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Zhang Y, Yue S, Gao Y, Zhao P, Liu M, Qiao Y, Xu S, Gu R, Zhang X, Zhou Y. Insights into response of seagrass (Zostera marina) to sulfide exposure at morphological, physiochemical and molecular levels in context of coastal eutrophication and warming. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39076032 DOI: 10.1111/pce.15048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 06/28/2024] [Indexed: 07/31/2024]
Abstract
Sulfide in sediment porewaters, is toxic to rooted macrophytes in both marine and freshwater environments. Current research on sulfide stress in seagrasses primarily focuses on morphological and physiological aspects, with little known about the molecular response and resistance mechanisms. This study first investigated the damage caused by sulfide to eelgrass (Zostera marina L.) using transcriptomic, metabolomic, and other physiological and biochemical indicators and explored the potential resistance of eelgrass at molecular level through laboratory simulated and in-situ sulfide stress experiments. Comprehensive results showed that sulfide stress severely inhibited the growth, photosynthesis, and antioxidant enzyme activities of eelgrass. Importantly, transcriptome analysis revealed significant activation of pathways related to carbohydrate and sulfur metabolism. This activation served a dual purpose: providing an energy source for eelgrass stress response and achieving detoxification through accelerated sulfur metabolism-a potential resistance mechanism. The toxicity of sulfide increased with rising temperature as evidenced by a decrease in EC50. Results from recovery experiments indicated that when Fv/Fm reduced to about 0 under sulfide stress, the growth and photosynthesis of eelgrass recovered to normal level after timely removal of sulfide. However, prolonged exposure to sulfide resulted in failure to recover, leading ultimately to plant death. This study not only enhances our understanding of the molecular-level impacts of sulfide on seagrasses but also provides guidance for the management and ecological restoration of seagrass meadows under sulfide stress.
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Affiliation(s)
- Yu Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
- Field Scientific Observation and Research Station of Yellow-Bohai Sea Temperate Seagrass Bed Ecosystems, Ministry of Natural Resources, Qingdao, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, China
| | - Shidong Yue
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
- Field Scientific Observation and Research Station of Yellow-Bohai Sea Temperate Seagrass Bed Ecosystems, Ministry of Natural Resources, Qingdao, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, China
| | - Yaping Gao
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Peng Zhao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Mingjie Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
- Field Scientific Observation and Research Station of Yellow-Bohai Sea Temperate Seagrass Bed Ecosystems, Ministry of Natural Resources, Qingdao, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, China
| | - Yongliang Qiao
- Qingdao University of Science and Technology, Qingdao, China
| | - Shaochun Xu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
- Field Scientific Observation and Research Station of Yellow-Bohai Sea Temperate Seagrass Bed Ecosystems, Ministry of Natural Resources, Qingdao, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, China
| | - Ruiting Gu
- East China Normal University, Shanghai, China
| | - Xiaomei Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
- Field Scientific Observation and Research Station of Yellow-Bohai Sea Temperate Seagrass Bed Ecosystems, Ministry of Natural Resources, Qingdao, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, China
| | - Yi Zhou
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, China
- Field Scientific Observation and Research Station of Yellow-Bohai Sea Temperate Seagrass Bed Ecosystems, Ministry of Natural Resources, Qingdao, China
- CAS Engineering Laboratory for Marine Ranching, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Province Key Laboratory of Experimental Marine Biology, Qingdao, China
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O'Connell BP, Wiley E. Heatwaves do not limit recovery following defoliation but alter leaf drought tolerance traits. PLANT, CELL & ENVIRONMENT 2024; 47:482-496. [PMID: 37877185 DOI: 10.1111/pce.14750] [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: 06/06/2023] [Revised: 09/20/2023] [Accepted: 10/16/2023] [Indexed: 10/26/2023]
Abstract
As heatwave frequency increases, they are more likely to coincide with other disturbances like insect defoliation. But it is unclear if high temperatures after defoliation impact canopy recovery or leaf traits which may affect response to further stressors like drought. To examine these stressor interactions, we subjected defoliated (DEF) and undefoliated (UNDEF) oak saplings to a simulated spring heatwave of +10°C for 25 days. We measured gas exchange, leaf area recovery, carbohydrate storage, turgor loss point (ΨTLP ), and minimum leaf conductance (gmin ). During the heatwave, stem respiration exhibited stronger thermal acclimation in DEF than UNDEF saplings, while stomatal conductance and net photosynthesis increased. The heatwave did not affect leaf area recovery or carbohydrate storage of DEF saplings, but reflush leaves had higher gmin than UNDEF leaves, and this was amplified by the heatwave. Across all treatments, higher gmin was associated with higher daytime stomatal conductance and a lower ΨTLP . The results suggest defoliation stress may not be exacerbated by higher temperatures. However, reflush leaves are less conservative in their water use, limiting their ability to minimise water loss. While lower ΨTLP could help DEF trees maintain gas exchange under mild drought, they may be more vulnerable to dehydration under severe drought.
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Affiliation(s)
| | - Erin Wiley
- Department of Biology, University of Central Arkansas, Conway, Arkansas, USA
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3
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Gong XW, Hao GY. The synergistic effect of hydraulic and thermal impairments accounts for the severe crown damage in Fraxinus mandshurica seedlings following the combined drought-heatwave stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159017. [PMID: 36167124 DOI: 10.1016/j.scitotenv.2022.159017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Drought combined with extreme heatwaves has been increasingly identified as the important trigger of worldwide tree mortality in the context of climate change; nonetheless, our understanding of the potential hydraulic and thermal impairments of hot droughts to trees and the subsequent post-recovery process remains limited. To investigate the response of tree water and carbon relations to drought, heatwave, and combined drought-heatwave stresses, three-year-old potted seedlings of Fraxinus mandshurica Rupr., a dominant tree species in temperate forests of northeast China, were grown under well-watered and drought-stressed conditions and exposed to a rapid, acute heatwave treatment. During the heatwave treatment with a maximum temperature exceeding 40 °C for two days, the leaf temperature of drought-stressed seedlings was, on average, 5 °C higher than that of well-watered counterparts due to less effective evaporative cooling, indicating that soil water availability influenced leaf thermoregulatory capacity during hot extremes. Consistently, more pronounced crown damage, as shown by 13 % irreversible leaf scorch, was found in seedlings under the drought-heatwave treatment relative to sole heatwave treatment, alongside the more severe stem xylem embolism and leaf electrolyte leakage. While the heatwave treatment accelerated the depletion of non-structural carbohydrates in drought-stressed seedlings, the increase of branch soluble sugar concentration in response to heatwave might be related to the requirement for maintaining hydraulic functioning via osmoregulation under high dehydration risk. The coordination between leaf stomatal conductance and total non-structural carbohydrate content during the post-heatwave recovery phase implied that plant-water relations and carbon physiology were closely coupled in coping with hot droughts. This study highlights that, under scenarios of aggravating drought co-occurring with heatwaves, tree seedlings could face a high risk of crown decline in relation to the synergistically increased hydraulic and thermal impairments.
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Affiliation(s)
- Xue-Wei Gong
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning Province, Shenyang 110016, China; Qingyuan Forest CERN, National Observation and Research Station, Liaoning Province, Shenyang 110016, China
| | - Guang-You Hao
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning Province, Shenyang 110016, China; Qingyuan Forest CERN, National Observation and Research Station, Liaoning Province, Shenyang 110016, China.
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Carter KR, Dickman LT. Recovery of seedling carbon balance despite hydraulic impairment following hot drought. TREE PHYSIOLOGY 2022; 42:1527-1531. [PMID: 35445728 DOI: 10.1093/treephys/tpac045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Affiliation(s)
- Kelsey R Carter
- Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - L Turin Dickman
- Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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Rehschuh R, Ruehr NK. Diverging responses of water and carbon relations during and after heat and hot drought stress in Pinus sylvestris. TREE PHYSIOLOGY 2022; 42:1532-1548. [PMID: 34740258 PMCID: PMC9366868 DOI: 10.1093/treephys/tpab141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Forests are increasingly affected by heatwaves, often co-occurring with drought, with consequences for water and carbon (C) cycling. However, our ability to project tree resilience to more intense hot droughts remains limited. Here, we used single tree chambers (n = 18) to investigate transpiration (E), net assimilation (Anet), root respiration (Rroot) and stem diameter change in Scots pine seedlings in a control treatment and during gradually intensifying heat or drought-heat stress (max. 42 °C), including recovery. Alongside this, we assessed indicators of stress impacts and recovery capacities. In the heat treatment, excessive leaf heating was mitigated via increased E, while under drought-heat, E ceased and leaf temperatures reached 46 °C. However, leaf electrolyte leakage was negligible, while light-adapted quantum yield of photosystem II (F'v/F'm) declined alongside Anet moderately in heat, but strongly in drought-heat seedlings, in which respiration exceeded C uptake. Drought-heat largely affected the hydraulic system as apparent in stem diameter shrinkage, declining relative needle water content (RWCNeedle) and water potential (ΨNeedle) reaching -2.7 MPa, alongside a 90% decline of leaf hydraulic conductance (KLeaf). Heat alone resulted in low functional impairment and all measured parameters recovered quickly. Contrary, following drought-heat, the recovery of KLeaf was incomplete and stem hydraulic conductivity (KS) was 25% lower than the control. However, F'v/F'm recovered and the tree net C balance reached control values 2 days post-stress, with stem increment rates accelerating during the second recovery week. This indicates a new equilibrium of C uptake and release in drought-heat seedlings independent of hydraulic impairment, which may slowly contribute to the repair of damaged tissues. In summary, Scots pine recovered rapidly following moderate heat stress, while combined with drought, hydraulic and thermal stress intensified, resulting in functional damage and slow recovery of hydraulic conductance. This incomplete hydraulic recovery could critically limit evaporative cooling capacities and C uptake under repeated heatwaves.
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Affiliation(s)
| | - Nadine K Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research-Atmospheric Environmental Research (KIT/IMK-IFU), Kreuzeckbahnstraße 19, 82467 Garmisch-Partenkirchen, Germany
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6
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Combining Spatial and Temporal Data to Create a Fine-Resolution Daily Urban Air Temperature Product from Remote Sensing Land Surface Temperature (LST) Data. ATMOSPHERE 2022. [DOI: 10.3390/atmos13071152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Remotely sensed land surface temperature (LST) is often used as a proxy for air temperature in urban heat island studies, particularly to illustrate relative temperature differences between locations. Two sensors are used predominantly in the literature, Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS). However, each has shortcomings that currently limit its utility for many urban applications. Landsat has high spatial resolution but low temporal resolution, and may miss hot days, while MODIS has high temporal resolution but low spatial resolution, which is inadequate to represent the fine grain heterogeneity in cities. In this paper, we overcome this inadequacy by combining high spatial frequency Environmental Services (ES), Landsat-driven Normalized Difference Vegetation Index (NDVI), and MODIS low spatial frequency background LST at different spatial frequency bands (spatial spectral composition). The method is able to provide fine scale LST four times daily on any day of the year. Using data from Paris in 2019 we show that (1) daytime cooling by vegetation reaches a maximum of 30 °C, above which there is no further increase in cooling. In addition, (2) the cooling is relatively local and does not extend further than 200 m beyond the boundary of the NBS. This model can be used to quantify the benefits of NBS in providing cooling in cities.
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Chowdhury FI, Arteaga C, Alam MS, Alam I, Resco de Dios V. Drivers of nocturnal stomatal conductance in C 3 and C 4 plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:151952. [PMID: 34843766 DOI: 10.1016/j.scitotenv.2021.151952] [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: 10/07/2021] [Revised: 11/17/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Nocturnal water losses were for long considered negligible, but it is now known that incomplete stomatal closure during the night leads to significant water losses at leaf, plant and ecosystem scales. However, only daytime transpiration is currently accounted for in evapotranspiration studies. Important uncertainties on the drivers of nocturnal water fluxes hinder its incorporation within modelling frameworks because some studies indicate that night-time stomatal drivers may differ from day-time responses. Here, we synthesise the studies on nocturnal stomatal conductance (gn) to determine underlying drivers through a systematic literature review and, whenever possible, meta-analytical techniques. Similar to daytime responses, we found negative effects of vapour pressure deficit, predawn water potential, air temperature, and salinity on gn across the plant species. However, the most apparent trend was an increase of gn from the beginning until the end of the night, indicating significant and widespread endogenous regulation by the circadian clock. We further observed how neither elevated CO2 nor nutrient status affected gn significantly across species. We also did not find any significant associations between gn and elevated ozone or increasing plant age. There was a paucity of studies on climatic extremes such heat waves and also few studies connected gn with anatomical features such as leaf specific area or stomatal density. Further studies are also needed to address the effects of plant sex, abscisic acid concentrations and genotypic variations on gn. Our findings solve the long-term conundrum on whether stomatal responses to daytime drivers are the same as those that during the nighttime.
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Affiliation(s)
- Faqrul Islam Chowdhury
- Institute of Forestry and Environmental Sciences, University of Chittagong, Chattogram 4331, Bangladesh; Erasmus Mundus Master Course in Mediterranean Forestry and Natural Resources Management, University of Lleida, Lleida, Spain.
| | - Carles Arteaga
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
| | - Mohammed Shafiul Alam
- Institute of Forestry and Environmental Sciences, University of Chittagong, Chattogram 4331, Bangladesh
| | - Iftakharul Alam
- Centre for Tropical Environmental and Sustainability Science, College of Science and Engineering, James Cook University, Cairns, Queensland 4878, Australia
| | - Víctor Resco de Dios
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain; School of Life Science and Engineering, Southwest University of Science and Technology, 621010 Mianyang, China; Joint Research Unit CTFC-AGROTECNIO-CERCA Center, Lleida, Spain
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Arain MA, Xu B, Brodeur JJ, Khomik M, Peichl M, Beamesderfer E, Restrepo-Couple N, Thorne R. Heat and drought impact on carbon exchange in an age-sequence of temperate pine forests. ECOLOGICAL PROCESSES 2022; 11:7. [PMID: 35127311 PMCID: PMC8786774 DOI: 10.1186/s13717-021-00349-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Most North American temperate forests are plantation or regrowth forests, which are actively managed. These forests are in different stages of their growth cycles and their ability to sequester atmospheric carbon is affected by extreme weather events. In this study, the impact of heat and drought events on carbon sequestration in an age-sequence (80, 45, and 17 years as of 2019) of eastern white pine (Pinus strobus L.) forests in southern Ontario, Canada was examined using eddy covariance flux measurements from 2003 to 2019. RESULTS Over the 17-year study period, the mean annual values of net ecosystem productivity (NEP) were 180 ± 96, 538 ± 177 and 64 ± 165 g C m-2 yr-1 in the 80-, 45- and 17-year-old stands, respectively, with the highest annual carbon sequestration rate observed in the 45-year-old stand. We found that air temperature (Ta) was the dominant control on NEP in all three different-aged stands and drought, which was a limiting factor for both gross ecosystem productivity (GEP) and ecosystems respiration (RE), had a smaller impact on NEP. However, the simultaneous occurrence of heat and drought events during the early growing seasons or over the consecutive years had a significant negative impact on annual NEP in all three forests. We observed a similar trend of NEP decline in all three stands over three consecutive years that experienced extreme weather events, with 2016 being a hot and dry, 2017 being a dry, and 2018 being a hot year. The youngest stand became a net source of carbon for all three of these years and the oldest stand became a small source of carbon for the first time in 2018 since observations started in 2003. However, in 2019, all three stands reverted to annual net carbon sinks. CONCLUSIONS Our study results indicate that the timing, frequency and concurrent or consecutive occurrence of extreme weather events may have significant implications for carbon sequestration in temperate conifer forests in Eastern North America. This study is one of few globally available to provide long-term observational data on carbon exchanges in different-aged temperate plantation forests. It highlights interannual variability in carbon fluxes and enhances our understanding of the responses of these forest ecosystems to extreme weather events. Study results will help in developing climate resilient and sustainable forestry practices to offset atmospheric greenhouse gas emissions and improving simulation of carbon exchange processes in terrestrial ecosystem models.
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Affiliation(s)
- M. Altaf Arain
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
| | - Bing Xu
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
- Department of Biological Sciences, University of Calgary, Alberta, Canada
| | - Jason J. Brodeur
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
| | - Myroslava Khomik
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
- Department of Geography and Environmental Management, University of Waterloo, Waterloo, ON Canada
| | - Matthias Peichl
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Eric Beamesderfer
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ USA
| | - Natalia Restrepo-Couple
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ USA
| | - Robin Thorne
- School of Earth, Environment and Society and McMaster Centre for Climate Change, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada
- Department of Geography, Wilfrid Laurier University, Waterloo, ON Canada
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Ahrens CW, Challis A, Byrne M, Leigh A, Nicotra AB, Tissue D, Rymer P. Repeated extreme heatwaves result in higher leaf thermal tolerances and greater safety margins. THE NEW PHYTOLOGIST 2021; 232:1212-1225. [PMID: 34292598 DOI: 10.1111/nph.17640] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
The frequency and severity of heatwave events are increasing, exposing species to conditions beyond their physiological limits. Species respond to heatwaves in different ways, however it remains unclear if plants have the adaptive capacity to successfully respond to hotter and more frequent heatwaves. We exposed eight tree populations from two climate regions grown under cool and warm temperatures to repeated heatwave events of moderate (40°C) and extreme (46°C) severity to assess adaptive capacity to heatwaves. Leaf damage and maximum quantum efficiency of photosystem II (Fv /Fm ) were significantly impacted by heatwave severity and growth temperatures, respectively; populations from a warm-origin avoided damage under moderate heatwaves compared to those from a cool-origin, indicating a degree of local adaptation. We found that plasticity to heatwave severity and repeated heatwaves contributed to enhanced thermal tolerance and lower leaf temperatures, leading to greater thermal safety margins (thermal tolerance minus leaf temperature) in a second heatwave. Notably, while we show that adaptation and physiological plasticity are important factors affecting plant adaptive capacity to thermal stress, plasticity of thermal tolerances and thermal safety margins provides the opportunity for trees to persist among fluctuating heatwave exposures.
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Affiliation(s)
- Collin W Ahrens
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Margaret Byrne
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, Locked Bag 104, Bentley, WA, 6983, Australia
| | - Andrea Leigh
- School of Life Sciences, University of Technology Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Adrienne B Nicotra
- Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Paul Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
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Birami B, Bamberger I, Ghirardo A, Grote R, Arneth A, Gaona-Colmán E, Nadal-Sala D, Ruehr NK. Heatwave frequency and seedling death alter stress-specific emissions of volatile organic compounds in Aleppo pine. Oecologia 2021; 197:939-956. [PMID: 33835242 PMCID: PMC8591014 DOI: 10.1007/s00442-021-04905-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 03/23/2021] [Indexed: 11/28/2022]
Abstract
Biogenic volatile organic compounds (BVOC) play important roles in plant stress responses and can serve as stress indicators. While the impacts of gradual environmental changes on BVOCs have been studied extensively, insights in emission responses to repeated stress and recovery are widely absent. Therefore, we studied the dynamics of shoot gas exchange and BVOC emissions in Pinus halepensis seedlings during an induced moderate drought, two four-day-long heatwaves, and the combination of drought and heatwaves. We found clear stress-specific responses of BVOC emissions. Reductions in acetone emissions with declining soil water content and transpiration stood out as a clear drought indicator. All other measured BVOC emissions responded exponentially to rising temperatures during heat stress (maximum of 43 °C), but monoterpenes and methyl salicylate showed a reduced temperature sensitivity during the second heatwave. We found that these decreases in monoterpene emissions between heatwaves were not reflected by similar declines in their internal storage pools. Because stress intensity was extremely severe, most of the seedlings in the heat-drought treatment died at the end of the second heatwave (dark respiration ceased). Interestingly, BVOC emissions (methanol, monoterpenes, methyl salicylate, and acetaldehyde) differed between dying and surviving seedlings, already well before indications of a reduced vitality became visible in gas exchange dynamics. In summary, we could clearly show that the dynamics of BVOC emissions are sensitive to stress type, stress frequency, and stress severity. Moreover, we found indications that stress-induced seedling mortality was preceded by altered methanol, monoterpene, and acetaldehyde emission dynamics.
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Affiliation(s)
- Benjamin Birami
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research-Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany. .,University of Bayreuth, Chair of Plant Ecology, Universitätsstraße 30, 95440, Bayreuth, Germany.
| | - Ines Bamberger
- University of Bayreuth, Bayreuth Center of Ecology and Environmental Research (BayCEER), Atmospheric Chemistry, Dr.-Hans-Frisch-Straße 1-3, 95448, Bayreuth, Germany
| | - Andrea Ghirardo
- Research Unit Environmental Simulation, Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Rüdiger Grote
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research-Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany
| | - Almut Arneth
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research-Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany
| | - Elizabeth Gaona-Colmán
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research-Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany
| | - Daniel Nadal-Sala
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research-Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany
| | - Nadine K Ruehr
- Karlsruhe Institute of Technology KIT, Institute of Meteorology and Climate Research-Atmospheric Environmental Research, 82467, Garmisch-Partenkirchen, Germany
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Qin H, Arteaga C, Chowdhury FI, Granda E, Yao Y, Han Y, Resco de Dios V. Radiation and Drought Impact Residual Leaf Conductance in Two Oak Species With Implications for Water Use Models. FRONTIERS IN PLANT SCIENCE 2020; 11:603581. [PMID: 33329674 PMCID: PMC7732681 DOI: 10.3389/fpls.2020.603581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/10/2020] [Indexed: 05/27/2023]
Abstract
Stomatal closure is one of the earliest responses to water stress but residual water losses may continue through the cuticle and incomplete stomatal closure. Residual conductance (g res ) plays a large role in determining time to mortality but we currently do not understand how do drought and shade interact to alter g res because the underlying drivers are largely unknown. Furthermore, g res may play an important role in models of water use, but the exact form in which g res should be incorporated into modeling schemes is currently being discussed. Here we report the results of a study where two different oak species were experimentally subjected to highly contrasting levels of drought (resulting in 0, 50 and 80% losses of hydraulic conductivity) and radiation (photosynthetic photon flux density at 1,500 μmol m-2 s-1 or 35-45 μmol m-2 s-1). We observed that the effects of radiation and drought were interactive and species-specific and g res correlated positively with concentrations of leaf non-structural carbohydrates and negatively with leaf nitrogen. We observed that different forms of measuring g res , based on either nocturnal conductance under high atmospheric water demand or on the water mass loss of detached leaves, exerted only a small influence on a model of stomatal conductance and also on a coupled leaf gas exchange model. Our results indicate that, while understanding the drivers of g res and the effects of different stressors may be important to better understand mortality, small differences in g res across treatments and measurements exert only a minor impact on stomatal models in two closely related species.
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Affiliation(s)
- Haiyan Qin
- School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Carles Arteaga
- Department of Crop and Forest Sciences, University of Lleida, Lleida, Spain
| | - Faqrul Islam Chowdhury
- Institute of Forestry and Environmental Sciences, University of Chittagong, Chattogram, Bangladesh
| | - Elena Granda
- Department of Life Sciences, University of Alcalá, Alcalá de Henares, Spain
| | - Yinan Yao
- School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Ying Han
- School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang, China
| | - Víctor Resco de Dios
- School of Life Sciences 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, Universitat de Lleida, Lleida, Spain
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Zhu L, Cernusak LA, Song X. Dynamic responses of gas exchange and photochemistry to heat interference during drought in wheat and sorghum. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:611-627. [PMID: 32393434 DOI: 10.1071/fp19242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 01/14/2020] [Indexed: 06/11/2023]
Abstract
Drought and heat stress significantly affect crop growth and productivity worldwide. It is unknown how heat interference during drought affects physiological processes dynamically in crops. Here we focussed on gas exchange and photochemistry in wheat and sorghum in response to simulated heat interference via +15°C of temperature during ~2 week drought and re-watering. Results showed that drought decreased net photosynthesis (Anet), stomatal conductance (gs), maximum velocity of ribulose-1, 5-bisphosphate carboxylase/oxygenase carboxylation (Vcmax) and electron transport rate (J) in both wheat and sorghum. Heat interference did not further reduce Anet or gs. Drought increased non-photochemical quenching (Φnpq), whereas heat interference decreased Φnpq. The δ13C of leaf, stem and roots was higher in drought-treated wheat but lower in drought-treated sorghum. The results suggest that (1) even under drought conditions wheat and sorghum increased or maintained gs for transpirational cooling to alleviate negative effects by heat interference; (2) non-photochemical quenching responded differently to drought and heat stress; (3) wheat and sorghum responded in opposing patterns in δ13C. These findings point to the importance of stomatal regulation under heat crossed with drought stress and could provide useful information on development of better strategies to secure crop production for future climate change.
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Affiliation(s)
- Lingling Zhu
- Shenzhen Key Laboratory of Marine Biological Resources and Ecological Environment, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; and Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Australia
| | - Xin Song
- Shenzhen Key Laboratory of Marine Biological Resources and Ecological Environment, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China; and Corresponding author.
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Dikšaitytė A, Viršilė A, Žaltauskaitė J, Januškaitienė I, Praspaliauskas M, Pedišius N. Do plants respond and recover from a combination of drought and heatwave in the same manner under adequate and deprived soil nutrient conditions? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 291:110333. [PMID: 31928679 DOI: 10.1016/j.plantsci.2019.110333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/25/2019] [Accepted: 11/03/2019] [Indexed: 06/10/2023]
Abstract
Extreme climatic conditions with extended drought periods and heatwaves are predicted to increase in frequency and severity in many regions of the world. Aside from this, other abiotic stress factors such as nutrient deficiency could pose a serious problem to plants when combined with other stressors resulting in more complex underpinning mechanisms. In the present study, we evaluated the response of Brassica napus to single and combined impacts of drought and heatwave (HW) under adequate or deprived (N-A and N-D) soil nutrient conditions. In addition, to get better insights in the plant response to combined stress, a post-stress period, pointing out a degree of the recovery after the cessation of stress, was also included. The results showed a different manner of single drought and heatwave action. The adverse effect of drought on leaf gas exchange was lagged on the growth and became more apparent only after recovery period with no obvious difference between different nutrient levels. Contrary, the growth response of nutrient-deprived plants to single HW was weak and in most cases, insignificant. Heatwave applied simultaneously with drought highly exacerbated the adverse effect of drought both under N-A and N-D conditions. Combined drought and heatwave stress resulted in the sharper decline of Asat and it was attributed to both stomatal and non-stomatal limitations. Interestingly, plants underwent combined drought and HW treatment under N-D conditions showed better aboveground growth recovery, compared to those grown under N-A conditions, while displayed far more diminished photochemistry of photosystem II and badly disturbed the C/N balance. This discrepancy came from the fact that soil nutrient deficiency, by itself, evoked strong stress under control climate conditions resulting in a dramatically slower aboveground growth of nutrient-deprived plant. In turn, although combined drought and HW stress had similar effect on the aboveground growth either under N-A or N-D conditions, the recovery of later one was better. These results highlight the necessity to look at plants' performance under unfavorable environmental conditions beyond the actual event, since it can be depended not only on the duration of exposure but also on the legacy effect after treatment.
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Affiliation(s)
- Austra Dikšaitytė
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, Kauno St. 30, LT-54333, Babtai, Kaunas Distr., Lithuania; Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT-44404, Kaunas, Lithuania.
| | - Akvilė Viršilė
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, Kauno St. 30, LT-54333, Babtai, Kaunas Distr., Lithuania
| | - Jūratė Žaltauskaitė
- Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT-44404, Kaunas, Lithuania
| | - Irena Januškaitienė
- Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT-44404, Kaunas, Lithuania
| | - Marius Praspaliauskas
- Lithuanian Energy Institute, Laboratory of Heat-Equipment Research and Testing, Breslaujos St. 3, LT-44403, Kaunas, Lithuania
| | - Nerijus Pedišius
- Lithuanian Energy Institute, Laboratory of Heat-Equipment Research and Testing, Breslaujos St. 3, LT-44403, Kaunas, Lithuania
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Xu B, Arain MA, Black TA, Law BE, Pastorello GZ, Chu H. Seasonal variability of forest sensitivity to heat and drought stresses: A synthesis based on carbon fluxes from North American forest ecosystems. GLOBAL CHANGE BIOLOGY 2020; 26:901-918. [PMID: 31529736 DOI: 10.1111/gcb.14843] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Climate extremes such as heat waves and droughts are projected to occur more frequently with increasing temperature and an intensified hydrological cycle. It is important to understand and quantify how forest carbon fluxes respond to heat and drought stress. In this study, we developed a series of daily indices of sensitivity to heat and drought stress as indicated by air temperature (Ta ) and evaporative fraction (EF). Using normalized daily carbon fluxes from the FLUXNET Network for 34 forest sites in North America, the seasonal pattern of sensitivities of net ecosystem productivity (NEP), gross ecosystem productivity (GEP) and ecosystem respiration (RE) in response to Ta and EF anomalies were compared for different forest types. The results showed that warm temperatures in spring had a positive effect on NEP in conifer forests but a negative impact in deciduous forests. GEP in conifer forests increased with higher temperature anomalies in spring but decreased in summer. The drought-induced decrease in NEP, which mostly occurred in the deciduous forests, was mostly driven by the reduction in GEP. In conifer forests, drought had a similar dampening effect on both GEP and RE, therefore leading to a neutral NEP response. The NEP sensitivity to Ta anomalies increased with increasing mean annual temperature. Drier sites were less sensitive to drought stress in summer. Natural forests with older stand age tended to be more resilient to the climate stresses compared to managed younger forests. The results of the Classification and Regression Tree analysis showed that seasons and ecosystem productivity were the most powerful variables in explaining the variation of forest sensitivity to heat and drought stress. Our results implied that the magnitude and direction of carbon flux changes in response to climate extremes are highly dependent on the seasonal dynamics of forests and the timing of the climate extremes.
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Affiliation(s)
- Bing Xu
- School of Geography and Earth Sciences and McMaster Centre for Climate Change, McMaster University, Hamilton, ON, Canada
| | - M Altaf Arain
- School of Geography and Earth Sciences and McMaster Centre for Climate Change, McMaster University, Hamilton, ON, Canada
| | - T Andrew Black
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
| | - Beverly E Law
- Department of Forest Ecosystems and Society, College of Forestry, Oregon State University, Corvallis, OR, USA
| | - Gilberto Z Pastorello
- Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Housen Chu
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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15
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Dikšaitytė A, Viršilė A, Žaltauskaitė J, Januškaitienė I, Juozapaitienė G. Growth and photosynthetic responses in Brassica napus differ during stress and recovery periods when exposed to combined heat, drought and elevated CO 2. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 142:59-72. [PMID: 31272036 DOI: 10.1016/j.plaphy.2019.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 05/23/2023]
Abstract
This study was intended to investigate how an agronomically important crop Brassica napus will be able to cope with the combined impact of a heatwave (21/14 °C vs. 33/26 °C day/night) and drought under ambient or elevated CO2 (800 vs. 400 μmol mol-1) and to what degree their recovery will be ensured after the stress, when additional CO2 is also removed. The obtained results revealed that, in the presence of an adequate water supply, B. napus performed well under heatwave conditions. However, drought fully negated all the advantages gained from hotter climate and led to a slower and incomplete recovery of gas exchange and retarded growth after the stress, regardless mitigating the effect of elevated CO2 during the stress. The mechanism by which the elevated CO2 diminished the adverse effect of a combined heat and drought stress on photosynthetic rate at saturating light (Asat) was attributed to the improved plant water relations. However, it had little effect on the recovery of Asat. In contrast, the mechanism by which photosynthesis was more impaired under the combination of heatwave and drought, compared to single drought treatment, was attributed mainly to the faster soil drying as well as faster and sharper decrease in stomatal conductance and subsequent in Ci/Ca. Keeping in mind that photosynthesis can acclimatize by downregulation to higher CO2, the results of this study, showing a weak memory of mitigating the effect of elevated CO2, highlight a potential risk of more intense and frequent heatwaves and droughts on B. napus.
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Affiliation(s)
- Austra Dikšaitytė
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, Kauno St. 30 Babtai, Kaunas Distr, LT54333, Lithuania; Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT44404, Kaunas, Lithuania.
| | - Akvilė Viršilė
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, Kauno St. 30 Babtai, Kaunas Distr, LT54333, Lithuania
| | - Jūratė Žaltauskaitė
- Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT44404, Kaunas, Lithuania
| | - Irena Januškaitienė
- Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT44404, Kaunas, Lithuania
| | - Gintarė Juozapaitienė
- Department of Environmental Sciences, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos St. 8, LT44404, Kaunas, Lithuania
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16
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Ruehr NK, Grote R, Mayr S, Arneth A. Beyond the extreme: recovery of carbon and water relations in woody plants following heat and drought stress. TREE PHYSIOLOGY 2019; 39:1285-1299. [PMID: 30924906 PMCID: PMC6703153 DOI: 10.1093/treephys/tpz032] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 01/08/2019] [Accepted: 03/13/2019] [Indexed: 05/19/2023]
Abstract
Plant responses to drought and heat stress have been extensively studied, whereas post-stress recovery, which is fundamental to understanding stress resilience, has received much less attention. Here, we present a conceptual stress-recovery framework with respect to hydraulic and metabolic functioning in woody plants. We further synthesize results from controlled experimental studies following heat or drought events and highlight underlying mechanisms that drive post-stress recovery. We find that the pace of recovery differs among physiological processes. Leaf water potential and abscisic acid concentration typically recover within few days upon rewetting, while leaf gas exchange-related variables lag behind. Under increased drought severity as indicated by a loss in xylem hydraulic conductance, the time for stomatal conductance recovery increases markedly. Following heat stress release, a similar delay in leaf gas exchange recovery has been observed, but the reasons are most likely a slow reversal of photosynthetic impairment and other temperature-related leaf damages, which typically manifest at temperatures above 40 °C. Based thereon, we suggest that recovery of gas exchange is fast following mild stress, while recovery is slow and reliant on the efficiency of repair and regrowth when stress results in functional impairment and damage to critical plant processes. We further propose that increasing stress severity, particular after critical stress levels have been reached, increases the carbon cost involved in reestablishing functionality. This concept can guide future experimental research and provides a base for modeling post-stress recovery of carbon and water relations in trees.
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Affiliation(s)
- Nadine K Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research—Atmospheric Environmental Research (KIT/IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Rüdiger Grote
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research—Atmospheric Environmental Research (KIT/IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Stefan Mayr
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Almut Arneth
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research—Atmospheric Environmental Research (KIT/IMK-IFU), Garmisch-Partenkirchen, Germany
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17
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Aspinwall MJ, Pfautsch S, Tjoelker MG, Vårhammar A, Possell M, Drake JE, Reich PB, Tissue DT, Atkin OK, Rymer PD, Dennison S, Van Sluyter SC. Range size and growth temperature influence Eucalyptus species responses to an experimental heatwave. GLOBAL CHANGE BIOLOGY 2019; 25:1665-1684. [PMID: 30746837 DOI: 10.1111/gcb.14590] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/03/2019] [Accepted: 02/04/2019] [Indexed: 05/24/2023]
Abstract
Understanding forest tree responses to climate warming and heatwaves is important for predicting changes in tree species diversity, forest C uptake, and vegetation-climate interactions. Yet, tree species differences in heatwave tolerance and their plasticity to growth temperature remain poorly understood. In this study, populations of four Eucalyptus species, two with large range sizes and two with comparatively small range sizes, were grown under two temperature treatments (cool and warm) before being exposed to an equivalent experimental heatwave. We tested whether the species with large and small range sizes differed in heatwave tolerance, and whether trees grown under warmer temperatures were more tolerant of heatwave conditions than trees grown under cooler temperatures. Visible heatwave damage was more common and severe in the species with small rather than large range sizes. In general, species that showed less tissue damage maintained higher stomatal conductance, lower leaf temperatures, larger increases in isoprene emissions, and less photosynthetic inhibition than species that showed more damage. Species exhibiting more severe visible damage had larger increases in heat shock proteins (HSPs) and respiratory thermotolerance (Tmax ). Thus, across species, increases in HSPs and Tmax were positively correlated, but inversely related to increases in isoprene emissions. Integration of leaf gas-exchange, isoprene emissions, proteomics, and respiratory thermotolerance measurements provided new insight into mechanisms underlying variability in tree species heatwave tolerance. Importantly, warm-grown seedlings were, surprisingly, more susceptible to heatwave damage than cool-grown seedlings, which could be associated with reduced enzyme concentrations in leaves. We conclude that species with restricted range sizes, along with trees growing under climate warming, may be more vulnerable to heatwaves of the future.
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Affiliation(s)
- Michael J Aspinwall
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Department of Biology, University of North Florida, Jacksonville, Florida
| | - Sebastian Pfautsch
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Mark G Tjoelker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Angelica Vårhammar
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Malcolm Possell
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - John E Drake
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Forest and Natural Resources Management, SUNY-ESF, Syracuse, New York
| | - Peter B Reich
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- Department of Forest Resources, University of Minnesota, Minnesota
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Owen K Atkin
- Division of Plant Sciences, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Paul D Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Siobhan Dennison
- Department of Biological Science, Macquarie University, North Ryde, NSW, Australia
| | - Steven C Van Sluyter
- Department of Biological Science, Macquarie University, North Ryde, NSW, Australia
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18
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Duursma RA, Blackman CJ, Lopéz R, Martin-StPaul NK, Cochard H, Medlyn BE. On the minimum leaf conductance: its role in models of plant water use, and ecological and environmental controls. THE NEW PHYTOLOGIST 2019; 221:693-705. [PMID: 30144393 DOI: 10.1111/nph.15395] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/15/2018] [Indexed: 05/22/2023]
Abstract
Contents Summary 693 I. Introduction 693 II. Comparison of various definitions and measurement techniques of minimum conductance 694 III. Cuticular conductance 695 IV. Contribution of stomata 696 V. Environmental and ecological variation in minimum conductance 696 VI. Use of minimum conductance in models 698 VII. Conclusions 703 Acknowledgements 703 References 703 SUMMARY: When the rate of photosynthesis is greatly diminished, such as during severe drought, extreme temperature or low light, it seems advantageous for plants to close stomata and completely halt water loss. However, water loss continues through the cuticle and incompletely closed stomata, together constituting the leaf minimum conductance (gmin ). In this review, we critically evaluate the sources of variation in gmin , quantitatively compare various methods for its estimation, and illustrate the role of gmin in models of leaf gas exchange. A literature compilation of gmin as measured by the weight loss of detached leaves is presented, which shows much variation in this trait, which is not clearly related to species groups, climate of origin or leaf type. Much evidence points to the idea that gmin is highly responsive to the growing conditions of the plant, including soil water availability, temperature and air humidity - as we further demonstrate with two case studies. We pay special attention to the role of the minimum conductance in the Ball-Berry model of stomatal conductance, and caution against the usual regression-based method for its estimation. The synthesis presented here provides guidelines for the use of gmin in ecosystem models, and points to clear research gaps for this drought tolerance trait.
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Affiliation(s)
- Remko A Duursma
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
| | - Christopher J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
| | - Rosana Lopéz
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
- Université Clermont-Auvergne, INRA, PIAF, 63000, Clermont-Ferrand, France
| | | | - Hervé Cochard
- Université Clermont-Auvergne, INRA, PIAF, 63000, Clermont-Ferrand, France
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
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19
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Effects of a Heat Wave on Nocturnal Stomatal Conductance in Eucalyptus camaldulensis. FORESTS 2018. [DOI: 10.3390/f9060319] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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