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Tonet V, Brodribb T, Bourbia I. Variation in xylem vulnerability to cavitation shapes the photosynthetic legacy of drought. PLANT, CELL & ENVIRONMENT 2024; 47:1160-1170. [PMID: 38108586 DOI: 10.1111/pce.14788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 11/08/2023] [Accepted: 12/01/2023] [Indexed: 12/19/2023]
Abstract
Increased drought conditions impact tree health, negatively disrupting plant water transport which, in turn, affects plant growth and survival. Persistent drought legacy effects have been documented in many diverse ecosystems, yet we still lack a mechanistic understanding of the physiological processes limiting tree recovery after drought. Tackling this question, we exposed saplings of a common Australian evergreen tree (Eucalyptus viminalis) to a cycle of drought and rewatering, seeking evidence for a link between the spread of xylem cavitation within the crown and the degree of photosynthetic recovery postdrought. Individual leaves experiencing >35% vein cavitation quickly died but this did not translate to a rapid overall canopy damage. Rather, whole canopies showed a gradual decline in mean postdrought gas exchange rates as water stress increased. This gradual loss of canopy function postdrought was due to a significant variation in cavitation vulnerability of leaves within canopies leading to diversity in the capacity of leaves within a single crown to recover function after drought. These results from the evergreen E. viminalis emphasise the importance of within-crown variation in xylem vulnerability as a central character regulating the dynamics of canopy death and the severity of drought legacy through time.
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Affiliation(s)
- Vanessa Tonet
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
- School of Forestry & Environmental Studies, Yale University, New Haven, Connecticut, USA
| | - Timothy Brodribb
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
| | - Ibrahim Bourbia
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Australia
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2
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Zhang X, Li B, Peñuelas J, Sardans J, Cheng D, Yu H, Zhong Q. Resource-acquisitive species have greater plasticity in leaf functional traits than resource-conservative species in response to nitrogen addition in subtropical China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166177. [PMID: 37572896 DOI: 10.1016/j.scitotenv.2023.166177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/07/2023] [Accepted: 08/07/2023] [Indexed: 08/14/2023]
Abstract
The evergreen broad-leaf forest is subtropical zonal vegetation in China, and its species diversity and stability are crucial for maintaining forest ecosystem functions. The region is generally affected by global changes such as high levels of nitrogen deposition. Therefore, it is critical to determine the adaptation strategies of subtropical dominant species under nitrogen addition. Here, we conducted two-year field experiments with nitrogen addition levels as 0 kg N ha-1 yr-1 (CK), 50 kg N ha-1 yr-1 (LN) and 100 kg N ha-1 yr-1 (HN). We investigated the effects of nitrogen addition on leaf functional traits (including nutrition, structural and physiological characteristics) of five dominant species in subtropical evergreen broad-leaf forest. Results suggested that the effect of nitrogen addition on leaf functional traits was species-specific. Contrary to Rhododendron delavayi and Eurya muricata, Quercus glauca, Schima superba and Castanopsis eyrei all responded more to the HN treatment than LN treatment. Compared to other leaf functional traits, leaf anatomical structure traits had the highest average plasticity (0.246), and the relative effect of leaf photosynthetic property was highest (7.785) under N addition. Among the five species, S. superba was highest in terms of the index of plasticity for leaf functional traits under nitrogen addition, followed by Q. glauca, E. muricata, C. eyrei and R. delavayi. The major leaf functional traits representing the economic spectrum of leaves (LES) showed resource acquisitive strategy (high SLA, LNC, LPC, Pn) and conservative strategy (high LTD, LDMC, C/N) clustering on the opposite ends of the PCA axis. The PCA analysis indicated that species with high leaf plasticity adopt resource acquisitive strategy (S. superba and Q. glauca), whereas species with low leaf plasticity adopt resource conservative strategy (E. muricata, C. eyrei and R. delavayi). In aggregate, resource-acquisitive species benefit from nitrogen addition more than resource-conservative species, suggesting that S. superba and Q. glauca will occupy the dominant position in community succession under persistently elevated nitrogen deposition.
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Affiliation(s)
- Xue Zhang
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, Fujian Province 350007, China; College of Geographical Science, Fujian Normal University, Fuzhou, Fujian Province 350007, China
| | - Baoyin Li
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, Fujian Province 350007, China; College of Geographical Science, Fujian Normal University, Fuzhou, Fujian Province 350007, China; State Key Laboratory of Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province funded), Fuzhou, Fujian Province 350007, China
| | - Josep Peñuelas
- Global Ecology Unit, CSIC, CREAF-CSIC-UAB, 08193 Bellaterra, Catalonia, Spain; CREAF, 08193 Cerdanyola del Vallès, Catalonia, Spain
| | - Jordi Sardans
- Global Ecology Unit, CSIC, CREAF-CSIC-UAB, 08193 Bellaterra, Catalonia, Spain; CREAF, 08193 Cerdanyola del Vallès, Catalonia, Spain
| | - Dongliang Cheng
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, Fujian Province 350007, China; College of Geographical Science, Fujian Normal University, Fuzhou, Fujian Province 350007, China; State Key Laboratory of Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province funded), Fuzhou, Fujian Province 350007, China
| | - Hua Yu
- Ocean College, Minjiang University, Fuzhou, Fujian Province 350007, China
| | - Quanlin Zhong
- Fujian Provincial Key Laboratory of Plant Ecophysiology, Fujian Normal University, Fuzhou, Fujian Province 350007, China; College of Geographical Science, Fujian Normal University, Fuzhou, Fujian Province 350007, China; State Key Laboratory of Subtropical Mountain Ecology (Ministry of Science and Technology and Fujian Province funded), Fuzhou, Fujian Province 350007, China.
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3
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Gardner A, Jiang M, Ellsworth DS, MacKenzie AR, Pritchard J, Bader MKF, Barton CVM, Bernacchi C, Calfapietra C, Crous KY, Dusenge ME, Gimeno TE, Hall M, Lamba S, Leuzinger S, Uddling J, Warren J, Wallin G, Medlyn BE. Optimal stomatal theory predicts CO 2 responses of stomatal conductance in both gymnosperm and angiosperm trees. THE NEW PHYTOLOGIST 2023; 237:1229-1241. [PMID: 36373000 DOI: 10.1111/nph.18618] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Optimal stomatal theory predicts that stomata operate to maximise photosynthesis (Anet ) and minimise transpirational water loss to achieve optimal intrinsic water-use efficiency (iWUE). We tested whether this theory can predict stomatal responses to elevated atmospheric CO2 (eCO2 ), and whether it can capture differences in responsiveness among woody plant functional types (PFTs). We conducted a meta-analysis of tree studies of the effect of eCO2 on iWUE and its components Anet and stomatal conductance (gs ). We compared three PFTs, using the unified stomatal optimisation (USO) model to account for confounding effects of leaf-air vapour pressure difference (D). We expected smaller gs , but greater Anet , responses to eCO2 in gymnosperms compared with angiosperm PFTs. We found that iWUE increased in proportion to increasing eCO2 in all PFTs, and that increases in Anet had stronger effects than reductions in gs . The USO model correctly captured stomatal behaviour with eCO2 across most datasets. The chief difference among PFTs was a lower stomatal slope parameter (g1 ) for the gymnosperm, compared with angiosperm, species. Land surface models can use the USO model to describe stomatal behaviour under changing atmospheric CO2 conditions.
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Affiliation(s)
- Anna Gardner
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, B15 2TT, UK
- School of Biological Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- College of Life Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou, Zhejiang Province, China
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - A Robert MacKenzie
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, B15 2TT, UK
- School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Jeremy Pritchard
- Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, B15 2TT, UK
- School of Biological Sciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | | | - Craig V M Barton
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Carl Bernacchi
- USDA-ARS Global Change and Photosynthesis Research Unit, Urbana, IL, 61801, USA
| | - Carlo Calfapietra
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Porano, 05010, Italy
| | - Kristine Y Crous
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Mirindi Eric Dusenge
- Western Centre for Climate Change, Sustainable Livelihoods and Health, Department of Geography, The University of Western Ontario, London, ON, N6A 5C2, Canada
| | - Teresa E Gimeno
- CREAF, Bellaterra (Cerdanyola del Vallès), Catalonia, 08193, Spain
- Basque Centre for Climate Change (BC3), Leioa, 48940, Spain
| | - Marianne Hall
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Shubhangi Lamba
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, 40530, Sweden
| | - Sebastian Leuzinger
- Auckland University of Technology, Institute of Earth and Oceanic Sciences, School of Applied Sciences, Private Bag 92006 (Mail No C-43), Auckland, 1142, New Zealand
| | - Johan Uddling
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, 40530, Sweden
| | - Jeffrey Warren
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Göran Wallin
- Department of Biological and Environmental Sciences, University of Gothenburg, PO Box 461, Gothenburg, 40530, Sweden
- Environmental Change Institute, School of Geography and the Environment, University of Oxford, South Parks Road, Oxford, OX1 3QY, UK
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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Costa e Silva J, Potts BM, Wiehl G, Prober SM. Linking leaf economic and hydraulic traits with early-age growth performance and survival of Eucalyptus pauciflora. FRONTIERS IN PLANT SCIENCE 2022; 13:973087. [PMID: 36426150 PMCID: PMC9679299 DOI: 10.3389/fpls.2022.973087] [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: 06/19/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Selection on plant functional traits may occur through their direct effects on fitness (or a fitness component), or may be mediated by attributes of plant performance which have a direct impact on fitness. Understanding this link is particularly challenging for long-lived organisms, such as forest trees, where lifetime fitness assessments are rarely achievable, and performance features and fitness components are usually quantified from early-life history stages. Accordingly, we studied a cohort of trees from multiple populations of Eucalyptus pauciflora grown in a common-garden field trial established at the hot and dry end of the species distribution on the island of Tasmania, Australia. We related the within-population variation in leaf economic (leaf thickness, leaf area and leaf density) and hydraulic (stomatal density, stomatal length and vein density) traits, measured from two-year-old plants, to two-year growth performance (height and stem diameter) and to a fitness component (seven-year survival). When performance-trait relationships were modelled for all traits simultaneously, statistical support for direct effects on growth performance was only observed for leaf thickness and leaf density. Performance-based estimators of directional selection indicated that individuals with reduced leaf thickness and increased leaf density were favoured. Survival-performance relationships were consistent with size-dependent mortality, with fitness-based selection gradients estimated for performance measures providing evidence for directional selection favouring individuals with faster growth. There was no statistical support for an effect associated with the fitness-based quadratic selection gradient estimated for growth performance. Conditional on a performance measure, fitness-based directional selection gradients estimated for the leaf traits did not provide statistical support for direct effects of the focal traits on tree survival. This suggested that, under the environmental conditions of the trial site and time period covered in the current study, early-stage selection on the studied leaf traits may be mediated by their effects on growth performance, which in turn has a positive direct influence on later-age survival. We discuss the potential mechanistic basis of the direct effects of the focal leaf traits on tree growth, and the relevance of a putative causal pathway of trait effects on fitness through mediation by growth performance in the studied hot and dry environment.
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Affiliation(s)
- João Costa e Silva
- Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal
| | - Brad M. Potts
- School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
- Australian Research Council (ARC) Training Centre for Forest Value, University of Tasmania, Hobart, TAS, Australia
| | - Georg Wiehl
- CSIRO Land and Water, Private Bag 5, Wembley, WA, Australia
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5
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Mizokami Y, Oguchi R, Sugiura D, Yamori W, Noguchi K, Terashima I. Cost-benefit analysis of mesophyll conductance: diversities of anatomical, biochemical and environmental determinants. ANNALS OF BOTANY 2022; 130:265-283. [PMID: 35947983 PMCID: PMC9487971 DOI: 10.1093/aob/mcac100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/08/2022] [Indexed: 06/09/2023]
Abstract
BACKGROUND Plants invest photosynthates in construction and maintenance of their structures and functions. Such investments are considered costs. These costs are recovered by the CO2 assimilation rate (A) in the leaves, and thus A is regarded as the immediate, short-term benefit. In photosynthesizing leaves, CO2 diffusion from the air to the carboxylation site is hindered by several structural and biochemical barriers. CO2 diffusion from the intercellular air space to the chloroplast stroma is obstructed by the mesophyll resistance. The inverses is the mesophyll conductance (gm). Whether various plants realize an optimal gm, and how much investment is needed for a relevant gm, remain unsolved. SCOPE This review examines relationships among leaf construction costs (CC), leaf maintenance costs (MC) and gm in various plants under diverse growth conditions. Through a literature survey, we demonstrate a strong linear relationship between leaf mass per area (LMA) and leaf CC. The overall correlation of CC vs. gm across plant phylogenetic groups is weak, but significant trends are evident within specific groups and/or environments. Investment in CC is necessary for an increase in LMA and mesophyll cell surface area (Smes). This allows the leaf to accommodate more chloroplasts, thus increasing A. However, increases in LMA and/or Smes often accompany other changes, such as cell wall thickening, which diminishes gm. Such factors that make the correlations of CC and gm elusive are identified. CONCLUSIONS For evaluation of the contribution of gm to recover CC, leaf life span is the key factor. The estimation of MC in relation to gm, especially in terms of costs required to regulate aquaporins, could be essential for efficient control of gm over the short term. Over the long term, costs are mainly reflected in CC, while benefits also include ultimate fitness attributes in terms of integrated carbon gain over the life of a leaf, plant survival and reproductive output.
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Affiliation(s)
- Yusuke Mizokami
- Department of Life Science, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Riichi Oguchi
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Daisuke Sugiura
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo, Chikusa-ku, Nagoya 464-8601, Japan
| | - Wataru Yamori
- Graduate School of Agricultural and Life Science, Institute for Sustainable Agri-ecosystem, The University of Tokyo, 1-1-1, Midoricho, Nishitokyo, Tokyo 188-0002, Japan
| | - Ko Noguchi
- Department of Life Science, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Ichiro Terashima
- Department of Biological Sciences, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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6
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Sabot MEB, De Kauwe MG, Pitman AJ, Ellsworth DS, Medlyn BE, Caldararu S, Zaehle S, Crous KY, Gimeno TE, Wujeska-Klause A, Mu M, Yang J. Predicting resilience through the lens of competing adjustments to vegetation function. PLANT, CELL & ENVIRONMENT 2022; 45:2744-2761. [PMID: 35686437 DOI: 10.1111/pce.14376] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/18/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
There is a pressing need to better understand ecosystem resilience to droughts and heatwaves. Eco-evolutionary optimization approaches have been proposed as means to build this understanding in land surface models and improve their predictive capability, but competing approaches are yet to be tested together. Here, we coupled approaches that optimize canopy gas exchange and leaf nitrogen investment, respectively, extending both approaches to account for hydraulic impairment. We assessed model predictions using observations from a native Eucalyptus woodland that experienced repeated droughts and heatwaves between 2013 and 2020, whilst exposed to an elevated [CO2 ] treatment. Our combined approaches improved predictions of transpiration and enhanced the simulated magnitude of the CO2 fertilization effect on gross primary productivity. The competing approaches also worked consistently along axes of change in soil moisture, leaf area, and [CO2 ]. Despite predictions of a significant percentage loss of hydraulic conductivity due to embolism (PLC) in 2013, 2014, 2016, and 2017 (99th percentile PLC > 45%), simulated hydraulic legacy effects were small and short-lived (2 months). Our analysis suggests that leaf shedding and/or suppressed foliage growth formed a strategy to mitigate drought risk. Accounting for foliage responses to water availability has the potential to improve model predictions of ecosystem resilience.
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Affiliation(s)
- Manon E B Sabot
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - Martin G De Kauwe
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Andy J Pitman
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - David S Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | | | - Sönke Zaehle
- Max Planck Institute for Biogeochemistry, Jena, Germany
- Michael Stifel Center Jena for Data-driven and Simulation Science, Jena, Germany
| | - Kristine Y Crous
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Teresa E Gimeno
- CREAF, 08193 Bellaterra (Cerdanyola del Vallès), Catalonia, Spain
- Basque Centre for Climate Change (BC3), Leioa, Spain
| | - Agnieszka Wujeska-Klause
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- Urban Studies, School of Social Sciences, Penrith, New South Wales, Australia
| | - Mengyuan Mu
- ARC Centre of Excellence for Climate Extremes, Sydney, New South Wales, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - Jinyan Yang
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
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The Morpho-Physio-Biochemical Attributes of Urban Trees for Resilience in Regional Ecosystems in Cities: A Mini-Review. URBAN SCIENCE 2022. [DOI: 10.3390/urbansci6020037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Increased urbanization means human beings become the dominant species and reduction in canopy cover. Globally, urban trees grow under challenging and complex circumstances with urbanization trends of increasing anthropogenic carbon dioxide (CO2) emissions, high temperature and drought stress. This study aims to provide a better understanding of urban trees’ morpho-physio-biochemical attributes that can support sustainable urban greening programs and urban climate change mitigation policies. Globally, urban dwellers’ population is on the rise and spreading to suburban areas over time with an increase in domestic CO2 emissions. Uncertainty and less information on urban tree diversification and resistance to abiotic stress may create deterioration of ecosystem resilience over time. This review uses general parameters for urban tree physiology studies and employs three approaches for evaluating ecosystem resilience based on urban stress resistance in relation to trees’ morphological, physiological and biochemical attributes. Due to the lack of a research model of ecosystem resilience and urban stress resistance of trees, this review demonstrates that the model concept supports future urban tree physiology research needs. In particular, it is necessary to develop integral methodologies and an urban tree research concept to assess how main and combined effects of drought and/or climate changes affect indigenous and exotic trees that are commonly grown in cities.
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8
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Native Trees as a Provider of Vital Urban Ecosystem Services in Urbanizing New Zealand: Status Quo, Challenges and Prospects. LAND 2022. [DOI: 10.3390/land11010092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In New Zealand, over 87% of the population currently resides in cities. Urban trees can face a myriad of complex challenges including loss of green space, public health issues, and harm to the existence of urban dwellers and trees, along with domestic greenhouse gas (GHG) and air pollutant emissions. Despite New Zealand being a biodiversity hotspot in terms of natural environments, there is a lack of knowledge about native tree species’ regulating service (i.e., tree development and eco-physiological responses to low air quality, GHG, rising air temperatures, and drought) and how they grow in built-up environments such as cities. Therefore, we argue for the value of these native species in terms of ecosystem services and insist that they need to be viewed in relation to how they will respond to urban abiotic extremes and climate change. We propose to diversify planted forests for several reasons: (1) to improve awareness of the benefits of diverse planted urban forests; (2) to foster native tree research in urban environments, finding new keystone species; and (3) to improve the evidence of urban ecosystem resilience based on New Zealand native trees’ regulating services. This article aims to re-evaluate our understanding of whether New Zealand’s native trees can deal with environmental stress conditions similarly to more commonly planted alien species.
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Byeon S, Song W, Park M, Kim S, Kim S, Lee H, Jeon J, Kim K, Lee M, Lim H, Han SH, Oh C, Kim HS. Canopy height affects the allocation of photosynthetic carbon and nitrogen in two deciduous tree species under elevated CO 2. JOURNAL OF PLANT PHYSIOLOGY 2022; 268:153584. [PMID: 34890847 DOI: 10.1016/j.jplph.2021.153584] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/15/2021] [Accepted: 11/29/2021] [Indexed: 06/13/2023]
Abstract
Down-regulation of leaf N and Rubisco under elevated CO2 (eCO2) are accompanied by increased non-structural carbohydrates (NSC) due to the sink-source imbalance. Here, to investigate whether the canopy position affects the down-regulation of Rubisco, we measured leaf N, NSC and N allocation in two species with different heights at maturity [Fraxinus rhynchophylla (6.8 ± 0.3 m) and Sorbus alnifolia (3.6 ± 0.2 m)] from 2017 to 2019. Since 2009, both species were grown at three different CO2 concentrations in open-top chambers: ambient CO2 (400 ppm; aCO2); ambient CO2 × 1.4 (560 ppm; eCO21.4); and ambient CO2 × 1.8 (720 ppm; eCO21.8). Leaf N per unit mass (Nmass) decreased under eCO2, except under eCO21.8 in S. alnifolia and coincided with increased NSC. NSC increased under eCO2 in F. rhynchophylla, but the increment of NSC was greater in the upper canopy of S. alnifolia. Conversely, Rubisco content per unit area was reduced under eCO2 in S. alnifolia and there was no interaction between CO2 and canopy position. In contrast, the reduction of Rubisco content per unit area was greater in the upper canopy of F. rhynchophylla, with a significant interaction between CO2 and canopy position. Rubisco was negatively correlated with NSC only in the upper canopy of F. rhynchophylla, and at the same NSC, Rubisco was lower under eCO2 than under aCO2. Contrary to Rubisco, chlorophyll increased under eCO2 in both species, although there was no interaction between CO2 and canopy position. Finally, photosynthetic N content (Rubisco + chlorophyll + PSII) was reduced and consistent with down-regulation of Rubisco. Therefore, the observed Nmass reduction under eCO2 was associated with dilution due to NSC accumulation. Moreover, down-regulation of Rubisco under eCO2 was more sensitive to NSC accumulation in the upper canopy. Our findings emphasize the need for the modification of the canopy level model in the context of climate change.
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Affiliation(s)
- Siyeon Byeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Wookyung Song
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Minjee Park
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, 47907, USA; Center for Plant Biology, Purdue University, West Lafayette, IN, 47907, USA
| | - Sukyung Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Seohyun Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - HoonTaek Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Department of Biogeochemical Integration, Max-Planck-Institute for Biogeochemistry, 07745, Jena, Germany; Technische Universität Dresden, Institute of Photogrammetry and Remote Sensing, 01069, Dresden, Germany
| | - Jihyeon Jeon
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Kunhyo Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Minsu Lee
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea
| | - Hyemin Lim
- Department of Forest Bioresources, National Institute of Forest Science, Suwon, 16631, Republic of Korea
| | - Sim-Hee Han
- Department of Forest Bioresources, National Institute of Forest Science, Suwon, 16631, Republic of Korea
| | - Changyoung Oh
- Department of Forest Bioresources, National Institute of Forest Science, Suwon, 16631, Republic of Korea
| | - Hyun Seok Kim
- Department of Agriculture, Forestry and Bioresources, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; Interdisciplinary Program in Agricultural and Forest Meteorology, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea; National Center for Agro Meteorology, Seoul, 08826, Republic of Korea; Research Institute of Agriculture and Life Sciences, Seoul National University College of Agriculture and Life Sciences, Seoul, 08826, Republic of Korea.
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Carter KR, Wood TE, Reed SC, Butts KM, Cavaleri MA. Experimental warming across a tropical forest canopy height gradient reveals minimal photosynthetic and respiratory acclimation. PLANT, CELL & ENVIRONMENT 2021; 44:2879-2897. [PMID: 34169547 DOI: 10.1111/pce.14134] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 06/08/2021] [Indexed: 06/13/2023]
Abstract
Tropical forest canopies cycle vast amounts of carbon, yet we still have a limited understanding of how these critical ecosystems will respond to climate warming. We implemented in situ leaf-level + 3°C experimental warming from the understory to the upper canopy of two Puerto Rican tropical tree species, Guarea guidonia and Ocotea sintenisii. After approximately 1 month of continuous warming, we assessed adjustments in photosynthesis, chlorophyll fluorescence, stomatal conductance, leaf traits and foliar respiration. Warming did not alter net photosynthetic temperature response for either species; however, the optimum temperature of Ocotea understory leaf photosynthetic electron transport shifted upward. There was no Ocotea respiratory treatment effect, while Guarea respiratory temperature sensitivity (Q10 ) was down-regulated in heated leaves. The optimum temperatures for photosynthesis (Topt ) decreased 3-5°C from understory to the highest canopy position, perhaps due to upper canopy stomatal conductance limitations. Guarea upper canopy Topt was similar to the mean daytime temperatures, while Ocotea canopy leaves often operated above Topt . With minimal acclimation to warmer temperatures in the upper canopy, further warming could put these forests at risk of reduced CO2 uptake, which could weaken the overall carbon sink strength of this tropical forest.
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Affiliation(s)
- Kelsey R Carter
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, Michigan, USA
- Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Tana E Wood
- United States Department of Agriculture, Forest Service, International Institute of Tropical Forestry, Jardin Botánico Sur, Río Piedras, Puerto Rico, USA
| | - Sasha C Reed
- U.S. Geological Survey, Southwest Biological Science Center, Moab, Utah, USA
| | - Kaylie M Butts
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, Michigan, USA
| | - Molly A Cavaleri
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, Michigan, USA
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