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Oberhuber W, Gruber A, Wieser G. Seasonal and Daily Xylem Radius Variations in Scots Pine Are Closely Linked to Environmental Factors Affecting Transpiration. BIOLOGY 2023; 12:1251. [PMID: 37759650 PMCID: PMC10525319 DOI: 10.3390/biology12091251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023]
Abstract
Seasonal and daily radius variations in the xylem (XRV) and inner bark (IBV) of mature Scots pine trees (Pinus sylvestris) were determined during April 2019-October 2021 at a drought-prone inner alpine site (c. 750 m asl; Tyrol, Austria) by applying point dendrometers. XRVs were also related to environmental factors to evaluate the drivers of XRV during the growing season. XRV records revealed that the xylem width (i) started to shrink around the onset of radial stem growth in April, (ii) consistently decreased by c. 50 µm at the time when air temperature (T) and vapor pressure deficit (VPD) reached their maximum in late June through mid-July, and (iii) recovered until November/December. Although in daily cycles of radius variations XRV preceded IBV by about two hours and the daily amplitude of XRV was about 1/10 that of IBV, XRV and IBV (seasonal trends removed) were closely linked (ρ = 0.755; p < 0.001), indicating tight hydraulic coupling between these tissues. Furthermore, the daily amplitude of XRV was linearly and closely related to daily maximum T (ρ = 0.802; p < 0.001), mean daily solar radiation (ρ = 0.809; p < 0.001), and non-linearly related to daily maximum VPD (R2= 0.837; p < 0.001), indicating that the xylem of Pinus sylvestris reacts like a transpiration-driven passive hydraulic system.
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Affiliation(s)
- Walter Oberhuber
- Department of Botany, University of Innsbruck, Sternwartestrasse 15, A-6020 Innsbruck, Austria; (A.G.); (G.W.)
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Bucci SJ, Carbonell-Silletta L, Cavallaro A, Arias NS, Campanello PI, Goldstein G, Scholz FG. Bark and sapwood water storage and the atypical pattern of recharge and discharge of water reservoirs indicate low vulnerability to drought in Araucaria araucana. TREE PHYSIOLOGY 2023; 43:248-261. [PMID: 36209429 DOI: 10.1093/treephys/tpac113] [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: 08/13/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Stored water in inner tissues influences the plant water economy, which might be particularly relevant for trees facing increasing dry conditions due to climate change. We studied the water storage in the inner bark and the sapwood of Araucaria araucana (Molina) K. Koch. This species has an extremely thick inner bark and thus it can be used as a model system to assess the impact of internal water storage on plant water balance. Specifically, we analyzed the water circulation pathways in and out of the elastic water storages by using simultaneously frequency domain moisture sensors and dendrometers inserted in the inner bark and in the sapwood, and sap flow determinations during the dry season. The daily patterns of water content and expansion and contraction of the stem tissues were similar to the sap flow pattern. The whole-stem water content and diameter increased in the morning and decreased in the afternoon, contrary to the typical pattern observed in most tree species. An osmotic gradient favoring the water influx from sapwood to inner bark was observed in the morning. There were no lags in the onset of sap flow between different stem heights at the time that recharge of reservoirs occurred. Sap flow at 6 m height was higher than basal sap flow in the afternoon, when the sapwood water content started to decline followed by the water content of the inner bark. Inner bark and sapwood contributed 5-11% to total daily transpiration, allowing the maintenance of high water potentials in the dry season. Our results suggest that the stored water in the stems, the atypical dynamic of recharge and discharge of water from reservoirs and the high tissue capacitance may make an important contribution to the survival of A. araucana during drought periods by maintaining the water balance.
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Affiliation(s)
- Sandra Janet Bucci
- Grupo de Estudios Biofísicos y Ecofisiológicos (GEBEF), Instituto de Biociencias de la Patagonia (INBIOP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
- Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
| | - Luisina Carbonell-Silletta
- Grupo de Estudios Biofísicos y Ecofisiológicos (GEBEF), Instituto de Biociencias de la Patagonia (INBIOP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
- Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
| | - Agustin Cavallaro
- Grupo de Estudios Biofísicos y Ecofisiológicos (GEBEF), Instituto de Biociencias de la Patagonia (INBIOP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
- Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
| | - Nadia Soledad Arias
- Grupo de Estudios Biofísicos y Ecofisiológicos (GEBEF), Instituto de Biociencias de la Patagonia (INBIOP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
- Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
| | - Paula Inés Campanello
- CONICET and Departamento de Ingeniería Forestal, Facultad de Ingeniería, UNPSJB, Esquel U9200, Argentina
| | - Guillermo Goldstein
- Instituto de Ecología, Genética y Evolución de Buenos Aires. UBA-CONICET, Buenos Aires 1425, Argentina
- University of Miami, Coral Gables, FL 33124, USA
| | - Fabián Gustavo Scholz
- Grupo de Estudios Biofísicos y Ecofisiológicos (GEBEF), Instituto de Biociencias de la Patagonia (INBIOP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
- Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), 9000 Comodoro Rivadavia, Argentina
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Preisler Y, Hölttä T, Grünzweig JM, Oz I, Tatarinov F, Ruehr NK, Rotenberg E, Yakir D. The importance of tree internal water storage under drought conditions. TREE PHYSIOLOGY 2022; 42:771-783. [PMID: 34726242 DOI: 10.1093/treephys/tpab144] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Global warming and drying trends, as well as the increase in frequency and intensity of droughts, may have unprecedented impacts on various forest ecosystems. We assessed the role of internal water storage (WS) in drought resistance of mature pine trees in the semi-arid Yatir Forest. Transpiration (T), soil moisture and sap flow (SF) were measured continuously, accompanied by periodical measurements of leaf and branch water potential (Ψleaf) and water content (WC). The data were used to parameterize a tree hydraulics model to examine the impact of WS capacitance on the tree water relations. The results of the continuous measurements showed a 5-h time lag between T and SF in the dry season, which peaked in the early morning and early afternoon, respectively. A good fit between model results and observations was only obtained when the empirically estimated WS capacitance was included in the model. Without WS during the dry season, Ψleaf would drop below a threshold known to cause hydraulic failure and cessation of gas exchange in the studied tree species. Our results indicate that tree WS capacitance is a key drought resistance trait that could enhance tree survival in a drying climate, contributing up to 45% of the total daily transpiration during the dry season.
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Affiliation(s)
- Yakir Preisler
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street POB 12, Rehovot 7610001, Israel
| | - Teemu Hölttä
- Faculty of Agriculture and Forestry, Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, 3 Yliopistonkatu st, 0001 Helsinki, Finland
| | - José M Grünzweig
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street POB 12, Rehovot 7610001, Israel
| | - Itay Oz
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
- Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street POB 12, Rehovot 7610001, Israel
| | - Fedor Tatarinov
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
| | - Nadine K Ruehr
- Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research-Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen 82467, Germany
| | - Eyal Rotenberg
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
| | - Dan Yakir
- Earth and Planetary Science, Weizmann Institute of Science, 234 Herzl St. Rehovot, Rehovot 7610001, Israel
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Epron D, Kamakura M, Azuma W, Dannoura M, Kosugi Y. Diurnal variations in the thickness of the inner bark of tree trunks in relation to xylem water potential and phloem turgor. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2021; 2:112-124. [PMID: 37283860 PMCID: PMC10168075 DOI: 10.1002/pei3.10045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 06/08/2023]
Abstract
The inner bark plays important roles in tree stems, including radial exchange of water with the xylem and translocation of carbohydrates. Both processes affect the water content and the thickness of the inner bark on a diurnal basis. For the first time, we simultaneously measured the diurnal variations in the inner bark thickness of hinoki cypress (Chamaecyparis obtusa) by using point dendrometers and those of local xylem potential by using stem psychrometers located next to the dendrometers to determine how these variations were related to each other, to phloem turgor and carbohydrate transport. We also estimated the axial hydrostatic pressure gradient by measuring the osmolality of the sap extracted from the inner bark. The inner bark shrunk during the day and swelled during the night with an amplitude related to day-to-day and seasonal variations in climate. The relationship between changes in xylem water potential and inner bark thickness exhibited a hysteresis loop during the day with a median lag of 2 h. A phloem turgor-related signal can be retrieved from the diurnal variations in the inner bark thickness, which was higher at the upper than at the lower position along the trunk. However, a downward hydrostatic pressure gradient was only observed at dawn, suggesting diurnal variations in the phloem sap flow velocity.
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Affiliation(s)
- Daniel Epron
- Graduate School of AgricultureKyoto UniversityKyotoJapan
- AgroParisTechINRAEUMR SILVAUniversité de LorraineNancyFrance
| | - Mai Kamakura
- Graduate School of AgricultureKyoto UniversityKyotoJapan
| | - Wakana Azuma
- Graduate School of Agricultural ScienceKobe UniversityKobeJapan
| | | | - Yoshiko Kosugi
- Graduate School of AgricultureKyoto UniversityKyotoJapan
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Zweifel R, Etzold S, Sterck F, Gessler A, Anfodillo T, Mencuccini M, von Arx G, Lazzarin M, Haeni M, Feichtinger L, Meusburger K, Knuesel S, Walthert L, Salmon Y, Bose AK, Schoenbeck L, Hug C, De Girardi N, Giuggiola A, Schaub M, Rigling A. Determinants of legacy effects in pine trees - implications from an irrigation-stop experiment. THE NEW PHYTOLOGIST 2020; 227:1081-1096. [PMID: 32259280 PMCID: PMC7383578 DOI: 10.1111/nph.16582] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/24/2020] [Indexed: 05/02/2023]
Abstract
Tree responses to altered water availability range from immediate (e.g. stomatal regulation) to delayed (e.g. crown size adjustment). The interplay of the different response times and processes, and their effects on long-term whole-tree performance, however, is hardly understood. Here we investigated legacy effects on structures and functions of mature Scots pine in a dry inner-Alpine Swiss valley after stopping an 11-yr lasting irrigation treatment. Measured ecophysiological time series were analysed and interpreted with a system-analytic tree model. We found that the irrigation stop led to a cascade of downregulations of physiological and morphological processes with different response times. Biophysical processes responded within days, whereas needle and shoot lengths, crown transparency, and radial stem growth reached control levels after up to 4 yr only. Modelling suggested that organ and carbon reserve turnover rates play a key role for a tree's responsiveness to environmental changes. Needle turnover rate was found to be most important to accurately model stem growth dynamics. We conclude that leaf area and its adjustment time to new conditions is the main determinant for radial stem growth of pine trees as the transpiring area needs to be supported by a proportional amount of sapwood, despite the growth-inhibiting environmental conditions.
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Affiliation(s)
- Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Frank Sterck
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Forest Ecology and Management GroupWageningen University6701Wageningenthe Netherlands
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Institute of Terrestrial EcosystemsETH Zurich8092ZurichSwitzerland
| | - Tommaso Anfodillo
- Dipartimento Territorio e Sistemi Agro‐ForestaliUniversity of Padova35020LegnaroItaly
| | - Maurizio Mencuccini
- ICREA08010BarcelonaSpain
- CREAFUniversidad Autonoma de Barcelona08193BarcelonaSpain
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Martina Lazzarin
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Horticulture and Product PhysiologyWageningen UniversityWageningen6701the Netherlands
| | - Matthias Haeni
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Linda Feichtinger
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Katrin Meusburger
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Simon Knuesel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Lorenz Walthert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Yann Salmon
- Institute for Atmospheric and Earth System Research/PhysicsUniversity of Helsinki00100HelsinkiFinland
- Institute for Atmospheric and Earth System Research/Forest SciencesUniversity of Helsinki00100HelsinkiFinland
| | - Arun K. Bose
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Forestry and Wood Technology DisciplineKhulna University9208KhulnaBangladesh
| | - Leonie Schoenbeck
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Christian Hug
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Nicolas De Girardi
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Arnaud Giuggiola
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Marcus Schaub
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Andreas Rigling
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
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Environmental Controls of Diurnal and Seasonal Variations in the Stem Radius of Platycladus orientalis in Northern China. FORESTS 2019. [DOI: 10.3390/f10090784] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fine-resolution studies of stem radial variation over short timescales throughout the year can provide insight into intra-annual stem dynamics and improve our understanding of climate impacts on tree physiology and growth processes. Using data from high-resolution point dendrometers collected from Platycladus orientalis (Linn.) trees between September 2013 and December 2014, this study investigated the daily and seasonal patterns of stem radial variation in addition to the relationships between daily stem radial variation and environmental factors over the growing season. Two contrasting daily cycle patterns were observed for warm and cold seasons. A daily mean air temperature of 0 °C was a critical threshold that was related to seasonal shifts in stem diurnal cycle patterns, indicating that air temperature critically influences diurnal stem cycles. The annual variation in P. orientalis stem radius variation can be divided into four distinct periods including (1) spring rehydration, (2) the summer growing season, (3) autumn stagnation, and (4) winter contraction. These periods reflect seasonal changes in tree water status that are especially pronounced in spring and winter. During the growing season, the maximum daily shrinkage (MDS) of P. orientalis was positively correlated with air temperature (Ta) and negatively correlated with soil water content (SWC) and precipitation (P). The vapor pressure deficit (VPD) also exhibited a threshold-based control on MDS at values below or above 0.8 kPa. Daily radial changes (DRC) were negatively correlated with Ta and VPD but positively correlated with relative air humidity (RH) and P. These results suggest that the above environmental factors are associated with tree water status via their influence on moisture availability to trees, which in turn affects the metrics of daily stem variation including MDS and DRC.
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Vilas MP, Adams MP, Ball MC, Meynecke JO, Santini NS, Swales A, Lovelock CE. Night and day: Shrinking and swelling of stems of diverse mangrove species growing along environmental gradients. PLoS One 2019; 14:e0221950. [PMID: 31479477 PMCID: PMC6719867 DOI: 10.1371/journal.pone.0221950] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 08/19/2019] [Indexed: 12/22/2022] Open
Abstract
Tree stems swell and shrink daily, which is thought to reflect changes in the volume of water within stem tissues. We observed these daily patterns using automatic dendrometer bands in a diverse group of mangrove species over five mangrove forests across Australia and New Caledonia. We found that mangrove stems swelled during the day and shrank at night. Maximum swelling was highly correlated with daily maxima in air temperature. Variation in soil salinity and levels of tidal inundation did not influence the timing of stem swelling over all species. Medium-term increases in stem circumference were highly sensitive to rainfall. We defoliated trees to assess the role of foliar transpiration in stem swelling and shrinking. Defoliated trees showed maintenance of the pattern of daytime swelling, indicating that processes other than canopy transpiration influence the temporary stem diameter increments, which could include thermal swelling of stems. More research is required to understand the processes contributing to stem shrinking and swelling. Automatic Dendrometer Bands could provide a useful tool for monitoring the response of mangroves to extreme climatic events as they provide high-frequency, long-term, and large-scale information on tree water status.
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Affiliation(s)
- Maria P. Vilas
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, Australia
- CSIRO Agriculture and Food, Biosciences Precinct, St Lucia, QLD, Australia
| | - Matthew P. Adams
- School of Chemical Engineering, The University of Queensland, St Lucia, QLD, Australia
- School of Earth and Environmental Sciences, The University of Queensland, St Lucia, QLD, Australia
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Marilyn C. Ball
- Research School of Biology, Australian National University College of Science, Australian National University, Canberra ACT, Australia
| | - Jan-Olaf Meynecke
- Griffith Centre for Coastal Management, Griffith University, Gold Coast, QLD, Australia
| | - Nadia S. Santini
- Cátedra Consejo Nacional de Ciencia y Tecnología, Crédito Constructor, Benito Juárez, Ciudad de México, México
- Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, México
| | - Andrew Swales
- National Institute of Water and Atmospheric Research, Hamilton, New Zealand
| | - Catherine E. Lovelock
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia
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Yu MH, Ding GD, Gao GL, Zhao YY, Sai K. Hysteresis resulting in forestry heat storage underestimation: A case study of plantation forestry in northern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 671:608-616. [PMID: 30933817 DOI: 10.1016/j.scitotenv.2019.03.340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/11/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Heat storage (Q) is an important component of the near-surface energy balance, and has been increasingly considered in recent energy balance studies. Studies have revealed that the hysteresis of heat storage was always been ignored, which leaded to the underestimation of heat storage proportion in energy balance. So, for further understanding the role of hysteresis effect in forestry heat storage, an observation experiment of heat storage in forestry of Pinus sylvestris var. mongolica Litv forestry - a common species in northern China - was conducted. Heat storage in the atmosphere beneath canopy, in the canopy biomass, and in the soil above a soil heat-flow plate were monitored continuously, to determine the distribution of stored heat, and solar radiation was simultaneously monitored to verify the hysteresis of heat storage versus radiation. Seasonal variations were separately analyzed to further clarify phenological effect on hysteresis. Correlation relationship was tested of lag time and underestimated energy versus climatic factors and physiological characteristics, for clarifying the reasons that resulting in hysteresis differences under different experimental day. The main results were as follows: (1) Hysteresis exists in heat storage and the lag time was 3.79 h in our study area; (2) The evaluation of hysteresis is crucial to avoid an underestimation of heat storage. Correction of lag time increases the heat storage proportion in R from 3.78% to 8.48%; (3) Increasing of air temperature and humility daily differences will enhance the underestimated energy. High radiation condition will weak the underestimation on heat storage and short the lag time. Soil moisture and leaf area index were not effect energy hysteresis significantly in sandy vegetation. Climatic factors were the main reason that resulting in the differences of hysteresis. This study helps to improve understanding energy transmitting in canopy and offering a new view in solving surface energy imbalance.
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Affiliation(s)
- Ming-Han Yu
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
| | - Guo-Dong Ding
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
| | - Guang-Lei Gao
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Yuan-Yuan Zhao
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
| | - Ke Sai
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China; Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
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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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10
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Donnellan Barraclough A, Zweifel R, Cusens J, Leuzinger S. Disentangling the net: concomitant xylem and over-bark size measurements reveal the phloem-generated turgor signal behind daytime stem swelling in the mangrove Avicennia marina. FUNCTIONAL PLANT BIOLOGY : FPB 2019; 46:393-406. [PMID: 30940339 DOI: 10.1071/fp18155] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 12/25/2018] [Indexed: 06/09/2023]
Abstract
Daytime stem shrinking is a well recorded phenomenon: trees dip into their internal water stores to meet imbalances between water supply and demand. Uncertainty surrounds the mechanisms behind the unusual pattern of daytime stem swelling, presented by species like the mangrove Avicennia marina (Forssk.) Vierh., and which is thought to originate in the osmotic adjustment of storage tissues. We performed on-xylem radius change (XRC) and whole-stem radius change (SRC) measurements with point dendrometers to ascertain if the swelling of the stem is due to an increase in the thickness of the phloem and inner-bark (BRC). We measured leaf water potential (ψleaf), sap flow, leaf turgor and microclimate to understand the coupling between BRC and transpiration-driven changes in XRC. Our results present direct evidence of the type of mechanism responsible for daytime stem swelling. Inner-bark thickness increase concurrent with XRC decrease, sap-flow increase and leaf turgor loss, reveals a phloem-generated turgor signal behind daytime stem swelling of tree stems. On-xylem measurements were highly heterogeneous due to the variability in the three dimensional fish-net wood structure of the stem of A. marina. As daytime decreases in XRC were compensated by BRC and correlated with conditions of high water demand, we suggest a potential role of daytime stem swelling in the hydraulic safety of A. marina.
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Affiliation(s)
- Alicia Donnellan Barraclough
- Institute of Applied Ecology New Zealand, Auckland University of Technology, 34 St Paul Street, Auckland 1010, New Zealand; and Corresponding author.
| | - Roman Zweifel
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
| | - Jarrod Cusens
- Institute of Applied Ecology New Zealand, Auckland University of Technology, 34 St Paul Street, Auckland 1010, New Zealand; and Wildland Consultants Ltd, 12 Nixon Street, Grey Lynn, Auckland 1021, New Zealand
| | - Sebastian Leuzinger
- Institute of Applied Ecology New Zealand, Auckland University of Technology, 34 St Paul Street, Auckland 1010, New Zealand
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Hilty J, Pook C, Leuzinger S. Water relations determine short time leaf growth patterns in the mangrove Avicennia marina (Forssk.) Vierh. PLANT, CELL & ENVIRONMENT 2019; 42:527-535. [PMID: 30171613 DOI: 10.1111/pce.13435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/13/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
High-resolution leaf growth is rarely studied despite its importance as a metric for plant performance and resource use efficiency. This is in part due to methodological challenges. Here, we present a method for in situ leaf growth measurements in a natural environment. We measured instantaneous leaf growth on a mature Avicennia marina subsp. australasica tree over several weeks. We measured leaf expansion by taking time-lapse images and analysing them using marker tracking software. A custom-made instrument was designed to enable long-term field studies. We detected a distinct diel growth pattern with leaf area shrinkage in the morning and leaf expansion in the afternoon and at night. On average, the observed daily shrinkage was 37% of the net growth. Most of the net growth occurred at night. Diel leaf area shrinkage and recovery continued after growth cessation. The amount of daily growth was negatively correlated with shrinkage, and instantaneous leaf growth and shrinkage were correlated with changes in leaf turgor. We conclude that, at least in this tree species, instantaneous leaf growth patterns are very strongly linked to, and most likely driven by, leaf water relations, suggesting decoupling of short-term growth patterns from carbon assimilation.
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Affiliation(s)
- Jonas Hilty
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
| | - Chris Pook
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
| | - Sebastian Leuzinger
- Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New Zealand
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Sellier D, Mammeri Y. Diurnal dynamics of phloem loading: theoretical consequences for transport efficiency and flow characteristics. TREE PHYSIOLOGY 2019; 39:300-311. [PMID: 30753675 DOI: 10.1093/treephys/tpz001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 12/20/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Phloem transport is the process by which plants internally distribute assimilates. The loading of assimilates near the photosynthetic source is responsible for generating enough osmotic pressure to drive sap flow towards the sink tissues where assimilates are consumed. Phloem loading is variable and subject to a diurnal cycle. It is dominated by photosynthesis during the day and by degradation of leaf starch to sugars at night. Most studies ignore the effect of the loading cycle on transport and assume that sugar flow operates at equilibrium. In this study, phloem transport was simulated for three successive days using a finite element model of time-dependent Münch-Horwitz equations. The spatial and temporal distributions of phloem pressure, sucrose concentration, sap velocity and sucrose flux were predicted for five different time variations in sucrose loading. Results showed that periodic loading induces an alternance of two distinct transport phases: one with high pressure, concentration and sucrose flux magnitudes and another with low magnitudes. In contrast, phloem water velocity remained remarkably stable. The alternating phases persisted over time and, under source-driven variation, transport did not reach steady-state conditions for the tested configuration. However, the impact of loading dynamics on transport was mitigated by pathway effects. Oscillations were not only delayed as one travelled away from the source, their amplitude was also reduced over distance. That behaviour stabilized the supply of sucrose to the sink, which continued at moderate levels during the dark cycles. This finding suggests that transport would assist night conversion of starch to sugars in the leaf to prevent carbon starvation at distant sinks in the early morning. The propagation velocity of pressure/concentration waves in phloem was predicted to vary by a factor up to 2.5 depending on the time series chosen to describe the dynamics of loading. Finally, the model predicted that up to 87% of the amount of sucrose loaded over 48 h would be unloaded under time-dependent loading, whereas only 76% would under constant-rate loading. This additional efficiency was periodic. It did not increase significantly the overall efficiency of the system but could be responsible for inducing rhythms in sink activity.
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Affiliation(s)
- Damien Sellier
- New Zealand Forest Research Institute (trading as SCION), Private Bag 3020, Rotorua, New Zealand
| | - Youcef Mammeri
- Laboratoire Amiénois de Mathématique Fondamentale et Appliquée, CNRS UMR 7352, Université de Picardie Jules Verne, Amiens, France
- Institut de Génétique, Environnement et Protection des Plantes, INRA UMR 1349, Le Rheu, France
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Lazzarin M, Zweifel R, Anten N, Sterck FJ. Does phloem osmolality affect diurnal diameter changes of twigs but not of stems in Scots pine? TREE PHYSIOLOGY 2019; 39:275-283. [PMID: 30371898 DOI: 10.1093/treephys/tpy121] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/12/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
Diel stem diameter changes measured at the stem base of temperate tree species can be mostly explained by a hydraulic system of flow and storage compartments passively driven by transpiration. Active, osmotic processes are considered to play a minor role only. Here we explore whether such osmotic processes have a stronger impact on diel changes in twig diameter than in stem diameter because twigs are closer to the leaves, the main source of newly acquired carbon. We investigated stem and twig diameter changes of wood and bark of pine trees in parallel to fluctuations of the osmolality in needles and in the bark at the stem base. We found consistent twig bark size increments concurrent with twig wood size decreases during daylight hours whereas needle osmolality was not consistently increasing even on sunny days. The size changes of bark and wood either reversed or ran in parallel from late afternoon onwards until the next morning. No such patterns were measurable at the stem base. Stem wood was hardly changing in size, whereas stem bark followed the regular pattern of a decrease during the daylight hours and an increase during the night. Osmolality at the stem base showed no particular course over 24 h. We conclude that assimilates from the needles were rapidly transported to the twigs where they increased the osmolality of the bark tissue by sugar loading, explaining the bark size increase (over-) compensating the xylem size decrease. The stem base largely followed the expectation of a passive, hydraulic system without a measurable role of osmoregulation. Diameter changes thus follow different diurnal dynamics in twigs and at the stem base.
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Affiliation(s)
- Martina Lazzarin
- Forest Ecology and Forest Management Group, Wageningen, The Netherlands
| | - Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) Zürcherstrasse 111, Birmensdorf, Switzerland
| | - Niels Anten
- Centre for Crop Systems Analysis, 6708PB Wageningen, The Netherlands
| | - Frank J Sterck
- Forest Ecology and Forest Management Group, Wageningen, The Netherlands
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