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Walthert L, Etzold S, Carminati A, Saurer M, Köchli R, Zweifel R. Coordination between degree of isohydricity and depth of root water uptake in temperate tree species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174346. [PMID: 38944298 DOI: 10.1016/j.scitotenv.2024.174346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/26/2024] [Accepted: 06/26/2024] [Indexed: 07/01/2024]
Abstract
In an increasingly dry environment, it is crucial to understand how tree species use soil water and cope with drought. However, there is still a knowledge gap regarding the relationships between species-specific stomatal behaviour, spatial root distribution, and root water uptake (RWU) dynamics. Our study aimed to investigate above- and below-ground aspects of water use during soil drying periods in four temperate tree species that differ in stomatal behaviour: two isohydric tracheid-bearing conifers, Scots pine and Norway spruce, and two more anisohydric deciduous species, the diffuse-porous European beech, and the ring-porous Downy oak. From 2015 to 2020, soil-tree-atmosphere-continuum parameters were measured for each species in monospecific forests where trees had no access to groundwater. The hourly time series included data on air temperature, vapor pressure deficit, soil water potential, soil hydraulic conductivity, and RWU to a depth of 2 m. Analysis of drought responses included data on stem radius, leaf water potential, estimated osmotically active compounds, and drought damage. Our study reveals an inherent coordination between stomatal regulation, fine root distribution and water uptake. Compared to conifers, the more anisohydric water use of oak and beech was associated with less strict stomatal closure, greater investment in deep roots, four times higher maximum RWU, a shift of RWU to deeper soil layers as the topsoil dried, and a more pronounced soil drying below 1 m depth. Soil hydraulic conductivity started to limit RWU when values fell below 10-3 to 10-5 cm/d, depending on the soil. As drought progressed, oak and beech may also have benefited from their leaf osmoregulatory capacity, but at the cost of xylem embolism with around 50 % loss of hydraulic conductivity when soil water potential dropped below -1.25 MPa. Consideration of species-specific water use is crucial for forest management and vegetation modelling to improve forest resilience to drought.
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Affiliation(s)
- Lorenz Walthert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland.
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Andrea Carminati
- Physics of Soils and Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland
| | - Matthias Saurer
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roger Köchli
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
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2
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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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3
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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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Miller TW, Stangler DF, Larysch E, Honer H, Puhlmann H, Schindler D, Jung C, Seifert T, Rigling A, Kahle HP. Later growth onsets or reduced growth rates: What characterises legacy effects at the tree-ring level in conifers after the severe 2018 drought? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 854:158703. [PMID: 36099953 DOI: 10.1016/j.scitotenv.2022.158703] [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: 06/17/2022] [Revised: 09/06/2022] [Accepted: 09/08/2022] [Indexed: 06/15/2023]
Abstract
Severe drought events negatively affect tree growth and often cause legacy effects, expressed by smaller tree rings in the post-drought recovery years. While the pattern of reduced tree-ring widths is frequently described the processes underlying such legacy effects, i.e., whether it is due to shorter growth periods or lower growth rates, remains unclear and is investigated in this study. To elucidate these post-drought effects, we examined radial stem growth dynamics monitored with precision band-dendrometers on 144 Douglas fir, Norway spruce and silver fir sample trees distributed along four elevational gradients in the Black Forest (Southwest Germany) during the post-drought years 2019 and 2020. Growth onset of all investigated species occurred between 11 and 24 days significantly earlier in 2020 compared to 2019. Modelling growth onset based on chilling and forcing units and taking the study year into account explained 88-98 % of the variance in the growth onset data. The highly significant effect of the study year (p < 0.001) led to the conclusion, that other factors than the prevailing site conditions (chilling and forcing units) must have triggered the earlier growth onset in 2020. On the other hand, for Douglas fir growth rates were significantly higher in 2020 compared to 2019 (2.9 μm d-1) and marginally significantly higher for silver fir (1.3 μm d-1), underlining the explanatory power of growth rate on recovery processes in general and suggesting that Douglas fir copes better with droughts, as it recovered faster. Growth dynamics at the beginning of the year showed limited growth for earlier growth onsets, which, however, could not explain the difference between the investigated years. Our results provide evidence that legacy effects of drought events are expressed by a delayed growth onset and a reduced growth rate in the post-drought year and that Douglas fir has a superior recovery potential.
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Affiliation(s)
- Tobias Walter Miller
- Institute of Forest Sciences, Chair of Forest Growth and Dendroecology, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany.
| | - Dominik Florian Stangler
- Institute of Forest Sciences, Chair of Forest Growth and Dendroecology, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany
| | - Elena Larysch
- Institute of Forest Sciences, Chair of Forest Growth and Dendroecology, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany
| | - Harald Honer
- Institute of Forest Sciences, Chair of Forest Growth and Dendroecology, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany
| | - Heike Puhlmann
- Department of Soil and Environment, Forest Research Institute Baden-Württemberg, Freiburg, Germany
| | - Dirk Schindler
- Environmental Meteorology, University of Freiburg, Werthmann-str. 10, 79085 Freiburg, Germany
| | - Christopher Jung
- Environmental Meteorology, University of Freiburg, Werthmann-str. 10, 79085 Freiburg, Germany
| | - Thomas Seifert
- Institute of Forest Sciences, Chair of Forest Growth and Dendroecology, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany; Department for Forest and Wood Science, Stellenbosch University, Private Bag X1, 7602 Matieland, South Africa
| | - Andreas Rigling
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; SwissForestLab, Birmensdorf, Switzerland; Institute of Terrestrial Ecology, ETH Zürich, Zürich, Switzerland
| | - Hans-Peter Kahle
- Institute of Forest Sciences, Chair of Forest Growth and Dendroecology, University of Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany
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5
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Potkay A, Hölttä T, Trugman AT, Fan Y. Turgor-limited predictions of tree growth, height and metabolic scaling over tree lifespans. TREE PHYSIOLOGY 2022; 42:229-252. [PMID: 34296275 DOI: 10.1093/treephys/tpab094] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/18/2021] [Indexed: 06/13/2023]
Abstract
Increasing evidence suggests that tree growth is sink-limited by environmental and internal controls rather than by carbon availability. However, the mechanisms underlying sink-limitations are not fully understood and thus not represented in large-scale vegetation models. We develop a simple, analytically solved, mechanistic, turgor-driven growth model (TDGM) and a phloem transport model (PTM) to explore the mechanics of phloem transport and evaluate three hypotheses. First, phloem transport must be explicitly considered to accurately predict turgor distributions and thus growth. Second, turgor-limitations can explain growth-scaling with size (metabolic scaling). Third, turgor can explain realistic growth rates and increments. We show that mechanistic, sink-limited growth schemes based on plant turgor limitations are feasible for large-scale model implementations with minimal computational demands. Our PTM predicted nearly uniform sugar concentrations along the phloem transport path regardless of phloem conductance, stem water potential gradients and the strength of sink-demands contrary to our first hypothesis, suggesting that phloem transport is not limited generally by phloem transport capacity per se but rather by carbon demand for growth and respiration. These results enabled TDGM implementation without explicit coupling to the PTM, further simplifying computation. We test the TDGM by comparing predictions of whole-tree growth rate to well-established observations (site indices) and allometric theory. Our simple TDGM predicts realistic tree heights, growth rates and metabolic scaling over decadal to centurial timescales, suggesting that tree growth is generally sink and turgor limited. Like observed trees, our TDGM captures tree-size- and resource-based deviations from the classical ¾ power-law metabolic scaling for which turgor is responsible.
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Affiliation(s)
- Aaron Potkay
- Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ 08854, USA
| | - Teemu Hölttä
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki FI-00014, Finland
| | - Anna T Trugman
- Department of Geography, University of California at Santa Barbara, Santa Barbara, CA 93106, USA
| | - Ying Fan
- Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ 08854, USA
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6
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Zweifel R, Sterck F, Braun S, Buchmann N, Eugster W, Gessler A, Häni M, Peters RL, Walthert L, Wilhelm M, Ziemińska K, Etzold S. Why trees grow at night. THE NEW PHYTOLOGIST 2021; 231:2174-2185. [PMID: 34118158 PMCID: PMC8457160 DOI: 10.1111/nph.17552] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 06/07/2021] [Indexed: 05/22/2023]
Abstract
The timing of diel stem growth of mature forest trees is still largely unknown, as empirical data with high temporal resolution have not been available so far. Consequently, the effects of day-night conditions on tree growth remained uncertain. Here we present the first comprehensive field study of hourly-resolved radial stem growth of seven temperate tree species, based on 57 million underlying data points over a period of up to 8 yr. We show that trees grow mainly at night, with a peak after midnight, when the vapour pressure deficit (VPD) is among the lowest. A high VPD strictly limits radial stem growth and allows little growth during daylight hours, except in the early morning. Surprisingly, trees also grow in moderately dry soil when the VPD is low. Species-specific differences in diel growth dynamics show that species able to grow earlier during the night are associated with the highest number of hours with growth per year and the largest annual growth increment. We conclude that species with the ability to overcome daily water deficits faster have greater growth potential. Furthermore, we conclude that growth is more sensitive than carbon uptake to dry air, as growth stops before stomata are known to close.
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Affiliation(s)
- Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
| | - Frank Sterck
- Forest Ecology and Management GroupWageningen UniversityWageningen6708 PBthe Netherlands
| | - Sabine Braun
- Institute for Applied Plant BiologyWitterswil4108Switzerland
| | - Nina Buchmann
- Department of Environmental Systems ScienceInstitute of Agricultural SciencesETH ZurichZurich8092Switzerland
| | - Werner Eugster
- Department of Environmental Systems ScienceInstitute of Agricultural SciencesETH ZurichZurich8092Switzerland
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
| | - Matthias Häni
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
| | - Richard L. Peters
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
- Laboratory of Plant EcologyGhent UniversityGhent9000Belgium
| | - Lorenz Walthert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
| | - Micah Wilhelm
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
| | - Kasia Ziemińska
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
- Department of Plant Ecology and EvolutionUppsala UniversityUppsalaSE‐751 05Sweden
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf8903Switzerland
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7
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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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8
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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: 29] [Impact Index Per Article: 7.3] [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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9
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Oren I, Mannerheim N, Dumbur R, Fangmeier A, Buchmann N, Grünzweig JM. Patterns and dynamics of canopy-root coupling in tropical tree saplings vary with light intensity but not with root depth. THE NEW PHYTOLOGIST 2020; 225:727-739. [PMID: 31469437 DOI: 10.1111/nph.16153] [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: 06/20/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
Carbon (C) dynamics in canopy and roots influence whole-tree carbon fluxes, but little is known about canopy regulation of tree-root activity. Here, the patterns and dynamics of canopy-root C coupling are assessed in tropical trees. Large aeroponics facility was used to study the root systems of Ceiba pentandra and Khaya anthotheca saplings directly at different light intensities. In Ceiba, root respiration (Rr ) co-varied with photosynthesis (An ) in large saplings (3-to-7-m canopy-root axis) at high-light, but showed no consistent pattern at low-light. At medium-light and in small saplings (c. 1-m axis), Rr tended to decrease transiently towards midday. Proximal roots had higher Rr and nonstructural carbohydrate concentrations than distal roots, but canopy-root coupling was unaffected by root location. In medium-sized Khaya, no Rr pattern was observed, and in both species, Rr was unrelated to temperature. The early-afternoon increase in Rr suggests that canopy-root coupling is based on mass flow of newly fixed C in the phloem, whereas the early-morning rise in Rr with An indicates an additional coupling signal that travels faster than the phloem sap. In large saplings and potentially also in higher trees, light and possibly additional environmental factors control the diurnal patterns of canopy-root coupling, irrespective of root location.
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Affiliation(s)
- Israel Oren
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, 7610001, Rehovot, Israel
| | - Neringa Mannerheim
- Institute of Agricultural Sciences, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - Rita Dumbur
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, 7610001, Rehovot, Israel
| | - Andreas Fangmeier
- Institute of Landscape and Plant Ecology, University of Hohenheim, August-von-Hartmann-Str. 3, 70599, Stuttgart, Germany
| | - Nina Buchmann
- Institute of Agricultural Sciences, ETH Zürich, Universitätstrasse 2, 8092, Zürich, Switzerland
| | - José M Grünzweig
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, 7610001, Rehovot, Israel
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