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Lehmann MM, Diao H, Ouyang S, Gessler A. Different responses of oxygen and hydrogen isotopes in leaf and tree-ring organic matter to lethal soil drought. TREE PHYSIOLOGY 2024; 44:tpae043. [PMID: 38618738 DOI: 10.1093/treephys/tpae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 03/02/2024] [Accepted: 03/23/2024] [Indexed: 04/16/2024]
Abstract
The oxygen and hydrogen isotopic composition (δ18O, δ2H) of plant tissues are key tools for the reconstruction of hydrological and plant physiological processes and may therefore be used to disentangle the reasons for tree mortality. However, how both elements respond to soil drought conditions before death has rarely been investigated. To test this, we performed a greenhouse study and determined predisposing fertilization and lethal soil drought effects on δ18O and δ2H values of organic matter in leaves and tree rings of living and dead saplings of five European tree species. For mechanistic insights, we additionally measured isotopic (i.e. δ18O and δ2H values of leaf and twig water), physiological (i.e. leaf water potential and gas-exchange) and metabolic traits (i.e. leaf and stem non-structural carbohydrate concentration, carbon-to-nitrogen ratios). Across all species, lethal soil drought generally caused a homogenous 2H-enrichment in leaf and tree-ring organic matter, but a low and heterogenous δ18O response in the same tissues. Unlike δ18O values, δ2H values of tree-ring organic matter were correlated with those of leaf and twig water and with plant physiological traits across treatments and species. The 2H-enrichment in plant organic matter also went along with a decrease in stem starch concentrations under soil drought compared with well-watered conditions. In contrast, the predisposing fertilization had generally no significant effect on any tested isotopic, physiological and metabolic traits. We propose that the 2H-enrichment in the dead trees is related to (i) the plant water isotopic composition, (ii) metabolic processes shaping leaf non-structural carbohydrates, (iii) the use of carbon reserves for growth and (iv) species-specific physiological adjustments. The homogenous stress imprint on δ2H but not on δ18O suggests that the former could be used as a proxy to reconstruct soil droughts and underlying processes of tree mortality.
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Affiliation(s)
- Marco M Lehmann
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Forest Soils and Biogeochemistry, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Haoyu Diao
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Shengnan Ouyang
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Institute for Forest Resources and Environment of Guizhou, Guizhou University, Jiaxiu South Road, Huaxi District, Guiyang 550025, China
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
- Institute of Terrestrial Ecosystems, ETH Zurich, Universitätstrasse 16, 8092 Zurich, Switzerland
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2
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Depardieu C, Lenz P, Marion J, Nadeau S, Girardin MP, Marchand W, Bégin C, Treydte K, Gessler A, Bousquet J, Savard MM, Isabel N. Contrasting physiological strategies explain heterogeneous responses to severe drought conditions within local populations of a widespread conifer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171174. [PMID: 38402972 DOI: 10.1016/j.scitotenv.2024.171174] [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: 10/23/2023] [Revised: 01/12/2024] [Accepted: 02/20/2024] [Indexed: 02/27/2024]
Abstract
Understanding how trees prioritize carbon gain at the cost of drought vulnerability under severe drought conditions is crucial for predicting which genetic groups and individuals will be resilient to future climate conditions. In this study, we investigated variations in growth, tree-ring anatomy as well as carbon and oxygen isotope ratios to assess the sensitivity and the xylem formation process in response to an episode of severe drought in 29 mature white spruce (Picea glauca [Moench] Voss) families grown in a common garden trial. During the drought episode, the majority of families displayed decreased growth and exhibited either sustained or increased intrinsic water-use efficiency (iWUE), which was largely influenced by reduced stomatal conductance as revealed by the dual carbon‑oxygen isotope approach. Different water-use strategies were detected within white spruce populations in response to drought conditions. Our results revealed intraspecific variation in the prevailing physiological mechanisms underlying drought response within and among populations of Picea glauca. The presence of different genetic groups reflecting diverse water-use strategies within this largely-distributed conifer is likely to lessen the negative effects of drought and decrease the overall forest ecosystems' sensitivity to it.
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Affiliation(s)
- Claire Depardieu
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Forest Research Centre, Département des sciences du bois et de la forêt, Université Laval, Québec, QC G1V 0A6, Canada; Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada.
| | - Patrick Lenz
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Natural Resources Canada, Canadian Forest Service, Canadian Wood Fibre Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada
| | - Joelle Marion
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Simon Nadeau
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Natural Resources Canada, Canadian Forest Service, Canadian Wood Fibre Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada
| | - Martin P Girardin
- Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada; Centre d'étude de la forêt, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montréal, QC H3C 3P8, Canada; Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l'Université, Rouyn-Noranda, QC J9X 5E4, Canada
| | - William Marchand
- Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada; Centre d'étude de la forêt, Université du Québec à Montréal, C.P. 8888, Succ. Centre-ville, Montréal, QC H3C 3P8, Canada; Forest Research Institute, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l'Université, Rouyn-Noranda, QC J9X 5E4, Canada
| | - Christian Bégin
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Kerstin Treydte
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; Institute of Terrestrial Ecosystems, ETH Zurich, Zurich, Switzerland
| | - Jean Bousquet
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Forest Research Centre, Département des sciences du bois et de la forêt, Université Laval, Québec, QC G1V 0A6, Canada
| | - Martine M Savard
- Geological Survey of Canada, Natural Resources Canada, 490 rue de la Couronne, Québec, QC G1K 9A9, Canada
| | - Nathalie Isabel
- Canada Research Chair in Forest Genomics, Institute for Systems and Integrative Biology, Université Laval, Québec, QC G1V 0A6, Canada; Natural Ressources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, Canada
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3
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Morgner E, Holloway-Phillips M, Basler D, Nelson DB, Kahmen A. Effects of increasing atmospheric CO 2 on leaf water δ 18O values are small and are attenuated in grasses and amplified in dicotyledonous herbs and legumes when transferred to cellulose δ 18O values. THE NEW PHYTOLOGIST 2024. [PMID: 38575849 DOI: 10.1111/nph.19713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 03/08/2024] [Indexed: 04/06/2024]
Abstract
The oxygen isotope composition of cellulose (δ18O values) has been suggested to contain information on stomatal conductance (gs) responses to rising pCO2. The extent by which pCO2 affects leaf water and cellulose δ18O values (δ18OLW and δ18OC) and the isotope processes that determine pCO2 effects on δ18OLW and δ18OC are, however, unknown. We tested the effects of pCO2 on gs, δ18OLW and δ18OC in a glasshouse experiment, where six plant species were grown under pCO2 ranging from 200 to 500 ppm. Increasing pCO2 caused a decline in gs and an increase in δ18OLW, as expected. Importantly, the effects of pCO2 on gs and δ18OLW were small and pCO2 effects on δ18OLW were not directly transferred to δ18OC but were attenuated in grasses and amplified in dicotyledonous herbs and legumes. This is likely because of functional group-specific pCO2 effects on the model parameter pxpex. Our study highlights important uncertainties when using δ18OC as a proxy for gs. Specifically, pCO2-triggered gs effects on δ18OLW and δ18OC are possibly too small to be detected in natural settings and a pCO2 effect on pxpex may render the commonly assumed negative linkage between δ18OC and gs to be incorrect, potentially confounding δ18OC based gs reconstructions.
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Affiliation(s)
- Eva Morgner
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
| | | | - David Basler
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
| | - Daniel B Nelson
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
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Tikkasalo OP, Leppä K, Launiainen S, Peltoniemi M, Mäkipää R, Rinne-Garmston KT, Sahlstedt E, Young GHF, Bokareva A, Lohila A, Korkiakoski M, Schiestl-Aalto P, Lehtonen A. Modeling the response of Norway spruce tree-ring carbon and oxygen isotopes to selection harvest on a drained peatland forest. TREE PHYSIOLOGY 2024; 44:tpad119. [PMID: 37756632 PMCID: PMC10993295 DOI: 10.1093/treephys/tpad119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/22/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
Continuous cover forestry (CCF) has gained interest as an alternative to even-aged management particularly on drained peatland forests. However, relatively little is known about the physiological response of suppressed trees when larger trees are removed as a part of CCF practices. Consequently, studies concentrating on process-level modeling of the response of trees to selection harvesting are also rare. Here, we compared, modeled and measured harvest response of previously suppressed Norway spruce (Picea abies) trees to a selection harvest. We quantified the harvest response by collecting Norway spruce tree-ring samples in a drained peatland forest site and measuring the change in stable carbon and oxygen isotopic ratios of wood formed during 2010-20, including five post-harvest years. The measured isotopic ratios were compared with ecosystem-level process model predictions for ${\kern0em }^{13}$C discrimination and ${\kern0em }^{18}$O leaf water enrichment. We found that the model predicted similar but lower harvest response than the measurements. Furthermore, accounting for mesophyll conductance was important for capturing the variation in ${\kern0em }^{13}$C discrimination. In addition, we performed sensitivity analysis on the model, which suggests that the modeled ${\kern0em }^{13}$C discrimination is sensitive to parameters related to CO2 transport through stomata to the mesophyll.
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Affiliation(s)
- Olli-Pekka Tikkasalo
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Kersti Leppä
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Samuli Launiainen
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Mikko Peltoniemi
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Raisa Mäkipää
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Katja T Rinne-Garmston
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Elina Sahlstedt
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Giles H F Young
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Aleksandra Bokareva
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Annalea Lohila
- Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Sciences, University of Helsinki, P.O. Box 68, FI-00014 Helsinki, Finland
| | - Mika Korkiakoski
- Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland
| | - Pauliina Schiestl-Aalto
- Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Sciences, University of Helsinki, P.O. Box 68, FI-00014 Helsinki, Finland
| | - Aleksi Lehtonen
- Natural Resources Institute Finland (LUKE), Latokartanonkaari 9, FI-00790 Helsinki, Finland
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5
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Shestakova TA, Sin E, Gordo J, Voltas J. Tree-ring isotopic imprints on time series of reproductive effort indicate warming-induced co-limitation by sink and source processes in stone pine. TREE PHYSIOLOGY 2024; 44:tpad147. [PMID: 38079520 DOI: 10.1093/treephys/tpad147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 12/01/2023] [Indexed: 02/09/2024]
Abstract
Increasing evidence indicates that tree growth processes, including reproduction, can be either sink- or source-limited, or simultaneously co-limited by sink and source, depending on the interplay between internal and environmental factors. We tested the hypothesis that the relative strengths of photosynthate supply and demand by stem growth and reproduction create variable competition for substrate that is imprinted in the tree-ring isotopes (C and O) of stone pine (Pinus pinea L.), a masting gymnosperm with large costs of reproduction, under warming-induced drought. Across five representative stands of the Spanish Northern Plateau, we also identified reproductive phases where weather drivers of cone yield (CY) have varied over a 60-year period (1960-2016). We found that these drivers gradually shifted from winter-spring conditions 3 years before seed rain (cone setting) to a combination of 3- and 1-year lagged effects (kernel filling). Additionally, we observed positive regional associations between carbon isotope discrimination (Δ13C) of the year of kernel filling and CY arising at the turn of this century, which progressively offset similarly positive relationships between Δ13C of the year of cone setting and CY found during the first half of the study period. Altogether, these results pinpoint the increasing dependence of reproduction on fresh assimilates and suggest sink and source co-limitation superseding the sink-limited functioning of reproduction dominant before 2000. Under climate warming, it could be expected that drier conditions reinforce the role of source limitation on reproduction and, hence, on regeneration, forest structure and economic profit of the nutlike seeds of the species.
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Affiliation(s)
- Tatiana A Shestakova
- Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
| | - Ester Sin
- Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
| | - Javier Gordo
- Servicio Territorial de Medio Ambiente, Junta de Castilla y León, Duque de la Victoria 5, Valladolid, Castile and León E-47071, Spain
| | - Jordi Voltas
- Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA, Av. Alcalde Rovira Roure 191, Lleida, Catalonia E-25198, Spain
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Zhang Y, Qin Q, Zhu Q, Sun X, Bai Y, Liu Y. Stable isotopes in tree rings record physiological trends in Larix gmelinii after fires. TREE PHYSIOLOGY 2023:tpad033. [PMID: 36928744 DOI: 10.1093/treephys/tpad033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Fire is an important regulator of ecosystem dynamics in boreal forests, and especially has a complicated association with growth and physiological processes of fire-tolerant tree species. Stable isotope ratios in tree rings are used extensively in eco-physiological studies for evaluating the impact of past environmental (e.g., drought, air pollution) factors on tree growth and physiological processes. Yet, such studies based on carbon (δ13C) and oxygen (δ18O) isotope ratios in tree rings are rarely conducted on fire effect, especially not well explored for fire-tolerant trees. In this study, we investigated variations in basal area increment and isotopes of Larix gmelinii (Rupr.) Rupr. before and after three moderate fires (different fire years) at three sites across the Great Xing'an Mountains, Northeastern China. We found that the radial growth of L. gmelinii trees has significantly declined after the fires across study sites. Following the fires, a simultaneous increase in δ13C and δ18O has strengthened the link between the two isotopes. Further, fires have significantly enhanced the 13C-derived intrinsic water-use efficiency (iWUE) and largely altered the relationships between δ13C, δ18O, iWUE and climate (temperature and precipitation). A dual-isotope conceptual model revealed that an initial co-increase in δ13C and δ18O in the fire year can be mainly attributed to a reduction in stomatal conductance with a constant photosynthetic rate. However, this physiological response would shift to different patterns over post-fire time between sites, which might be partly related to spring temperature. This study is beneficial to better understand, in a physiological perspective, how fire-tolerant tree species adapt to a fire-prone environment. We also remind that the limitation of model assumptions and constraints may challenge model applicability and further inferred physiological response.
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Affiliation(s)
- Yujian Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, 100083, Beijing, China
| | - Qianqian Qin
- School of Ecology and Nature Conservation, Beijing Forestry University, 100083, Beijing, China
| | - Qiang Zhu
- School of Ecology and Nature Conservation, Beijing Forestry University, 100083, Beijing, China
| | - Xingyue Sun
- School of Ecology and Nature Conservation, Beijing Forestry University, 100083, Beijing, China
| | - Yansong Bai
- School of Ecology and Nature Conservation, Beijing Forestry University, 100083, Beijing, China
| | - Yanhong Liu
- Beijing Key Laboratory of Forest Resources and Ecosystem Process, Beijing Forestry University, 100083, Beijing, China
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Costa A, Cherubini P, Graça J, Spiecker H, Barbosa I, Máguas C. Beyond width and density: stable carbon and oxygen isotopes in cork-rings provide insights of physiological responses to water stress in Quercus suber L. PeerJ 2022; 10:e14270. [PMID: 36405020 PMCID: PMC9671033 DOI: 10.7717/peerj.14270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
As climate change increasingly affects forest ecosystems, detailed understanding of major effects is important to anticipate their consequences under future climate scenarios. The Mediterranean region is a prominent climate change hotspot, and evergreen cork oak (Quercus suber L.) woodlands are particularly climatically sensitive due to cork (bark) harvesting. Cork oak's drought avoidance strategy is well-known and includes structural and physiological adaptations that maximise soil water uptake and transport and limit water use, potentially leading to reduced stem and cork growth. Trees' responses to cope with water-limited conditions have been extensively described based on cork-rings width and, more recently, on cork-rings density, in dendroecological studies. However, so far, tree functional attributes and physiological strategies, namely photosynthetic metabolism adjustments affecting cork formation, have never been addressed and/or integrated on these previous cork-rings-based studies. In this study, we address the relation between carbon and oxygen stable isotopes of cork rings and precipitation and temperature, in two distinct locations of southwestern Portugal-the (wetter) Tagus basin peneplain and the (drier) Grândola mountains. We aimed at assessing whether the two climatic factors affect cork-ring isotopic composition under contrasting conditions of water availability, and, therefore, if carbon and oxygen signatures in cork can reflect tree functional (physiological and structural) responses to stressful conditions, which might be aggravated by climate change. Our results indicate differences between the study areas. At the drier site, the stronger statistically significant negative cork δ 13C correlations were found with mean temperature, whereas strong positive cork δ 18O correlations were fewer and found only with precipitation. Moreover, at the wetter site, cork rings are enriched in 18O and depleted in 13C, indicating, respectively, shallow groundwater as the water source for physiological processes related with biosynthesis of non-photosynthetic secondary tissues, such as suberin, and a weak stomatal regulation under high water availability, consistent with non-existent water availability constrains. In contrast, at the drier site, trees use water from deeper ground layers, depleted in 18O, and strongly regulate stomatal conductance under water stress, thus reducing photosynthetic carbon uptake and probably relying on stored carbon reserves for cork ring formation. These results suggest that although stable isotopes signatures in cork rings are not proxies for net growth, they may be (fairly) robust indicators of trees' physiological and structural adjustments to climate and environmental changes in Mediterranean environments.
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Affiliation(s)
- Augusta Costa
- Instituto Nacional de Investigação Agrária e Veterinária, I.P., Oeiras, Portugal,Center for Environmental and Sustainability Research, NOVA University of Lisbon, Caparica, Portugal, Caparica, Portugal
| | - Paolo Cherubini
- Swiss Federal Research Institute WSL, Birmensdorf, Switzerland,Department of Forest and Nature Conservation, Faculty of Forestry, Technical University of British Columbia, Vancouver BC, Canada
| | - José Graça
- Instituto Superior de Agronomia, Centro de Estudos Florestais, Universidade de Lisboa, Lisboa, Portugal
| | - Heinrich Spiecker
- Chair of Forest Growth and Dendroecology, Albert-Ludwigs-University, Freiburg, Germany
| | - Inês Barbosa
- Center for Environmental and Sustainability Research, NOVA University of Lisbon, Caparica, Portugal, Caparica, Portugal
| | - Cristina Máguas
- Faculdade de Ciências—cE3c, Centre for Ecology, Evolution and Environmental Changes, Universidade de Lisboa, Lisboa, Portugal
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Hydroclimatic record from an Altiplano cushion peatland (24°S) indicates large-scale reorganisation of atmospheric circulation for the late Holocene. PLoS One 2022; 17:e0277027. [PMID: 36355747 PMCID: PMC9648708 DOI: 10.1371/journal.pone.0277027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 10/18/2022] [Indexed: 11/12/2022] Open
Abstract
The hydroclimate of South America is characterized by the South American summer monsoon (SASM), a tropical atmospheric circulation that induces a summer precipitation regime, and the Southern Hemisphere Westerlies (SHW), an extratropical atmospheric circulation that induces a winter precipitation regime. Stretched between these two systems is a NW-SE-oriented region dominated by descending air masses, resulting in the South American subtropical dry zone (SASDZ), also known as the arid diagonal. We investigated the Cerro Tuzgle cushion peatland (CTP) located on the Argentine Altiplano, north of the present-day SASDZ. Previous work revealed that the CTP was consistently in the SASM regime during the last 2900 cal yr BP. Here, we extend the CTP record to the middle Holocene covering the last 7200 cal yr BP to gain further knowledge of the Holocene development of the SASM and potential modulations of the SASDZ. The prominent feature of the entire record is a distinct and lasting transition centred around 3100 cal yr BP characterized by declining minerogenic content, increasing organic carbon content, rising stable carbon isotope values of organic matter and cellulose, and increasing stable oxygen isotope values of cellulose. We interpret this specific proxy pattern as a hydroclimatic transition towards less arid conditions at the CTP after 3100 cal yr BP. The transition corresponds with the end of the continuous Holocene strengthening of the SASM between 3500 cal yr BP and 3000 cal yr BP indicated by proxy records from north and east of the CTP. The CTP does not reflect this strengthening of the SASM and rather exhibits a threshold response indicating the effective establishment of the SASM summer precipitation regime at 24°S. This suggests that moisture supply during a more arid middle Holocene was provided by isotopically depleted precipitation, while moisture supply after the transition originated from isotopically enriched SASM summer precipitation. Concurrent hydroclimatic changes in the SHW winter precipitation regime south of the SASDZ are documented in a distinct lake level rise of Laguna Aculeo (33°50´S) around 3200 cal yr BP. These coinciding hydrological changes of the SASM and the SHW precipitation regimes indicate larger scale reorganisations of atmospheric circulation components, potentially connected to major modulations of the SASDZ. Thus, our CTP record sheds light on the middle to late Holocene development of the SASM at its southern limit and corroborates connections between the tropical and extratropical hydroclimate of South America.
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Xu G, Liu X, Hu J, Dorado-Liñán I, Gagen M, Szejner P, Chen T, Trouet V. Intra-annual tree-ring δ18O and δ13C reveal a trade-off between isotopic source and humidity in moist environments. TREE PHYSIOLOGY 2022; 42:2203-2223. [PMID: 35796563 DOI: 10.1093/treephys/tpac076] [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: 10/18/2021] [Accepted: 07/02/2022] [Indexed: 06/15/2023]
Abstract
Tree-ring intra-annual stable isotopes (δ13C and δ18O) are powerful tools for revealing plant ecophysiological responses to climatic extremes. We analyzed interannual and fine-scale intra-annual variability of tree-ring δ13C and δ18O in Chinese red pine (Pinus massoniana) from southeastern China to explore environmental drivers and potential trade-offs between the main physiological controls. We show that wet season relative humidity (May-October RH) drove interannual variability of δ18O and intra-annual variability of tree-ring δ18O. It also drove intra-annual variability of tree-ring δ13C, whereas interannual variability was mainly controlled by February-May temperature and September-October RH. Furthermore, intra-annual tree-ring δ18O variability was larger during wet years compared with dry years, whereas δ13C variability was lower during wet years compared with dry years. As a result of these differences in intra-annual variability amplitude, process-based models (we used the Roden model for δ18O and the Farquhar model for δ13C) captured the intra-annual δ18O pattern better in wet years compared with dry years, whereas intra-annual δ13C pattern was better simulated in dry years compared with wet years. This result suggests a potential asymmetric bias in process-based models in capturing the interplay of the different mechanistic processes (i.e., isotopic source and leaf-level enrichment) operating in dry versus wet years. We therefore propose an intra-annual conceptual model considering a dynamic trade-off between the isotopic source and leaf-level enrichment in different tree-ring parts to understand how climate and ecophysiological processes drive intra-annual tree-ring stable isotopic variability under humid climate conditions.
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Affiliation(s)
- Guobao Xu
- National Field Science Observation and Research Station of Yulong Mountain Cryosphere and Sustainable Development, State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- Laboratory of Tree-Ring Research, University of Arizona, Tucson 85721, USA
- Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
| | - Xiaohong Liu
- National Field Science Observation and Research Station of Yulong Mountain Cryosphere and Sustainable Development, State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
- School of Geography and Tourism, Shaanxi Normal University, Xi'an 710119, China
| | - Jia Hu
- Laboratory of Tree-Ring Research, University of Arizona, Tucson 85721, USA
- School of Natural Resources and the Environment, University of Arizona, Tucson 85721, USA
| | - Isabel Dorado-Liñán
- Dpto. de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, Madrid, Spain
| | - Mary Gagen
- Department of Geography, Swansea University, Singleton Park, Swansea SA28PP, UK
| | - Paul Szejner
- Laboratory of Tree-Ring Research, University of Arizona, Tucson 85721, USA
- Instituto de Geología, Universidad Nacional Autónoma de México, México City 04510, México
| | - Tuo Chen
- National Field Science Observation and Research Station of Yulong Mountain Cryosphere and Sustainable Development, State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Valerie Trouet
- Laboratory of Tree-Ring Research, University of Arizona, Tucson 85721, USA
- School of Natural Resources and the Environment, University of Arizona, Tucson 85721, USA
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10
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Lin W, Barbour MM, Song X. Do changes in tree-ring δ 18 O indicate changes in stomatal conductance? THE NEW PHYTOLOGIST 2022; 236:803-808. [PMID: 36200332 DOI: 10.1111/nph.18431] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/31/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Wen Lin
- School of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518000, China
- Shenzhen Key Laboratory of Marine Bio-resource and Eco-environmental Sciences, Shenzhen University, Shenzhen, 518000, China
| | - Margaret M Barbour
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3240, New Zealand
| | - Xin Song
- School of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518000, China
- Shenzhen Key Laboratory of Marine Bio-resource and Eco-environmental Sciences, Shenzhen University, Shenzhen, 518000, China
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11
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Snyder KA, Robinson SA, Schmidt S, Hultine KR. Stable isotope approaches and opportunities for improving plant conservation. CONSERVATION PHYSIOLOGY 2022; 10:coac056. [PMID: 35966756 PMCID: PMC9367551 DOI: 10.1093/conphys/coac056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 04/15/2021] [Accepted: 08/01/2022] [Indexed: 06/01/2023]
Abstract
Successful conservation of threatened species and ecosystems in a rapidly changing world requires scientifically sound decision-making tools that are readily accessible to conservation practitioners. Physiological applications that examine how plants and animals interact with their environment are now widely used when planning, implementing and monitoring conservation. Among these tools, stable-isotope physiology is a potentially powerful, yet under-utilized cornerstone of current and future conservation efforts of threatened and endangered plants. We review the underlying concepts and theory of stable-isotope physiology and describe how stable-isotope applications can support plant conservation. We focus on stable isotopes of carbon, hydrogen, oxygen and nitrogen to address plant ecophysiological responses to changing environmental conditions across temporal scales from hours to centuries. We review examples from a broad range of plant taxa, life forms and habitats and provide specific examples where stable-isotope analysis can directly improve conservation, in part by helping identify resilient, locally adapted genotypes or populations. Our review aims to provide a guide for practitioners to easily access and evaluate the information that can be derived from stable-isotope signatures, their limitations and how stable isotopes can improve conservation efforts.
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Affiliation(s)
- Keirith A Snyder
- Corresponding author: USDA Agricultural Research Service, Great Basin Rangelands Research Unit, Reno,
920 Valley Road, NV 89512, USA.
| | - Sharon A Robinson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Securing Antarctica’s Environmental Future, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Susanne Schmidt
- School of Agriculture and Food Sciences, The University of Queensland, Building 62, Brisbane Queensland 4075, Australia
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 Galvin Parkway, Phoenix, AZ 85008, USA
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12
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Wang J, Wen X. Limiting resource and leaf functional traits jointly determine distribution patterns of leaf intrinsic water use efficiency along aridity gradients. FRONTIERS IN PLANT SCIENCE 2022; 13:909603. [PMID: 35968133 PMCID: PMC9372487 DOI: 10.3389/fpls.2022.909603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
Intrinsic water use efficiency (iWUE) is a critical eco-physiological function allowing plants to adapt to water- and nutrient-limited habitats in arid and semi-arid regions. However, the distribution of iWUE in coexisting species along aridity gradients and its controlling factors are unknown. We established two transects along an aridity gradient in the grasslands of Losses Plateau (LP) and Inner Mongolia Plateau (MP) to elucidate the patterns and underlying mechanisms of iWUE distribution in coexisting species along aridity gradient. We determined leaf carbon (δ13C) and oxygen (δ18O) stable isotopes, functional traits related to carbon fixation, and limiting resources. Bulk leaf δ13C and δ18O were used as proxies for time-integrated iWUE and stomatal conductance (gs) during the growing season. Our results showed that variability in iWUE within transect was primarily controlled by species, sampling sites and an interactive effect between species and sampling sites. Mean values of iWUE (iWUEMean) increased and coefficient of variation (CV) in iWUE (iWUECV) decreased with an increase in aridity, demonstrating that increases in aridity lead to conservative and convergent water use strategies. Patterns of iWUEMean and iWUECV were controlled primarily by the ratio of soil organic carbon to total nitrogen in LP and soil moisture in MP. This revealed that the most limited resource drove the distribution patterns of iWUE along aridity gradients. Interspecific variation in iWUE within transect was positively correlated with Δ18O, indicating that interspecific variation in iWUE was primarily regulated by gs. Furthermore, relationship between iWUE and multi-dimensional functional trait spectrum indicated that species evolved species-specific strategies to adapt to a harsh habitat by partitioning limiting resources. Overall, these findings highlighted the interactive effects of limiting resources and leaf functional traits on plant adaptation strategies for iWUE, and emphasized the importance of considering biological processes in dissecting the underlying mechanisms of plant adaptation strategies at large regional scales.
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Affiliation(s)
- Jing Wang
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Xuefa Wen
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
- Beijing Yanshan Earth Critical Zone National Research Station, University of Chinese Academy of Sciences, Beijing, China
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13
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Liu W, Duan H, Shen F, Liao Y, Li Q, Wu J. Effects of long‐term nitrogen addition on water use by
Cunninghamia lanceolate
in a subtropical plantation. Ecosphere 2022. [DOI: 10.1002/ecs2.4033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Wenfei Liu
- Jiangxi Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology Nanchang Institute of Technology Nanchang China
| | - Honglang Duan
- College of Forestry Guizhou University Guiyang China
| | - Fangfang Shen
- Jiangxi Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology Nanchang Institute of Technology Nanchang China
| | - Yingchun Liao
- Jiangxi Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology Nanchang Institute of Technology Nanchang China
| | - Qiang Li
- Department of Civil Engineering University of Victoria Victoria British Columbia Canada
| | - Jianping Wu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology Yunnan University Kunming China
- Key Laboratory of Soil Ecology and Health in Universities of Yunnan Province, School of Ecology and Environmental Sciences Yunnan University Kunming China
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14
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Goud EM, Prehmus SK, Sparks JP. Is variation in inter-annual precipitation a mechanism for maintaining plant metabolic diversity? Oecologia 2021; 197:1039-1047. [PMID: 34647166 DOI: 10.1007/s00442-021-05046-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 09/21/2021] [Indexed: 11/29/2022]
Abstract
In order for diverse species to coexist in ecological communities, they must vary in ways that reduce competition. Often, this is done by some form of spatial niche separation where small differences in environment allow for coexistence among species. However, temporal separation of resources could also be a factor in driving community diversity. Here, we ask whether inter-annual variation in growing season precipitation could provide sufficient variation in water availability to allow plant species with different intrinsic metabolism to co-occur. We hypothesized that species would differentially respond to soil water availability, and that species with a metabolic strategy to conserve water at the expense of carbon gain would grow better in dry conditions relative to species with a metabolic strategy to gain carbon at the expense of foliar water loss. We measured above-ground biomass and leaf-level metabolism using carbon and oxygen stable isotope ratios for seven Asteraceae species across five experimental water treatments. Species differentially responded to variation in growing season water availability and, importantly, how they responded could be explained by differences in metabolism. Water-conservative species grew best in the dry treatments and had lower growth in wet treatments. Carbon-acquisitive species displayed the opposite pattern, with maximal growth in wet treatments and steep declines in dry treatments. Metabolic differences among co-occurring species may help explain temporal variation in growth, and could provide an underlying physiological mechanism for long-term dynamics that promote biodiversity.
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Affiliation(s)
- Ellie M Goud
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA. .,Department of Geography and Environmental Management, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - Sylvia K Prehmus
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| | - Jed P Sparks
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
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15
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Abstract
In Mediterranean seasonally dry regions, the rise in dieback and mortality episodes observed in pine afforestations has been related to higher drought intensity and lack of appropriate management, which enhance competition between trees for water and light. However, there is little understanding of the benefits of silviculture for plantations under seasonal drought stress. A combination of dendrochronology and wood C and O isotope analyses was used in three Black pine (Pinus nigra) plantations to work out the responses of radial growth (BAI, basal area increment) and water-use efficiency (WUEi) to thinning treatments (removal of 40% of the stand basal area). Thinning had a positive effect on BAI and WUEi, reduced drought sensitivity, and reduced the temporal dependence on the previous year’s growth. These results were significant even 13–14 years after thinning and coherent for the three study sites. Differences were found between the sites regarding the physiological mechanisms of adaptation. In two sites, we inferred the enhanced WUEi was due to increased photosynthetic rates (A) at constant stomatal conductance (gs). In the third site, which had higher tree density and therefore competition, we inferred increases in both A and gs, with the former being proportionally larger than the latter.
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16
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Baca Cabrera JC, Hirl RT, Schäufele R, Macdonald A, Schnyder H. Stomatal conductance limited the CO 2 response of grassland in the last century. BMC Biol 2021; 19:50. [PMID: 33757496 PMCID: PMC7989024 DOI: 10.1186/s12915-021-00988-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The anthropogenic increase of atmospheric CO2 concentration (ca) is impacting carbon (C), water, and nitrogen (N) cycles in grassland and other terrestrial biomes. Plant canopy stomatal conductance is a key player in these coupled cycles: it is a physiological control of vegetation water use efficiency (the ratio of C gain by photosynthesis to water loss by transpiration), and it responds to photosynthetic activity, which is influenced by vegetation N status. It is unknown if the ca-increase and climate change over the last century have already affected canopy stomatal conductance and its links with C and N processes in grassland. RESULTS Here, we assessed two independent proxies of (growing season-integrating canopy-scale) stomatal conductance changes over the last century: trends of δ18O in cellulose (δ18Ocellulose) in archived herbage from a wide range of grassland communities on the Park Grass Experiment at Rothamsted (U.K.) and changes of the ratio of yields to the CO2 concentration gradient between the atmosphere and the leaf internal gas space (ca - ci). The two proxies correlated closely (R2 = 0.70), in agreement with the hypothesis. In addition, the sensitivity of δ18Ocellulose changes to estimated stomatal conductance changes agreed broadly with published sensitivities across a range of contemporary field and controlled environment studies, further supporting the utility of δ18Ocellulose changes for historical reconstruction of stomatal conductance changes at Park Grass. Trends of δ18Ocellulose differed strongly between plots and indicated much greater reductions of stomatal conductance in grass-rich than dicot-rich communities. Reductions of stomatal conductance were connected with reductions of yield trends, nitrogen acquisition, and nitrogen nutrition index. Although all plots were nitrogen-limited or phosphorus- and nitrogen-co-limited to different degrees, long-term reductions of stomatal conductance were largely independent of fertilizer regimes and soil pH, except for nitrogen fertilizer supply which promoted the abundance of grasses. CONCLUSIONS Our data indicate that some types of temperate grassland may have attained saturation of C sink activity more than one century ago. Increasing N fertilizer supply may not be an effective climate change mitigation strategy in many grasslands, as it promotes the expansion of grasses at the disadvantage of the more CO2 responsive forbs and N-fixing legumes.
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Affiliation(s)
- Juan C Baca Cabrera
- Technical University of Munich, Lehrstuhl für Grünlandlehre, Alte Akademie 12, 85354, Freising-Weihenstephan, Germany
| | - Regina T Hirl
- Technical University of Munich, Lehrstuhl für Grünlandlehre, Alte Akademie 12, 85354, Freising-Weihenstephan, Germany
| | - Rudi Schäufele
- Technical University of Munich, Lehrstuhl für Grünlandlehre, Alte Akademie 12, 85354, Freising-Weihenstephan, Germany
| | - Andy Macdonald
- Rothamsted Research, Sustainable Agriculture Sciences Department, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Hans Schnyder
- Technical University of Munich, Lehrstuhl für Grünlandlehre, Alte Akademie 12, 85354, Freising-Weihenstephan, Germany.
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17
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Broz A, Retallack GJ, Maxwell TM, Silva LCR. A record of vapour pressure deficit preserved in wood and soil across biomes. Sci Rep 2021; 11:662. [PMID: 33436864 PMCID: PMC7804288 DOI: 10.1038/s41598-020-80006-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 12/09/2020] [Indexed: 01/29/2023] Open
Abstract
The drying power of air, or vapour pressure deficit (VPD), is an important measurement of potential plant stress and productivity. Estimates of VPD values of the past are integral for understanding the link between rising modern atmospheric carbon dioxide (pCO2) and global water balance. A geological record of VPD is needed for paleoclimate studies of past greenhouse spikes which attempt to constrain future climate, but at present there are few quantitative atmospheric moisture proxies that can be applied to fossil material. Here we show that VPD leaves a permanent record in the slope (S) of least-squares regressions between stable isotope ratios of carbon and oxygen (13C and 18O) found in cellulose and pedogenic carbonate. Using previously published data collected across four continents we show that S can be used to reconstruct VPD within and across biomes. As one application, we used S to estimate VPD of 0.46 kPa ± 0.26 kPa for cellulose preserved tens of millions of years ago-in the Eocene (45 Ma) Metasequoia from Axel Heiberg Island, Canada-and 0.82 kPa ± 0.52 kPa-in the Oligocene (26 Ma) for pedogenic carbonate from Oregon, USA-both of which are consistent with existing records at those locations. Finally, we discuss mechanisms that contribute to the positive correlation observed between VPD and S, which could help reconstruct past climatic conditions and constrain future alterations of global carbon and water cycles resulting from modern climate change.
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Affiliation(s)
- Adrian Broz
- Department of Earth Sciences, University of Oregon, Eugene, 97403, USA.
| | | | - Toby M Maxwell
- Department of Biological Sciences, Boise State University, Boise, ID, 83725, USA
| | - Lucas C R Silva
- Environmental Studies Program, Department of Geography, University of Oregon, Eugene, 97403, USA
- Institute of Ecology and Evolution, University of Oregon, Eugene, 97403, USA
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18
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Battipaglia G, Awada T, Der Au RA, Innangi M, Saurer M, Cherubini P. Increasing atmospheric CO2 concentrations outweighs effects of stand density in determining growth and water use efficiency in Pinus ponderosa of the semi-arid grasslands of Nebraska (U.S.A.). Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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19
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Barçante Ladvocat Cintra B, Gloor M, Boom A, Schöngart J, Locosselli GM, Brienen R. Contrasting controls on tree ring isotope variation for Amazon floodplain and terra firme trees. TREE PHYSIOLOGY 2019; 39:845-860. [PMID: 30824929 PMCID: PMC6594573 DOI: 10.1093/treephys/tpz009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/10/2018] [Accepted: 01/15/2019] [Indexed: 05/04/2023]
Abstract
Isotopes in tropical trees rings can improve our understanding of tree responses to climate. We assessed how climate and growing conditions affect tree-ring oxygen and carbon isotopes (δ18OTR and δ13CTR) in four Amazon trees. We analysed within-ring isotope variation for two terra firme (non-flooded) and two floodplain trees growing at sites with varying seasonality. We find distinct intra-annual patterns of δ18OTR and δ13CTR driven mostly by seasonal variation in weather and source water δ18O. Seasonal variation in isotopes was lowest for the tree growing under the wettest conditions. Tree ring cellulose isotope models based on existing theory reproduced well observed within-ring variation with possible contributions of both stomatal and mesophyll conductance to variation in δ13CTR. Climate analysis reveal that terra firme δ18OTR signals were related to basin-wide precipitation, indicating a source water δ18O influence, while floodplain trees recorded leaf enrichment effects related to local climate. Thus, intrinsically different processes (source water vs leaf enrichment) affect δ18OTR in the two different species analysed. These differences are likely a result of both species-specific traits and of the contrasting growing conditions in the floodplains and terra firme environments. Simultaneous analysis of δ13CTR and δ18OTR supports this interpretation as it shows strongly similar intra-annual patterns for both isotopes in the floodplain trees arising from a common control by leaf stomatal conductance, while terra firme trees showed less covariation between the two isotopes. Our results are interesting from a plant physiological perspective and have implications for climate reconstructions as trees record intrinsically different processes.
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Affiliation(s)
| | - Manuel Gloor
- School of Geography, University of Leeds, Leeds, Garstang North
| | - Arnoud Boom
- School of Geology, Geography and the Environment, Bennett Building, University Road, University of Leicester, Leicester, UK
| | - Jochen Schöngart
- National Institute for Amazon Research, Av. André Araújo, 2.936, Petrópolis, CEP 69.067-375, Manaus, Amazonas Brazil
| | - Giuliano Maselli Locosselli
- Institute of Biosciences, University of São Paulo, Rua do Matão, 14, Butantã, São Paulo, CEP 05508-090, Brazil
| | - Roel Brienen
- School of Geography, University of Leeds, Leeds, Garstang North
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20
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Carbon Isotopes of Riparian Forests Trees in the Savannas of the Volta Sub-Basin of Ghana Reveal Contrasting Responses to Climatic and Environmental Variations. FORESTS 2019. [DOI: 10.3390/f10030251] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Stable isotopes of tree rings are frequently used as proxies in climate change studies. However, species-specific relationships between climate and tree-ring stable isotopes have not yet been studied in riparian forests in the savannas of West Africa. Four cross-dated discs, each of Afzelia africana Sm. (evergreen) and Anogeissus leiocarpus (DC.) Guill. & Perr. (deciduous) in the humid (HSZ) and dry (DSZ) savanna zones of the Volta basin in Ghana were selected from a larger tree-ring dataset to assess the relationships between the tree-ring carbon isotope composition (δ13C values) and climatic parameters. The atmospherically corrected δ13C values of both studied species showed that A. africana was enriched in 13C compared to A. leiocarpus. Strong correlations were found between δ13C values of A. africana and A. leiocarpus with temperature, but weak correlations with precipitation. Spatial correlation analysis revealed significant relationships between δ13C values of both tree species and Sea Surface Temperatures in the Gulf of Guinea in the southern Atlantic Ocean. The results suggest that the carbon isotope composition of riparian trees in the Volta river basin has a potential to reconstruct climate variability and to assess tree ecological responses to climate change.
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21
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Leaf Gas Exchange, Plant Water Relations and Water Use Efficiency of Vigna Unguiculata L. Walp. Inoculated with Rhizobia under Different Soil Water Regimes. WATER 2019. [DOI: 10.3390/w11030498] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Impact of soil water regimes on physiological responses and water use efficiency (WUE) for Vigna unguiculata L. Walp. (cowpea) inoculated with rhizobia still remains implicit. Therefore, the goal of the current study was to examine the leaf gas exchange, abscisic acid (ABA) and hydraulic signaling, WUE and carbon and oxygen isotopic compositions (δ13C and δ18O) of cowpea under different soil water levels. The treatments included soil water regimes at three levels (90%, 70%, and 50% of soil water holding capacity (SWHC)) and two inoculation forms (inoculated and non-inoculated with rhizobia). The results showed that across the inoculation treatments, reduced soil water regimes depressed both stomatal conductance (gs) and photosynthesis (An) of the leaves, nonetheless, the decrease of gs was more pronounced compared with the reduction in An. Consequently, the intrinsic water use efficiency (WUEi) was improved in the treatments under decreased soil water conditions. Plant WUE was also improved when soil water contents decreased as exemplified by the increased leaf δ13C and δ18O, indicating the enhanced plant WUE was mainly attributed to the decrease of gs. Significant interactions between soil water regimes and rhizobia treatments for root water potential (RWP), leaf water potential (LWP), and gs were found due to the different responses of rhizobia to varied soil water regimes. Inoculation could improve plant water status and gs under 70% and 90% SWHC compared to 50% SWHC with negative effect from rhizobia. A moderate soil water regime is suggested for cowpea production in terms of high WUE with a minor biomass reduction.
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22
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Disentangling Contributions of CO2 Concentration and Climate to Changes in Intrinsic Water-Use Efficiency in the Arid Boreal Forest in China’s Altay Mountains. FORESTS 2018. [DOI: 10.3390/f9100642] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intrinsic water-use efficiency (iWUE) is affected by the balance of photosynthetic rate, stomatal conductance, and climate, along with many other exogenous factors, such as the CO2 concentration in the atmosphere (CO2atm), nutrients, and water holding capacity of the soil. The relative contributions of CO2atm and climate to iWUE are still incompletely understood, particularly for boreal forests where the climate is undergoing unprecedented warming. We combined δ13C and δ18O in tree rings from the Siberian larch (Larix sibirica Ledeb.) in Northwestern China’s Altay Mountains, which receives 190 mm in annual precipitation, to detect the drivers of long-term iWUE changes and their time-varying contributions over the past 222 years. A climate optimization approach was used to isolate the influence of climate from CO2atm influence on iWUE. We found that iWUE increased about 33.6% from 1790 to 2011, and rising CO2atm contributed 48.8% to this iWUE increase. The contributions of CO2atm and climate (drought conditions) varied during the study period 1790–2011. From 1790 to 1876, the climate was the most important factor contributing to the changes in iWUE. From 1877 to 1972, CO2atm was the main contributor; however, after 1973, the climate was again the dominant contributor to the increase in iWUE, especially during 1996–2011. During the period 1996–2011, climate substantially (83%) contributed to the iWUE increase. Our findings imply that, in the boreal forest in Northwestern China’s arid region, iWUE experienced three changes: (1) the climate dominating from 1790 to 1876; (2) CO2atm dominating from 1877 to 1972, and (3) climate dominating again during the past four decades. We observed that the relationships between iWUE and tree-ring width shifted from positive to negative from 1996 onwards. These relationship changes indicate that CO2atm-mediated effects of increasing iWUE on tree growth are counteracted by climatic drought stress and iWUE increase cannot counter the stress from drought on tree growth in China’s arid boreal forest.
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23
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Lopez Caceres ML, Nakano S, Ferrio JP, Hayashi M, Nakatsuka T, Sano M, Yamanaka T, Nobori Y. Evaluation of the effect of the 2011 Tsunami on coastal forests by means of multiple isotopic analyses of tree-rings. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2018; 54:494-507. [PMID: 30001638 DOI: 10.1080/10256016.2018.1495203] [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: 11/25/2017] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
The March 2011 Mega-Tsunami in eastern Japan damaged at different degrees the black pine (Pinus thunbergii) forests along the coast. In order to evaluate the recovery of black pine four years later, tree-ring samples from 9 trees for the period 2002-2014 were analyzed for ring growth and stable isotopes (δ13C, δ15N and δ18O). The results showed that annual tree-ring width decreased approximately 70 % from the year 2011 to 2014 compared to the period previous to the tsunami (2002-2010). The multiple isotopic analyses showed that the reduction in growth was caused by soil salinity that prompted stomatal closure and an abrupt increase of tree-ring δ13C. Sea water deposition in the soil did not affect tree-ring δ18O values. Two years after the tsunami, decreasing tree-ring δ13C values caused by apparently photosynthetic recovery did not translate into radial tree-growth, indicating a possible shift in carbon allocation to foliage and mainly roots as a defense mechanism to sodium toxicity. The dual δ13C-δ18O model explains neither the limited growth nor the subsequent recovery in δ13C. Similarly tree-ring δ15N indicated that there was no difference in nitrogen availability before and after the tsunami, suggesting that nutrients were not a limitation but rather soil salinity.
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Affiliation(s)
| | - Sayako Nakano
- a Faculty of Agriculture , Yamagata University , Tsuruoka , Japan
| | - Juan Pedro Ferrio
- b Department of Crop and Forests Sciences , ETSEA-Universitat de Lleida , Lleida , Spain
- c ARAID-Forests Resources Unit, Agrifood Research and Technology Centre of Aragón , Zaragoza , Spain
| | - Mika Hayashi
- a Faculty of Agriculture , Yamagata University , Tsuruoka , Japan
| | - Takeshi Nakatsuka
- d Research Department , Research Institute for Humanity and Nature , Kyoto , Japan
| | - Masaki Sano
- e Faculty of Human Sciences , Waseda University , Tokorozawa , Japan
| | - Toshiro Yamanaka
- f Department of Ocean and Environmental Sciences , Tokyo University of Marine Science and Technology , Tokyo , Japan
| | - Yoshihiro Nobori
- a Faculty of Agriculture , Yamagata University , Tsuruoka , Japan
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Ma R, Zhu Z, Wang B, Zhao Y, Yin X, Lu F, Wang Y, Su J, Hocart CH, Zhou Y. Novel Position-Specific 18O/16O Measurement of Carbohydrates. I. O-3 of Glucose and Confirmation of 18O/16O Heterogeneity at Natural Abundance Levels in Glucose from Starch in a C4 Plant. Anal Chem 2018; 90:10293-10301. [DOI: 10.1021/acs.analchem.8b02022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ran Ma
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Zhenyu Zhu
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Bo Wang
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Yu Zhao
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Xijie Yin
- SOA Third Institute of Oceanography, Xiamen 361005, China
| | - Fengyan Lu
- Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
| | - Ying Wang
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
| | - Jing Su
- SOA Third Institute of Oceanography, Xiamen 361005, China
| | - Charles H. Hocart
- Research School of Biology, Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Youping Zhou
- Isotopomics in Chemical Biology & Shaanxi Key Laboratory of Chemical Additives for Industry, School of Chemistry & Chemical Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China
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Zalloni E, Battipaglia G, Cherubini P, Saurer M, De Micco V. Contrasting physiological responses to Mediterranean climate variability are revealed by intra-annual density fluctuations in tree rings of Quercus ilex L. and Pinus pinea L. TREE PHYSIOLOGY 2018; 38:1213-1224. [PMID: 29920596 DOI: 10.1093/treephys/tpy061] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 06/01/2018] [Indexed: 06/08/2023]
Abstract
Mixed forests of Quercus ilex L. and Pinus pinea L. are widely found throughout the Mediterranean Basin, being representative of two co-existing functional types: evergreen-sclerophyllous drought-resistant species and Mediterranean-adapted drought-avoidant conifers. Their contrasting physiological strategies to cope with water deficit influence all the processes regulating their growth such as wood formation, leading to peculiar tree-ring anatomical features such as intra-annual density fluctuations (IADFs). Intra-annual density fluctuations are abrupt changes in wood anatomical traits within a tree ring, appearing as latewood-like cells within earlywood or earlywood-like cells within latewood, and are frequently found in Mediterranean species as a response to seasonal climate changes. In this study, we characterized the anatomical traits and composition of carbon and oxygen stable isotopes in IADFs occurring in tree rings of Q. ilex and P. pinea trees co-existing at a same site in Southern Italy, in order to link their xylem hydraulic properties with the related physiological mechanisms. The relationships between IADF occurrence and seasonal mean temperature and total precipitation were investigated, with the aim of assessing whether they can be used as indicators of species-specific responses to intra-annual climate fluctuations. Results show that IADF period of formation is during autumn months for both species. The influence of climate on IADF occurrence was found to be an indicator of species-specific response to climate: an increased stomatal conductance associated to the formation of a wood safer against embolism was found in Q. ilex, while a tighter stomatal control associated to a more efficient wood with regard to hydraulic conductivity occurred in P. pinea. Moreover, the assessment of the influence of climate on IADF occurrence indicates that, with rising temperatures, Q. ilex would form fewer IADFs compared with P. pinea. Other study cases are desirable to assess the suggested forecasts and to link the plasticity of the species to form IADFs with their effective adaptive capability to compete for resources, and to explain how it may influence future population development.
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Affiliation(s)
- Enrica Zalloni
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, Portici, Naples, Italy
| | - Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania 'L. Vanvitelli', Via Vivaldi 43, Caserta, Italy
| | - Paolo Cherubini
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, Birmensdorf, Zurich, Switzerland
| | - Matthias Saurer
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, Birmensdorf, Zurich, Switzerland
| | - Veronica De Micco
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, Portici, Naples, Italy
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Helliker BR, Song X, Goulden ML, Clark K, Bolstad P, Munger JW, Chen J, Noormets A, Hollinger D, Wofsy S, Martin T, Baldocchi D, Euskirchenn E, Desai A, Burns SP. Assessing the interplay between canopy energy balance and photosynthesis with cellulose δ18O: large-scale patterns and independent ground-truthing. Oecologia 2018; 187:995-1007. [DOI: 10.1007/s00442-018-4198-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 06/05/2018] [Indexed: 10/28/2022]
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Weigt RB, Streit K, Saurer M, Siegwolf RTW. The influence of increasing temperature and CO2 concentration on recent growth of old-growth larch: contrasting responses at leaf and stem processes derived from tree-ring width and stable isotopes. TREE PHYSIOLOGY 2018; 38:706-720. [PMID: 29194509 DOI: 10.1093/treephys/tpx148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 11/03/2017] [Indexed: 06/07/2023]
Abstract
Time series of tree-ring growth show significant increases since the early 1970s at the alpine tree line, with simultaneously increasing temperatures and atmospheric CO2 concentration. For a comprehensive understanding of this growth change, the physiological response patterns at both the leaf and stem level need to be separately analyzed and identified, and can be retrieved from tree-ring growth and isotope (δ13C, δ18O) series. In this study, we assessed the relative contribution of environmental factors to interannual tree-ring variability by multivariate linear mixed-effects models and the dual isotope approach on a dataset of tree-ring records of ~400-year-old larch (Larix decidua Mill.) from a non-water-limited high-elevation site in the Swiss Alps. The models suggest that summer temperatures and the recent lack of larch budmoth outbreaks were most important for explaining growth variations and trends, while a significant direct effect of the continuously increasing CO2 concentration could not be confirmed. In contrast, δ13C and δ18O, which are strongly influenced by fractionation changes in the leaf, clearly reflected the impact of air humidity (precipitation and vapor pressure deficit) and CO2 concentration: the increase in (δ13C-derived) intrinsic water-use efficiency over the second half of the 20th century suggests an increase in carbon assimilation as a result of enhanced CO2 concentration. The tree-ring δ18O largely reflected recent precipitation as source water, thus indicating a low variability in stomatal conductance, which was confirmed by the dual isotope approach. These leaf-level effects were not reflected in stem growth as they may have been masked by the temperature-caused growth limitation controlling the allocation of increased amounts of photosynthates into wood growth. Our approach demonstrates that the identification of different roles of environmental factors on leaf and stem processes helps to improve the assessment of site-specific changes of carbon fluxes and growth performance under future environmental conditions.
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Affiliation(s)
- Rosemarie B Weigt
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Kathrin Streit
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Matthias Saurer
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Rolf T W Siegwolf
- Laboratory of Atmospheric Chemistry, Ecosystem Fluxes, Paul Scherrer Institute, 5232 Villigen, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
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Integrating effects of species composition and soil properties to predict shifts in montane forest carbon-water relations. Proc Natl Acad Sci U S A 2018; 115:E4219-E4226. [PMID: 29666233 PMCID: PMC5939077 DOI: 10.1073/pnas.1718864115] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
This research focuses on how species composition and soil properties interact to control carbon fixation and water loss in California’s montane forests. Two conclusions arise: (i) The amount of carbon fixed per unit of water lost via transpiration varies widely among forest stands depending on dominant tree species and their inherent leaf characteristics, and (ii) different parent materials and stages of soil development regulate the effect of climate on water-use efficiency and productivity of trees across altitudinal gradients. Taken together, dynamic biological processes related to species composition and relatively inert physicochemical properties that characterize soil development can be combined to anticipate changes in forest carbon and water balances. This study was designed to address a major source of uncertainty pertaining to coupled carbon–water cycles in montane forest ecosystems. The Sierra Nevada of California was used as a model system to investigate connections between the physiological performance of trees and landscape patterns of forest carbon and water use. The intrinsic water-use efficiency (iWUE)—an index of CO2 fixed per unit of potential water lost via transpiration—of nine dominant species was determined in replicated transects along an ∼1,500-m elevation gradient, spanning a broad range of climatic conditions and soils derived from three different parent materials. Stable isotope ratios of carbon and oxygen measured at the leaf level were combined with field-based and remotely sensed metrics of stand productivity, revealing that variation in iWUE depends primarily on leaf traits (∼24% of the variability), followed by stand productivity (∼16% of the variability), climatic regime (∼13% of the variability), and soil development (∼12% of the variability). Significant interactions between species composition and soil properties proved useful to predict changes in forest carbon–water relations. On the basis of observed shifts in tree species composition, ongoing since the 1950s and intensified in recent years, an increase in water loss through transpiration (ranging from 10 to 60% depending on parent material) is now expected in mixed conifer forests throughout the region.
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Weiwei LU, Xinxiao YU, Guodong JIA, Hanzhi LI, Ziqiang LIU. Responses of Intrinsic Water-use Efficiency and Tree Growth to Climate Change in Semi-Arid Areas of North China. Sci Rep 2018; 8:308. [PMID: 29321679 PMCID: PMC5762888 DOI: 10.1038/s41598-017-18694-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/13/2017] [Indexed: 11/19/2022] Open
Abstract
Tree-level intrinsic water-use efficiency (iWUE) is derived from the tree-ring 13C isotope composition (δ13C) and is an important indicator of the adaptability for trees to climate change. However, there is still uncertainty regarding the relationship between long-term forest ecosystem carbon sequestration capacity and iWUE. To determine whether elevated atmospheric CO2 concentration (Ca) increase iWUE and tree growth (basal area increment, BAI), dendrochronological methods and stable isotope analyses were used to examine annual changes in the tree-ring width and carbon isotope composition (δ13C) of Platycladus orientalis in northern China. The iWUE derived from δ13C has increased significantly (p < 0.01). Long-term iWUE trend was largely and positively driven by the elevated atmospheric CO2 concentration and temperature. We observed a general increase in averaged BAI, which had significant positive correlation with iWUE (R2 = 0.3186, p < 0.01). Increases in iWUE indeed translated into enhanced P. orientalis growth in semi-arid areas of northern China. Elevated atmospheric CO2 concentration significantly (p < 0.01) stimulated P. orientalis biomass accumulation when Ca was less than approximately 320 ppm in the early phase; however, this effect was not pronounced when Ca exceeded 320 ppm.
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Affiliation(s)
- L U Weiwei
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
| | - Y U Xinxiao
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China.
| | - J I A Guodong
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
| | - L I Hanzhi
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
| | - L I U Ziqiang
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
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Garrido M, Silva H, Franck N, Arenas J, Acevedo E. Evaluation of Morpho-Physiological Traits Adjustment of Prosopis tamarugo Under Long-Term Groundwater Depletion in the Hyper-Arid Atacama Desert. FRONTIERS IN PLANT SCIENCE 2018; 9:453. [PMID: 29686691 PMCID: PMC5900453 DOI: 10.3389/fpls.2018.00453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/22/2018] [Indexed: 05/06/2023]
Abstract
Water extraction from the underground aquifers of the Pampa del Tamarugal (Atacama Desert, Chile) reduced the growing area of Prosopis tamarugo, a strict phreatic species endemic to northern Chile. The objective of this work was to evaluate the effect of various architectural and morpho-physiological traits adjustment of P. tamarugo subjected to three groundwater depletion intervals (GWDr): <1 m (control), 1-4 m and 6-9 m. The traits were evaluated at three levels, plant [height, trunk cross-section area, leaf fraction (fGCC), and crown size], organ [length of internodes, leaf mass per unit area (LMA), leaflet mass and area], and tissue level [wood density (WD), leaf 13C, 18O isotope composition (δ), and intrinsic water use efficiency (iWUE)]. In addition, soil water content (VWC) to 1.3 m soil depth, pre-dawn and midday water potential difference (ΔΨ), and stomatal conductance (gs) were evaluated. At the deeper GWDr, P. tamarugo experienced significant growth restriction and reduced fGCC, the remaining canopy had a significantly higher LMA associated with smaller leaflets. No differences in internode length and WD were observed. Values for δ13C and δ18O indicated that as GWDr increased, iWUE increased as a result of partial stomata closure with no significant effect on net assimilation over time. The morpho-physiological changes experienced by P. tamarugo allowed it to acclimate and survive in a condition of groundwater depletion, keeping a functional but diminished canopy. These adjustments allowed maintenance of a relatively high gs; ΔΨ was not different among GWDrs despite smaller VWC at greater GWDr. Although current conservation initiatives of this species are promising, forest deterioration is expected continue as groundwater depth increases.
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Affiliation(s)
- Marco Garrido
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
| | - Herman Silva
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
| | - Nicolás Franck
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
| | - Jorge Arenas
- Faculty of Natural Renewable Resources, Desert Agriculture, Universidad Arturo Prat, Iquique, Chile
| | - Edmundo Acevedo
- Soil-Plant-Water Relations Laboratory, Agricultural Production Department, Faculty of Agronomical Sciences, Universidad de Chile, Santiago, Chile
- *Correspondence: Edmundo Acevedo
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Guerrieri R, Jennings K, Belmecheri S, Asbjornsen H, Ollinger S. Evaluating climate signal recorded in tree-ring δ 13 C and δ 18 O values from bulk wood and α-cellulose for six species across four sites in the northeastern US. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:2081-2091. [PMID: 28940773 DOI: 10.1002/rcm.7995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/08/2017] [Accepted: 09/11/2017] [Indexed: 05/08/2023]
Abstract
RATIONALE We evaluated the applicability of tree-ring δ13 C and δ18 O values in bulk wood - instead of the more time and lab-consuming α-cellulose δ13 C and δ18 O values, to assess climate and physiological signals across multiple sites and for six tree species along a latitudinal gradient (35°97'N to 45°20'N) of the northeastern United States. METHODS Wood cores (n = 4 per tree) were sampled from ten trees per species. Cores were cross-dated within and across trees at each site, and for the last 30 years. Seven years, including the driest on record, were selected for this study. The δ13 C and δ18 O values were measured on two of the ten trees from the bulk wood and the α-cellulose. The offsets between materials in δ13 C and δ18 O values were assessed. Correlation and multiple regression analyses were used to evaluate the strength of the climate signal across sites. Finally the relationship between δ13 C and δ18 O values in bulk wood vs α-cellulose was analyzed to assess the consistency of the interpretation, in terms of CO2 assimilation and stomatal conductance, from both materials. RESULTS We found offsets of 1.1‰ and 5.6‰ between bulk and α-cellulose for δ13 C and δ18 O values, respectively, consistent with offset values reported in the literature. Bulk wood showed similar or stronger correlations to climate parameters than α-cellulose for the investigated sites. In particular, temperature and vapor pressure deficit and standard precipitation-evaporation index (SPEI) were the most visible climate signals recorded in δ13 C and δ18 O values, respectively. For most of the species, there was no relationship between δ13 C and δ18 O values, regardless of the wood material considered. CONCLUSIONS Extraction of α-cellulose was not necessary to detect climate signals in tree rings across the four investigated sites. Furthermore, the physiological information inferred from the dual isotope approach was similar for most of the species regardless of the material considered.
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Affiliation(s)
- Rossella Guerrieri
- Earth Systems Research Center, University of New Hampshire, Durham, NH, 03824, USA
| | - Katie Jennings
- Earth Systems Research Center, University of New Hampshire, Durham, NH, 03824, USA
| | - Soumaya Belmecheri
- Laboratory of Tree Ring Research, University of Arizona, Tucson, AZ, 85721-0045, USA
| | - Heidi Asbjornsen
- Earth Systems Research Center, University of New Hampshire, Durham, NH, 03824, USA
| | - Scott Ollinger
- Earth Systems Research Center, University of New Hampshire, Durham, NH, 03824, USA
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Barbeta A, Peñuelas J. Increasing carbon discrimination rates and depth of water uptake favor the growth of Mediterranean evergreen trees in the ecotone with temperate deciduous forests. GLOBAL CHANGE BIOLOGY 2017; 23:5054-5068. [PMID: 28544424 DOI: 10.1111/gcb.13770] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 05/04/2017] [Accepted: 05/16/2017] [Indexed: 05/17/2023]
Abstract
Tree populations at the low-altitudinal or -latitudinal limits of species' distributional ranges are predicted to retreat toward higher altitudes and latitudes to track the ongoing changes in climate. Studies have focused on the climatic sensitivity of the retreating species, whereas little is known about the potential replacements. Competition between tree species in forest ecotones will likely be strongly influenced by the ecophysiological responses to heat and drought. We used tree-ring widths and δ13 C and δ18 O chronologies to compare the growth rates and long-term ecophysiological responses to climate in the temperate-Mediterranean ecotone formed by the deciduous Fagus sylvatica and the evergreen Quercus ilex at the low altitudinal and southern latitudinal limit of F. sylvatica (NE Iberian Peninsula). F. sylvatica growth rates were similar to those of other southern populations and were surprisingly not higher than those of Q. ilex, which were an order of magnitude higher than those in nearby drier sites. Higher Q. ilex growth rates were associated with high temperatures, which have increased carbon discrimination rates in the last 25 years. In contrast, stomatal regulation in F. sylvatica was proportional to the increase in atmospheric CO2 . Tree-ring δ18 O for both species were mostly correlated with δ18 O in the source water. In contrast to many previous studies, relative humidity was not negatively correlated with tree-ring δ18 O but had a positive effect on Q. ilex tree-ring δ18 O. Furthermore, tree-ring δ18 O decreased in Q. ilex over time. The sensitivity of Q. ilex to climate likely reflects the uptake of deep water that allowed it to benefit from the effect of CO2 fertilization, in contrast to the water-limited F. sylvatica. Consequently, Q. ilex is a strong competitor at sites currently dominated by F. sylvatica and could be favored by increasingly warmer conditions.
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Affiliation(s)
- Adrià Barbeta
- ISPA, Bordeaux Science Agro, INRA, Villenave d'Ornon, 33140, France
- Global Ecology Unit CREAF-CSIC-UAB, CSIC, E-08193, Bellaterra, Catalonia, Spain
- CREAF, E-08193, Cerdanyola del Vallès, Catalonia, Spain
| | - Josep Peñuelas
- Global Ecology Unit CREAF-CSIC-UAB, CSIC, E-08193, Bellaterra, Catalonia, Spain
- CREAF, E-08193, Cerdanyola del Vallès, Catalonia, Spain
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Reconstructing Extinct Plant Water Use for Understanding Vegetation–Climate Feedbacks: Methods, Synthesis, and a Case Study Using the Paleozoic-Era Medullosan Seed Ferns. ACTA ACUST UNITED AC 2017. [DOI: 10.1017/s1089332600003004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Vegetation affects feedbacks in Earth's hydrologic system, but is constrained by physiological adaptations. In extant ecosystems, the mechanisms controlling plant water used can be measured experimentally; for extinct plants in the recent geological past, water use can be inferred from nearest living relatives, assuming minimal evolutionary change. In deep time, where no close living relatives exist, fossil material provides the only information for inferring plant water use. However, mechanistic models for extinct plant water use must be built on first principles and tested on extant plants. Plants serve as a conduit for water movement from the soil to the atmosphere, constrained by tissue-level construction and gross architecture. No single feature, such as stomata or veins, encompasses enough of the complexity underpinning water-use physiology to serve as the basis of a model of functional water use in all (or perhaps any) extinct plants. Rather, a “functional whole plant” model must be used. To understand the interplay between plant and atmosphere, water use in relation to environmental conditions is investigated in an extinct plant, the seed fernMedullosa((Division Pteridospermatophyta), by reviewing methods for reconstructing physiological variables such as leaf and stem hydraulic capacity, photosynthetic rate, transpiration rate, stomatal conductance, and albedo. Medullosans had the potential for extremely high photosynthetic and assimilation rates, water transport, stomatal conductance, and transpiration—rates comparable to later angiosperms. When these high growth and gas exchange rates of medullosans are combined with the unique atmospheric gas composition of the late Paleozoic atmosphere, complex vegetation-environmental feedbacks are expected despite their basal phylogenetic position relative to post-Paleozoic seed plants.
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Bögelein R, Thomas FM, Kahmen A. Leaf water 18 O and 2 H enrichment along vertical canopy profiles in a broadleaved and a conifer forest tree. PLANT, CELL & ENVIRONMENT 2017; 40:1086-1103. [PMID: 28042668 DOI: 10.1111/pce.12895] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 12/16/2016] [Accepted: 12/28/2016] [Indexed: 06/06/2023]
Abstract
Distinguishing meteorological and plant-mediated drivers of leaf water isotopic enrichment is prerequisite for ecological interpretations of stable hydrogen and oxygen isotopes in plant tissue. We measured input and leaf water δ2 H and δ18 O as well as micrometeorological and leaf morpho-physiological variables along a vertical gradient in a mature angiosperm (European beech) and gymnosperm (Douglas fir) tree. We used these variables and different enrichment models to quantify the influence of Péclet and non-steady state effects and of the biophysical drivers on leaf water enrichment. The two-pool model accurately described the diurnal variation of leaf water enrichment. The estimated unenriched water fraction was linked to leaf dry matter content across the canopy heights. Non-steady state effects and reduced stomatal conductance caused a higher enrichment of Douglas fir compared to beech leaf water. A dynamic effect analyses revealed that the light-induced vertical gradients of stomatal conductance and leaf temperature outbalanced each other in their effects on evaporative enrichment. We conclude that neither vertical canopy gradients nor the Péclet effect is important for estimates and interpretation of isotopic leaf water enrichment in hypostomatous trees. Contrarily, species-specific non-steady state effects and leaf temperatures as well as the water vapour isotope composition need careful consideration.
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Affiliation(s)
- Rebekka Bögelein
- Faculty of Regional and Environmental Sciences - Geobotany, University of Trier, 54296, Trier, Germany
| | - Frank M Thomas
- Faculty of Regional and Environmental Sciences - Geobotany, University of Trier, 54296, Trier, Germany
| | - Ansgar Kahmen
- Department of Environmental Sciences - Botany, University of Basel, 4056, Basel, Switzerland
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Ellsworth PZ, Ellsworth PV, Cousins AB. Relationship of leaf oxygen and carbon isotopic composition with transpiration efficiency in the C4 grasses Setaria viridis and Setaria italica. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3513-3528. [PMID: 28859378 PMCID: PMC5853516 DOI: 10.1093/jxb/erx185] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 05/26/2017] [Indexed: 05/20/2023]
Abstract
Leaf carbon and oxygen isotope ratios can potentially provide a time-integrated proxy for stomatal conductance (gs) and transpiration rate (E), and can be used to estimate transpiration efficiency (TE). In this study, we found significant relationships of bulk leaf carbon isotopic signature (δ13CBL) and bulk leaf oxygen enrichment above source water (Δ18OBL) with gas exchange and TE in the model C4 grasses Setaria viridis and S. italica. Leaf δ13C had strong relationships with E, gs, water use, biomass, and TE. Additionally, the consistent difference in δ13CBL between well-watered and water-limited plants suggests that δ13CBL is effective in separating C4 plants with different availability of water. Alternatively, the use of Δ18OBL as a proxy for E and TE in S. viridis and S. italica was problematic. First, the oxygen isotopic composition of source water, used to calculate leaf water enrichment (Δ18OLW), was variable with time and differed across water treatments. Second, water limitations changed leaf size and masked the relationship of Δ18OLW and Δ18OBL with E. Therefore, the data collected here suggest that δ13CBL but not Δ18OBL may be an effective proxy for TE in C4 grasses.
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Affiliation(s)
- Patrick Z Ellsworth
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | | | - Asaph B Cousins
- School of Biological Sciences, Washington State University, Pullman, WA, USA
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Colangelo M, Camarero JJ, Battipaglia G, Borghetti M, De Micco V, Gentilesca T, Ripullone F. A multi-proxy assessment of dieback causes in a Mediterranean oak species. TREE PHYSIOLOGY 2017; 37:617-631. [PMID: 28338766 DOI: 10.1093/treephys/tpx002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/20/2017] [Indexed: 05/22/2023]
Abstract
Drought stress causes forest dieback that is often explained by two interrelated mechanisms, namely hydraulic failure and carbon starvation. However, it is still unclear which functional and structural alterations, related to these mechanisms, predispose to dieback. Here we apply a multi-proxy approach for the characterization of tree structure (radial growth, wood anatomy) and functioning (δ13C, δ18O and non-structural carbohydrates (NSCs)) in tree rings before and after drought-induced dieback. We aim to discriminate which is the main mechanism and to assess which variables can act as early-warning proxies of drought-triggered damage. The study was tailored in southern Italy in two forests (i.e., San Paolo (SP) and Oriolo (OR)) where declining and non-declining trees of a ring-porous tree species (Quercus frainetto Ten.) showing anisohydric behavior coexist. Both stands showed growth decline in response to warm and dry spring conditions, although the onset of dieback was shifted between them (2002 in SP and 2009 in OR). Declining trees displayed a sharp growth drop after this onset with reductions of 49% and 44% at SP and OR sites, respectively. Further, contrary to what we expected, declining trees showed a lower intrinsic water-use efficiency compared with non-declining trees after the dieback onset (with reductions of 9.7% and 5.6% at sites SP and OR, respectively), due to enhanced water loss through transpiration, as indicated by the lower δ18O values. This was more noticeable at the most drought-affected SP stand. Sapwood NSCs did not differ between declining and non-declining trees, indicating no carbon starvation in affected trees. Thus, the characterized structural and functional alterations partially support the hydraulic failure mechanism of dieback. Finally, we show that growth data are reliable early-warning proxies of drought-triggered dieback.
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Affiliation(s)
- Michele Colangelo
- School of Agricultural, Forest, Food and Environmental Sciences, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - J Julio Camarero
- Pyrenean Institute of Ecology (IPE-CSIC), Avda Montañana 1005, 50192 Zaragoza, Spain
| | - Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta, Italy
- École Pratique des Hautes Études (PALECO EPHE), Institut des Sciences de l'Évolution, University of Montpellier 2, F-34090 Montpellier, France
| | - Marco Borghetti
- School of Agricultural, Forest, Food and Environmental Sciences, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - Veronica De Micco
- Department of Agricultural Sciences, University of Naples Federico II, Portici (Naples), Italy
| | - Tiziana Gentilesca
- School of Agricultural, Forest, Food and Environmental Sciences, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
| | - Francesco Ripullone
- School of Agricultural, Forest, Food and Environmental Sciences, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza, Italy
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Cornejo-Oviedo EH, Voelker SL, Mainwaring DB, Maguire DA, Meinzer FC, Brooks JR. Basal area growth, carbon isotope discrimination, and intrinsic water use efficiency after fertilization of Douglas-fir in the Oregon Coast Range. FOREST ECOLOGY AND MANAGEMENT 2017; 389:285-295. [PMID: 31666758 PMCID: PMC6820146 DOI: 10.1016/j.foreco.2017.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Many hectares of intensively managed Douglas-fir (Pseudotsuga menziesii Mirb. Franco) stands in western North America are fertilized with nitrogen (N) to increase growth rates, but only about ⅔ of all stands respond. Understanding the mechanisms of response facilitates prioritization of stands for treatment. The primary objective of this study was to test the hypothesis that the short-term basal area growth response to a single application of 224 kg N ha-1 as urea was associated with reduced stable carbon isotope discrimination (Δ13C) and increased intrinsic water use efficiency (iWUE) in a 20-yr-old plantation of Douglas-fir in the Oregon Coast Range, USA. Increment cores were measured to estimate earlywood, latewood, and total basal area increment over a time series from 1997 to 2015. Stable carbon isotope discrimination and iWUE were estimated using earlywood and latewood stable carbon isotope concentrations in tree-ring holocellulose starting seven years before fertilization in early 2009 and ending seven years after treatment. A highly significant (p<0.01) interaction effect between fertilization treatment and year was found for total basal area growth and earlywood basal area increment. Specifically, fertilized trees showed significant responses (p<0.05) in total basal area growth and earlywood basal area increment in the first (2009) and second (2010) growing seasons after fertilization in 2009. A marginally significant (p<0.10) fertilization effect was found for latewood basal area increment only in the first growing season after treatment. A significant treatment x year interaction was also found for Δ13C and iWUE in earlywood and latewood. Fertilization significantly reduced earlywood Δ13C and increased earlywood iWUE in the first and second growing seasons after fertilization. Only a marginally significant fertilization effect was detected for latewood Δ13C and iWUE in the second growing season after treatment. Previous studies of N fertilization of Douglas-fir forests have reported consistently increased growth and iWUE on low productivity sites treated with relatively high fertilization rates. This study suggested that these responses can also be observed on highly productive sites despite their lower frequency and apparently shorter duration. Other key mechanisms driving growth responses appear less important than iWUE, including an increase in LAI and shift from belowground to aboveground carbon allocation.
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Affiliation(s)
- Eladio H Cornejo-Oviedo
- Departamento Forestal. Universidad Autónoma Agraria Antonio Narro. Calzada Antonio Narro # 1923. Buenavista, Saltillo, Coahuila, México. CP 25315
| | - Steven L Voelker
- Department of Forest Ecosystems and Society. Oregon State University. 321 Richardson Hall, Corvallis, OR 97331
| | - Douglas B Mainwaring
- Department of Forest Engineering, Resources and Management. Oregon State University. 280 Peavy Hall, Corvallis, Oregon 97331-8615
| | - Douglas A Maguire
- Department of Forest Engineering, Resources and Management. Oregon State University. 280 Peavy Hall, Corvallis, Oregon 97331-8615
| | - Frederick C Meinzer
- Pacific Northwest Research Station, USDA Forest Service, Corvallis, OR 97331, USA
| | - J Renée Brooks
- National Health and Environmental Effect Research Laboratory, Western Ecology Division, US EPA, Corvallis, OR 97333, USA
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Battipaglia G, Savi T, Ascoli D, Castagneri D, Esposito A, Mayr S, Nardini A. Effects of prescribed burning on ecophysiological, anatomical and stem hydraulic properties in Pinus pinea L. TREE PHYSIOLOGY 2016; 36:1019-1031. [PMID: 27178842 DOI: 10.1093/treephys/tpw034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 03/22/2016] [Indexed: 06/05/2023]
Abstract
Prescribed burning (PB) is a widespread management technique for wildfire hazard abatement. Understanding PB effects on tree ecophysiology is key to defining burn prescriptions aimed at reducing fire hazard in Mediterranean pine plantations, such as Pinus pinea L. stands. We assessed physiological responses of adult P. pinea trees to PB using a combination of dendroecological, anatomical, hydraulic and isotopic analyses. Tree-ring widths, xylem cell wall thickness, lumen area, hydraulic diameter and tree-ring δ(13)C and δ(18)O were measured in trees on burned and control sites. Vulnerability curves were elaborated to assess tree hydraulic efficiency or safety. Despite the relatively intense thermal treatment (the residence time of temperatures above 50 °C at the stem surface ranged between 242 and 2239 s), burned trees did not suffer mechanical damage to stems, nor significant reduction in radial growth. Moreover, the PB did not affect xylem structure and tree hydraulics. No variations in (13)C-derived water use efficiency were recorded. This confirmed the high resistance of P. pinea to surface fire at the stem base. However, burned trees showed consistently lower δ(18)O values in the PB year, as a likely consequence of reduced competition for water and nutrients due to the understory burning, which increased both photosynthetic activity and stomatal conductance. Our multi-approach analysis offers new perspectives on post-fire survival strategies of P. pinea in an environment where fires are predicted to increase in frequency and severity during the 21st century.
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Affiliation(s)
- Giovanna Battipaglia
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy Ecole Pratique des Hautes Etudes (PALECO EPHE), Centre for Bio-Archaeology and Ecology, Institut des Sciences de l'Evolution, University of Montpellier 2, F-34090 Montpellier, France CMCC, Euro-Mediterranean Center on Climate Change, via Augusto Imperatore 16, 73100 Lecce, Italy
| | - Tadeja Savi
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Davide Ascoli
- Department of Agricultural, Forest and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco (TO), Italy
| | - Daniele Castagneri
- Department of Land, Environment, Agriculture and Forestry, University of Padua, Via dell'Università 16, 35020 Legnaro (PD), Italy
| | - Assunta Esposito
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy
| | - Stefan Mayr
- Institut für Botanik Universität Innsbruck, Sternwartestr. 15, 6020 Innsbruck, Austria
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
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Wieser G, Oberhuber W, Gruber A, Leo M, Matyssek R, Grams TEE. Stable Water Use Efficiency under Climate Change of Three Sympatric Conifer Species at the Alpine Treeline. FRONTIERS IN PLANT SCIENCE 2016; 7:799. [PMID: 27375653 PMCID: PMC4894875 DOI: 10.3389/fpls.2016.00799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/22/2016] [Indexed: 05/23/2023]
Abstract
The ability of treeline associated conifers in the Central Alps to cope with recent climate warming and increasing CO2 concentration is still poorly understood. We determined tree ring stable carbon and oxygen isotope ratios of Pinus cembra, Picea abies, and Larix decidua trees from 1975 to 2010. Stable isotope ratios were compared with leaf level gas exchange measurements carried out in situ between 1979 and 2007. Results indicate that tree ring derived intrinsic water-use efficiency (iWUE) of P. cembra, P. abies and L. decidua remained constant during the last 36 years despite climate warming and rising atmospheric CO2. Temporal patterns in Δ(13)C and Δ(18)O mirrored leaf level gas exchange assessments, suggesting parallel increases of CO2-fixation and stomatal conductance of treeline conifer species. As at the study site soil water availability was not a limiting factor iWUE remained largely stable throughout the study period. The stability in iWUE was accompanied by an increase in basal area increment (BAI) suggesting that treeline trees benefit from both recent climate warming and CO2 fertilization. Finally, our results suggest that iWUE may not change species composition at treeline in the Austrian Alps due to similar ecophysiological responses to climatic changes of the three sympatric study species.
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Affiliation(s)
- Gerhard Wieser
- Department of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and LandscapeInnsbruck, Austria
| | - Walter Oberhuber
- Institute of Botany, Leopold-Franzens-Universität InnsbruckInnsbruck, Austria
| | - Andreas Gruber
- Institute of Botany, Leopold-Franzens-Universität InnsbruckInnsbruck, Austria
| | - Marco Leo
- Department of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and LandscapeInnsbruck, Austria
| | - Rainer Matyssek
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
| | - Thorsten Erhard Edgar Grams
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
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Billings SA, Boone AS, Stephen FM. Tree-ring δ13C and δ18O, leaf δ13C and wood and leaf N status demonstrate tree growth strategies and predict susceptibility to disturbance. TREE PHYSIOLOGY 2016; 36:576-88. [PMID: 26960389 PMCID: PMC4886288 DOI: 10.1093/treephys/tpw010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/27/2016] [Indexed: 05/30/2023]
Abstract
Understanding how tree growth strategies may influence tree susceptibility to disturbance is an important goal, especially given projected increases in diverse ecological disturbances this century. We use growth responses of tree rings to climate, relationships between tree-ring stable isotopic signatures of carbon (δ(13)C) and oxygen (δ(18)O), wood nitrogen concentration [N], and contemporary leaf [N] and δ(13)C values to assess potential historic drivers of tree photosynthesis in dying and apparently healthy co-occurring northern red oak (Quercus rubra L. (Fagaceae)) during a region-wide oak decline event in Arkansas, USA. Bole growth of both healthy and dying trees responded negatively to drought severity (Palmer Drought Severity Index) and temperature; healthy trees exhibited a positive, but small, response to growing season precipitation. Contrary to expectations, tree-ring δ(13)C did not increase with drought severity. A significantly positive relationship between tree-ring δ(13)C and δ(18)O was evident in dying trees (P < 0.05) but not in healthy trees. Healthy trees' wood exhibited lower [N] than that of dying trees throughout most of their lives (P < 0.05), and we observed a significant, positive relationship (P < 0.05) in healthy trees between contemporary leaf δ(13)C and leaf N (by mass), but not in dying trees. Our work provides evidence that for plants in which strong relationships between δ(13)C and δ(18)O are not evident, δ(13)C may be governed by plant N status. The data further imply that historic photosynthesis in healthy trees was linked to N status and, perhaps, C sink strength to a greater extent than in dying trees, in which tree-ring stable isotopes suggest that historic photosynthesis was governed primarily by stomatal regulation. This, in turn, suggests that assessing the relative dominance of photosynthetic capacity vs stomatal regulation as drivers of trees' C accrual may be a feasible means of predicting tree responses to some disturbance events. Our work demonstrates that a dual isotope, tree-ring approach can be integrated with tree N status to begin to unravel a fundamental question in forest ecology: why do some trees die during a disturbance, while other conspecifics with apparently similar access to resources remain healthy?
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Affiliation(s)
- S A Billings
- Department of Ecology and Evolutionary Biology, Kansas Biological Survey, University of Kansas, Lawrence, KS 66047, USA
| | - A S Boone
- Department of Ecology and Evolutionary Biology, Kansas Biological Survey, University of Kansas, Lawrence, KS 66047, USA
| | - F M Stephen
- Department of Entomology, University of Arkansas, Fayetteville, AR 72701, USA
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41
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Jennings KA, Guerrieri R, Vadeboncoeur MA, Asbjornsen H. Response of Quercus velutina growth and water use efficiency to climate variability and nitrogen fertilization in a temperate deciduous forest in the northeastern USA. TREE PHYSIOLOGY 2016; 36:428-443. [PMID: 26917704 DOI: 10.1093/treephys/tpw003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 01/06/2016] [Indexed: 06/05/2023]
Abstract
Nitrogen (N) deposition and changing climate patterns in the northeastern USA can influence forest productivity through effects on plant nutrient relations and water use. This study evaluates the combined effects of N fertilization, climate and rising atmospheric CO2on tree growth and ecophysiology in a temperate deciduous forest. Tree ring widths and stable carbon (δ(13)C) and oxygen (δ(18)O) isotopes were used to assess tree growth (basal area increment, BAI) and intrinsic water use efficiency (iWUE) ofQuercus velutinaLamb., the dominant tree species in a 20+ year N fertilization experiment at Harvard Forest (MA, USA). We found that fertilized trees exhibited a pronounced and sustained growth enhancement relative to control trees, with the low- and high-N treatments responding similarly. All treatments exhibited improved iWUE over the study period (1984-2011). Intrinsic water use efficiency trends in the control trees were primarily driven by changes in stomatal conductance, while a stimulation in photosynthesis, supported by an increase in foliar %N, contributed to enhancing iWUE in fertilized trees. All treatments were predominantly influenced by growing season vapor pressure deficit (VPD), with BAI responding most strongly to early season VPD and iWUE responding most strongly to late season VPD. Nitrogen fertilization increasedQ. velutinasensitivity to July temperature and precipitation. Combined, these results suggest that ambient N deposition in N-limited northeastern US forests has enhanced tree growth over the past 30 years, while rising ambient CO2has improved iWUE, with N fertilization and CO2having synergistic effects on iWUE.
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Affiliation(s)
- Katie A Jennings
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA
| | - Rossella Guerrieri
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA
| | | | - Heidi Asbjornsen
- Earth Systems Research Center, University of New Hampshire, Durham, NH 03824, USA Department of Natural Resources and the Environment and Earth Systems Research Center, University of New Hampshire, 114 James Hall, Durham, NH 03824, USA
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42
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Pflug EE, Siegwolf R, Buchmann N, Dobbertin M, Kuster TM, Günthardt-Goerg MS, Arend M. Growth cessation uncouples isotopic signals in leaves and tree rings of drought-exposed oak trees. TREE PHYSIOLOGY 2015; 35:1095-1105. [PMID: 26377873 DOI: 10.1093/treephys/tpv079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/15/2015] [Indexed: 06/05/2023]
Abstract
An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (δ(13)C and δ(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased δ(18)O and δ(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in δ(18)O, was observed in tree rings but not in leaves. This decrease in δ(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses.
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Affiliation(s)
- Ellen E Pflug
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland Department of Environmental Systems Science, ETH Zurich, Universitätsstrasse 2, CH-8092 Zurich, Switzerland
| | - R Siegwolf
- Department of Environmental Systems Science, ETH Zurich, Universitätsstrasse 2, CH-8092 Zurich, Switzerland Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, CH-5232 Villigen, Switzerland
| | - N Buchmann
- Department of Environmental Systems Science, ETH Zurich, Universitätsstrasse 2, CH-8092 Zurich, Switzerland
| | - M Dobbertin
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
| | - T M Kuster
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland Department of Environmental Systems Science, ETH Zurich, Universitätsstrasse 2, CH-8092 Zurich, Switzerland Institute for Plant Production Sciences, Agroscope, CH-8820 Wädenswil, Switzerland
| | - M S Günthardt-Goerg
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
| | - M Arend
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
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Rasheed F, Dreyer E, Richard B, Brignolas F, Brendel O, Le Thiec D. Vapour pressure deficit during growth has little impact on genotypic differences of transpiration efficiency at leaf and whole-plant level: an example from Populus nigra L. PLANT, CELL & ENVIRONMENT 2015; 38:670-84. [PMID: 25099629 DOI: 10.1111/pce.12423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 07/23/2014] [Accepted: 07/27/2014] [Indexed: 05/02/2023]
Abstract
Poplar genotypes differ in transpiration efficiency (TE) at leaf and whole-plant level under similar conditions. We tested whether atmospheric vapour pressure deficit (VPD) affected TE to the same extent across genotypes. Six Populus nigra genotypes were grown under two VPD. We recorded (1) (13)C content in soluble sugars; (2) (18)O enrichment in leaf water; (3) leaf-level gas exchange; and (4) whole-plant biomass accumulation and water use. Whole-plant and intrinsic leaf TE and (13)C content in soluble sugars differed significantly among genotypes. Stomatal conductance contributed more to these differences than net CO2 assimilation rate. VPD increased water use and reduced whole-plant TE. It increased intrinsic leaf-level TE due to a decline in stomatal conductance. It also promoted higher (18)O enrichment in leaf water. VPD had no genotype-specific effect. We detected a deviation in the relationship between (13)C in leaf sugars and (13)C predicted from gas exchange and the standard discrimination model. This may be partly due to genotypic differences in mesophyll conductance, and to its lack of sensitivity to VPD. Leaf-level (13)C discrimination was a powerful predictor of the genetic variability of whole-plant TE irrespective of VPD during growth.
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Affiliation(s)
- Fahad Rasheed
- INRA, UMR 1137 Ecologie et Ecophysiologie Forestières, F-54280, Champenoux, France; University of Agriculture, Department of Forestry, Range Management & Wildlife, 38000, Faisalabad, Pakistan; Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Faculté des Sciences, F-54500, Vandoeuvre-lès-Nancy, France; INRA, EA 1207, Laboratoire de Biologie des Ligneux et des Grandes Cultures, Université d'Orléans, Orléans, F-45067, France
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Schmidt HL, Robins RJ, Werner RA. Multi-factorial in vivo stable isotope fractionation: causes, correlations, consequences and applications. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2015; 51:155-199. [PMID: 25894429 DOI: 10.1080/10256016.2015.1014355] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many physical and chemical processes in living systems are accompanied by isotope fractionation on H, C, N, O and S. Although kinetic or thermodynamic isotope effects are always the basis, their in vivo manifestation is often modulated by secondary influences. These include metabolic branching events or metabolite channeling, metabolite pool sizes, reaction mechanisms, anatomical properties and compartmentation of plants and animals, and climatological or environmental conditions. In the present contribution, the fundamentals of isotope effects and their manifestation under in vivo conditions are outlined. The knowledge about and the understanding of these interferences provide a potent tool for the reconstruction of physiological events in plants and animals, their geographical origin, the history of bulk biomass and the biosynthesis of defined representatives. It allows the use of isotope characteristics of biomass for the elucidation of biochemical pathways and reaction mechanisms and for the reconstruction of climatic, physiological, ecological and environmental conditions during biosynthesis. Thus, it can be used for the origin and authenticity control of food, the study of ecosystems and animal physiology, the reconstruction of present and prehistoric nutrition chains and paleaoclimatological conditions. This is demonstrated by the outline of fundamental and application-orientated examples for all bio-elements. The aim of the review is to inform (advanced) students from various disciplines about the whole potential and the scope of stable isotope characteristics and fractionations and to provide them with a comprehensive introduction to the literature on fundamental aspects and applications.
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Affiliation(s)
- Hanns-Ludwig Schmidt
- a Lehrstuhl für Biologische Chemie , Technische Universität München , Freising-Weihenstephan, Germany
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45
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Tognetti R, Lombardi F, Lasserre B, Cherubini P, Marchetti M. Tree-ring stable isotopes reveal twentieth-century increases in water-use efficiency of Fagus sylvatica and Nothofagus spp. in Italian and Chilean mountains. PLoS One 2014; 9:e113136. [PMID: 25398040 PMCID: PMC4232607 DOI: 10.1371/journal.pone.0113136] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 10/22/2014] [Indexed: 11/21/2022] Open
Abstract
Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in δ13C, Δ13C, δ18O, Ci (internal CO2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, δ13C and δ18O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and δ13C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations.
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Affiliation(s)
- Roberto Tognetti
- Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Pesche, Italy
- The EFI Project Centre on Mountain Forests (MOUNTFOR), Edmund Mach Foundation, San Michele all'Adige, Italy
| | - Fabio Lombardi
- Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Pesche, Italy
| | - Bruno Lasserre
- Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Pesche, Italy
| | - Paolo Cherubini
- WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | - Marco Marchetti
- Dipartimento di Bioscienze e Territorio, Università degli Studi del Molise, Pesche, Italy
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Song X, Clark KS, Helliker BR. Interpreting species-specific variation in tree-ring oxygen isotope ratios among three temperate forest trees. PLANT, CELL & ENVIRONMENT 2014; 37:2169-82. [PMID: 24588709 DOI: 10.1111/pce.12317] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 05/13/2023]
Abstract
Although considerable variation has been documented in tree-ring cellulose oxygen isotope ratios (δ(18)O(cell)) among co-occurring species, the underlying causes are unknown. Here, we used a combination of field measurements and modelling to investigate the mechanisms behind variations in late-wood δ(18) O(cell) (δ(18)O(lc)) among three co-occurring species (chestnut oak, black oak and pitch pine) in a temperate forest. For two growing seasons, we quantified among-species variation in δ(18)O(lc), as well as several variables that could potentially cause the δ(18)O(lc) variation. Data analysis based on the δ(18) O(cell) model rules out leaf water enrichment (Δ(18)O(lw)) and tree-ring formation period (Δt), but highlights source water δ(18) O (δ(18) O(sw)) as an important driver for the measured difference in δ(18)O(lc) between black and chestnut oak. However, the enriched δ(18)O(lc) in pitch pine relative to the oaks could not be sufficiently explained by consideration of the above three variables only, but rather, we show that differences in the proportion of oxygen exchange during cellulose synthesis (p(ex)) is most likely a key mechanism. Our demonstration of the relevance of some species-specific features (or lack thereof) to δ(18)O(cell) has important implications for isotope based ecophysiological/paleoclimate studies.
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Affiliation(s)
- Xin Song
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
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Barbour MM, Song X. Do tree-ring stable isotope compositions faithfully record tree carbon/water dynamics? TREE PHYSIOLOGY 2014; 34:792-795. [PMID: 25117269 DOI: 10.1093/treephys/tpu064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Margaret M Barbour
- Centre for Carbon, Water and Food, The University of Sydney, 380 Werombi Road, Brownlow Hill, NSW 2570, Australia;
| | - Xin Song
- Centre for Carbon, Water and Food, The University of Sydney, 380 Werombi Road, Brownlow Hill, NSW 2570, Australia
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Shestakova TA, Aguilera M, Ferrio JP, Gutierrez E, Voltas J. Unravelling spatiotemporal tree-ring signals in Mediterranean oaks: a variance-covariance modelling approach of carbon and oxygen isotope ratios. TREE PHYSIOLOGY 2014; 34:819-38. [PMID: 0 DOI: 10.1093/treephys/tpu037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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49
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Gessler A, Ferrio JP, Hommel R, Treydte K, Werner RA, Monson RK. Stable isotopes in tree rings: towards a mechanistic understanding of isotope fractionation and mixing processes from the leaves to the wood. TREE PHYSIOLOGY 2014; 34:796-818. [PMID: 24907466 DOI: 10.1093/treephys/tpu040] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The mechanistic understanding of isotope fractionation processes is increasing but we still lack detailed knowledge of the processes that determine the isotopic composition of the tree-ring archive over the long term. Especially with regard to the path from leaf photosynthate production to wood formation, post-assimilation fractionations/processes might cause at least a partial decoupling between the leaf isotope signals that record processes such as stomatal conductance, transpiration and photosynthesis, and the wood or cellulose signals that are stored in the paleophysiological record. In this review, we start from the rather well understood processes at the leaf level such as photosynthetic carbon isotope fractionation, leaf water evaporative isotope enrichment and the issue of the isotopic composition of inorganic sources (CO2 and H2O), though we focus on the less explored 'downstream' processes related to metabolism and transport. We further summarize the roles of cellulose and lignin as important chemical constituents of wood, and the processes that determine the transfer of photosynthate (sucrose) and associated isotopic signals to wood production. We cover the broad topics of post-carboxylation carbon isotope fractionation and of the exchange of organic oxygen with water within the tree. In two case studies, we assess the transfer of carbon and oxygen isotopic signals from leaves to tree rings. Finally we address the issue of different temporal scales and link isotope fractionation at the shorter time scale for processes in the leaf to the isotopic ratio as recorded across longer time scales of the tree-ring archive.
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Affiliation(s)
- Arthur Gessler
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany Long-term Forest Ecosystem Research (LWF), Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Juan Pedro Ferrio
- Department of Crop and Forest Science-AGROTECNIO Center, University of Lleida, Avda Rovira Roure 191, 25198 Lleida, Spain
| | - Robert Hommel
- Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalderstr. 84, 15374 Müncheberg, Germany
| | - Kerstin Treydte
- Research Unit Landscape Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Roland A Werner
- Institute of Agricultural Sciences, ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland
| | - Russell K Monson
- School of Natural Resources and the Environment and Laboratory for Tree Ring Research, University of Arizona, Tucson, AZ 85721, USA
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Moreno‐Gutiérrez C, Battipaglia G, Cherubini P, Delgado Huertas A, Querejeta JI. Pine afforestation decreases the long‐term performance of understorey shrubs in a semi‐arid Mediterranean ecosystem: a stable isotope approach. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12311] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Cristina Moreno‐Gutiérrez
- Centro de Edafología y Biología Aplicada del Segura (CEBAS‐CSIC) Campus Universitario de Espinardo P.O. Box 164 30100 Murcia Spain
- WSL Swiss Federal Institute for Forest Snow and Landscape Research CH‐8903 Birmensdorf Switzerland
| | - Giovanna Battipaglia
- WSL Swiss Federal Institute for Forest Snow and Landscape Research CH‐8903 Birmensdorf Switzerland
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies Second University of Naples via Vivaldi 43 – 81100 Caserta Italy
- Ecole Pratique des Hautes Etudes (PALECO EPHE) Centre for Bio‐Archeology and Ecology Institut de Botanique University of Montpellier 2 F‐34090 Montpellier France
| | - Paolo Cherubini
- WSL Swiss Federal Institute for Forest Snow and Landscape Research CH‐8903 Birmensdorf Switzerland
| | - Antonio Delgado Huertas
- Laboratorio de Biogeoquímica de Isótopos Estables Instituto Andaluz de Ciencias de la Tierra IACT (CSIC‐UGR) Avda. de las Palmeras 4. 18100 Armilla Granada Spain
| | - José Ignacio Querejeta
- Centro de Edafología y Biología Aplicada del Segura (CEBAS‐CSIC) Campus Universitario de Espinardo P.O. Box 164 30100 Murcia Spain
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