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Zambonini D, Savi T, Rosner S, Petit G. Consistent decrease in conifer embolism resistance from the stem apex to base resulting from axial trends in tracheid and pit traits. FRONTIERS IN PLANT SCIENCE 2024; 15:1414448. [PMID: 38988629 PMCID: PMC11234846 DOI: 10.3389/fpls.2024.1414448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/03/2024] [Indexed: 07/12/2024]
Abstract
Introduction Drought-induced embolism formation in conifers is associated with several tracheid and pit traits, which vary in parallel from stem apex to base. We tested whether this axial anatomical variability is associated with a progressive variation in embolism vulnerability along the stem from apex to base. Methods We assessed the tracheid hydraulic diameter (Dh), mean pit membrane area (PMA) and the xylem pressure at 50% loss of conductivity (P50) on longitudinal stem segments extracted at different distances from the stem apex (DFA) in a Picea abies and an Abies alba tree. Results In both trees, Dh and PMA scaled with DFA 0.2. P50 varied for more than 3 MPa from the treetop to the stem base, according to a scaling of -P50 with DFA-0.2 . The largest Dh, PMA and P50 variation occurred for DFA<1.5 m. PMA and Dh scaled more than isometrically (exponent b=1.2). Pit traits vary proportionally with tracheid lumen diameter. Discussion and conclusions Apex-to-base trends in tracheid and pit traits, along with variations in P50, suggest a strong structure-function relationship that is influenced by DFA. Although the effect of DFA on P50 has not been extensively explored previously, we propose that analyzing the relationship between P50 and DFA could be crucial for a comprehensive assessment of embolism vulnerability at the individual level.
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Affiliation(s)
- Dario Zambonini
- Dept. Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Legnaro (PD), Italy
| | - Tadeja Savi
- Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna (BOKU), Institute of Botany, Vienna, Austria
| | - Sabine Rosner
- Department of Integrative Biology and Biodiversity Research, University of Natural Resources and Life Sciences, Vienna (BOKU), Institute of Botany, Vienna, Austria
| | - Giai Petit
- Dept. Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Legnaro (PD), Italy
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Li Y, Hoch G. The sensitivity of root water uptake to cold root temperature follows species-specific upper elevational distribution limits of temperate tree species. PLANT, CELL & ENVIRONMENT 2024; 47:2192-2205. [PMID: 38481108 DOI: 10.1111/pce.14874] [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: 11/16/2023] [Revised: 02/21/2024] [Accepted: 02/24/2024] [Indexed: 04/30/2024]
Abstract
Physiological water stress induced by low root temperatures might contribute to species-specific climatic limits of tree distribution. We investigated the low temperature sensitivity of root water uptake and transport in seedlings of 16 European tree species which reach their natural upper elevation distribution limits at different distances to the alpine treeline. We used 2H-H2O pulse-labelling to quantify the water uptake and transport velocity from roots to leaves in seedlings exposed to constant 15°C, 7°C or 2°C root temperature, but identical aboveground temperatures between 20°C and 25°C. In all species, low root temperatures reduced the water transport rate, accompanied by reduced stem water potentials and stomatal conductance. At 7°C root temperature, the relative water uptake rates among species correlated positively with the species-specific upper elevation limits, indicating an increasingly higher sensitivity to lower root zone temperatures, the lower a species' natural elevational distribution limit. Conversely, 2°C root temperature severely inhibited water uptake in all species, irrespective of the species' thermal elevational limits. We conclude that low temperature-induced hydraulic constraints contribute to the cold distribution limits of temperate tree species and are a potential physiological cause behind the low temperature limits of plant growth in general.
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Affiliation(s)
- Yating Li
- Department of Environmental Sciences-Botany, University of Basel, Basel, Switzerland
| | - Günter Hoch
- Department of Environmental Sciences-Botany, University of Basel, Basel, Switzerland
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3
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Rajarajan K, Verma S, Sahu S, Radhakrishna A, Kumar N, Priyadarshini E, Handa AK, Arunachalam A. Differential gene expression analysis reveals the fast-growth mechanisms in Melia dubia at different stand ages. Mol Biol Rep 2023; 50:10671-10675. [PMID: 37934367 DOI: 10.1007/s11033-023-08873-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/02/2023] [Indexed: 11/08/2023]
Abstract
BACKGROUND Melia dubia Cav. is a fast-growing multipurpose tree suitable for agroforestry and has been widely cultivated for wood-based industries, particularly pulp and paper production. Despite its high economic value in India, there is a lack of information regarding the molecular mechanism driving its fast-growth. Therefore, this study aimed to elucidate the molecular mechanisms responsible for fast-growth by expression analysis of selective candidate genes. METHODS AND RESULTS Initially, growth traits were assessed, including tree height and diameter at breast height (DBH), across three different ages (one-year-old, two-year-old, and three-year-old) of M. dubia plantations. Tree volume based on tree height and DBH, was also calculated. The analysis of annual tree height increment revealed that the second-year plantation exhibited the higher increment, followed by first and third years. In contrast, DBH was maximum in third-year plantation, followed by the second and first years. Similarly, annual tree volume increment showed a similar trend with DBH that maximum in the third year, followed by second and first years. Furthermore, a differential gene expression analysis was performed using qRT-PCR on four genes such as Phloem Intercalated with Xylem (PXY), Clavata3/Embryo Surrounding Region-Related 41 (CLE41), 1-aminocyclopropane-1-carboxylic acid synthase (ACS-1) and Hemoglobin1 (Hb1) for downstream analysis. The relative gene expression showed up-regulation of CLE41, ACS-1, and Hb1 genes, while the PXY gene was downregulated across the tree ages. Interestingly, a positive association was observed between tree growth and the expression of the selected candidate genes. CONCLUSION Our results pave the way for further research on the regulatory mechanisms of genes involved in fast-growth and provide a basis for genetic improvement of Melia dubia.
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Affiliation(s)
- K Rajarajan
- ICAR-Central Agroforestry Research Institute, Jhansi, India.
| | - Shailesh Verma
- ICAR-Central Agroforestry Research Institute, Jhansi, India
| | - Sakshi Sahu
- ICAR-Central Agroforestry Research Institute, Jhansi, India
| | - A Radhakrishna
- ICAR-Directorate of Onion and Garlic Research, Pune, India
| | - Naresh Kumar
- ICAR-Central Agroforestry Research Institute, Jhansi, India
| | - E Priyadarshini
- ICAR- Indian Grassland and Fodder Research Institute, Jhansi, India
| | - A K Handa
- ICAR-Central Agroforestry Research Institute, Jhansi, India
| | - A Arunachalam
- ICAR-Central Agroforestry Research Institute, Jhansi, India
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4
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Petit G, Mencuccini M, Carrer M, Prendin AL, Hölttä T. Axial conduit widening, tree height, and height growth rate set the hydraulic transition of sapwood into heartwood. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5072-5087. [PMID: 37352139 DOI: 10.1093/jxb/erad227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/12/2023] [Indexed: 06/25/2023]
Abstract
The size-related xylem adjustments required to maintain a constant leaf-specific sapwood conductance (KLEAF) with increasing height (H) are still under discussion. Alternative hypotheses are that: (i) the conduit hydraulic diameter (Dh) at any position in the stem and/or (ii) the number of sapwood rings at stem base (NSWr) increase with H. In addition, (iii) reduced stem elongation (ΔH) increases the tip-to-base conductance through inner xylem rings, thus possibly the NSWr contributing to KLEAF. A detailed stem analysis showed that Dh increased with the distance from the ring apex (DCA) in all rings of a Picea abies and a Fagus sylvatica tree. Net of DCA effect, Dh did not increase with H. Using sapwood traits from a global dataset, NSWr increased with H, decreased with ΔH, and the mean sapwood ring width (SWrw) increased with ΔH. A numerical model based on anatomical patterns predicted the effects of H and ΔH on the conductance of inner xylem rings. Our results suggest that the sapwood/heartwood transition depends on both H and ΔH, and is set when the carbon allocation to maintenance respiration of living cells in inner sapwood rings produces a lower gain in total conductance than investing the same carbon in new vascular conduits.
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Affiliation(s)
- Giai Petit
- Università degli Studi di Padova, Dept. TeSAF, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Maurizio Mencuccini
- CREAF, Bellaterra (Cerdanyola del Vallès), E08193, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, 08010, Spain
| | - Marco Carrer
- Università degli Studi di Padova, Dept. TeSAF, Viale dell'Università 16, 35020 Legnaro (PD), Italy
| | - Angela Luisa Prendin
- Università degli Studi di Padova, Dept. TeSAF, Viale dell'Università 16, 35020 Legnaro (PD), Italy
- Department of Biology, Ecoinformatics and Biodiversity, Aarhus University, Ny Munkegade 114-116, building 1540, 8000 Aarhus C, Denmark University of Aarhus, Denmark
| | - Teemu Hölttä
- Institute for Atmospheric and Earth System Research/ Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Latokartanonkaari 7, FI 00014 Helsinki, Finland
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Crivellaro A, Piermattei A, Dolezal J, Dupree P, Büntgen U. Biogeographic implication of temperature-induced plant cell wall lignification. Commun Biol 2022; 5:767. [PMID: 35906325 PMCID: PMC9338036 DOI: 10.1038/s42003-022-03732-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/15/2022] [Indexed: 12/02/2022] Open
Abstract
More than 200 years after von Humboldt’s pioneering work on the treeline, our understanding of the cold distribution limit of upright plant growth is still incomplete. Here, we use wood anatomical techniques to estimate the degree of stem cell wall lignification in 1770 plant species from six continents. Contrary to the frequent belief that small plants are less lignified, we show that cell wall lignification in ‘woody’ herbs varies considerably. Although trees and shrubs always exhibit lignified cell walls in their upright stems, small plants above the treeline may contain less lignin. Our findings suggest that extremely cold growing season temperatures can reduce the ability of plants to lignify their secondary cell walls. Corroborating experimental and observational evidence, this study proposes to revisit existing theories about the thermal distribution limit of upright plant growth and to consider biochemical and biomechanical factors for explaining the global treeline position. A global survey of lignin content in plant cell walls corroborates suggestions that cold temperature limits upright tree growth.
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Affiliation(s)
- Alan Crivellaro
- Department of Geography, University of Cambridge, CB2 3EN, Cambridge, United Kingdom.,Forest Biometrics Laboratory, Faculty of Forestry, Stefan cel Mare University of Suceava, 720229, Suceava, Romania
| | - Alma Piermattei
- Department of Geography, University of Cambridge, CB2 3EN, Cambridge, United Kingdom
| | - Jiri Dolezal
- Institute of Botany, Academy of Sciences of the Czech Republic, 379 01, Trebon, Czech Republic.,Department of Botany, Faculty of Science University of South Bohemia, 370 05, Ceske Budejovice, Czech Republic
| | - Paul Dupree
- Department of Biochemistry, University of Cambridge, CB2 1QW, Cambridge, United Kingdom
| | - Ulf Büntgen
- Department of Geography, University of Cambridge, CB2 3EN, Cambridge, United Kingdom. .,Swiss Federal Research Institute WSL, 8903, Birmensdorf, Switzerland. .,Global Change Research Institute CAS, 603 00, Brno, Czech Republic. .,Department of Geography, Faculty of Science Masaryk University, 611 37, Brno, Czech Republic.
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6
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Tree Regeneration Patterns on Contrasting Slopes at Treeline Ecotones in Eastern Tibet. FORESTS 2021. [DOI: 10.3390/f12111605] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Alpine treelines are projected to shift upslope in response to climate warming, but empirical studies have yielded inconsistent results, with both upshifted and stable alpine treelines. Additionally, treelines on different slope aspects of the same mountain can differ. Thus, for a better understanding of the mechanisms of treeline formation and treeline responses to climate change, we need to elucidate the population dynamics at treelines on different slope aspects. Here, we quantified the population dynamics of Balfour spruce (Picea likiangensis var. rubescens) at treeline ecotones on contrasting north- and east-facing slopes on the eastern Tibetan Plateau based on field surveys. The alpine treeline positions of Balfour spruce have not advanced toward higher altitudes on the contrasting slopes in recent decades. Compared with the east-facing slope, more recruits occurred on the north-facing slope above the present treeline, indicating a more favorable regeneration condition. However, on the north-facing slope, the individual growth rate of Balfour spruce was lower, and the number of adult trees above the present treeline was higher than that on the east-facing slope. Thus, slope aspects mediate a trade-off between the growth and survival of treeline species, explaining the absence of an impact of slope aspects on treeline responses to climate change. Our results highlight the importance of considering the effect of topography on population dynamics in predicting alpine treeline dynamics under the scenario of climate change.
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Pampuch T, Anadon-Rosell A, Trouillier M, Lange J, Wilmking M. Direct and Indirect Effects of Environmental Limitations on White Spruce Xylem Anatomy at Treeline. FRONTIERS IN PLANT SCIENCE 2021; 12:748055. [PMID: 34759941 PMCID: PMC8573320 DOI: 10.3389/fpls.2021.748055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
Treeline ecosystems are of great scientific interest to study the effects of limiting environmental conditions on tree growth. However, tree growth is multidimensional, with complex interactions between height and radial growth. In this study, we aimed to disentangle effects of height and climate on xylem anatomy of white spruce [Picea glauca (Moench) Voss] at three treeline sites in Alaska; i.e., one warm and drought-limited, and two cold, temperature-limited. To analyze general growth differences between trees from different sites, we used data on annual ring width, diameter at breast height (DBH), and tree height. A representative subset of the samples was used to investigate xylem anatomical traits. We then used linear mixed-effects models to estimate the effects of height and climatic variables on our study traits. Our study showed that xylem anatomical traits in white spruce can be directly and indirectly controlled by environmental conditions: hydraulic-related traits seem to be mainly influenced by tree height, especially in the earlywood. Thus, they are indirectly driven by environmental conditions, through the environment's effects on tree height. Traits related to mechanical support show a direct response to environmental conditions, mainly temperature, especially in the latewood. These results highlight the importance of assessing tree growth in a multidimensional way by considering both direct and indirect effects of environmental forcing to better understand the complexity of tree growth responses to the environment.
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Affiliation(s)
- Timo Pampuch
- Institute of Botany and Landscape Ecology, University Greifswald, Greifswald, Germany
| | - Alba Anadon-Rosell
- Institute of Botany and Landscape Ecology, University Greifswald, Greifswald, Germany
- CREAF – Centre for Research on Ecology and Forestry Applications, Barcelona, Spain
| | - Mario Trouillier
- Institute of Botany and Landscape Ecology, University Greifswald, Greifswald, Germany
| | - Jelena Lange
- Institute of Botany and Landscape Ecology, University Greifswald, Greifswald, Germany
- Department of Physical Geography and Geoecology, Charles University in Prague, Prague, Czechia
| | - Martin Wilmking
- Institute of Botany and Landscape Ecology, University Greifswald, Greifswald, Germany
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8
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Yang D, Zhang Y, Zhou D, Zhang YJ, Peng G, Tyree MT. The hydraulic architecture of an arborescent monocot: ontogeny-related adjustments in vessel size and leaf area compensate for increased resistance. THE NEW PHYTOLOGIST 2021; 231:273-284. [PMID: 33621370 DOI: 10.1111/nph.17294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Bamboos are arborescent monocotyledons that have no secondary growth, but can continually produce conduits with diameters appropriate to the current size of the plant. Here, we studied bamboo hydraulic architecture to address the mechanisms involved in compensating for the increase in hydraulic resistance during ontogeny. We measured the hydraulic weighted vessel diameters (Dh ) at different distances from the apex along the stem of Bambusa textilis. The hydraulic resistance of different components and individuals of different heights were quantified using the high-pressure flowmeter method. The Dh showed tip-to-base widening with a scaling exponent in the range of those reported for trees. Although theoretical hydraulic conductivity decreased from base-to-tip, leaf-specific conductivity did not change. Leaves contributed the most to the whole-shoot hydraulic resistance, followed by the leaf-bearing branches. Roots contributed c. 13% to whole-plant resistance. Interestingly, taller individuals showed lower whole-shoot resistance owing to an increased number of resistances in parallel (side-branches), while leaf-specific resistance was independent of plant size. Tip-to-base vessel widening and height-independent constant leaf-specific conductance could be mechanisms for hydraulic optimization in B. textilis. Similar patterns have also been found in woody plants with secondary growth, but this bamboo exhibits them without secondary growth.
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Affiliation(s)
- Dongmei Yang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, 321004, China
| | - Yinshuang Zhang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, 321004, China
| | - Dan Zhou
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, 321004, China
| | - Yong-Jiang Zhang
- School of Biology and Ecology, University of Maine, Orono, ME, 04469, USA
| | - Guoquan Peng
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, 321004, China
| | - Melvin T Tyree
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, 321004, China
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9
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Olson ME, Anfodillo T, Gleason SM, McCulloh KA. Tip-to-base xylem conduit widening as an adaptation: causes, consequences, and empirical priorities. THE NEW PHYTOLOGIST 2021; 229:1877-1893. [PMID: 32984967 DOI: 10.1111/nph.16961] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/14/2020] [Indexed: 06/11/2023]
Abstract
In the stems of terrestrial vascular plants studied to date, the diameter of xylem water-conducting conduits D widens predictably with distance from the stem tip L approximating D ∝ Lb , with b ≈ 0.2. Because conduit diameter is central for conductance, it is essential to understand the cause of this remarkably pervasive pattern. We give reason to suspect that tip-to-base conduit widening is an adaptation, favored by natural selection because widening helps minimize the increase in hydraulic resistance that would otherwise occur as an individual stem grows longer and conductive path length increases. Evidence consistent with adaptation includes optimality models that predict the 0.2 exponent. The fact that this prediction can be made with a simple model of a single capillary, omitting much biological detail, itself makes numerous important predictions, e.g. that pit resistance must scale isometrically with conduit resistance. The idea that tip-to-base conduit widening has a nonadaptive cause, with temperature, drought, or turgor limiting the conduit diameters that plants are able to produce, is less consistent with the data than an adaptive explanation. We identify empirical priorities for testing the cause of tip-to-base conduit widening and underscore the need to study plant hydraulic systems leaf to root as integrated wholes.
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Affiliation(s)
- Mark E Olson
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Mexico City, 04510, Mexico
| | - Tommaso Anfodillo
- Department Territorio e Sistemi Agro-Forestali, University of Padova, Legnaro (PD), 35020, Italy
| | - Sean M Gleason
- Water Management and Systems Research Unit, United States Department of Agriculture, Agricultural Research Service, Fort Collins, CO, 80526, USA
- Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, CO, 80523, USA
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10
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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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11
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Cabon A, Peters RL, Fonti P, Martínez-Vilalta J, De Cáceres M. Temperature and water potential co-limit stem cambial activity along a steep elevational gradient. THE NEW PHYTOLOGIST 2020; 226:1325-1340. [PMID: 31998968 DOI: 10.1111/nph.16456] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/22/2020] [Indexed: 05/17/2023]
Abstract
Efforts to develop mechanistic tree growth models are hindered by the uncertainty of whether and when tree growth responses to environmental factors are driven by carbon assimilation or by biophysical limitations of wood formation. In this study, we used multiannual weekly wood-formation monitoring of two conifer species (Larix decidua and Picea abies) along a 900 m elevational gradient in the Swiss Alps to assess the biophysical effect of temperature and water potential on wood formation. To this end, we developed a model that simulates the effect of water potential on turgor-driven cambial division, modulated by the effect of temperature on enzymatic activity. The model reproduced the observed phenology of tracheid production, as well as intra- and interannual tracheid production dynamics of both species along the elevational gradient, although interannual model performance was lower. We found that temperature alone explains the onset of tracheid production, yet water potential appears necessary to predict the ending and the total amount of tracheids produced annually. We conclude that intra-annual cambial activity is strongly constrained by both temperature and water potential at all elevations, independently of carbon assimilation. At the interannual scale, biophysical constraints likely interact with other factors.
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Affiliation(s)
- Antoine Cabon
- Joint Research Unit CTFC - AGROTECNIO, 25280, Solsona, Spain
- CREAF, Bellaterra (Cerdanyola del Vallès), E08193, Catalonia, Spain
| | - Richard L Peters
- Dendrosciences, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
- Department of Environmental Sciences - Botany, Basel University, Schönbeinstrasse 6, CH-4056, Basel, Switzerland
- Laboratory of Plant Ecology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium
| | - Patrick Fonti
- Dendrosciences, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès), E08193, Catalonia, Spain
- Universitat Autònoma de Barcelona, E08193, Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
| | - Miquel De Cáceres
- Joint Research Unit CTFC - AGROTECNIO, 25280, Solsona, Spain
- CREAF, Bellaterra (Cerdanyola del Vallès), E08193, Catalonia, Spain
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12
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Losso A, Sailer J, Bär A, Ganthaler A, Mayr S. Insights into trunks of Pinus cembra L.: analyses of hydraulics via electrical resistivity tomography. TREES (BERLIN, GERMANY : WEST) 2020; 34:999-1008. [PMID: 32848296 PMCID: PMC7437670 DOI: 10.1007/s00468-020-01976-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 04/03/2020] [Indexed: 05/31/2023]
Abstract
KEY MESSAGE The lack of elevational changes in electrical resistivity in Pinus cembra trunks indicated consistent growth and hydraulics across elevations. Though, electrical resistivity tomograms exhibited pronounced temperature-driven seasonal changes. ABSTRACT Alpine conifers growing at high elevation are exposed to low temperatures, which may limit xylogenesis and cause pronounced seasonal changes in tree hydraulics. Electrical resistivity (ER) tomography enables minimal invasive monitoring of stems in situ. We used this technique to analyze Pinus cembra trunks along a 400 m elevational gradient up to the timberline and over seasons. Furthermore, ER data of earlywood across tree rings were compared with the respective specific hydraulic conductivity (K S), measured on extracted wood cores. ER tomograms revealed pronounced changes over the year and a strong correlation between average ER (ERmean) and air and xylem temperatures. Surprisingly, no elevational changes in ERmean, earlywood ER or K S were observed. ER data corresponded to variation in earlywood K S, which decreased from the youngest (ca. 4-5 cm2s-1 MPa-1) to the oldest tree rings (0.63 ± 0.22 cm2s-1 MPa-1). The lack of changes in ER data and earlywood K S along the study transect indicated consistent growth patterns and no major changes in structural and functional hydraulic traits across elevation. The constant decrease in earlywood K S with tree ring age throughout all elevations highlights the hydraulic relevance of the outermost tree rings in P. cembra. Seasonal measurements demonstrated pronounced temperature effects on ER, and we thus recommend a detailed monitoring of trunk temperatures for ER tomography.
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Affiliation(s)
- Adriano Losso
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW 2753 Australia
| | - Julia Sailer
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Andreas Bär
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Andrea Ganthaler
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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13
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Ribeiro CL, Conde D, Balmant KM, Dervinis C, Johnson MG, McGrath AP, Szewczyk P, Unda F, Finegan CA, Schmidt HW, Miles B, Drost DR, Novaes E, Gonzalez-Benecke CA, Peter GF, Burleigh JG, Martin TA, Mansfield SD, Chang G, Wickett NJ, Kirst M. The uncharacterized gene EVE contributes to vessel element dimensions in Populus. Proc Natl Acad Sci U S A 2020; 117:5059-5066. [PMID: 32041869 PMCID: PMC7060721 DOI: 10.1073/pnas.1912434117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The radiation of angiosperms led to the emergence of the vast majority of today's plant species and all our major food crops. Their extraordinary diversification occurred in conjunction with the evolution of a more efficient vascular system for the transport of water, composed of vessel elements. The physical dimensions of these water-conducting specialized cells have played a critical role in angiosperm evolution; they determine resistance to water flow, influence photosynthesis rate, and contribute to plant stature. However, the genetic factors that determine their dimensions are unclear. Here we show that a previously uncharacterized gene, ENLARGED VESSEL ELEMENT (EVE), contributes to the dimensions of vessel elements in Populus, impacting hydraulic conductivity. Our data suggest that EVE is localized in the plasma membrane and is involved in potassium uptake of differentiating xylem cells during vessel development. In plants, EVE first emerged in streptophyte algae, but expanded dramatically among vessel-containing angiosperms. The phylogeny, structure and composition of EVE indicates that it may have been involved in an ancient horizontal gene-transfer event.
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Affiliation(s)
- Cíntia L Ribeiro
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL 32611
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | - Daniel Conde
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | - Kelly M Balmant
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | - Christopher Dervinis
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | | | - Aaron P McGrath
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego, La Jolla, CA 92093
| | - Paul Szewczyk
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego, La Jolla, CA 92093
| | - Faride Unda
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Christina A Finegan
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL 32611
| | - Henry W Schmidt
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | - Brianna Miles
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | - Derek R Drost
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL 32611
| | - Evandro Novaes
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | | | - Gary F Peter
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL 32611
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
- Genetics Institute, University of Florida, Gainesville, FL 32611
| | - J Gordon Burleigh
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL 32611
- Department of Biology, University of Florida, Gainesville, FL 32611
| | - Timothy A Martin
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
| | - Shawn D Mansfield
- Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Geoffrey Chang
- Skaggs School of Pharmacy and Pharmaceutical Science, University of California San Diego, La Jolla, CA 92093
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Norman J Wickett
- Plant Science and Conservation, Chicago Botanic Garden, Glencoe, IL 60622
- Plant Biology and Conservation, Northwestern University, Evanston, IL 60208
| | - Matias Kirst
- Plant Molecular and Cellular Biology Graduate Program, University of Florida, Gainesville, FL 32611;
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
- Genetics Institute, University of Florida, Gainesville, FL 32611
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14
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He P, Gleason SM, Wright IJ, Weng E, Liu H, Zhu S, Lu M, Luo Q, Li R, Wu G, Yan E, Song Y, Mi X, Hao G, Reich PB, Wang Y, Ellsworth DS, Ye Q. Growing-season temperature and precipitation are independent drivers of global variation in xylem hydraulic conductivity. GLOBAL CHANGE BIOLOGY 2020; 26:1833-1841. [PMID: 31749261 DOI: 10.1111/gcb.14929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Stem xylem-specific hydraulic conductivity (KS ) represents the potential for plant water transport normalized by xylem cross section, length, and driving force. Variation in KS has implications for plant transpiration and photosynthesis, growth and survival, and also the geographic distribution of species. Clarifying the global-scale patterns of KS and its major drivers is needed to achieve a better understanding of how plants adapt to different environmental conditions, particularly under climate change scenarios. Here, we compiled a xylem hydraulics dataset with 1,186 species-at-site combinations (975 woody species representing 146 families, from 199 sites worldwide), and investigated how KS varied with climatic variables, plant functional types, and biomes. Growing-season temperature and growing-season precipitation drove global variation in KS independently. Both the mean and the variation in KS were highest in the warm and wet tropical regions, and lower in cold and dry regions, such as tundra and desert biomes. Our results suggest that future warming and redistribution of seasonal precipitation may have a significant impact on species functional diversity, and is likely to be particularly important in regions becoming warmer or drier, such as high latitudes. This highlights an important role for KS in predicting shifts in community composition in the face of climate change.
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Affiliation(s)
- Pengcheng He
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Sean M Gleason
- USDA-ARS Water Management and Systems Research Unit, Fort Collins, CO, USA
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ensheng Weng
- Center for Climate Systems Research, Columbia University, New York, NY, USA
| | - Hui Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Shidan Zhu
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Mingzhen Lu
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Qi Luo
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Ronghua Li
- Institute of Tropical and Subtropical Ecology, South China Agricultural University, Guangzhou, China
| | - Guilin Wu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Enrong Yan
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Yanjun Song
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Xiangcheng Mi
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangyou Hao
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, MN, USA
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Yingping Wang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- CSIRO Oceans and Atmosphere, Aspendale, Vic., Australia
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center for Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
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15
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Fajardo A, Martínez-Pérez C, Cervantes-Alcayde MA, Olson ME. Stem length, not climate, controls vessel diameter in two trees species across a sharp precipitation gradient. THE NEW PHYTOLOGIST 2020; 225:2347-2355. [PMID: 31657018 DOI: 10.1111/nph.16287] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 10/23/2019] [Indexed: 05/29/2023]
Abstract
Variation in xylem conduit diameter traditionally has been explained by climate, whereas other evidence suggests that tree height is the main driver of conduit diameter. The effect of climate versus stem length on vessel diameter was tested in two tree species (Embothrium coccineum, Nothofagus antarctica) that both span an exceptionally wide precipitation gradient (2300-500 mm). To see whether, when taking stem length into account, plants in wetter areas had wider vessels, not only the scaling of vessel diameter at the stem base across individuals of different heights, but also the tip-to-base scaling along individuals of similar heights across sites were examined. Within each species, plants of similar heights had similar mean vessel diameters and similar tip-to-base widening of vessel diameter, regardless of climate, with the slopes and intercepts of the vessel diameter-stem length relationship remaining invariant within species across climates. This study focusing on within-species variation--thus, avoiding noise associated with the great morphological variation across species--showed unequivocally that plant size, not climate, is the main driver of variation in vessel diameter. Therefore, to the extent that climate selects for differing vessel diameters, it will inevitably also affect plant height.
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Affiliation(s)
- Alex Fajardo
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP) Camino Baguales s/n, Coyhaique, 5951601, Chile
| | - Cecilia Martínez-Pérez
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510, México
| | - María Angélica Cervantes-Alcayde
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510, México
| | - Mark E Olson
- Instituto de Biología, Universidad Nacional Autónoma de México, Tercer Circuito s/n de Ciudad Universitaria, Ciudad de México, 04510, México
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16
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Lange J, Carrer M, Pisaric MFJ, Porter TJ, Seo JW, Trouillier M, Wilmking M. Moisture-driven shift in the climate sensitivity of white spruce xylem anatomical traits is coupled to large-scale oscillation patterns across northern treeline in northwest North America. GLOBAL CHANGE BIOLOGY 2020; 26:1842-1856. [PMID: 31799729 DOI: 10.1111/gcb.14947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
Tree growth at northern treelines is generally temperature-limited due to cold and short growing seasons. However, temperature-induced drought stress was repeatedly reported for certain regions of the boreal forest in northwestern North America, provoked by a significant increase in temperature and possibly reinforced by a regime shift of the pacific decadal oscillation (PDO). The aim of this study is to better understand physiological growth reactions of white spruce, a dominant species of the North American boreal forest, to PDO regime shifts using quantitative wood anatomy and traditional tree-ring width (TRW) analysis. We investigated white spruce growth at latitudinal treeline across a >1,000 km gradient in northwestern North America. Functionally important xylem anatomical traits (lumen area, cell-wall thickness, cell number) and TRW were correlated with the drought-sensitive standardized precipitation-evapotranspiration index of the growing season. Correlations were computed separately for complete phases of the PDO in the 20th century, representing alternating warm/dry (1925-1946), cool/wet (1947-1976) and again warm/dry (1977-1998) climate regimes. Xylem anatomical traits revealed water-limiting conditions in both warm/dry PDO regimes, while no or spatially contrasting associations were found for the cool/wet regime, indicating a moisture-driven shift in growth-limiting factors between PDO periods. TRW reflected only the last shift of 1976/1977, suggesting different climate thresholds and a higher sensitivity to moisture availability of xylem anatomical traits compared to TRW. This high sensitivity of xylem anatomical traits permits to identify first signs of moisture-driven growth in treeline white spruce at an early stage, suggesting quantitative wood anatomy being a powerful tool to study climate change effects in the northwestern North American treeline ecotone. Projected temperature increase might challenge growth performance of white spruce as a key component of the North American boreal forest biome in the future, when drier conditions are likely to occur with higher frequency and intensity.
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Affiliation(s)
- Jelena Lange
- Institute of Botany and Landscape Ecology, University of Greifswald, Greifswald, Germany
| | - Marco Carrer
- Department TESAF, University of Padova, Padova, Italy
| | - Michael F J Pisaric
- Department of Geography and Tourism Studies, Brock University, Saint Catharines, ON, Canada
| | - Trevor J Porter
- Department of Geography, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Jeong-Wook Seo
- Department of Wood & Paper Science, Chungbuk National University, Cheongju, Republic of Korea
| | - Mario Trouillier
- Institute of Botany and Landscape Ecology, University of Greifswald, Greifswald, Germany
| | - Martin Wilmking
- Institute of Botany and Landscape Ecology, University of Greifswald, Greifswald, Germany
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17
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Lechthaler S, Turnbull TL, Gelmini Y, Pirotti F, Anfodillo T, Adams MA, Petit G. A standardization method to disentangle environmental information from axial trends of xylem anatomical traits. TREE PHYSIOLOGY 2019; 39:495-502. [PMID: 30299505 DOI: 10.1093/treephys/tpy110] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 09/05/2018] [Accepted: 09/13/2018] [Indexed: 06/08/2023]
Abstract
Anatomical traits such as xylem conduit diameter and vessel connectivity are fundamental characteristics of the hydraulic architecture of vascular plants. Stem xylem conduits are narrow at the stem apex, and this confers resistance to embolisms that might otherwise be induced by large, negative water potentials at the top of tall trees. Below the apex, conduits progressively widen and this characteristic minimizes effects of path length on total hydraulic resistance. While interconnections among xylem vessels have been noted for decades, their role(s) are not fully clarified. For example, we do not know if they allow water to bypass embolized vessels, or increase the risk of spread of embolisms, or how their arrangement varies within a tree. Here we demonstrate the benefit of removing the independent effect of stem length on assessment of effects of external (e.g., climatic) factors on such xylem traits. We measured the hydraulic diameter (Dh) and vessel conductivity index (VCI) along the stem of 21 shrubs/trees of similar height (1.19 < H < 5.45 m) belonging to seven Acacia species, across a wide aridity gradient in Australia. All trees showed similar scaling exponents of Dh (b = 0.33) and VCI (b = 0.53) vs axial distance from the apex (L), thus conforming with general patterns in woody plants. After de-trending for L, neither Dh (P = 0.21) nor VCI (P = 0.109) differed across the aridity gradient. We found that across a wide gradient of aridity, climate had no effect on xylem anatomy of Acacia spp, which was instead dictated by axial distances from stem apices. We argue that the use of standardization procedures to filter out intrinsic patterns of vascular traits is an essential step in assessing climate-driven modifications of xylem architecture.
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Affiliation(s)
- Silvia Lechthaler
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Forest Ecology Research Unit, Viale dell'Università 16, Legnaro (PD), Italy
| | - Tarryn L Turnbull
- Centre for Carbon Water and Food, Faculty of Science, University of Sydney, 380 Werombi Road, Brownlow Hill, NSW, Australia
| | - Ylenia Gelmini
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Forest Ecology Research Unit, Viale dell'Università 16, Legnaro (PD), Italy
| | - Francesco Pirotti
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Forest Ecology Research Unit, Viale dell'Università 16, Legnaro (PD), Italy
| | - Tommaso Anfodillo
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Forest Ecology Research Unit, Viale dell'Università 16, Legnaro (PD), Italy
| | - Mark A Adams
- Centre for Carbon Water and Food, Faculty of Science, University of Sydney, 380 Werombi Road, Brownlow Hill, NSW, Australia
| | - Giai Petit
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Forest Ecology Research Unit, Viale dell'Università 16, Legnaro (PD), Italy
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18
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Anadon-Rosell A, Dawes MA, Fonti P, Hagedorn F, Rixen C, von Arx G. Xylem anatomical and growth responses of the dwarf shrub Vaccinium myrtillus to experimental CO 2 enrichment and soil warming at treeline. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 642:1172-1183. [PMID: 30045499 DOI: 10.1016/j.scitotenv.2018.06.117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/08/2018] [Accepted: 06/10/2018] [Indexed: 06/08/2023]
Abstract
Plant growth responses to environmental changes may be linked to xylem anatomical adjustments. The study of such links is essential for improving our understanding of plant functioning under global change. We investigated the xylem anatomy and above-ground growth of the dwarf shrub Vaccinium myrtillus in the understorey of Larix decidua and Pinus uncinata at the Swiss treeline after 9 years of free-air CO2 enrichment (+200 ppm) and 6 years of soil warming (+4 °C). We aimed to determine the responses of xylem anatomical traits and growth to these treatments, and to analyse xylem anatomy-growth relationships. We quantified anatomical characteristics of vessels and ray parenchyma and measured xylem ring width (RW), above-ground biomass and shoot elongation as growth parameters. Our results showed strong positive correlations between theoretical hydraulic conductivity (Kh) and shoot increment length or total biomass across all treatments. However, while soil warming stimulated shoot elongation and RW, it reduced vessel size (Dh) by 14%. Elevated CO2 had smaller effects than soil warming: it increased Dh (5%) in the last experimental years and only influenced growth by increasing basal stem size. The abundance of ray parenchyma, representing storage capacity, did not change under any treatment. Our results demonstrate a link between growth and stem Kh in V. myrtillus, but its growth responses to warming were not explained by the observed xylem anatomical changes. Smaller Dh under warming may increase resistance to freezing events frequently occurring at treeline and suggests that hydraulic efficiency is not limiting for V. myrtillus growing on moist soils at treeline. Our findings suggest that future higher atmospheric CO2 concentrations will have smaller effects on V. myrtillus growth and functioning than rising temperatures at high elevations; further, growth stimulation of this species under future warmer conditions may not be synchronized with xylem adjustments favouring hydraulic efficiency.
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Affiliation(s)
- Alba Anadon-Rosell
- Institute of Botany and Landscape Ecology, University of Greifswald, Soldmannstrasse 15, D-17487 Greifswald, Germany; Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Av. Diagonal 643, E-08028 Barcelona, Catalonia, Spain; Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8093 Birmensdorf, Switzerland.
| | - Melissa A Dawes
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8093 Birmensdorf, Switzerland; WSL Institute for Snow and Avalanche Research - SLF, Flüelastrasse 11, CH-7260 Davos, Switzerland
| | - Patrick Fonti
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8093 Birmensdorf, Switzerland
| | - Frank Hagedorn
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8093 Birmensdorf, Switzerland
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research - SLF, Flüelastrasse 11, CH-7260 Davos, Switzerland
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, CH-8093 Birmensdorf, Switzerland; Climatic Change and Climate Impacts, Institute for Environmental Sciences, 66 Blvd Carl Vogt, CH-1205 Geneva, Switzerland
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19
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Carrer M, Unterholzner L, Castagneri D. Wood anatomical traits highlight complex temperature influence on Pinus cembra at high elevation in the Eastern Alps. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2018; 62:1745-1753. [PMID: 29961923 DOI: 10.1007/s00484-018-1577-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/11/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
Climate sensitivity of populations at the margins of their distribution range is of key importance to understand species' responses to future warming conditions. Pinus cembra is of particular interest being a typical high-elevation taxon, spread with mostly scattered populations within its actual range, but still overlooked in traditional dendrochronological researches due to low tree-ring variability and climate sensitivity. With a different approach, we analyzed time series of xylem anatomical traits, split into intra-ring sectors, and used daily climate records over 89 years (1926-2014) aiming to improve the quality and time resolution of the climate/growth associations. From nine trees growing at their altitudinal limit and on 1.5 × 106 tracheids, we measured ring width (MRW), cell number per ring, lumen area (LA), and cell-wall thickness (CWT). We then computed correlations with monthly and fortnightly climate data. Late-spring and summer temperature emerged as the most important factors. LA and especially CWT showed a stronger temperature response than MRW, starting in mid-May and early June, respectively. CWT also evidenced the longest period of correlations with temperature and a significant difference between latewood radial and tangential walls. Analysis of xylem anatomical traits at intra-ring level and the use of daily temperature records proved to be useful for high resolution and detailed climate/growth association inferences in Pinus cembra.
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Affiliation(s)
- Marco Carrer
- Università degli Studi di Padova, Dip. TeSAF - Agripolis, I-35020, Legnaro, PD, Italy.
| | - Lucrezia Unterholzner
- Università degli Studi di Padova, Dip. TeSAF - Agripolis, I-35020, Legnaro, PD, Italy
| | - Daniele Castagneri
- Università degli Studi di Padova, Dip. TeSAF - Agripolis, I-35020, Legnaro, PD, Italy
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20
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Prendin AL, Mayr S, Beikircher B, von Arx G, Petit G. Xylem anatomical adjustments prioritize hydraulic efficiency over safety as Norway spruce trees grow taller. TREE PHYSIOLOGY 2018; 38:1088-1097. [PMID: 29920598 DOI: 10.1093/treephys/tpy065] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 05/16/2018] [Indexed: 05/23/2023]
Abstract
As a tree grows taller, the increase in gravitational pressure and path length resistance results in lower water potentials at a given flow rate and higher carbon construction costs to transport a given amount of water to the leaves. We investigated how hydraulic safety and efficiency are coordinated under the constraints of higher cavitation risks and higher carbon construction costs with increasing tree height. We combined measurements of xylem tracheid anatomical traits with the vulnerability to drought-induced embolism and hydraulic conductivity of the apical shoots of 2- to 37-m tall Picea abies trees growing at two sites in the Dolomites (Italian Eastern Alps). We found that the theoretical hydraulic conductivity of the apical shoots increased with tree height at both sites (P < 0.001) as a result of an increase in either total tracheid number or mean hydraulic diameter. The xylem water potential inducing 50% loss of apical conductance significantly increased from small (-4.45 ± 0.20 MPa) to tall trees (-3.65 ± 0.03 MPa) (P = 0.007). The more conductive xylem at the treetop of taller trees allows the full compensation for the height-related hydraulic constraints and minimizes the additional carbon costs of transporting water over a longer path length. The corresponding increase in vulnerability to cavitation shows that hydraulic efficiency is prioritized over safety during height growth.
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Affiliation(s)
- Angela Luisa Prendin
- Department TeSAF-Department of Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, viale dell'Università 16, Legnaro (PD), Italy
| | - Stefan Mayr
- Institut für Botanik, Universität Innsbruck, Sternwartestraße 15, Innsbruck, Austria
| | - Barbara Beikircher
- Institut für Botanik, Universität Innsbruck, Sternwartestraße 15, Innsbruck, Austria
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, Switzerland
- Climatic Change and Climate Impacts, Institute for Environmental Sciences, 66 Boulevard Carl-Vogt, Geneva, Switzerland
| | - Giai Petit
- Department TeSAF-Department of Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, viale dell'Università 16, Legnaro (PD), Italy
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21
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Losso A, Anfodillo T, Ganthaler A, Kofler W, Markl Y, Nardini A, Oberhuber W, Purin G, Mayr S. Robustness of xylem properties in conifers: analyses of tracheid and pit dimensions along elevational transects. TREE PHYSIOLOGY 2018; 38:212-222. [PMID: 29309674 DOI: 10.1093/treephys/tpx168] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 11/30/2017] [Indexed: 06/07/2023]
Abstract
In alpine regions, tree hydraulics are limited by low temperatures that restrict xylem growth and induce winter frost drought and freezing stress. While several studies have dealt with functional limitations, data on elevational changes in functionally relevant xylem anatomical parameters are still scarce. In wood cores of Pinus cembra L. and Picea abies (L.) Karst. trunks, harvested along five elevational transects, xylem anatomical parameters (tracheid hydraulic diameter dh, wall reinforcement (t/b)2), pit dimensions (pit aperture Da, pit membrane Dm and torus Dt diameters) and respective functional indices (torus overlap O, margo flexibility) were measured. In both species, tracheid diameters decreased and (t/b)2 increased with increasing elevation, while pit dimensions and functional indices remained rather constant (P. cembra: Dt 10.3 ± 0.2 μm, O 0.477 ± 0.005; P. abies: Dt 9.30 ± 0.18 μm, O 0.492 ± 0.005). However, dh increased with tree height following a power trajectory with an exponent of 0.21, and also pit dimensions increased with tree height (exponents: Dm 0.18; Dt 0.14; Da 0.11). Observed elevational trends in xylem structures were predominantly determined by changes in tree size. Tree height-related changes in anatomical traits showed a remarkable robustness, regardless of the distributional ranges of study species. Despite increasing stress intensities towards the timberline, no adjustment in hydraulic safety at the pit level was observed.
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Affiliation(s)
- Adriano Losso
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Tommaso Anfodillo
- Dipartimento Territorio e Sistemi Agro Forestali, Università degli Studi di Padova, 35020 Legnaro, PD, Italy
| | - Andrea Ganthaler
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Werner Kofler
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Yvonne Markl
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Walter Oberhuber
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
| | - Gerhard Purin
- Sportgymnasium Dornbirn, Messestraße 4, 6850 Dornbirn, Austria
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck, Austria
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22
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Growth and Its Relationship to Individual Genetic Diversity of Mountain Hemlock (Tsuga mertensiana) at Alpine Treeline in Alaska: Combining Dendrochronology and Genomics. FORESTS 2017. [DOI: 10.3390/f8110418] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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23
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Björklund J, Seftigen K, Schweingruber F, Fonti P, von Arx G, Bryukhanova MV, Cuny HE, Carrer M, Castagneri D, Frank DC. Cell size and wall dimensions drive distinct variability of earlywood and latewood density in Northern Hemisphere conifers. THE NEW PHYTOLOGIST 2017; 216:728-740. [PMID: 28636081 DOI: 10.1111/nph.14639] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 04/27/2017] [Indexed: 05/29/2023]
Abstract
Interannual variability of wood density - an important plant functional trait and environmental proxy - in conifers is poorly understood. We therefore explored the anatomical basis of density. We hypothesized that earlywood density is determined by tracheid size and latewood density by wall dimensions, reflecting their different functional tasks. To determine general patterns of variability, density parameters from 27 species and 349 sites across the Northern Hemisphere were correlated to tree-ring width parameters and local climate. We performed the same analyses with density and width derived from anatomical data comprising two species and eight sites. The contributions of tracheid size and wall dimensions to density were disentangled with sensitivity analyses. Notably, correlations between density and width shifted from negative to positive moving from earlywood to latewood. Temperature responses of density varied intraseasonally in strength and sign. The sensitivity analyses revealed tracheid size as the main determinant of earlywood density, while wall dimensions become more influential for latewood density. Our novel approach of integrating detailed anatomical data with large-scale tree-ring data allowed us to contribute to an improved understanding of interannual variations of conifer growth and to illustrate how conifers balance investments in the competing xylem functions of hydraulics and mechanical support.
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Affiliation(s)
- Jesper Björklund
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Kristina Seftigen
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
- Gothenburg University Laboratory for Dendrochronology, Department of Earth Sciences, University of Gothenburg, Guldhedsgatan 5a, Göteborg, 40530, Sweden
- Université catholique de Louvain, Earth and Life Institute, Georges Lemaître Centre for Earth and Climate Research, Place Louis Pasteur, Louvain-la-Neuve, B-1348, Belgium
| | - Fritz Schweingruber
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Patrick Fonti
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Georg von Arx
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
- Climatic Change and Climate Impacts, Institute for Environmental Sciences, 66 Blvd Carl Vogt, Geneva, CH-1205, Switzerland
| | - Marina V Bryukhanova
- V.N. Sukachev Institute of Forest SB RAS, Akademgorodok 50, bld.28, Krasnoyarsk, 660036, Russia
- Siberian Federal University, Svobodny pr. 79, Krasnoyarsk, 660041, Russia
| | - Henri E Cuny
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Marco Carrer
- Dept. TeSAF, University of Padova, Via dell'Università 16, Legnaro (PD), I-35020, Italy
| | - Daniele Castagneri
- Dept. TeSAF, University of Padova, Via dell'Università 16, Legnaro (PD), I-35020, Italy
| | - David C Frank
- Swiss Federal Institute for Forest Snow and Landscape Research WSL, Zuercherstrasse 111, Birmensdorf, 8903, Switzerland
- Laboratory of Tree-Ring Research, University of Arizona, 1215 E Lowell St, Tucson, AZ, 85721, USA
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24
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Prendin AL, Petit G, Fonti P, Rixen C, Dawes MA, Arx G. Axial xylem architecture of
Larix decidua
exposed to CO
2
enrichment and soil warming at the tree line. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12986] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Angela Luisa Prendin
- Dipartimento Territorio e Sistemi Agro‐ForestaliUniversità degli Studi di Padova Legnaro PD Italy
| | - Giai Petit
- Dipartimento Territorio e Sistemi Agro‐ForestaliUniversità degli Studi di Padova Legnaro PD Italy
| | - Patrick Fonti
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
| | - Christian Rixen
- WSL Institute for Snow and Avalanche Research SLF Davos Switzerland
| | - Melissa Autumn Dawes
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
- WSL Institute for Snow and Avalanche Research SLF Davos Switzerland
| | - Georg Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL Birmensdorf Switzerland
- Climatic Change and Climate ImpactsInstitute for Environmental Sciences Geneva Switzerland
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25
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Castagneri D, Fonti P, von Arx G, Carrer M. How does climate influence xylem morphogenesis over the growing season? Insights from long-term intra-ring anatomy in Picea abies. ANNALS OF BOTANY 2017; 119:1011-1020. [PMID: 28130220 PMCID: PMC5604563 DOI: 10.1093/aob/mcw274] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 11/30/2016] [Indexed: 05/17/2023]
Abstract
BACKGROUND AND AIMS During the growing season, the cambium of conifer trees produces successive rows of xylem cells, the tracheids, that sequentially pass through the phases of enlargement and secondary wall thickening before dying and becoming functional. Climate variability can strongly influence the kinetics of morphogenetic processes, eventually affecting tracheid shape and size. This study investigates xylem anatomical structure in the stem of Picea abies to retrospectively infer how, in the long term, climate affects the processes of cell enlargement and wall thickening. METHODS Tracheid anatomical traits related to the phases of enlargement (diameter) and wall thickening (wall thickness) were innovatively inspected at the intra-ring level on 87-year-long tree-ring series in Picea abies trees along a 900 m elevation gradient in the Italian Alps. Anatomical traits in ten successive tree-ring sectors were related to daily temperature and precipitation data using running correlations. KEY RESULTS Close to the altitudinal tree limit, low early-summer temperature negatively affected cell enlargement. At lower elevation, water availability in early summer was positively related to cell diameter. The timing of these relationships shifted forward by about 20 (high elevation) to 40 (low elevation) d from the first to the last tracheids in the ring. Cell wall thickening was affected by climate in a different period in the season. In particular, wall thickness of late-formed tracheids was strongly positively related to August-September temperature at high elevation. CONCLUSIONS Morphogenesis of tracheids sequentially formed in the growing season is influenced by climate conditions in successive periods. The distinct climate impacts on cell enlargement and wall thickening indicate that different morphogenetic mechanisms are responsible for different tracheid traits. Our approach of long-term and high-resolution analysis of xylem anatomy can support and extend short-term xylogenesis observations, and increase our understanding of climate control of tree growth and functioning under different environmental conditions.
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Affiliation(s)
- Daniele Castagneri
- Università degli Studi di Padova, Dept. TeSAF, Viale dell’Università 16, 35020 Legnaro (PD), Italy
- For correspondence. E-mail
| | - Patrick Fonti
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf (ZH), Switzerland
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf (ZH), Switzerland
| | - Marco Carrer
- Università degli Studi di Padova, Dept. TeSAF, Viale dell’Università 16, 35020 Legnaro (PD), Italy
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26
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Sun H, Wang X, Fan Y, Liu C, Wu P, Li Q, Yin W. Effects of biophysical constraints, climate and phylogeny on forest shrub allometries along an altitudinal gradient in Northeast China. Sci Rep 2017; 7:43769. [PMID: 28266604 PMCID: PMC5339776 DOI: 10.1038/srep43769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 01/27/2017] [Indexed: 11/08/2022] Open
Abstract
Whether there is a general allometry law across plant species with different sizes and under different environment has long been controversial and shrubs are particularly useful to examine these questions. Here we sampled 939 individuals from 50 forest shrub species along a large altitudinal gradient. We tested several allometry models with four relationships simultaneously (between stem diameter, height, leaf, stem and aboveground biomass), including geometric, elastic and stress similarity, and metabolic scaling theory's predictions on small plants (MSTs) and trees (MSTt). We also tested if allometric exponents change markedly with climate and phylogeny. The predicted exponents of MSTt, elastic similarity and stress similarity (models for trees) were not supported by our data, while MSTs and geometric similarity gained more support, suggesting the finite size effect is more important for shrub allometries than being a woody plant. The influence of climate and phylogeny on allometric exponents were not significant or very weak, again suggesting strong biophysical constraints on shrub allometries. Our results reveal clear differences of shrub allometries from previous findings on trees (e.g. much weaker climatic and phylogenic control). Comparisons of herbs, shrubs and trees along a same climatic gradient are needed for better understanding of plant allometries.
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Affiliation(s)
- Han Sun
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Xiangping Wang
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Yanwen Fan
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Chao Liu
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Peng Wu
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Qiaoyan Li
- College of Forestry, Beijing Forestry University, Beijing 100083, China
| | - Weilun Yin
- College of Forestry, Beijing Forestry University, Beijing 100083, China
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27
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Petit G, Savi T, Consolini M, Anfodillo T, Nardini A. Interplay of growth rate and xylem plasticity for optimal coordination of carbon and hydraulic economies in Fraxinus ornus trees. TREE PHYSIOLOGY 2016; 36:1310-1319. [PMID: 27587483 DOI: 10.1093/treephys/tpw069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/17/2016] [Accepted: 07/02/2016] [Indexed: 05/22/2023]
Abstract
Efficient leaf water supply is fundamental for assimilation processes and tree growth. Renovating the architecture of the xylem transport system requires an increasing carbon investment while growing taller, and any deficiency of carbon availability may result in increasing hydraulic constraints to water flow. Therefore, plants need to coordinate carbon assimilation and biomass allocation to guarantee an efficient and safe long-distance transport system. We tested the hypothesis that reduced branch elongation rates together with carbon-saving adjustments of xylem anatomy hydraulically compensate for the reduction in biomass allocation to xylem. We measured leaf biomass, hydraulic and anatomical properties of wood segments along the main axis of branches in 10 slow growing (SG) and 10 fast growing (FG) Fraxinus ornus L. trees. Branches of SG trees had five times slower branch elongation rate (7 vs 35 cm year-1), and produced a higher leaf biomass (P < 0.0001) and thinner xylem rings with fewer but larger vessels (P < 0.0001). On the contrary, we found no differences between SG and FG trees in terms of leaf-specific conductivity (P > 0.05) and xylem safety (Ψ50 ≈ -3.2 MPa). Slower elongation rate coupled with thinner annual rings and larger vessels allows the reduction of carbon costs associated with growth, while maintaining similar leaf-specific conductivity and xylem safety.
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Affiliation(s)
- Giai Petit
- Dipartimento Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
| | - Tadeja Savi
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Martina Consolini
- Dipartimento Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
| | - Tommaso Anfodillo
- Dipartimento Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
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28
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Wood anatomy of Juniperus communis: a promising proxy for palaeoclimate reconstructions in the Arctic. Polar Biol 2016. [DOI: 10.1007/s00300-016-2021-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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29
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Carrer M, Brunetti M, Castagneri D. The Imprint of Extreme Climate Events in Century-Long Time Series of Wood Anatomical Traits in High-Elevation Conifers. FRONTIERS IN PLANT SCIENCE 2016; 7:683. [PMID: 27242880 PMCID: PMC4870858 DOI: 10.3389/fpls.2016.00683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 05/03/2016] [Indexed: 05/04/2023]
Abstract
Extreme climate events are of key importance for forest ecosystems. However, both the inherent infrequency, stochasticity and multiplicity of extreme climate events, and the array of biological responses, challenges investigations. To cope with the long life cycle of trees and the paucity of the extreme events themselves, our inferences should be based on long-term observations. In this context, tree rings and the related xylem anatomical traits represent promising sources of information, due to the wide time perspective and quality of the information they can provide. Here we test, on two high-elevation conifers (Larix decidua and Picea abies sampled at 2100 m a.s.l. in the Eastern Alps), the associations among temperature extremes during the growing season and xylem anatomical traits, specifically the number of cells per ring (CN), cell wall thickness (CWT), and cell diameter (CD). To better track the effect of extreme events over the growing season, tree rings were partitioned in 10 sectors. Climate variability has been reconstructed, for 1800-2011 at monthly resolution and for 1926-2011 at daily resolution, by exploiting the excellent availability of very long and high quality instrumental records available for the surrounding area, and taking into account the relationship between meteorological variables and site topographical settings. Summer temperature influenced anatomical traits of both species, and tree-ring anatomical profiles resulted as being associated to temperature extremes. Most of the extreme values in anatomical traits occurred with warm (positive extremes) or cold (negative) conditions. However, 0-34% of occurrences did not match a temperature extreme event. Specifically, CWT and CN extremes were more clearly associated to climate than CD, which presented a bias to track cold extremes. Dendroanatomical analysis, coupled to high-quality daily-resolved climate records, seems a promising approach to study the effects of extreme events on trees, but further investigations are needed to improve our comprehension of the critical role of such elusive events in forest ecosystems.
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Affiliation(s)
- Marco Carrer
- TeSAF Department, Università degli Studi di PadovaPadova, Italy
| | - Michele Brunetti
- Institute of Atmospheric Sciences and Climate, National Research CouncilBologna, Italy
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30
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von Arx G, Crivellaro A, Prendin AL, Čufar K, Carrer M. Quantitative Wood Anatomy-Practical Guidelines. FRONTIERS IN PLANT SCIENCE 2016; 7:781. [PMID: 27375641 PMCID: PMC4891576 DOI: 10.3389/fpls.2016.00781] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/20/2016] [Indexed: 05/04/2023]
Abstract
Quantitative wood anatomy analyzes the variability of xylem anatomical features in trees, shrubs, and herbaceous species to address research questions related to plant functioning, growth, and environment. Among the more frequently considered anatomical features are lumen dimensions and wall thickness of conducting cells, fibers, and several ray properties. The structural properties of each xylem anatomical feature are mostly fixed once they are formed, and define to a large extent its functionality, including transport and storage of water, nutrients, sugars, and hormones, and providing mechanical support. The anatomical features can often be localized within an annual growth ring, which allows to establish intra-annual past and present structure-function relationships and its sensitivity to environmental variability. However, there are many methodological challenges to handle when aiming at producing (large) data sets of xylem anatomical data. Here we describe the different steps from wood sample collection to xylem anatomical data, provide guidance and identify pitfalls, and present different image-analysis tools for the quantification of anatomical features, in particular conducting cells. We show that each data production step from sample collection in the field, microslide preparation in the lab, image capturing through an optical microscope and image analysis with specific tools can readily introduce measurement errors between 5 and 30% and more, whereby the magnitude usually increases the smaller the anatomical features. Such measurement errors-if not avoided or corrected-may make it impossible to extract meaningful xylem anatomical data in light of the rather small range of variability in many anatomical features as observed, for example, within time series of individual plants. Following a rigid protocol and quality control as proposed in this paper is thus mandatory to use quantitative data of xylem anatomical features as a powerful source for many research topics.
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Affiliation(s)
- Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSLBirmensdorf, Switzerland
- *Correspondence: Georg von Arx
| | - Alan Crivellaro
- Dipartimento Territorio e Sistemi Agro Forestali, Università degli Studi di PadovaPadua, Italy
| | - Angela L. Prendin
- Dipartimento Territorio e Sistemi Agro Forestali, Università degli Studi di PadovaPadua, Italy
| | - Katarina Čufar
- Department of Wood Science and Technology, Biotechnical Faculty, University of LjubljanaLjubljana, Slovenia
| | - Marco Carrer
- Dipartimento Territorio e Sistemi Agro Forestali, Università degli Studi di PadovaPadua, Italy
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31
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Elevational trends in hydraulic efficiency and safety of Pinus cembra roots. Oecologia 2015; 180:1091-102. [PMID: 26678990 PMCID: PMC4943587 DOI: 10.1007/s00442-015-3513-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 11/17/2015] [Indexed: 11/25/2022]
Abstract
In alpine regions, elevational gradients in environmental parameters
are reflected by structural and functional changes in plant traits. Elevational
changes in plant water relations have also been demonstrated, but comparable
information on root hydraulics is generally lacking. We analyzed the hydraulic
efficiency (specific hydraulic conductivity ks, entire root system conductance KR) and vulnerability to drought-induced embolism (water
potential at 50 % loss of conductivity Ψ50) of the roots of Pinus
cembra trees growing along an elevational transect of 600 m. Hydraulic
parameters of the roots were compared with those of the stem and related to
anatomical traits {mean conduit diameter (d),
wall reinforcement [(t/b)2]}. We hypothesized that
temperature-related restrictions in root function would cause a progressive
limitation of hydraulic efficiency and safety with increasing elevation. We found
that both root ks and KR decreased from low (1600 m a.s.l.: ks
5.6 ± 0.7 kg m−1 s−1 MPa−1,
KR
0.049 ± 0.005 kg m−2 s −1 MPa−1)
to high elevation (2100 m a.s.l.: ks
4.2 ± 0.6 kg m−1 s−1 MPa−1,
KR
0.035 ± 0.006 kg m−2 s−1 MPa−1),
with small trees showing higher KR than large trees. ks was higher in roots than in stems
(0.5 ± 0.05 kg m−1s−1MPa−1).
Ψ50 values were similar across elevations and overall less
negative in roots (Ψ50 −3.6 ± 0.1 MPa) than in stems (Ψ50 −3.9 ± 0.1 MPa). In roots, large-diameter tracheids were
lacking at high elevation and (t/b)2 increased, while d did not change. The elevational decrease in root
hydraulic efficiency reflects a limitation in timberline tree hydraulics. In
contrast, hydraulic safety was similar across elevations, indicating that avoidance
of hydraulic failure is important for timberline trees. As hydraulic patterns can
only partly be explained by the anatomical parameters studied, limitations and/or
adaptations at the pit level are likely.
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32
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Castagneri D, Petit G, Carrer M. Divergent climate response on hydraulic-related xylem anatomical traits of Picea abies along a 900-m altitudinal gradient. TREE PHYSIOLOGY 2015; 35:1378-87. [PMID: 26377871 DOI: 10.1093/treephys/tpv085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 08/05/2015] [Indexed: 05/04/2023]
Abstract
Climate change can induce substantial modifications in xylem structure and water transport capacity of trees exposed to environmental constraints. To elucidate mechanisms of xylem plasticity in response to climate, we retrospectively analysed different cell anatomical parameters over tree-ring series in Norway spruce (Picea abies L. Karst.). We sampled 24 trees along an altitudinal gradient (1200, 1600 and 2100 m above sea level, a.s.l.) and processed 2335 ± 1809 cells per ring. Time series for median cell lumen area (MCA), cell number (CN), tree-ring width (RW) and tree-ring-specific hydraulic conductivity (Kr) were crossed with daily temperature and precipitation records (1926-2011) to identify climate influence on xylem anatomical traits. Higher Kr at the low elevation site was due to higher MCA and CN. These variables were related to different aspects of intra-seasonal climatic variability under different environmental conditions, with MCA being more sensitive to summer precipitation. Winter precipitation (snow) benefited most parameters in all the sites. Descending the gradient, sensitivity of xylem features to summer climate shifted mostly from temperature to precipitation. In the context of climate change, our results indicate that higher summer temperatures at high elevations will benefit cell production and xylem hydraulic efficiency, whereas reduced water availability at lower elevations could negatively affect tracheids enlargement and thus stem capacity to transport water.
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Affiliation(s)
- Daniele Castagneri
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
| | - Giai Petit
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
| | - Marco Carrer
- Università degli Studi di Padova, Dept Territorio e Sistemi Agro-Forestali, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
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33
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Dawes MA, Philipson CD, Fonti P, Bebi P, Hättenschwiler S, Hagedorn F, Rixen C. Soil warming and CO2 enrichment induce biomass shifts in alpine tree line vegetation. GLOBAL CHANGE BIOLOGY 2015; 21:2005-21. [PMID: 25471674 DOI: 10.1111/gcb.12819] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 11/18/2014] [Indexed: 05/26/2023]
Abstract
Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss tree line to investigate changes in vegetation biomass after 9 years of free air CO2 enrichment (+200 ppm; 2001-2009) and 6 years of soil warming (+4 °C; 2007-2012). The study contained two key tree line species, Larix decidua and Pinus uncinata, both approximately 40 years old, growing in heath vegetation dominated by dwarf shrubs. In 2012, we harvested and measured biomass of all trees (including root systems), above-ground understorey vegetation and fine roots. Overall, soil warming had clearer effects on plant biomass than CO2 enrichment, and there were no interactive effects between treatments. Total plant biomass increased in warmed plots containing Pinus but not in those with Larix. This response was driven by changes in tree mass (+50%), which contributed an average of 84% (5.7 kg m(-2) ) of total plant mass. Pinus coarse root mass was especially enhanced by warming (+100%), yielding an increased root mass fraction. Elevated CO2 led to an increased relative growth rate of Larix stem basal area but no change in the final biomass of either tree species. Total understorey above-ground mass was not altered by soil warming or elevated CO2 . However, Vaccinium myrtillus mass increased with both treatments, graminoid mass declined with warming, and forb and nonvascular plant (moss and lichen) mass decreased with both treatments. Fine roots showed a substantial reduction under soil warming (-40% for all roots <2 mm in diameter at 0-20 cm soil depth) but no change with CO2 enrichment. Our findings suggest that enhanced overall productivity and shifts in biomass allocation will occur at the tree line, particularly with global warming. However, individual species and functional groups will respond differently to these environmental changes, with consequences for ecosystem structure and functioning.
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Affiliation(s)
- Melissa A Dawes
- WSL Institute for Snow and Avalanche Research - SLF, Flüelastrasse 11, CH-7260, Davos Dorf, Switzerland; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903, Birmensdorf, Switzerland
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Ma F, Xu TT, Ji MF, Zhao CM. Differential drought tolerance in tree populations from contrasting elevations. AOB PLANTS 2014; 6:plu069. [PMID: 25387750 PMCID: PMC4268489 DOI: 10.1093/aobpla/plu069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 10/23/2014] [Indexed: 05/04/2023]
Abstract
To predict the ecological consequences of climate change for a widely distributed tree species, it is essential to develop a deep understanding of the ecophysiological responses of populations from contrasting climates to varied soil water availabilities. In the present study, we focused on Pinus tabuliformis, one of the most economically and ecologically important tree species in China. In a greenhouse experiment, we exposed trees from high-elevation (HP) and low-elevation (LP) populations to low (80 % of field capacity, FC), mild (60 % FC), moderate (40 % FC) and severe (20 % FC) water stresses. Leaf gas exchange, biomass production and allocation, as well as water-use efficiency, were measured during the experiment. Increasing soil water stress clearly decreased the relative growth rate (RGR), total dry mass (TDM), light-saturated photosynthetic rate (Asat), stomatal conductance (gs), total water use (TWU) and whole-plant water-use efficiency (WUEWP). In contrast, intrinsic water-use efficiency (WUEi) and carbon isotope composition (δ(13)C) both increased significantly with increasing soil water stress for both populations. Only in the LP did the root/shoot ratio (R/S ratio) significantly increase when the water stress increased. A strong positive correlation between Asat and gs coupled with a reduced intercellular CO2 concentration (Ci) probably suggested that stomatal limitations were the main cause of the decreased Asat. However, all the measured variables from the HP were affected less by drought compared with those of the LP, and most aspects of the HP were canalized against drought stress, which was reflected by the relatively higher RGR, TDM and WUEWP. Overall, the results suggest that the two populations responded differentially to drought stress with the HP showing higher drought tolerance than the LP, which was reflected by its faster seedling growth rate and more efficient water use under drought conditions.
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Affiliation(s)
- Fei Ma
- New Technology Application, Research and Development Center, Ningxia University, Yinchuan 750021, PR China
| | - Ting Ting Xu
- School of Life Science, Ningxia University, Yinchuan 750021, PR China
| | - Ming Fei Ji
- State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Chang Ming Zhao
- State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
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Vermeulen PJ. Crown depth as a result of evolutionary games: decreasing solar angle should lead to shallower, not deeper crowns. THE NEW PHYTOLOGIST 2014; 202:1249-1256. [PMID: 24548219 DOI: 10.1111/nph.12729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 01/19/2014] [Indexed: 06/03/2023]
Abstract
There is a general notion in the literature that, with increasing latitude, trees have deeper crowns as a result of a lower solar elevation angle. However, these predictions are based on models that did not include the effects of competition for light between individuals. Here, I argue that there should be selection for trees to increase the height of the crown base, as this decreases shading by neighbouring trees, leading to an evolutionarily stable strategy (ESS). Because the level of between-tree shading increases with decreasing solar angle, the predicted ESS will shift to higher crown base height. This argument is supported by a simulation model to check for the effects of crown shape and the change of light intensity that occurs with changing solar angle on model outcomes. So, the lower solar angle at higher latitudes would tend to select for shallower, and not deeper, crowns. This casts doubt on the common belief that a decreasing solar angle increases crown depth. More importantly, it shows that different assumptions about what should be optimized can lead to different predictions, not just for absolute trait values, but for the direction of selection itself.
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Affiliation(s)
- Peter Johannes Vermeulen
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
- Centre for Crop Systems Analysis, Wageningen University, PO Box 430, 6700, AK Wageningen, the Netherlands
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Zweifel R, Drew DM, Schweingruber F, Downes GM. Xylem as the main origin of stem radius changes in Eucalyptus. FUNCTIONAL PLANT BIOLOGY : FPB 2014; 41:520-534. [PMID: 32481010 DOI: 10.1071/fp13240] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 12/08/2013] [Indexed: 06/11/2023]
Abstract
The state-of-the-art interpretation of stem radius changes (DRTotal) for tree water relations is based on knowledge from mostly slow growing tree species. The ratio between diurnal size fluctuations of the rigid xylem (DRXylem) and the respective fluctuations of the elastic bark (DRBark) is known to be small (<0.4) and is of importance for the localisation of water storage dynamics in stems. In this study, fast growing Eucalyptus globulus Labill. in Tasmania were investigated by point dendrometers in order to investigate tree water relations. Unexpectedly, DRXylem was found to be the main driver of DRTotal with the bark acting as a passive layer on top of the fluctuating xylem under most conditions. Accordingly, the ratio between the diurnal fluctuations of the two tissues was found to be much higher (0.6-1.6) than everything reported before. Based on simulations using a hydraulic plant model, the high tissue-specific elasticity of the Eucalyptus xylem was found to explain this atypical response and not osmotically-driven processes or species-specific flow resistances. The wide zone of secondary thickening xylem in various stages of lignification is proposed to be an important component of the high wood elasticity. The tissue acts as additional water storage like the bark and may positively affect the water transport efficiency.
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Affiliation(s)
- Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, CH-8903 Birmensdorf, Switzerland
| | - David M Drew
- CSIRO Ecosystem Sciences, Private Bag 12, Hobart, Tas. 7001, Australia
| | - Fritz Schweingruber
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zuercherstrasse 111, CH-8903 Birmensdorf, Switzerland
| | - Geoffrey M Downes
- CSIRO Ecosystem Sciences, Private Bag 12, Hobart, Tas. 7001, Australia
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Petit G, DeClerck FAJ, Carrer M, Anfodillo T. Axial vessel widening in arborescent monocots. TREE PHYSIOLOGY 2014; 34:137-145. [PMID: 24488857 DOI: 10.1093/treephys/tpt118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dicotyledons have evolved a strategy to compensate for the increase in hydraulic resistance to water transport with height growth by widening xylem conduits downwards. In monocots, the accumulation of hydraulic resistance with height should be similar, but the absence of secondary growth represents a strong limitation for the maintenance of xylem hydraulic efficiency during ontogeny. The hydraulic architecture of monocots has been studied but it is unclear how monocots arrange their axial vascular structure during ontogeny to compensate for increases in height. We measured the vessel lumina and estimated the hydraulic diameter (Dh) at different heights along the stem of two arborescent monocots, Bactris gasipaes (Kunth) and Guadua angustifolia (Kunth). For the former, we also estimated the variation in Dh along the leaf rachis. Hydraulic diameter increased basally from the stem apex to the base with a scaling exponent (b) in the range of those reported for dicot trees (b = 0.22 in B. gasipaes; b = 0.31 and 0.23 in G. angustifolia). In B. gasipaes, vessels decrease in Dh from the stem's centre towards the periphery, an opposite pattern compared with dicot trees. Along the leaf rachis, a pattern of increasing Dh basally was also found (b = 0.13). The hydraulic design of the monocots studied revealed an axial pattern of xylem conduits similar to those evolved by dicots to compensate and minimize the negative effect of root-to-leaf length on hydrodynamic resistance to water flow.
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Affiliation(s)
- Giai Petit
- Department TeSAF, Forest Ecology Research Unit, University of Padova, Viale dell'Universita, 16-35020 Legnaro (PD), Italy
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Sorce C, Giovannelli A, Sebastiani L, Anfodillo T. Hormonal signals involved in the regulation of cambial activity, xylogenesis and vessel patterning in trees. PLANT CELL REPORTS 2013; 32:885-98. [PMID: 23553557 DOI: 10.1007/s00299-013-1431-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/14/2013] [Accepted: 03/19/2013] [Indexed: 05/21/2023]
Abstract
The radial growth of plant stem is based on the development of cribro-vascular cambium tissues. It affects the transport efficiency of water, mineral nutrients and photoassimilates and, ultimately, also plant height. The rate of cambial cell divisions for the assembly of new xylem and phloem tissue primordia and the rate of differentiation of the primordia into mature tissues determine the amount of biomass produced and, in the case of woody species, the wood quality. These complex physiological processes proceed at a rate which depends on several factors, acting at various levels: growth regulators, resource availability and environmental factors. Several hormonal signals and, more recently, further regulatory molecules, have been shown to be involved in the induction and maintenance of cambium and the formation of secondary vascular tissues. The control of xylem cell patterning is of particular interest, because it determines the diameter of xylem vessels, which is central to the efficiency of water and nutrient transport from roots to leaves through the stem and may strongly influence the growth in height of the tree. Increasing scientific evidence have proved the role of other hormones in cambial cell activities and the study of the hormonal signals and their crosstalking in cambial cells may foster our understanding of the dynamics of xylogenesis and of the mechanism of vessel size control along the stem. In this article, the role of the hormonal signals involved in the control of cambium and xylem development in trees and their crosstalking are reviewed.
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Affiliation(s)
- Carlo Sorce
- Department of Biology, University of Pisa, via L. Ghini, 13, 56126 Pisa, Italy.
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Chen H, Wang H, Liu Y, Dong L. Altitudinal variations of ground tissue and xylem tissue in terminal shoot of woody species: implications for treeline formation. PLoS One 2013; 8:e62163. [PMID: 23658621 PMCID: PMC3637301 DOI: 10.1371/journal.pone.0062163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 03/18/2013] [Indexed: 12/04/2022] Open
Abstract
1. The terminal shoot (or current-year shoot), as one of the most active parts on a woody plant, is a basic unit determining plant height and is potentially influenced by a variety of environmental factors. It has been predicted that tissues amount and their allocation in plant stems may play a critical role in determining plant size in alpine regions. The primary structure in terminal shoots is a key to our understanding treeline formation. The existing theories on treeline formation, however, are still largely lacking of evidence at the species level, much less from anatomy for the terminal shoot. 2. The primary structures within terminal shoot were measured quantitatively for 100 species from four elevation zones along the eastern slope of Gongga Mountain, southwestern China; one group was sampled from above the treeline. An allometric approach was employed to examine scaling relationships interspecifically, and a principal components analysis (PCA) was performed to test the relation among primary xylem, ground tissue, species growth form and altitude. 3. The results showed that xylem tissue size was closely correlated with ground tissue size isometrically across species, while undergoing significant y- or/and x-intercept shift in response to altitudinal belts. Further, a conspicuous characteristic of terminal shoot was its allocation of contrasting tissues between primary xylem and ground tissues with increasing elevation. The result of the PCA showed correlations between anatomical variation, species growth form/height classes and environment. 4. The current study presents a comparative assessment of the allocation of tissue in terminal shoot across phylogenically and ecologically diverse species, and analyzes tissue, function and climate associations with plant growth forms and height classes among species. The interspecific connection between primary xylem ratio and plant size along an elevation gradient suggests the importance of primary xylem in explaining the treeline formation.
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Affiliation(s)
- Hong Chen
- Institute of Landscape Ecology of Mountainous Horticulture, Southwest University, Chongqing, China.
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Warming and the dependence of limber pine (Pinus flexilis) establishment on summer soil moisture within and above its current elevation range. Oecologia 2012; 171:271-82. [DOI: 10.1007/s00442-012-2410-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 06/23/2012] [Indexed: 11/26/2022]
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Wiley E, Helliker B. A re-evaluation of carbon storage in trees lends greater support for carbon limitation to growth. THE NEW PHYTOLOGIST 2012; 195:285-289. [PMID: 22568553 DOI: 10.1111/j.1469-8137.2012.04180.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- Erin Wiley
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- (Author for correspondence: tel +1 215 898 8608; email )
| | - Brent Helliker
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
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Wang Y, Čufar K, Eckstein D, Liang E. Variation of maximum tree height and annual shoot growth of Smith fir at various elevations in the Sygera Mountains, southeastern Tibetan Plateau. PLoS One 2012; 7:e31725. [PMID: 22396738 PMCID: PMC3291607 DOI: 10.1371/journal.pone.0031725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 01/12/2012] [Indexed: 11/18/2022] Open
Abstract
Little is known about tree height and height growth (as annual shoot elongation of the apical part of vertical stems) of coniferous trees growing at various altitudes on the Tibetan Plateau, which provides a high-elevation natural platform for assessing tree growth performance in relation to future climate change. We here investigated the variation of maximum tree height and annual height increment of Smith fir (Abies georgei var. smithii) in seven forest plots (30 m×40 m) along two altitudinal transects between 3,800 m and 4,200/4,390 m above sea level (a.s.l.) in the Sygera Mountains, southeastern Tibetan Plateau. Four plots were located on north-facing slopes and three plots on southeast-facing slopes. At each site, annual shoot growth was obtained by measuring the distance between successive terminal bud scars along the main stem of 25 trees that were between 2 and 4 m high. Maximum/mean tree height and mean annual height increment of Smith fir decreased with increasing altitude up to the tree line, indicative of a stress gradient (the dominant temperature gradient) along the altitudinal transect. Above-average mean minimum summer (particularly July) temperatures affected height increment positively, whereas precipitation had no significant effect on shoot growth. The time series of annual height increments of Smith fir can be used for the reconstruction of past climate on the southeastern Tibetan Plateau. In addition, it can be expected that the rising summer temperatures observed in the recent past and anticipated for the future will enhance Smith fir's growth throughout its altitudinal distribution range.
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Affiliation(s)
- Yafeng Wang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Katarina Čufar
- Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Dieter Eckstein
- Division Wood Biology, Department of Wood Science, University of Hamburg, Hamburg, Germany
| | - Eryuan Liang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Bettiati D, Petit G, Anfodillo T. Testing the equi-resistance principle of the xylem transport system in a small ash tree: empirical support from anatomical analyses. TREE PHYSIOLOGY 2012; 32:171-177. [PMID: 22262584 DOI: 10.1093/treephys/tpr137] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In plants, water flows from roots to leaves through a complex network of xylem conduits. The xylem architecture is characterized by the conduit enlargement towards the stem base and the multiplication of conduits near the apices of lateral branches. The xylem architecture of a small ash tree was analysed by measuring the vessel hydraulic diameter (Dh) and number (N) at different heights along the stem and branches. Along the stem, Dh and N increased from the apex to the point of crown insertion. Below, Dh and N decreased and remained constant, respectively. In branches, the Dh and N of apices increased with distance from the ground (PL) (P < 0.001 and P < 0.0001, respectively), indicating that apical resistance (R(APEX)) becomes lower in the most peripheral branches (P < 0.0001). At the level of branch nodes along the stem, the total conductive area (AC) of the stem and branches just above the node was 11% higher than that of the stem just below the node (P = 0.024), whereas the conductivity (Kh) remained invariant above and below (P = 0.76). The difference in AC (ΔAC) between the branches and stem above each node increased with the distance of the node position from the stem apex (L). The xylem architecture of the analysed tree was characterized by anatomical modifications likely aimed at equilibrating the different path length effects on the hydraulic resistance of the different branches. Conduit tapering and multiplication seem to play a crucial role for the achievement of equal hydraulic resistance of all the leaves in the crown.
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Affiliation(s)
- Daniele Bettiati
- Dept. Territorio e Sistemi Agro-Forestali, Università degli Studi di Padova, Viale dell'Università 16, I-35020 Legnaro (PD), Italy
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Piper FI, Fajardo A. No evidence of carbon limitation with tree age and height in Nothofagus pumilio under Mediterranean and temperate climate conditions. ANNALS OF BOTANY 2011; 108:907-17. [PMID: 21852277 PMCID: PMC3177673 DOI: 10.1093/aob/mcr195] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Accepted: 06/03/2011] [Indexed: 05/23/2023]
Abstract
BACKGROUND AND AIMS Trees universally decrease their growth with age. Most explanations for this trend so far support the hypothesis that carbon (C) gain becomes limited with age; though very few studies have directly assessed the relative reductions of C gain and C demand with tree age. It has also been suggested that drought enhances the effect of C gain limitation in trees. Here tests were carried out to determine whether C gain limitation is causing the growth decay with tree age, and whether drought accentuates its effect. METHODS The balance between C gain and C demand across tree age and height ranges was estimated. For this, the concentration of non-structural carbohydrates (NSCs) in stems and roots of trees of different ages and heights was measured in the deciduous temperate species Nothofagus pumilio. An ontogenetic decrease in NSCs indicates support for C limitation. Furthermore, the importance of drought in altering the C balance with ontogeny was assessed by sampling the same species in Mediterranean and humid climate locations in the southern Andes of Chile. Wood density (WD) and stable carbon isotope ratios (δ(13)C) were also determined to examine drought constraints on C gain. KEY RESULTS At both locations, it was effectively found that tree growth ultimately decreased with tree age and height. It was found, however, that NSC concentrations did not decrease with tree age or height when WD was considered, suggesting that C limitation is not the ultimate mechanism causing the age/height-related declining tree growth. δ(13)C decreased with tree age/height at the Mediterranean site only; drought effect increased with tree age/height, but this pattern was not mirrored by the levels of NSCs. CONCLUSIONS The results indicate that concentrations of C storage in N. pumilio trees do not decrease with tree age or height, and that reduced C assimilation due to summer drought does not alter this pattern.
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Affiliation(s)
- Frida I Piper
- Centro de Investigación en Ecosistemas de la Patagonia, Ignacio Serrano 509, Coyhaique, Chile.
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