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Tang W, Liu S, Jing M, Healey JR, Smith MN, Farooq TH, Zhu L, Zhao S, Wu Y. Vegetation growth responses to climate change: A cross-scale analysis of biological memory and time lags using tree ring and satellite data. GLOBAL CHANGE BIOLOGY 2024; 30:e17441. [PMID: 39054867 DOI: 10.1111/gcb.17441] [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: 02/10/2024] [Revised: 06/02/2024] [Accepted: 06/12/2024] [Indexed: 07/27/2024]
Abstract
Vegetation growth is affected by past growth rates and climate variability. However, the impacts of vegetation growth carryover (VGC; biotic) and lagged climatic effects (LCE; abiotic) on tree stem radial growth may be decoupled from photosynthetic capacity, as higher photosynthesis does not always translate into greater growth. To assess the interaction of tree-species level VGC and LCE with ecosystem-scale photosynthetic processes, we utilized tree-ring width (TRW) data for three tree species: Castanopsis eyrei (CE), Castanea henryi (CH, Chinese chinquapin), and Liquidambar formosana (LF, Chinese sweet gum), along with satellite-based data on canopy greenness (EVI, enhanced vegetation index), leaf area index (LAI), and gross primary productivity (GPP). We used vector autoregressive models, impulse response functions, and forecast error variance decomposition to analyze the duration, intensity, and drivers of VGC and of LCE response to precipitation, temperature, and sunshine duration. The results showed that at the tree-species level, VGC in TRW was strongest in the first year, with an average 77% reduction in response intensity by the fourth year. VGC and LCE exhibited species-specific patterns; compared to CE and CH (diffuse-porous species), LF (ring-porous species) exhibited stronger VGC but weaker LCE. For photosynthetic capacity at the ecosystem scale (EVI, LAI, and GPP), VGC and LCE occurred within 96 days. Our study demonstrates that VGC effects play a dominant role in vegetation function and productivity, and that vegetation responses to previous growth states are decoupled from climatic variability. Additionally, we discovered the possibility for tree-ring growth to be decoupled from canopy condition. Investigating VGC and LCE of multiple indicators of vegetation growth at multiple scales has the potential to improve the accuracy of terrestrial global change models.
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Affiliation(s)
- Wenxi Tang
- School of Ecology, Hainan University, Haikou, China
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Central South University of Forestry and Technology (CSUFT), Changsha, China
- College of Life and Environmental Sciences, CSUFT, Changsha, China
- Technology Innovation Center for Ecological Conservation and Restoration in Dongting Lake Basin, Ministry of Natural Resources, Changsha, China
| | - Shuguang Liu
- School of Ecology, Hainan University, Haikou, China
| | - Mengdan Jing
- Department of Earth & Environmental Science, Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - John R Healey
- School of Environmental and Natural Sciences, Bangor University, Bangor, Gwynedd, UK
| | - Marielle N Smith
- School of Environmental and Natural Sciences, Bangor University, Bangor, Gwynedd, UK
- Bangor College China, A Joint Unit of Bangor University and Central South University of Forestry and Technology, Changsha, China
| | - Taimoor Hassan Farooq
- Bangor College China, A Joint Unit of Bangor University and Central South University of Forestry and Technology, Changsha, China
| | - Liangjun Zhu
- National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Central South University of Forestry and Technology (CSUFT), Changsha, China
- College of Life and Environmental Sciences, CSUFT, Changsha, China
| | - Shuqing Zhao
- School of Ecology, Hainan University, Haikou, China
| | - Yiping Wu
- Department of Earth & Environmental Science, Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
- National Observation and Research Station of Regional Ecological Environment Change and Comprehensive Management in the Guanzhong Plain, Xi'an, China
- Technology Innovation Center for Land Engineering and Human Settlements, Shaanxi Land Engineering Construction Group Co. Ltd and Xi'an Jiaotong University, Xi'an, China
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2
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Huang J, Ladd SN, Ingrisch J, Kübert A, Meredith LK, van Haren J, Bamberger I, Daber LE, Kühnhammer K, Bailey K, Hu J, Fudyma J, Shi L, Dippold MA, Meeran K, Miller L, O'Brien MJ, Yang H, Herrera-Ramírez D, Hartmann H, Trumbore S, Bahn M, Werner C, Lehmann MM. The mobilization and transport of newly fixed carbon are driven by plant water use in an experimental rainforest under drought. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2545-2557. [PMID: 38271585 DOI: 10.1093/jxb/erae030] [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: 08/21/2023] [Accepted: 01/24/2024] [Indexed: 01/27/2024]
Abstract
Non-structural carbohydrates (NSCs) are building blocks for biomass and fuel metabolic processes. However, it remains unclear how tropical forests mobilize, export, and transport NSCs to cope with extreme droughts. We combined drought manipulation and ecosystem 13CO2 pulse-labeling in an enclosed rainforest at Biosphere 2, assessed changes in NSCs, and traced newly assimilated carbohydrates in plant species with diverse hydraulic traits and canopy positions. We show that drought caused a depletion of leaf starch reserves and slowed export and transport of newly assimilated carbohydrates below ground. Drought effects were more pronounced in conservative canopy trees with limited supply of new photosynthates and relatively constant water status than in those with continual photosynthetic supply and deteriorated water status. We provide experimental evidence that local utilization, export, and transport of newly assimilated carbon are closely coupled with plant water use in canopy trees. We highlight that these processes are critical for understanding and predicting tree resistance and ecosystem fluxes in tropical forest under drought.
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Affiliation(s)
- Jianbei Huang
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
| | - S Nemiah Ladd
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
- Department of Environmental Sciences, University of Basel, Bernoullistrasse 30, 4056 Basel, Switzerland
| | - Johannes Ingrisch
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
- Department of Ecology, University of Innsbruck, Sternwartestr 15, 6020 Innsbruck, Austria
| | - Angelika Kübert
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Laura K Meredith
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ 85721, USA
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
| | - Joost van Haren
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
- Honors College, University of Arizona, 1101 East Mabel Street, Tucson, AZ 85719, USA
| | - Ines Bamberger
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
- Atmospheric Chemistry Group, University of Bayreuth (BayCEER), Germany
| | - L Erik Daber
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Kathrin Kühnhammer
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Kinzie Bailey
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ 85721, USA
| | - Jia Hu
- School of Natural Resources and the Environment, University of Arizona, 1064 E. Lowell St., Tucson, AZ 85721, USA
| | - Jane Fudyma
- Department of Environmental Science, University of Arizona, Tucson, AZ, USA
- Department of Land, Air, and Water Resources, University of California, Davis, CA, USA
| | - Lingling Shi
- Biogeochemistry of Agroecosystems, University of Göttingen, Göttingen, Germany
- Geo-Biosphere Interactions, University of Tuebingen, Tuebingen, Germany
| | - Michaela A Dippold
- Biogeochemistry of Agroecosystems, University of Göttingen, Göttingen, Germany
- Geo-Biosphere Interactions, University of Tuebingen, Tuebingen, Germany
| | - Kathiravan Meeran
- Department of Ecology, University of Innsbruck, Sternwartestr 15, 6020 Innsbruck, Austria
| | - Luke Miller
- Biosphere 2, University of Arizona, 32540 S. Biosphere Rd, Oracle, AZ 85739, USA
| | - Michael J O'Brien
- Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almería, Spain
| | - Hui Yang
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
| | | | - Henrik Hartmann
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
- Institute for Forest Protection, Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Erwin-Baur-Straße 27, D-06484 Quedlinburg, Germany
| | - Susan Trumbore
- Max Planck Institute for Biogeochemistry, D-07745 Jena, Germany
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, Sternwartestr 15, 6020 Innsbruck, Austria
| | - Christiane Werner
- Ecosystem Physiology, Albert-Ludwig-University of Freiburg, Freiburg, Germany
| | - Marco M Lehmann
- Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
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3
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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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Pohl F, Werban U, Kumar R, Hildebrandt A, Rebmann C. Observational evidence of legacy effects of the 2018 drought on a mixed deciduous forest in Germany. Sci Rep 2023; 13:10863. [PMID: 37407831 DOI: 10.1038/s41598-023-38087-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/03/2023] [Indexed: 07/07/2023] Open
Abstract
Forests play a major role in the global carbon cycle, and droughts have been shown to explain much of the interannual variability in the terrestrial carbon sink capacity. The quantification of drought legacy effects on ecosystem carbon fluxes is a challenging task, and research on the ecosystem scale remains sparse. In this study we investigate the delayed response of an extreme drought event on the carbon cycle in the mixed deciduous forest site 'Hohes Holz' (DE-HoH) located in Central Germany, using the measurements taken between 2015 and 2020. Our analysis demonstrates that the extreme drought and heat event in 2018 had strong legacy effects on the carbon cycle in 2019, but not in 2020. On an annual basis, net ecosystem productivity was [Formula: see text] higher in 2018 ([Formula: see text]) and [Formula: see text] lower in 2019 ([Formula: see text]) compared to pre-drought years ([Formula: see text]). Using spline regression, we show that while current hydrometeorological conditions can explain forest productivity in 2020, they do not fully explain the decrease in productivity in 2019. Including long-term drought information in the statistical model reduces overestimation error of productivity in 2019 by nearly [Formula: see text]. We also found that short-term drought events have positive impacts on the carbon cycle at the beginning of the vegetation season, but negative impacts in later summer, while long-term drought events have generally negative impacts throughout the growing season. Overall, our findings highlight the importance of considering the diverse and complex impacts of extreme events on ecosystem fluxes, including the timing, temporal scale, and magnitude of the events, and the need to use consistent definitions of drought to clearly convey immediate and delayed responses.
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Affiliation(s)
- Felix Pohl
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany.
| | - Ulrike Werban
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
| | - Rohini Kumar
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
| | - Anke Hildebrandt
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
- Friedrich Schiller University Jena, Institute of Geoscience, Burgweg 11, 07749, Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstrasse 4, 04103, Leipzig, Germany
| | - Corinna Rebmann
- Helmholtz-Centre for Environmental Research - UFZ, Permoserstraße 15, 04318, Leipzig, Germany
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5
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Shao J, Zhou X, Zhang P, Zhai D, Yuan T, Li Z, He Y, McDowell NG. Embolism resistance explains mortality and recovery of five subtropical evergreen broadleaf trees to persistent drought. Ecology 2023; 104:e3877. [PMID: 36178039 DOI: 10.1002/ecy.3877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/05/2022] [Accepted: 08/25/2022] [Indexed: 02/03/2023]
Abstract
Subtropical evergreen broadleaf forests (SEBF) are experiencing and expected to suffer more frequent and severe drought events. However, how the hydraulic traits directly link to the mortality and recovery of SEBF trees remains unclear. In this study, we conducted a drought-rewatering experiment on tree seedlings of five dominant species to investigate how the hydraulic traits were related to tree mortality and the resistance and recovery of photosynthesis (A) and transpiration (E) under different drought severities. Species with greater embolism resistance (P50 ) survived longer than those with a weaker P50 . However, there was no general hydraulic threshold associated with tree mortality, with the lethal hydraulic failure varying from 64% to 93% loss of conductance. The photosynthesis and transpiration of tree species with a greater P50 were more resistant to and recovered faster from drought than those with lower P50 . Other plant traits could not explain the interspecific variation in tree mortality and drought resistance and recovery. These results highlight the unique importance of embolism resistance in driving carbon and water processes under persistent drought across different trees in SEBFs. The absence of multiple efficient drought strategies in SEBF seedlings implies the difficulty of natural seedling regeneration under future droughts, which often occurs after destructive disturbances (e.g., extreme drought events and typhoon), suggesting that this biome may be highly vulnerable to co-occurring climate extremes.
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Affiliation(s)
- Junjiong Shao
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.,State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
| | - Xuhui Zhou
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.,Northeast Asia ecosystem Carbon sink research Center (NACC), Center for Ecological Research, Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, China
| | - Peipei Zhang
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.,CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Deping Zhai
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.,School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Tengfei Yuan
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.,School of Atmospheric Sciences, Nanjing University, Nanjing, China
| | - Zhen Li
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Yanghui He
- Center for Global Change and Ecological Forecasting, Tiantong National Field Observation Station for Forest Ecosystem, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China.,Northeast Asia ecosystem Carbon sink research Center (NACC), Center for Ecological Research, Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Forestry, Northeast Forestry University, Harbin, China
| | - Nate G McDowell
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Lab, Richland, Washington, USA.,School of Biological Sciences, Washington State University, Pullman, Washington, USA
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Duan H, Wang D, Zhao N, Huang G, Resco de Dios V, Tissue DT. Limited hydraulic recovery in seedlings of six tree species with contrasting leaf habits in subtropical China. FRONTIERS IN PLANT SCIENCE 2022; 13:967187. [PMID: 36035730 PMCID: PMC9403191 DOI: 10.3389/fpls.2022.967187] [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: 06/12/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Subtropical tree species may experience severe drought stress due to variable rainfall under future climates. However, the capacity to restore hydraulic function post-drought might differ among co-occurring species with contrasting leaf habits (e.g., evergreen and deciduous) and have implications for future forest composition. Moreover, the links between hydraulic recovery and physiological and morphological traits related to water-carbon availability are still not well understood. Here, potted seedlings of six tree species (four evergreen and two deciduous) were grown outdoors under a rainout shelter. They grew under favorable water conditions until they were experimentally subjected to a soil water deficit leading to losses of ca. 50% of hydraulic conductivity, and then soils were re-watered to field capacity. Traits related to carbon and water relations were measured. There were differences in drought responses and recovery between species, but not as a function of evergreen or deciduous groups. Sapindus mukorossi exhibited the most rapid drought response, which was associated with a suite of physiological and morphological traits (larger plant size, the lowest hydraulic capacitance (C branch), higher minimum conductance (g min) and lower HV (Huber value)). Upon re-watering, xylem water potential exhibited fast recovery in 1-3 days among species, while photosynthesis at saturating light (A sat) and stomatal conductance (g s) recovery lagged behind water potential recovery depending on species, with g s recovery being more delayed than A sat in most species. Furthermore, none of the six species exhibited significant hydraulic recovery during the 7 days re-watering period, indicating that xylem refilling was apparently limited; in addition, NSC availability had a minimal role in facilitating hydraulic recovery during this short-term period. Collectively, if water supply is limited by insignificant hydraulic recovery post-drought, the observed carbon assimilation recovery of seedlings may not be sustained over the longer term, potentially altering seedling regeneration and shifting forest species composition in subtropical China under climate change.
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Affiliation(s)
- Honglang Duan
- Institute for Forest Resources and Environment of Guizhou, Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, College of Forestry, Guizhou University, Guiyang, China
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Defu Wang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Nan Zhao
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Guomin Huang
- Jiangxi Provincial Key Laboratory for Restoration of Degraded Ecosystems and Watershed Ecohydrology, Nanchang Institute of Technology, Nanchang, China
| | - Víctor Resco de Dios
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
- Joint Research Unit CTFC-AGROTECNIO-CERCA Center, Lleida, Spain
| | - David T. Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Richmond, NSW, Australia
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Liu M, Zhao Y, Wang Y, Korpelainen H, Li C. Stem xylem traits and wood formation affect sex-specific responses to drought and rewatering in Populus cathayana. TREE PHYSIOLOGY 2022; 42:1350-1363. [PMID: 35137223 DOI: 10.1093/treephys/tpac011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
The increased frequency and intensity of drought pose great threats to the survival of trees, especially in dioecious tree species with sexual differences in mortality and biased sex ratios. The sex-specific mechanisms underlying stem xylem anatomy and function and carbon metabolism in drought resistance and recovery were investigated in dioecious Populus cathayana Rehder. The sex-specific drought resistance and subsequent recovery were linked to the xylem anatomy and carbon metabolism. Females had a greater xylem vessel area per vessel, biomass and theoretically hydraulic efficiency under well-watered conditions. Conversely, males had a lower xylem lumen area, but greater vessel numbers, and a higher cell wall thickness, suggesting a theoretically conservative water-use strategy and drought resistance. The recovery of photosynthetic ability after drought in males was largely dependent on the recovery of xylem function and the regulation of the xylem carbohydrate metabolism. Additionally, the number of upregulated genes related to xylem cell wall biogenesis was greater in males relative to females under drought stress and subsequent rewatering, which facilitated drought resistance and xylem function restoration in males. These results suggested that sex-specific drought resistance and restoration were related to xylem anatomy and function, carbohydrate metabolism and cell turgor maintenance.
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Affiliation(s)
- Miao Liu
- College of Life and Environmental Sciences, Hangzhou Normal University, Yuhangtang Road 2318, Hangzhou 311121, China
| | - Yang Zhao
- College of Life and Environmental Sciences, Hangzhou Normal University, Yuhangtang Road 2318, Hangzhou 311121, China
| | - Yuting Wang
- College of Life and Environmental Sciences, Hangzhou Normal University, Yuhangtang Road 2318, Hangzhou 311121, China
| | - Helena Korpelainen
- Department of Agricultural Sciences, Viikki Plant Science Centre, University of Helsinki, PO Box 27, Latokartanonkaari 5, Helsinki FI-00014, Finland
| | - Chunyang Li
- College of Agriculture and Biotechnology, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
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8
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Hu Y, Xiang W, Schäfer KVR, Lei P, Deng X, Forrester DI, Fang X, Zeng Y, Ouyang S, Chen L, Peng C. Photosynthetic and hydraulic traits influence forest resistance and resilience to drought stress across different biomes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154517. [PMID: 35278541 DOI: 10.1016/j.scitotenv.2022.154517] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Drought events lead to depressions in gross primary productivity (GPP) of forest ecosystems. Photosynthetic and hydraulic traits are important factors governing GPP variation. However, how these functional traits affect GPP responses to drought has not been well understood. We quantified the capacity of GPP to withstand changes during droughts (GPP_resistance) and its post-drought responses (GPP_resilience) using eddy covariance data from the FLUXNET2015 dataset, and investigated how functional traits of dominant tree species that comprised >80% of the biomass (or composition) influenced GPP_resistance or GPP_resilience. Light-saturated photosynthetic rate of dominant tree species was negatively related to GPP_resistance, and was positively correlated with GPP_resilience. Forests dominated by species with higher hydraulic safety margins (HSM), smaller vessel diameter (Vdia) and lower sensitivity of canopy stomatal conductance per unit land area (Gs) to droughts had a higher GPP_resistance, while those dominated by species with lower HSM, larger Vdia and higher sensitivity of Gs to droughts exhibited a higher GPP_resilience. Differences in functional traits of forests located in diverse climate regions led to distinct GPP sensitivities to droughts. Forests located in humid regions had a higher GPP_resilience while those in arid regions exhibited a higher GPP_resistance. Forest GPP_resistance was negatively related to drought intensity, and GPP_resilience was negatively related to drought duration. Our findings highlight the significant role of functional traits in governing forest resistance and resilience to droughts. Overall, forests dominated by species with higher hydraulic safety were more resistant to droughts, while forests containing species with higher photosynthetic and hydraulic efficiency recovered better from drought stress.
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Affiliation(s)
- Yanting Hu
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - Wenhua Xiang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China.
| | - Karina V R Schäfer
- Department of Earth and Environmental Sciences, Rutgers University, 195 University Avenue, Newark 07102, NJ, USA
| | - Pifeng Lei
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - Xiangwen Deng
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - David I Forrester
- Swiss Federal Institute of Forest Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Xi Fang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - Yelin Zeng
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - Shuai Ouyang
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - Liang Chen
- Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, China; Huitong National Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystems in Hunan Province, Huitong, China
| | - Changhui Peng
- Department of Biological Sciences, Institute of Environment Sciences, University of Quebec at Montreal, Montreal, Quebec H3C 3P8, Canada
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9
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Lu R, Du Y, Sun H, Xu X, Yan L, Xia J. Nocturnal warming accelerates drought-induced seedling mortality of two evergreen tree species. TREE PHYSIOLOGY 2022; 42:1164-1176. [PMID: 34919711 DOI: 10.1093/treephys/tpab168] [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: 07/22/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
Abstract
Extreme drought is one of the key climatic drivers of tree mortality on a global scale. However, it remains unclear whether the drought-induced tree mortality will increase under nocturnal climate warming. Here we exposed seedlings of two wide-ranging subtropical tree species, Castanopsis sclerophylla and Schima superba, with contrasting stomatal regulation strategies to prolonged drought under ambient and elevated night-time temperature by 2 °C. We quantified the seedling survival time since drought treatment by measuring multiple leaf traits such as leaf gas exchange, predawn leaf water potential and water-use efficiency. The results showed that all seedlings in the ambient temperature died within 180 days and 167 days of drought for C. sclerophylla and S. superba, respectively. Night warming significantly shortened the survival time of C. sclerophylla, by 31 days, and S. superba by 28 days, under the drought treatment. A survival analysis further showed that seedlings under night warming suffered a 1.6 times greater mortality risk than those under ambient temperature. Further analyses revealed that night warming suppressed net leaf carbon gain in both species by increasing the nocturnal respiratory rate of S. superba across the first 120 days of drought and decreasing the photosynthetic rate of both species generally after 46 days of drought. These effects on net carbon gain were more pronounced in S. superba than C. sclerophylla. After 60 days of drought, night warming decreased the predawn leaf water potential and leaf water-use efficiency of C. sclerophylla but not S. superba. These contrasting responses are partially due to variations in stomatal control between the two species. These findings suggest that stomatal traits can regulate the response of leaf gas exchange and plant water-use to nocturnal warming during drought. This study indicates that nocturnal warming can accelerate tree mortality during drought. Night warming accelerates the mortality of two subtropical seedlings under drought.Night warming differently affects the drought response of leaf gas exchange and plant water-use between the two species due to species-specific stomatal morphological traits.Carbon metabolism changes and hydraulic damage play differential roles in driving night-warming impacts on the drought-induced mortality between the two species.
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Affiliation(s)
- Ruiling Lu
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Ying Du
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Huanfa Sun
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Xiaoni Xu
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Liming Yan
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
| | - Jianyang Xia
- Tiantong Forest Ecosystem National Observation and Research Station, Research Center for Global Change and Complex Ecosystems, School of Ecological and Environmental Sciences, East China Normal University, 500 Dongchuan Road, Minhang District, Shanghai 200241, China
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10
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Drought Sensitivity and Resilience of Oak–Hickory Stands in the Eastern United States. FORESTS 2022. [DOI: 10.3390/f13030389] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Forest composition in the eastern United States (US) has been shifting from an oak–hickory to maple–beech assemblage, but whether there are species-specific differences within these oak–hickory stands in their responses and recovery from drought remains unclear. Here, we examined drought responses and resilience derived from radial growth of 485 co-occurring Carya ovata and Quercus alba individual trees at 15 forests in the eastern US. Water availability over the growing season (May to August) of the current year controls growth variability of both C. ovata and Q. alba. Drought that occurred in June caused the greatest growth reduction for both species while interspecific differences inof drought-induced growth reduction was found in July, where Q. alba experienced stronger reduction than C. ovata. Both species are resilient to early growing season drought, but late growing season drought caused larger drought legacy effects for Q. alba. The increasing drought frequency and intensity will have a more prominent impact in oak–hickory stands in the eastern US. The species composition of a forest along with species-specific responses and recovery is likely to be a critical control on forest productivity and species abundance.
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11
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Goke A, Martin PH. Poor acclimation to experimental field drought in subalpine forest tree seedlings. AOB PLANTS 2022; 14:plab077. [PMID: 35079329 PMCID: PMC8782599 DOI: 10.1093/aobpla/plab077] [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: 07/20/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
The ability of tree species to acclimate and tolerate projected increases in drought frequency and intensity has fundamental implications for future forest dynamics with climate change. Inquiries to date on the drought tolerance capacities of tree species, however, have focused almost exclusively on mature trees with scant in situ work on seedlings, despite the central role that regeneration dynamics play in forest responses to changing conditions. We subjected naturally established seedlings of co-dominant subalpine conifer species (Abies lasiocarpa and Picea engelmannii) in the southern Rocky Mountains to 2 years of in situ summer precipitation exclusion, simulating summer drought conditions similar to a failure of the North American monsoon. We compared the morphological and physiological responses of seedlings growing in drought vs. ambient conditions to assess the relative changes in drought tolerance traits as a function of seedling size. Drought treatments had a marked impact on soil moisture: volumetric water content averaged ≈5-8 % in drought treatments and ≈8-12 % in ambient controls. We detected no significant shifts in morphology (e.g. root biomass, leaf:stem area ratio) in response to drought for either species, but net photosynthesis in drought treatments was 78 % lower for spruce and 37 % lower for fir. Greater stomatal control associated with increasing stem diameter conferred greater water use efficiencies in larger seedlings in both species but was not significantly different between drought and ambient conditions, suggesting an overall lack of responsivity to water stress and a prioritization of carbon gain over investment in drought mitigation traits. These results indicate a canonization of traits that, while useful for early seedling establishment, may portend substantial vulnerability of subalpine seedling populations to prolonged or recurrent droughts, especially for spruce.
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Affiliation(s)
- Alex Goke
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Patrick H Martin
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
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12
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Benson MC, Miniat CF, Oishi AC, Denham SO, Domec JC, Johnson DM, Missik JE, Phillips RP, Wood JD, Novick KA. The xylem of anisohydric Quercus alba L. is more vulnerable to embolism than isohydric codominants. PLANT, CELL & ENVIRONMENT 2022; 45:329-346. [PMID: 34902165 DOI: 10.1111/pce.14244] [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: 10/28/2020] [Revised: 12/01/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
The coordination of plant leaf water potential (ΨL ) regulation and xylem vulnerability to embolism is fundamental for understanding the tradeoffs between carbon uptake and risk of hydraulic damage. There is a general consensus that trees with vulnerable xylem more conservatively regulate ΨL than plants with resistant xylem. We evaluated if this paradigm applied to three important eastern US temperate tree species, Quercus alba L., Acer saccharum Marsh. and Liriodendron tulipifera L., by synthesizing 1600 ΨL observations, 122 xylem embolism curves and xylem anatomical measurements across 10 forests spanning pronounced hydroclimatological gradients and ages. We found that, unexpectedly, the species with the most vulnerable xylem (Q. alba) regulated ΨL less strictly than the other species. This relationship was found across all sites, such that coordination among traits was largely unaffected by climate and stand age. Quercus species are perceived to be among the most drought tolerant temperate US forest species; however, our results suggest their relatively loose ΨL regulation in response to hydrologic stress occurs with a substantial hydraulic cost that may expose them to novel risks in a more drought-prone future.
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Affiliation(s)
- Michael C Benson
- O'Neill School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Chelcy F Miniat
- USDA Forest Service, Southern Research Station, Coweeta Hydrologic Laboratory, Otto, North Carolina, USA
| | - Andrew C Oishi
- USDA Forest Service, Southern Research Station, Coweeta Hydrologic Laboratory, Otto, North Carolina, USA
| | - Sander O Denham
- O'Neill School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Jean-Christophe Domec
- Bordeaux Sciences Agro, INRA UMR 1391 ISPA, Gradignan, France
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Daniel M Johnson
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, USA
| | - Justine E Missik
- Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Richard P Phillips
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana, USA
| | - Jeffrey D Wood
- University of Missouri, School of Natural Resources, Columbia, Missouri, USA
| | - Kimberly A Novick
- O'Neill School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, Indiana, USA
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13
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Novick K, Jo I, D'Orangeville L, Benson M, Au TF, Barnes M, Denham S, Fei S, Heilman K, Hwang T, Keyser T, Maxwell J, Miniat C, McLachlan J, Pederson N, Wang L, Wood JD, Phillips RP. The Drought Response of Eastern US Oaks in the Context of Their Declining Abundance. Bioscience 2022. [DOI: 10.1093/biosci/biab135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
The oak (Quercus) species of eastern North America are declining in abundance, threatening the many socioecological benefits they provide. We discuss the mechanisms responsible for their loss, many of which are rooted in the prevailing view that oaks are drought tolerant. We then synthesize previously published data to comprehensively review the drought response strategies of eastern US oaks, concluding that whether or not eastern oaks are drought tolerant depends firmly on the metric of success. Although the anisohydric strategy of oaks sometimes confers a gas exchange and growth advantage, it exposes oaks to damaging hydraulic failure, such that oaks are just as or more likely to perish during drought than neighboring species. Consequently, drought frequency is not a strong predictor of historic patterns of oak abundance, although long-term climate and fire frequency are strongly correlated with declines in oak dominance. The oaks’ ability to survive drought may become increasingly difficult in a drier future.
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14
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Kannenberg SA, Guo JS, Novick KA, Anderegg WRL, Feng X, Kennedy D, Konings AG, Martínez‐Vilalta J, Matheny AM. Opportunities, challenges and pitfalls in characterizing plant water‐use strategies. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13945] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Jessica S. Guo
- Department of Geology and Geophysics University of Utah Salt Lake City UT USA
- Arizona Experiment Station, College of Agriculture and Life Sciences University of Arizona Tucson AZ USA
| | - Kimberly A. Novick
- O’Neill School of Public and Environmental Affairs Indiana University Bloomington IN USA
| | | | - Xue Feng
- Department of Civil, Environmental, and Geo‐Engineering University of Minnesota Minneapolis MN USA
- Saint Anthony Falls Laboratory University of Minnesota Minneapolis MN USA
| | | | | | - Jordi Martínez‐Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès) Catalonia Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès) Catalonia Spain
| | - Ashley M. Matheny
- Department of Geological Sciences Jackson School of Geosciences University of Texas Austin TX USA
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15
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Asbjornsen H, McIntire CD, Vadeboncoeur MA, Jennings KA, Coble AP, Berry ZC. Sensitivity and threshold dynamics of Pinus strobus and Quercus spp. in response to experimental and naturally occurring severe droughts. TREE PHYSIOLOGY 2021; 41:1819-1835. [PMID: 33904579 DOI: 10.1093/treephys/tpab056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
Increased drought frequency and severity are a pervasive global threat, yet the capacity of mesic temperate forests to maintain resilience in response to drought remains poorly understood. We deployed a throughfall removal experiment to simulate a once in a century drought in New Hampshire, USA, which coupled with the region-wide 2016 drought, intensified moisture stress beyond that experienced in the lifetimes of our study trees. To assess the sensitivity and threshold dynamics of two dominant northeastern tree genera (Quercus and Pinus), we monitored sap flux density (Js), leaf water potential and gas exchange, growth and intrinsic water-use efficiency (iWUE) for one pretreatment year (2015) and two treatment years (2016-17). Results showed that Js in pine (Pinus strobus L.) declined abruptly at a soil moisture threshold of 0.15 m3 m-3, whereas oak's (Quercus rubra L. and Quercus velutina Lam.) threshold was 0.11 m3 m-3-a finding consistent with pine's more isohydric strategy. Nevertheless, once oaks' moisture threshold was surpassed, Js declined abruptly, suggesting that while oaks are well adapted to moderate drought, they are highly susceptible to extreme drought. The radial growth reduction in response to the 2016 drought was more than twice as great for pine as for oaks (50 vs 18%, respectively). Despite relatively high precipitation in 2017, the oaks' growth continued to decline (low recovery), whereas pine showed neutral (treatment) or improved (control) growth. The iWUE increased in 2016 for both treatment and control pines, but only in treatment oaks. Notably, pines exhibited a significant linear relationship between iWUE and precipitation across years, whereas the oaks only showed a response during the driest conditions, further underscoring the different sensitivity thresholds for these species. Our results provide new insights into how interactions between temperate forest tree species' contrasting physiologies and soil moisture thresholds influence their responses and resilience to extreme drought.
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Affiliation(s)
- Heidi Asbjornsen
- Department of Natural Resources and the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
- Earth Systems Research Center, University of New Hampshire, 8 College Rd, Durham, NH 03824, USA
| | - Cameron D McIntire
- Department of Natural Resources and the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
- State and Private Forestry, USDA Forest Service, 271 Mast Road, Durham, NH 03824, USA
| | - Matthew A Vadeboncoeur
- Earth Systems Research Center, University of New Hampshire, 8 College Rd, Durham, NH 03824, USA
| | - Katie A Jennings
- Department of Natural Resources and the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
- Earth Systems Research Center, University of New Hampshire, 8 College Rd, Durham, NH 03824, USA
| | - Adam P Coble
- Department of Natural Resources and the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
- Private Forests Division, Oregon Department of Forestry, 2600 State St, Salem, OR 97310, USA
| | - Z Carter Berry
- Department of Natural Resources and the Environment, University of New Hampshire, 56 College Rd, Durham, NH 03824, USA
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
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16
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Bohner T, Diez J. Tree resistance and recovery from drought mediated by multiple abiotic and biotic processes across a large geographic gradient. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 789:147744. [PMID: 34051506 DOI: 10.1016/j.scitotenv.2021.147744] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 05/07/2021] [Accepted: 05/09/2021] [Indexed: 06/12/2023]
Abstract
Worldwide, increasing severity of droughts threatens to change forest ecosystem functioning and community structure. Understanding how forest resilience is determined by its two underlying components, resistance and recovery, will help elucidate the mechanisms of drought responses and help inform management strategies. However, drought responses are shaped by complex processes across different scales, including species-specific drought strategies, tree size, competition, local environmental conditions, and the intensity of the drought event. Here, we quantified the reduction in tree growth during drought (an inverse measure of drought resistance) and post-drought recovery for three montane conifers (Abies concolor, Pinus jeffreyi, and Pinus lambertiana) in California. We used tree ring analysis to quantify responses to drought events of varying intensity between 1895 and 2018 across a geographic climatic gradient, to examine the roles of tree size (DBH) and competition (tree density) in mediating drought responses. We found that years of more intense drought corresponded with larger growth reductions and recovery rates were lower following drought years where trees suffered larger reductions. We found little variation among species in their growth reductions during drought events, but significant differences among species in their recovery post-drought. Across the geographic gradient, trees in the driest locations were susceptible to large growth reductions, signaling either strong sensitivity to drought intensity or exposure to the most extreme drought conditions. These growth reductions were not always compensated for by higher recovery rates. We also found that larger trees were more susceptible to drought due to a steeper negative relationship between recovery rates and the intensity of growth reduction during the drought. Contrary to expectations, recovery rates following the most detrimental drought years were higher in denser forests. Our results demonstrate the importance of considering how factors at various spatial and temporal scales affect the different components of drought responses.
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Affiliation(s)
- Teresa Bohner
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA.
| | - Jeffrey Diez
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
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17
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Liu X, Wang N, Cui R, Song H, Wang F, Sun X, Du N, Wang H, Wang R. Quantifying Key Points of Hydraulic Vulnerability Curves From Drought-Rewatering Experiment Using Differential Method. FRONTIERS IN PLANT SCIENCE 2021; 12:627403. [PMID: 33603765 PMCID: PMC7884474 DOI: 10.3389/fpls.2021.627403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/08/2021] [Indexed: 05/06/2023]
Abstract
Precise and accurate estimation of key hydraulic points of plants is conducive to mastering the hydraulic status of plants under drought stress. This is crucial to grasping the hydraulic status before the dieback period to predict and prevent forest mortality. We tested three key points and compared the experimental results to the calculated results by applying two methods. Saplings (n = 180) of Robinia pseudoacacia L. were separated into nine treatments according to the duration of the drought and rewatering. We established the hydraulic vulnerability curve and measured the stem water potential and loss of conductivity to determine the key points. We then compared the differences between the calculated [differential method (DM) and traditional method (TM)] and experimental results to identify the validity of the calculation method. From the drought-rewatering experiment, the calculated results from the DM can be an accurate estimation of the experimental results, whereas the TM overestimated them. Our results defined the hydraulic status of each period of plants. By combining the experimental and calculated results, we divided the hydraulic vulnerability curve into four parts. This will generate more comprehensive and accurate methods for future research.
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Affiliation(s)
- Xiao Liu
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Rong Cui
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Huijia Song
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Feng Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Xiaohan Sun
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Du
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- *Correspondence: Ning Du
| | - Hui Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- Hui Wang
| | - Renqing Wang
- Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
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18
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Zweifel R, Etzold S, Sterck F, Gessler A, Anfodillo T, Mencuccini M, von Arx G, Lazzarin M, Haeni M, Feichtinger L, Meusburger K, Knuesel S, Walthert L, Salmon Y, Bose AK, Schoenbeck L, Hug C, De Girardi N, Giuggiola A, Schaub M, Rigling A. Determinants of legacy effects in pine trees - implications from an irrigation-stop experiment. THE NEW PHYTOLOGIST 2020; 227:1081-1096. [PMID: 32259280 PMCID: PMC7383578 DOI: 10.1111/nph.16582] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/24/2020] [Indexed: 05/02/2023]
Abstract
Tree responses to altered water availability range from immediate (e.g. stomatal regulation) to delayed (e.g. crown size adjustment). The interplay of the different response times and processes, and their effects on long-term whole-tree performance, however, is hardly understood. Here we investigated legacy effects on structures and functions of mature Scots pine in a dry inner-Alpine Swiss valley after stopping an 11-yr lasting irrigation treatment. Measured ecophysiological time series were analysed and interpreted with a system-analytic tree model. We found that the irrigation stop led to a cascade of downregulations of physiological and morphological processes with different response times. Biophysical processes responded within days, whereas needle and shoot lengths, crown transparency, and radial stem growth reached control levels after up to 4 yr only. Modelling suggested that organ and carbon reserve turnover rates play a key role for a tree's responsiveness to environmental changes. Needle turnover rate was found to be most important to accurately model stem growth dynamics. We conclude that leaf area and its adjustment time to new conditions is the main determinant for radial stem growth of pine trees as the transpiring area needs to be supported by a proportional amount of sapwood, despite the growth-inhibiting environmental conditions.
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Affiliation(s)
- Roman Zweifel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Sophia Etzold
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Frank Sterck
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Forest Ecology and Management GroupWageningen University6701Wageningenthe Netherlands
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Institute of Terrestrial EcosystemsETH Zurich8092ZurichSwitzerland
| | - Tommaso Anfodillo
- Dipartimento Territorio e Sistemi Agro‐ForestaliUniversity of Padova35020LegnaroItaly
| | - Maurizio Mencuccini
- ICREA08010BarcelonaSpain
- CREAFUniversidad Autonoma de Barcelona08193BarcelonaSpain
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Martina Lazzarin
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Horticulture and Product PhysiologyWageningen UniversityWageningen6701the Netherlands
| | - Matthias Haeni
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Linda Feichtinger
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Katrin Meusburger
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Simon Knuesel
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Lorenz Walthert
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Yann Salmon
- Institute for Atmospheric and Earth System Research/PhysicsUniversity of Helsinki00100HelsinkiFinland
- Institute for Atmospheric and Earth System Research/Forest SciencesUniversity of Helsinki00100HelsinkiFinland
| | - Arun K. Bose
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
- Forestry and Wood Technology DisciplineKhulna University9208KhulnaBangladesh
| | - Leonie Schoenbeck
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Christian Hug
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Nicolas De Girardi
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Arnaud Giuggiola
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Marcus Schaub
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
| | - Andreas Rigling
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL8903BirmensdorfSwitzerland
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19
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Jiang P, Meinzer FC, Wang H, Kou L, Dai X, Fu X. Below-ground determinants and ecological implications of shrub species' degree of isohydry in subtropical pine plantations. THE NEW PHYTOLOGIST 2020; 226:1656-1666. [PMID: 32096212 DOI: 10.1111/nph.16502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/16/2020] [Indexed: 06/10/2023]
Abstract
The degree of plant iso/anisohydry is a popular framework for characterising species-specific drought responses. However, we know little about associations between below-ground and above-ground hydraulic traits as well as the broader ecological implications of this framework. For 24 understory shrub species in seasonally dry subtropical coniferous plantations, we investigated contributions of the degree of isohydry to species' resource economy strategies, abundance, and importance value, and quantified the hydraulic conductance (Kh ) of above-ground and below-ground organs, magnitude of deep water acquisition (WAdeep ), shallow absorptive root traits (diameter, specific root length, tissue density), and resource-use efficiencies (Amax , maximum photosynthesis rate; PNUE, photosynthetic nitrogen-use efficiency). The extreme isohydric understory species had lower wood density (a proxy for higher growth rates) because their higher WAdeep and whole-plant Kh allowed higher Amax and PNUE, and thus did not necessarily show lower abundance and importance values. Although species' Kh was coordinated with their water foraging capacity in shallow soil, the more acquisitive deep roots were more crucial than shallow roots in shaping species' extreme isohydric behaviour. Our results provide new insights into the mechanisms through which below-ground hydraulic traits, especially those of deep roots, determine species' degree of isohydry and economic strategies.
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Affiliation(s)
- Peipei Jiang
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Frederick C Meinzer
- USDA Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR, 97331, USA
| | - Huimin Wang
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Liang Kou
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaoqin Dai
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaoli Fu
- Qianyanzhou Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100190, China
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20
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Lanning M, Wang L, Novick KA. The importance of cuticular permeance in assessing plant water-use strategies. TREE PHYSIOLOGY 2020; 40:425-432. [PMID: 32091105 DOI: 10.1093/treephys/tpaa020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/20/2020] [Accepted: 02/22/2020] [Indexed: 06/10/2023]
Abstract
Accurate understanding of plant responses to water stress is increasingly important for quantification of ecosystem carbon and water cycling under future climates. Plant water-use strategies can be characterized across a spectrum of water stress responses, from tight stomatal control (isohydric) to distinctly less stomatal control (anisohydric). A recent and popular classification method of plant water-use strategies utilizes the regression slope of predawn and midday leaf water potentials, σ, to reflect the coupling of soil water availability (predawn leaf water potential) and stomatal dynamics (daily decline in leaf water potential). This type of classification is important in predicting ecosystem drought response and resiliency. However, it fails to explain the relative stomatal responses to drought of Acer sacharrum and Quercus alba, improperly ranking them on the spectrum of isohydricity. We argue this inconsistency may be in part due to the cuticular conductance of different species. We used empirical and modeling evidence to show that plants with more permeable cuticles are more often classified as anisohydric; the σ values of those species were very well correlated with measured cuticular permeance. Furthermore, we found that midday leaf water potential in species with more permeable cuticles would continue to decrease as soils become drier, but not in those with less permeable cuticles. We devised a diagnostic parameter, Γ, to identify circumstances where the impact of cuticular conductance could cause species misclassification. The results suggest that cuticular conductance needs to be considered to better understand plant water-use strategies and to accurately predict forest responses to water stress under future climate scenarios.
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Affiliation(s)
- Matthew Lanning
- Department of Earth Science, Indiana University - Purdue University Indianapolis, 723 West Michigan Street, Indianapolis, IN 46202, USA
| | - Lixin Wang
- Department of Earth Science, Indiana University - Purdue University Indianapolis, 723 West Michigan Street, Indianapolis, IN 46202, USA
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University Bloomington, 1315 East Tenth Street, Bloomington, IN 47405, USA
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21
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Kannenberg SA, Schwalm CR, Anderegg WRL. Ghosts of the past: how drought legacy effects shape forest functioning and carbon cycling. Ecol Lett 2020; 23:891-901. [DOI: 10.1111/ele.13485] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/29/2019] [Accepted: 02/12/2020] [Indexed: 01/06/2023]
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22
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Godfrey JM, Riggio J, Orozco J, Guzmán-Delgado P, Chin ARO, Zwieniecki MA. Ray fractions and carbohydrate dynamics of tree species along a 2750 m elevation gradient indicate climate response, not spatial storage limitation. THE NEW PHYTOLOGIST 2020; 225:2314-2330. [PMID: 31808954 DOI: 10.1111/nph.16361] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/03/2019] [Indexed: 06/10/2023]
Abstract
Parenchyma cells in the xylem store nonstructural carbohydrates (NSC), providing reserves of energy that fuel woody perennials through periods of stress and/or limitations to photosynthesis. If the capacity for storage is subject to selection, then the fraction of wood occupied by living parenchyma should increase towards stressful environments. Ray parenchyma fraction (RPF) and seasonal NSC dynamics were quantified for 12 conifers and three oaks along a transect spanning warm dry foothills (500 m above sea level) to cold wet treeline (3250 m asl) in California's central Sierra Nevada. Mean RPF was lower for both conifer and oak species with warmer dryer ranges. RPF variability increased with elevation or in relation to associated climatic variables in conifers - treeline-dominant Pinus albicaulis had the lowest mean RPF measured (c. 3.7%), but the highest environmentally standardized variability index. Conifer RPF variability was explained by environment, increasing predominantly towards cooler wetter range edges. In oaks, NSC was explained by environment - values increasing for evergreen and decreasing for deciduous oaks with elevation. Lastly, all species surveyed appear to prioritize filling available RPF with sugar to achieve molarities that balance reasonable tensions over starch to maximize stored carbon. RPF responds to environment but is unlikely to spatially constrain NSC storage.
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Affiliation(s)
- Jessie M Godfrey
- Plant Sciences Department, University of California, Davis, CA, 95616, USA
| | - Jason Riggio
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, 95616, USA
| | - Jessica Orozco
- Plant Sciences Department, University of California, Davis, CA, 95616, USA
| | | | - Alana R O Chin
- Plant Sciences Department, University of California, Davis, CA, 95616, USA
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23
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Falchi R, Petrussa E, Braidot E, Sivilotti P, Boscutti F, Vuerich M, Calligaro C, Filippi A, Herrera JC, Sabbatini P, Zancani M, Nardini A, Peterlunger E, Casolo V. Analysis of Non-Structural Carbohydrates and Xylem Anatomy of Leaf Petioles Offers New Insights in the Drought Response of Two Grapevine Cultivars. Int J Mol Sci 2020; 21:E1457. [PMID: 32093416 PMCID: PMC7073087 DOI: 10.3390/ijms21041457] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 02/17/2020] [Indexed: 11/16/2022] Open
Abstract
In grapevine, the anatomy of xylem conduits and the non-structural carbohydrates (NSCs) content of the associated living parenchyma are expected to influence water transport under water limitation. In fact, both NSC and xylem features play a role in plant recovery from drought stress. We evaluated these traits in petioles of Cabernet Sauvignon (CS) and Syrah (SY) cultivars during water stress (WS) and recovery. In CS, the stress response was associated to NSC consumption, supporting the hypothesis that starch mobilization is related to an increased supply of maltose and sucrose, putatively involved in drought stress responses at the xylem level. In contrast, in SY, the WS-induced increase in the latter soluble NSCs was maintained even 2 days after re-watering, suggesting a different pattern of utilization of NSC resources. Interestingly, the anatomical analysis revealed that conduits are constitutively wider in SY in well-watered (WW) plants, and that water stress led to the production of narrower conduits only in this cultivar.
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Affiliation(s)
- Rachele Falchi
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Elisa Petrussa
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Enrico Braidot
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Paolo Sivilotti
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Francesco Boscutti
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Marco Vuerich
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Carla Calligaro
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Antonio Filippi
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - José Carlos Herrera
- Institute of Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz Straβe 24, 3430 Tulln, Austria;
| | - Paolo Sabbatini
- Department of Horticulture, Michigan State University, 1066 Bogue Street, East Lansing, MI 48824, USA;
| | - Marco Zancani
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Andrea Nardini
- Department of Life Sciences, University of Trieste, via Licio Giorgieri, 5, 34127 Trieste, Italy;
| | - Enrico Peterlunger
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
| | - Valentino Casolo
- Department of Agricultural Food, Animal and Environmental Sciences, University of Udine, via delle Scienze 206, 33100 Udine, Italy; (R.F.); (E.P.); (E.B.); (P.S.); (F.B.); (M.V.); (C.C.); (A.F.); (M.Z.); (E.P.)
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24
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Kannenberg SA, Phillips RP. Non-structural carbohydrate pools not linked to hydraulic strategies or carbon supply in tree saplings during severe drought and subsequent recovery. TREE PHYSIOLOGY 2020; 40:259-271. [PMID: 31860721 DOI: 10.1093/treephys/tpz132] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/16/2019] [Indexed: 06/10/2023]
Abstract
Non-structural carbohydrate (NSC) pools fluctuate based on the interplay between photosynthesis, demand from various carbon (C) sinks and tree hydraulic status. Thus, it has been hypothesized that tree species with isohydric stomatal control (i.e., trees that close stomata rapidly in response to drought) rely heavily on NSC pools to sustain metabolism, which can lead to negative physiological consequences such as C depletion. Here, we seek to use a species' degree of isohydry or anisohydry as a conceptual framework for understanding the interrelations between photosynthetic C supply, hydraulic damage and fluctuations in NSC pools. We conducted a 6-week experimental drought, followed by a 6-week recovery period, in a greenhouse on seven tree species that span the spectrum from isohydric to anisohydric. Throughout the experiment, we measured photosynthesis, hydraulic damage and NSC pools. Non-structural carbohydrate pools were remarkably stable across species and tissues-even highly isohydric species that drastically reduced C assimilation were able to maintain stored C. Despite these static NSC pools, we still inferred an important role for stored C during drought, as most species converted starches into sugars during water stress (and back again post-drought). Finally, we did not observe any linkages between C supply, hydraulic damage and NSC pools, indicating that NSC was maintained independent of variation in photosynthesis and hydraulic function. Our results advance the idea that C depletion is a rare phenomenon due to either active maintenance of NSC pools or sink limitation, and thus question the hypothesis that reductions in C assimilation necessarily lead to C depletion.
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Affiliation(s)
- Steven A Kannenberg
- School of Biological Sciences, University of Utah, 257 1400 East, Salt Lake City, UT 84112, USA
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
| | - Richard P Phillips
- Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA
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25
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Torquato PR, Zou CB, Adhikari A, Adams HD, Will RE. Drought Tolerance and Competition in Eastern Redcedar ( Juniperus virginiana) Encroachment of the Oak-Dominated Cross Timbers. FRONTIERS IN PLANT SCIENCE 2020; 11:59. [PMID: 32117395 PMCID: PMC7020614 DOI: 10.3389/fpls.2020.00059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/15/2020] [Indexed: 06/10/2023]
Abstract
On the dry, western edge of the eastern deciduous forest of the USA (Cross Timbers), the drought-tolerant, evergreen eastern redcedar (Juniperus virginiana) is encroaching into post oak- (Quercus stellata) dominated woodlands. The overall goal of this study was to examine whether the drought tolerance strategies of eastern redcedar provide it a competitive advantage over post oak and whether this is a key attribute facilitating its successful establishment in the Cross Timbers. Specifically, we assessed xylem water potential and leaf gas exchange of these two species growing in single-species stands and in a mixed-species stand. We found that both species exhibit a similar degree of isohydry and close their stomates to the same extent in response to declining xylem water potentials. Both species had similar relative reductions in gas exchange in response to drought, despite differences in xylem anatomy. However, post oak had leaf-level gas exchange rates approximately 5× greater than eastern redcedar during periods of high moisture availability. Therefore, it did not appear that eastern redcedar encroachment into an oak-dominated forest is facilitated by growing season differences in carbon gain, although evergreen eastern redcedar can conduct gas exchange year-round when conditions are favorable while post oak is deciduous. We found that volumetric soil water content (0-45 cm) was lower in the pure eastern redcedar stand than the mixed-species or pure post oak stand which may indicate that eastern redcedar may experience favorable soil moisture conditions when encroaching into open oak woodlands. Moreover, water potentials in eastern redcedar tended to be more negative in pure stands compared to the mixed stand. Our results suggest the two species may be using water from different depths, reducing competition. Overall, our findings indicate that eastern redcedar encroachment into formerly oak-dominated Cross Timbers forests likely will continue under moderate drought, in the absence of fire, with consequences for water budgets, carbon cycling, grazing forage, wildlife habitat, and wildfire risk.
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Affiliation(s)
- Patricia R. Torquato
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK, United States
- School of Ecosystem and Forest Sciences, The University of Melbourne, Burnley, VIC, Australia
| | - Chris B. Zou
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK, United States
| | - Arjun Adhikari
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK, United States
| | - Henry D. Adams
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK, United States
| | - Rodney E. Will
- Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK, United States
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26
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Guo JS, Hultine KR, Koch GW, Kropp H, Ogle K. Temporal shifts in iso/anisohydry revealed from daily observations of plant water potential in a dominant desert shrub. THE NEW PHYTOLOGIST 2020; 225:713-726. [PMID: 31519032 DOI: 10.1111/nph.16196] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/06/2019] [Indexed: 05/25/2023]
Abstract
Plant species are characterized along a spectrum of isohydry to anisohydry depending on their regulation of water potential (Ψ), but the plasticity of hydraulic strategies is largely unknown. The role of environmental drivers was evaluated in the hydraulic behavior of Larrea tridentata, a drought-tolerant desert shrub that withstands a wide range of environmental conditions. With a 1.5 yr time-series of 2324 in situ measurements of daily predawn and midday Ψ, the temporal variability of hydraulic behavior was explored in relation to soil water supply, atmospheric demand and temperature. Hydraulic behavior in Larrea was highly dynamic, ranging from partial isohydry to extreme anisohydry. Larrea exhibited extreme anisohydry under wet soil conditions corresponding to periods of high productivity, whereas partial isohydry was exhibited after prolonged dry or cold conditions, when productivity was low. Environmental conditions can strongly influence plant hydraulic behavior at relatively fast timescales, which enhances our understanding of plant drought responses. Although species may exhibit a dominant hydraulic behavior, variable environmental conditions can prompt plasticity in Ψ regulation, particularly for species in seasonally dry climates.
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Affiliation(s)
- Jessica S Guo
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Kevin R Hultine
- Department of Research, Conservation, and Collections, Desert Botanical Garden, Phoenix, AZ, 85008, USA
| | - George W Koch
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Heather Kropp
- Department of Geography, Colgate University, Hamilton, NY, 13346, USA
| | - Kiona Ogle
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, 86011, USA
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27
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McDowell NG, Brodribb TJ, Nardini A. Hydraulics in the 21 st century. THE NEW PHYTOLOGIST 2019; 224:537-542. [PMID: 31545889 DOI: 10.1111/nph.16151] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
| | - Timothy J Brodribb
- School of Biological Science, University of Tasmania, Hobart, TAS, Australia
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Trieste, Italy
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28
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Kannenberg SA, Novick KA, Alexander MR, Maxwell JT, Moore DJP, Phillips RP, Anderegg WRL. Linking drought legacy effects across scales: From leaves to tree rings to ecosystems. GLOBAL CHANGE BIOLOGY 2019; 25:2978-2992. [PMID: 31132225 DOI: 10.1111/gcb.14710] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/10/2019] [Accepted: 05/22/2019] [Indexed: 05/23/2023]
Abstract
Severe drought can cause lagged effects on tree physiology that negatively impact forest functioning for years. These "drought legacy effects" have been widely documented in tree-ring records and could have important implications for our understanding of broader scale forest carbon cycling. However, legacy effects in tree-ring increments may be decoupled from ecosystem fluxes due to (a) postdrought alterations in carbon allocation patterns; (b) temporal asynchrony between radial growth and carbon uptake; and (c) dendrochronological sampling biases. In order to link legacy effects from tree rings to whole forests, we leveraged a rich dataset from a Midwestern US forest that was severely impacted by a drought in 2012. At this site, we compiled tree-ring records, leaf-level gas exchange, eddy flux measurements, dendrometer band data, and satellite remote sensing estimates of greenness and leaf area before, during, and after the 2012 drought. After accounting for the relative abundance of tree species in the stand, we estimate that legacy effects led to ~10% reductions in tree-ring width increments in the year following the severe drought. Despite this stand-scale reduction in radial growth, we found that leaf-level photosynthesis, gross primary productivity (GPP), and vegetation greenness were not suppressed in the year following the 2012 drought. Neither temporal asynchrony between radial growth and carbon uptake nor sampling biases could explain our observations of legacy effects in tree rings but not in GPP. Instead, elevated leaf-level photosynthesis co-occurred with reduced leaf area in early 2013, indicating that resources may have been allocated away from radial growth in conjunction with postdrought upregulation of photosynthesis and repair of canopy damage. Collectively, our results indicate that tree-ring legacy effects were not observed in other canopy processes, and that postdrought canopy allocation could be an important mechanism that decouples tree-ring signals from GPP.
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Affiliation(s)
| | - Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University, Bloomington, Indiana
| | | | - Justin T Maxwell
- Department of Geography, Indiana University, Bloomington, Indiana
- Harvard Forest, Harvard University, Petersham, Massachusetts
| | - David J P Moore
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona
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29
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Novick KA, Konings AG, Gentine P. Beyond soil water potential: An expanded view on isohydricity including land-atmosphere interactions and phenology. PLANT, CELL & ENVIRONMENT 2019; 42:1802-1815. [PMID: 30632172 DOI: 10.1111/pce.13517] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 01/02/2019] [Accepted: 01/07/2019] [Indexed: 05/21/2023]
Abstract
Over the past decade, the concept of isohydry or anisohydry, which describes the link between soil water potential (ΨS ), leaf water potential (ΨL ), and stomatal conductance (gs ), has soared in popularity. However, its utility has recently been questioned, and a surprising lack of coordination between the dynamics of ΨL and gs across biomes has been reported. Here, we offer a more expanded view of the isohydricity concept that considers effects of vapour pressure deficit (VPD) and leaf area index (AL ) on the apparent sensitivities of ΨL and gs to drought. After validating the model with tree- and ecosystem-scale data, we find that within a site, isohydricity is a strong predictor of limitations to stomatal function, though variation in VPD and leaf area, among other factors, can challenge its diagnosis. Across sites, the theory predicts that the degree of isohydricity is a good predictor of the sensitivity of gs to declining soil water in the absence of confounding effects from other drivers. However, if VPD effects are significant, they alone are sufficient to decouple the dynamics of ΨL and gs entirely. We conclude with a set of practical recommendations for future applications of the isohydricity framework within and across sites.
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Affiliation(s)
- Kimberly A Novick
- School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, Indiana
| | - Alexandra G Konings
- Department of Earth System Science, Stanford University, Stanford, California
| | - Pierre Gentine
- Department of Earth and Environmental Engineering, Columbia University, New York, New York
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