditions under which it occurs. We hypothesized that the decline of leaf hydraulic conductance (Kleaf ) in response to dehydration may be recovered through SSWU, and that the hydraulic conductance to SSWU (Ksurf ) declines with dehydration. We quantified effects of leaf dehydration on Ksurf and effects of SSWU on recovery of Kleaf in dehydrated leaves of Avicennia marina. SSWU led to overnight recovery of Kleaf , with recovery retracing the same path as loss of Kleaf in response to dehydration. SSWU declined with dehydration. By contrast, Ksurf declined with rehydration time but not with dehydration. Our results showed a role of SSWU in the recovery of leaf hydraulic conductance and revealed that SSWU is sensitive to leaf hydration status. The prevalence of SSWU in vegetation suggests an important role for atmospheric water sources in maintenance of leaf hydraulic function, with implications for plant responses to changing environments.
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Affiliation(s)
- Tomás I Fuenzalida
- Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
| | - Callum J Bryant
- Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
| | - Leuwin I Ovington
- Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
| | - Hwan-Jin Yoon
- Statistical Consulting Unit, The Australian National University, Acton, ACT, 2601, Australia
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas - UNICAMP, Campinas, São Paulo, CP 6109, Brazil
| | - Lawren Sack
- Department of Ecology and Evolution, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Marilyn C Ball
- Plant Science Division, Research School of Biology, The Australian National University, Acton, ACT, 2601, Australia
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35
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Holanda AER, Souza BC, Carvalho ECD, Oliveira RS, Martins FR, Muniz CR, Costa RC, Soares AA. How do leaf wetting events affect gas exchange and leaf lifespan of plants from seasonally dry tropical vegetation? PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:1097-1109. [PMID: 31251437 DOI: 10.1111/plb.13023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 06/25/2019] [Indexed: 06/09/2023]
Abstract
Foliar uptake of dew is likely an important mechanism of water acquisition for plants from tropical dry environments. However, there is still limited experimental evidence describing the anatomical pathways involved in this process and the effects of this water subsidy on the maintenance of gas exchange and leaf lifespan of species from seasonally dry tropical vegetation such as the Brazilian caatinga. We performed scanning electron, bright-field and confocal microscopic analyses and used apoplastic tracers to examine the foliar water uptake (FWU) routes in four woody species with different foliar phenology and widely distributed in the caatinga. Leaves of plants subjected to water stress were exposed to dew simulation to evaluate the effects of the FWU on leaf water potentials, gas exchange and leaf lifespan. All species absorbed water through their leaf cuticles and/or peltate trichomes but FWU capacity differed among species. Leaf wetting by dew increased leaf lifespan duration up to 36 days compared to plants in the drought treatment. A positive effect on leaf gas exchange and new leaf production was only observed in the anisohydric and evergreen species. We showed that leaf wetting by dew is relevant for the physiology and leaf lifespan of plants from seasonally dry tropical vegetation, especially for evergreen species.
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Affiliation(s)
- A E R Holanda
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Brazil
| | - B C Souza
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Brazil
| | - E C D Carvalho
- Graduate Program in Ecology and Natural Resources, Department of Biology, Federal University of Ceará, Fortaleza, Brazil
| | - R S Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas - UNICAMP, Campinas, Brazil
| | - F R Martins
- Department of Plant Biology, Institute of Biology, University of Campinas - UNICAMP, Campinas, Brazil
| | - C R Muniz
- Embrapa Tropical Agroindustry, Fortaleza, Brazil
| | - R C Costa
- Department of Biology, Federal University of Ceará, Fortaleza, Brazil
| | - A A Soares
- Department of Biology, Federal University of Ceará, Fortaleza, Brazil
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Schreel JDM, Van de Wal BAE, Hervé-Fernandez P, Boeckx P, Steppe K. Hydraulic redistribution of foliar absorbed water causes turgor-driven growth in mangrove seedlings. PLANT, CELL & ENVIRONMENT 2019; 42:2437-2447. [PMID: 30953380 DOI: 10.1111/pce.13556] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 03/25/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
Although foliar water uptake (FWU) has been shown in mature Avicennia marina trees, the importance for its seedlings remains largely unknown. A series of experiments were therefore performed using artificial rainfall events in a greenhouse environment to assess the ecological implications of FWU in A. marina seedlings. One-hour artificial rainfall events resulted in an increased leaf water potential, a reversed sap flow, and a rapid diameter increment signifying a turgor-driven growth of up to 30.1 ± 5.4 μm. Furthermore, the application of an artificial rainfall event with deuterated water showed that the amount of water absorbed by the leaves and transported to the stem was directly and univocally correlated to the observed growth spurts. The observations in this process-based study show that FWU is an important water acquisition mechanism under certain circumstances and might be of ecological importance for the establishment of A. marina seedlings. Distribution of mangrove trees might hence be more significantly disturbed by climate change-driven changes in rainfall patterns than previously assumed.
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Affiliation(s)
- Jeroen D M Schreel
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
| | - Bart A E Van de Wal
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
| | - Pedro Hervé-Fernandez
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
- Isotope Bioscience Laboratory (ISOFYS), Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
| | - Pascal Boeckx
- Isotope Bioscience Laboratory (ISOFYS), Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
| | - Kathy Steppe
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, 9000, Belgium
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Binks O, Mencuccini M, Rowland L, da Costa ACL, de Carvalho CJR, Bittencourt P, Eller C, Teodoro GS, Carvalho EJM, Soza A, Ferreira L, Vasconcelos SS, Oliveira R, Meir P. Foliar water uptake in Amazonian trees: Evidence and consequences. GLOBAL CHANGE BIOLOGY 2019; 25:2678-2690. [PMID: 31012521 DOI: 10.1111/gcb.14666] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
The absorption of atmospheric water directly into leaves enables plants to alleviate the water stress caused by low soil moisture, hydraulic resistance in the xylem and the effect of gravity on the water column, while enabling plants to scavenge small inputs of water from leaf-wetting events. By increasing the availability of water, and supplying it from the top of the canopy (in a direction facilitated by gravity), foliar uptake (FU) may be a significant process in determining how forests interact with climate, and could alter our interpretation of current metrics for hydraulic stress and sensitivity. FU has not been reported for lowland tropical rainforests; we test whether FU occurs in six common Amazonian tree genera in lowland Amazônia, and make a first estimation of its contribution to canopy-atmosphere water exchange. We demonstrate that FU occurs in all six genera and that dew-derived water may therefore be used to "pay" for some morning transpiration in the dry season. Using meteorological and canopy wetness data, coupled with empirically derived estimates of leaf conductance to FU (kfu ), we estimate that the contribution by FU to annual transpiration at this site has a median value of 8.2% (103 mm/year) and an interquartile range of 3.4%-15.3%, with the biggest sources of uncertainty being kfu and the proportion of time the canopy is wet. Our results indicate that FU is likely to be a common strategy and may have significant implications for the Amazon carbon budget. The process of foliar water uptake may also have a profound impact on the drought tolerance of individual Amazonian trees and tree species, and on the cycling of water and carbon, regionally and globally.
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Affiliation(s)
- Oliver Binks
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | | | - Lucy Rowland
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | | | - Paulo Bittencourt
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Cleiton Eller
- Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | | | - Azul Soza
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | | | | - Rafael Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Patrick Meir
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
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38
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Boanares D, Kozovits AR, Lemos-Filho JP, Isaias RMS, Solar RRR, Duarte AA, Vilas-Boas T, França MGC. Foliar water-uptake strategies are related to leaf water status and gas exchange in plants from a ferruginous rupestrian field. AMERICAN JOURNAL OF BOTANY 2019; 106:935-942. [PMID: 31281976 DOI: 10.1002/ajb2.1322] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
PREMISE Fog is a frequent event in Brazilian rupestrian field and plays an important role in the physiology of several plant species. Foliar water uptake (FWU) of fog may be fast or slow depending on the species. However, fog water may negatively affect CO2 assimilation. Thus, the interference in the water and carbon balance as a result of different strategies of FWU was evaluated to verify whether fog may mitigate possible water deficit in leaves. METHODS Four plant species with different FWU strategies were studied in a ferruginous rupestrian field with frequent fog. Gas exchange and water potential were measured before dawn and at midday during the dry and rainy seasons, separating foggy from non-foggy days during the dry season. RESULTS The FWU speed negatively influences CO2 assimilation in the dry season, possibly because of its negative relationship with stomatal conductance, since reduced stomatal aperture impairs carbon entrance. Fog presence increased leaf water potential both in early morning and midday during the dry season. However, during the rainy season, the values of leaf water potential were lower at midday, than during the dry season with fog at midday, which favors leaf gas exchanges. CONCLUSIONS FWU interferes negatively, but briefly with CO2 assimilation. Nevertheless, FWU prevents water loss through transpiration and increases the water status of plants in the dry season. That is, FWU results in a compensation between CO2 assimilation and foliar hydration, which, in fact, is beneficial to the plants of this ecosystem.
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Affiliation(s)
- Daniela Boanares
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Alessandra R Kozovits
- Departamento de Biodiversidade, Evolução e Meio Ambiente, Universidade Federal de Ouro Preto, MG, Brasil
| | - José P Lemos-Filho
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Rosy M S Isaias
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Ricardo R R Solar
- Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Alexandre A Duarte
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Tiago Vilas-Boas
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
| | - Marcel G C França
- Departamento de Botânica, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil
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Gong XW, Lü GH, He XM, Sarkar B, Yang XD. High Air Humidity Causes Atmospheric Water Absorption via Assimilating Branches in the Deep-Rooted Tree Haloxylon ammodendron in an Arid Desert Region of Northwest China. FRONTIERS IN PLANT SCIENCE 2019; 10:573. [PMID: 31156661 PMCID: PMC6530360 DOI: 10.3389/fpls.2019.00573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 04/16/2019] [Indexed: 05/30/2023]
Abstract
Atmospheric water is one of the main water resources for plants in arid ecosystems. However, whether deep-rooted, tomentum-less desert trees can absorb atmospheric water via aerial organs and transport the water into their bodies remains poorly understood. In the present study, a woody, deep-rooted, tomentum-less plant, Haloxylon ammodendron (C.A. Mey.) Bunge, was selected as the experimental object to investigate the preconditions for and consequences of foliar water uptake. Plant water status, gas exchange, and 18O isotopic signatures of the plant were investigated following a typical rainfall pulse and a high-humidity exposure experiment. The results showed that a high content of atmospheric water was the prerequisite for foliar water uptake by H. ammodendron in the arid desert region. After atmospheric water was absorbed via the assimilating branches, which perform the function of leaves due to leaf degeneration, the plant transported the water to the secondary branches and trunk stems, but not to the taproot xylem or the soil, based on the 18O isotopic signatures of the specimen. Foliar water uptake altered the plant water status and gas exchange-related traits, i.e., water potential, stomatal conductance, transpiration rate, and instantaneous water use efficiency. Our results suggest that atmospheric water might be a subsidiary water resource for sustaining the survival and growth of deep-rooted plants in arid desert regions. These findings contribute to the knowledge of plant water physiology and restoration of desert plants in the arid regions of the planet.
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Affiliation(s)
- Xue-Wei Gong
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
| | - Guang-Hui Lü
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
- Institute of Arid Ecology and Environment, Xinjiang University, Urumqi, China
| | - Xue-Min He
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
- Institute of Arid Ecology and Environment, Xinjiang University, Urumqi, China
| | - Binoy Sarkar
- Department of Animal and Plant Sciences, The University of Sheffield, Sheffield, United Kingdom
- Future Industries Institute, University of South Australia, Mawson Lakes, SA, Australia
| | - Xiao-Dong Yang
- Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi, China
- College of Resources and Environmental Sciences, Xinjiang University, Urumqi, China
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40
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Helmer EH, Gerson EA, Baggett LS, Bird BJ, Ruzycki TS, Voggesser SM. Neotropical cloud forests and páramo to contract and dry from declines in cloud immersion and frost. PLoS One 2019; 14:e0213155. [PMID: 30995232 PMCID: PMC6469753 DOI: 10.1371/journal.pone.0213155] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 02/18/2019] [Indexed: 11/24/2022] Open
Abstract
Clouds persistently engulf many tropical mountains at elevations cool enough for clouds to form, creating isolated areas with frequent fog and mist. Under these isolated conditions, thousands of unique species have evolved in what are known as tropical montane cloud forests (TMCF) and páramo. Páramo comprises a set of alpine ecosystems that occur above TMCF from about 11° N to 9° S along the Americas continental divide. TMCF occur on all continents and island chains with tropical climates and mountains and are increasingly threatened by climate and land-use change. Climate change could impact a primary feature distinguishing these ecosystems, cloud immersion. But where and in what direction cloud immersion of TMCF and páramo will change with climate are fundamental unknowns. Prior studies at a few TMCF sites suggest that cloud immersion will increase in some places while declining in others. Other unknowns include the extent of deforestation in protected and unprotected cloud forest climatic zones, and deforestation extent compared with projected climate change. Here we use a new empirical approach combining relative humidity, frost, and novel application of maximum watershed elevation to project change in TMCF and páramo for Representative greenhouse gas emissions Concentration Pathways (RCPs) 4.5 and 8.5. Results suggest that in <25–45 yr, 70–86% of páramo will dry or be subject to tree invasion, and cloud immersion declines will shrink or dry 57–80% of Neotropical TMCF, including 100% of TMCF across Mexico, Central America, the Caribbean, much of Northern South America, and parts of Southeast Brazil. These estimates rise to 86% of Neotropical TMCF and 98% of páramo in <45–65 yr if greenhouse gas emissions continue rising throughout the 21st century. We also find that TMCF zones are largely forested, but some of the most deforested areas will undergo the least climate change. We project that cloud immersion will increase for only about 1% of all TMCF and in only a few places. Declines in cloud immersion dominate TMCF change across the Neotropics.
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Affiliation(s)
- E. H. Helmer
- International Institute of Tropical Forestry, United States Department of Agriculture, Forest Service, Río Piedras, Puerto Rico, United States of America
- * E-mail:
| | - E. A. Gerson
- Ecological Research Support, Houghton, Michigan, United States of America
| | - L. Scott Baggett
- Rocky Mountain Research Station, United States Department of Agriculture, Forest Service, Fort Collins, Colorado, United States of America
| | - Benjamin J. Bird
- Rocky Mountain Research Station, United States Department of Agriculture, Forest Service, Fort Collins, Colorado, United States of America
| | - Thomas S. Ruzycki
- Center for Environmental Management of Military Lands, Colorado State University, Fort Collins, Colorado, United States of America
| | - Shannon M. Voggesser
- Center for Environmental Management of Military Lands, Colorado State University, Fort Collins, Colorado, United States of America
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41
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Berry ZC, Emery NC, Gotsch SG, Goldsmith GR. Foliar water uptake: Processes, pathways, and integration into plant water budgets. PLANT, CELL & ENVIRONMENT 2019; 42:410-423. [PMID: 30194766 DOI: 10.1111/pce.13439] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 05/04/2023]
Abstract
Nearly all plant families, represented across most major biomes, absorb water directly through their leaves. This phenomenon is commonly referred to as foliar water uptake. Recent studies have suggested that foliar water uptake provides a significant water subsidy that can influence both plant water and carbon balance across multiple spatial and temporal scales. Despite this, our mechanistic understanding of when, where, how, and to what end water is absorbed through leaf surfaces remains limited. We first review the evidence for the biophysical conditions necessary for foliar water uptake to occur, focusing on the plant and atmospheric water potentials necessary to create a gradient for water flow. We then consider the different pathways for uptake, as well as the potential fates of the water once inside the leaf. Given that one fate of water from foliar uptake is to increase leaf water potentials and contribute to the demands of transpiration, we also provide a quantitative synthesis of observed rates of change in leaf water potential and total fluxes of water into the leaf. Finally, we identify critical research themes that should be addressed to effectively incorporate foliar water uptake into traditional frameworks of plant water movement.
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Affiliation(s)
- Z Carter Berry
- Schmid College of Science and Technology, Chapman University, Orange, California, USA
| | - Nathan C Emery
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | - Sybil G Gotsch
- Department of Biology, Franklin and Marshall College, Lancaster, Pennsylvania, USA
| | - Gregory R Goldsmith
- Schmid College of Science and Technology, Chapman University, Orange, California, USA
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42
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Yue C, Cao HL, Chen D, Lin HZ, Wang Z, Hu J, Yang GY, Guo YQ, Ye NX, Hao XY. Comparative transcriptome study of hairy and hairless tea plant (Camellia sinensis) shoots. JOURNAL OF PLANT PHYSIOLOGY 2018; 229:41-52. [PMID: 30032044 DOI: 10.1016/j.jplph.2018.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 07/14/2018] [Accepted: 07/14/2018] [Indexed: 06/08/2023]
Abstract
Trichome (also referred to as 'háo' in tea) is a key feature in both tea products and tea plant (Camellia sinensis) selection breeding. Although trichomes are used as a model for studying cell differentiation and have been well studied in many plant species, the regulation of trichome formation at the molecular level is poorly understood in tea plants. In the present study, the hairy and hairless tea plant cultivars Fudingdabaicha (FDDB) and Rongchunzao (RCZ), respectively, were used to study this mechanism. We characterised tea plant trichomes as unicellular and unbranched structures. High-throughput Illumina sequencing yielded approximately 277.0 million high-quality clean reads from the FDDB and RCZ cultivars. After de novo assembly, 161,444 unigenes were generated, with an average length of 937 bp. Among these unigenes, 81,425 were annotated using public databases, and 55,201 coding sequences and 4004 transcription factors (TFs) were identified. In total, 21,599 differentially expressed genes (DEGs) were identified between RCZ and FDDB, of which 10,785 DEGs were up-regulated and 10,814 DEGs were down-regulated. Genes involved in the DNA replication pathway were significantly enriched. Furthermore, between FDDB and RCZ, DEGs related to TFs, phytohormone signals, and cellulose synthesis were identified, suggesting that certain genes involved in these pathways are crucial for trichome initiation in tea plants. Together, the results of this study provide novel data to improve our understanding of the potential molecular mechanisms of trichome formation and lay a foundation for additional trichome studies in tea plants.
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Affiliation(s)
- Chuan Yue
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China.
| | - Hong-Li Cao
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Dan Chen
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Hong-Zheng Lin
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Zan Wang
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Juan Hu
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Guo-Yi Yang
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Yu-Qiong Guo
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China
| | - Nai-Xing Ye
- College of Horticulture, Fujian Agriculture and Forestry University, Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, China.
| | - Xin-Yuan Hao
- Tea Research Institute, Chinese Academy of Agricultural Sciences, National Center for Tea Improvement, Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, Hangzhou, China.
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43
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Boanares D, Isaias RRMS, de Sousa HC, Kozovits AR. Strategies of leaf water uptake based on anatomical traits. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:848-856. [PMID: 29673051 DOI: 10.1111/plb.12832] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
The ability of leaves to absorb fog water can positively contribute to the water and carbon balance of plants in montane ecosystems, especially in periods of soil water deficit. However, the ecophysiological traits and mechanisms responsible for variations in the speed and total water absorption capacity of leaves are still poorly known. This study investigated leaf anatomical attributes of seven species occurring in seasonal tropical high-altitude ecosystems (rocky outcrop and forest), which could explain differences in leaf water uptake (LWU) capacities. We tested the hypothesis that different sets of anatomical leaf attributes will be more marked in plant individuals living under these contrasting environmental conditions. Anatomical variations will affect the initial rate of water absorption and the total storage capacity, resulting in different strategies for using the water supplied by fog events. Water absorption by leaves was inferred indirectly, based on leaf anatomical structure and visual observation of the main access routes (using an apoplastic marker), the diffusion of water through the cuticle, and non-glandular or glandular trichomes in all species. The results suggest that three LWU strategies coexist in the species studied. The different anatomical patterns influenced the speed and maximum LWU capacity. The three LWU strategies can provide different adaptive advantages to adjust to temporal and spatial variations of water availability in these tropical high-altitude environments.
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Affiliation(s)
- D Boanares
- Department of Biodiversity, Evolution and Environment, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - R R M S Isaias
- Department of Botany, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - H C de Sousa
- Department of Biodiversity, Evolution and Environment, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - A R Kozovits
- Department of Biodiversity, Evolution and Environment, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil
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44
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Dawson TE, Goldsmith GR. The value of wet leaves. THE NEW PHYTOLOGIST 2018; 219:1156-1169. [PMID: 29959896 DOI: 10.1111/nph.15307] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/03/2018] [Indexed: 06/08/2023]
Abstract
Contents Summary 1156 I. Introduction 1156 II. How often are leaves wet? 1157 III. The costs of leaf wetting 1157 IV. The real and potential benefits of leaf wetting 1161 V. Wet leaves: costs, benefits and tradeoffs in a changing world 1165 Acknowledgements 1166 References 1166 SUMMARY: An often-overlooked feature of all plants is that their leaf surfaces are wet for significant periods over their lifetimes. Leaf wetting has a number of direct and indirect effects on plant function from the scale of the leaf to that of the ecosystem. The costs of leaf wetting for plant function, such as the growth of pathogens and the leaching of nutrients, have long been recognized. However, an emerging body of research has also begun to demonstrate some very clear benefits. For instance, leaf wetting can improve plant-water relations and lead to increased photosynthesis. Leaf wetting may also lead to synergistic effects on plant function, such as when leaf water potential improvements lead to enhanced growth that does not occur when plant leaves are dry. We identify important reasons why leaf wetting can be critical for plant sciences to not only acknowledge, but also directly address, in future research. To do so, we provide a framework for the consideration of the relative balance of the various costs and benefits resulting from leaf wetting, as well as how this balance may be expected to change given projected scenarios of global climate change in the future.
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Affiliation(s)
- Todd E Dawson
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
- Department of Environmental Science, Policy & Management, University of California, Berkeley, CA, 94720, USA
| | - Gregory R Goldsmith
- Ecosystem Fluxes Group, Laboratory for Atmospheric Chemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
- Schmid College of Science and Technology, Chapman University, Orange, CA, 92866, USA
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45
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Choat B, Brodribb TJ, Brodersen CR, Duursma RA, López R, Medlyn BE. Triggers of tree mortality under drought. Nature 2018; 558:531-539. [DOI: 10.1038/s41586-018-0240-x] [Citation(s) in RCA: 647] [Impact Index Per Article: 107.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 05/02/2018] [Indexed: 01/08/2023]
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46
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Monge M, Volet DP, Semir J. Five new species of Vernonieae (Asteraceae) from Espírito Santo, Brazil. RODRIGUÉSIA 2018. [DOI: 10.1590/2175-7860201869224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract Espírito Santo is a hotspot of diversity in the Atlantic Forest in Brazil, where five new species of Vernonieae from the genera Cololobus, Lepidaploa, Lessingianthus, Piptocarpha, and Vernonanthura were found, and four of them occur in the municipality of Santa Teresa. These discoveries show that current knowledge on biodiversity in Espírito Santo is incipient, even in sites with decades of biological inventories, such as Santa Teresa. Here, all five species are described with comments about distribution, conservations status, phenology and taxonomic affinities. We also provide illustrations and a distribution map of the new species. According to the criteria of IUCN red list, Cololobus argenteus and Vernonanthura spathulata must be included in endangered (EN) category.
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Affiliation(s)
| | | | - João Semir
- Universidade Estadual de Campinas, Brazil
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47
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Bahamonde HA, Gil L, Fernández V. Surface Properties and Permeability to Calcium Chloride of Fagus sylvatica and Quercus petraea Leaves of Different Canopy Heights. FRONTIERS IN PLANT SCIENCE 2018; 9:494. [PMID: 29720987 PMCID: PMC5915543 DOI: 10.3389/fpls.2018.00494] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/03/2018] [Indexed: 05/08/2023]
Abstract
Plant surfaces have a considerable degree of chemical and physical variability also in relation to different environmental conditions, organs and state of development. The potential changes on plant surface properties in association with environmental variations have been little explored so far. Using two model tree species (i.e., Quercus petraea, sessile oak and Fagus sylvatica, beech) growing in 'Montejo de la Sierra Forest,' we examined various traits of the abaxial and adaxial surface of leaves of both species collected at a height of approximately 15 m (top canopy), versus 3.5-5.5 m for beech and sessile oak, lower canopy leaves. Leaf surface ultra-structure was analyzed by scanning and transmission electron microscopy, and the surface free energy and related parameter were estimated after measuring drops of 3 liquids with different degrees of polarity and apolarity. The permeability of the adaxial and abaxial surface of top and bottom canopy leaves to CaCl2 was estimated by depositing 2 drops of 3-4 μl per cm2 and comparing the concentration of Ca in leaf tissues 24 h after treatment, and also Ca and Cl concentrations in the washing liquid. Higher Ca concentrations were recorded after the application of CaCl2 drops onto the veins and adaxial blade of top canopy beech leaves, while no significant evidence for foliar Ca absorption was gained with sessile oak leaves. Surprisingly, high amounts of Cl were recovered after washing untreated, top canopy beach and sessile oak leaves with deionised water, a phenomenon which was not traced to occur on lower canopy leaves of both species. It is concluded that the surface of the two species analyzed is heterogeneous in nature and may have areas favoring the absorption of water and solutes as observed for the veins of beech leaves.
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Affiliation(s)
- Héctor A. Bahamonde
- Instituto Nacional de Tecnología Agropecuaria, Buenos Aires, Argentina
- Department of Natural Resources, Universidad Nacional de la Patagonia Austral, Río Gallegos, Argentina
| | - Luis Gil
- Forest Genetics and Ecophysiology Research Group, School of Forest Engineering, Technical University of Madrid, Madrid, Spain
| | - Victoria Fernández
- Forest Genetics and Ecophysiology Research Group, School of Forest Engineering, Technical University of Madrid, Madrid, Spain
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48
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Eller CB, de V Barros F, Bittencourt PRL, Rowland L, Mencuccini M, Oliveira RS. Xylem hydraulic safety and construction costs determine tropical tree growth. PLANT, CELL & ENVIRONMENT 2018; 41:548-562. [PMID: 29211923 DOI: 10.1111/pce.13106] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 11/17/2017] [Indexed: 05/25/2023]
Abstract
Faster growth in tropical trees is usually associated with higher mortality rates, but the mechanisms underlying this relationship are poorly understood. In this study, we investigate how tree growth patterns are linked with environmental conditions and hydraulic traits, by monitoring the cambial growth of 9 tropical cloud forest tree species coupled with numerical simulations using an optimization model. We find that fast-growing trees have lower xylem safety margins than slow-growing trees and this pattern is not necessarily linked to differences in stomatal behaviour or environmental conditions when growth occurs. Instead, fast-growing trees have xylem vessels that are more vulnerable to cavitation and lower density wood. We propose the growth - xylem vulnerability trade-off represents a wood hydraulic economics spectrum similar to the classic leaf economic spectrum, and show through numerical simulations that this trade-off can emerge from the coordination between growth rates, wood density, and xylem vulnerability to cavitation. Our results suggest that vulnerability to hydraulic failure might be related with the growth-mortality trade-off in tropical trees, determining important life history differences. These findings are important in furthering our understanding of xylem hydraulic functioning and its implications on plant carbon economy.
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Affiliation(s)
- Cleiton B Eller
- Department of Plant Biology, Institute of Biology, UNICAMP, 6109, Campinas, Brazil
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, EX4 4RJ, Exeter, UK
| | - Fernanda de V Barros
- Department of Plant Biology, Institute of Biology, UNICAMP, 6109, Campinas, Brazil
| | | | - Lucy Rowland
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, EX4 4RJ, Exeter, UK
| | - Maurizio Mencuccini
- ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
- CREAF, Cerdanyola del Valles, 08193, Barcelona, Spain
| | - Rafael S Oliveira
- Department of Plant Biology, Institute of Biology, UNICAMP, 6109, Campinas, Brazil
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49
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Boanares D, Ferreira BG, Kozovits AR, Sousa HC, Isaias RMS, França MGC. Pectin and cellulose cell wall composition enables different strategies to leaf water uptake in plants from tropical fog mountain. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 122:57-64. [PMID: 29175637 DOI: 10.1016/j.plaphy.2017.11.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/08/2017] [Indexed: 06/07/2023]
Abstract
Leaf water uptake (LWU) has been observed in plants of different ecosystems and this process is distinct among different species. Four plant species from the Brazilian fog mountain fields were evaluated in order to detect if leaf water uptake capacity is related to the cell wall composition of leaf epidermis. LWU measurements and their relation to anatomical and biochemical traits were analyzed. Cell wall composition was verified through immunocytochemistry using monoclonal antibodies recognizing pectin compounds, and histochemistry with calcofluor white to track cellulose. Differences in LWU among the four species were clearly revealed. Two species presented higher maximum leaf water content and the lowest values of water absorption speed. The other two species presented opposite behavior, namely, low leaf water uptake and the highest values of water absorption speed. The anatomical traits associated with the cell wall composition corroborated the data on the different LWU strategies. The species with abundant detection of cellulose in their epidermal cell walls absorbed more water, but more slowly, while those with abundant detection of pectins absorbed water at a higher speed. These results indicate that cell wall composition regarding pectin and cellulose are significant for water uptake by the leaf epidermis. Pectin provides greater porosity and absorption speed, while cellulose provides greater hydrophilicity and greater water uptake capacity. Current data indicate that the composition of epidermal cell walls is a relevant trait for leaf water uptake.
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Affiliation(s)
- D Boanares
- Departamento de Botânica, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil
| | - B G Ferreira
- Departamento de Botânica, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil
| | - A R Kozovits
- Departamento de Biodiversidade, Evolução e Meio Ambiente, Universidade Federal de Ouro Preto, 35400-000, MG, Brazil
| | - H C Sousa
- Departamento de Biodiversidade, Evolução e Meio Ambiente, Universidade Federal de Ouro Preto, 35400-000, MG, Brazil
| | - R M S Isaias
- Departamento de Botânica, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil
| | - M G C França
- Departamento de Botânica, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG, Brazil.
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50
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da Costa ACL, Rowland L, Oliveira RS, Oliveira AAR, Binks OJ, Salmon Y, Vasconcelos SS, Junior JAS, Ferreira LV, Poyatos R, Mencuccini M, Meir P. Stand dynamics modulate water cycling and mortality risk in droughted tropical forest. GLOBAL CHANGE BIOLOGY 2018; 24:249-258. [PMID: 28752626 DOI: 10.1111/gcb.13851] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/09/2017] [Indexed: 05/25/2023]
Abstract
Transpiration from the Amazon rainforest generates an essential water source at a global and local scale. However, changes in rainforest function with climate change can disrupt this process, causing significant reductions in precipitation across Amazonia, and potentially at a global scale. We report the only study of forest transpiration following a long-term (>10 year) experimental drought treatment in Amazonian forest. After 15 years of receiving half the normal rainfall, drought-related tree mortality caused total forest transpiration to decrease by 30%. However, the surviving droughted trees maintained or increased transpiration because of reduced competition for water and increased light availability, which is consistent with increased growth rates. Consequently, the amount of water supplied as rainfall reaching the soil and directly recycled as transpiration increased to 100%. This value was 25% greater than for adjacent nondroughted forest. If these drought conditions were accompanied by a modest increase in temperature (e.g., 1.5°C), water demand would exceed supply, making the forest more prone to increased tree mortality.
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Affiliation(s)
| | - Lucy Rowland
- Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | | | | | - Oliver J Binks
- Research School of Biology, Australian National University, Canberra, Australia
| | - Yann Salmon
- Department of Physics, University of Helsinki, Helsinki, Finland
| | | | - João A S Junior
- Instituto de Geosciências, Universidade Federal do Pará, Belém, Brasil
| | | | - Rafael Poyatos
- CREAF, Campus UAB, Cerdanyola del Vallés, Spain
- Laboratory of Plant Ecology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | | | - Patrick Meir
- Research School of Biology, Australian National University, Canberra, Australia
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
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