1
|
Kim D, Guadagno CR, Ewers BE, Mackay DS. Combining PSII photochemistry and hydraulics improves predictions of photosynthesis and water use from mild to lethal drought. PLANT, CELL & ENVIRONMENT 2024; 47:1255-1268. [PMID: 38178610 DOI: 10.1111/pce.14806] [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: 02/04/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024]
Abstract
Rising temperatures and increases in drought negatively impact the efficiency and sustainability of both agricultural and forest ecosystems. Although hydraulic limitations on photosynthesis have been extensively studied, a solid understanding of the links between whole plant hydraulics and photosynthetic processes at the cellular level under changing environmental conditions is still missing, hampering our predictive power for plant mortality. Here, we examined plant hydraulic traits and CO2 assimilation rate under progressive water limitation by implementing Photosystem II (PSII) dynamics with a whole plant process model (TREES). The photosynthetic responses to plant water status were parameterized based on measurements of chlorophyll a fluorescence, gas exchange and water potential for Brassica rapa (R500) grown in a greenhouse under fully watered to lethal drought conditions. The updated model significantly improved predictions of photosynthesis, stomatal conductance and leaf water potential. TREES with PSII knowledge predicted a larger hydraulic safety margin and a decrease in percent loss of conductivity. TREES predicted a slower decrease in leaf water potential, which agreed with measurements. Our results highlight the pressing need for incorporating PSII drought photochemistry into current process models to capture cross-scale plant water dynamics from cell to whole plant level.
Collapse
Affiliation(s)
- Dohyoung Kim
- Department of Geography, State University of New York at Buffalo, Buffalo, New York, USA
| | | | - Brent E Ewers
- Department of Botany, University of Wyoming, Laramie, Wyoming, USA
| | - D Scott Mackay
- Department of Geography, State University of New York at Buffalo, Buffalo, New York, USA
| |
Collapse
|
2
|
Popa A, van der Maaten E, Popa I, van der Maaten-Theunissen M. Early warning signals indicate climate change-induced stress in Norway spruce in the Eastern Carpathians. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169167. [PMID: 38072249 DOI: 10.1016/j.scitotenv.2023.169167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/22/2023] [Accepted: 12/05/2023] [Indexed: 12/22/2023]
Abstract
Climate change is affecting forest ecosystems globally, in particular through warming as well as increases in the frequency and intensity of extreme events. Norway spruce (Picea abies (L.) Karst.) is one of the most important coniferous tree species in Europe. In recent extremely dry years in Central Europe, spruce suffered and large dieback has been observed. In parts of Eastern Europe, however, no large-scale decline in spruce has been reported so far, though anticipated changes in climate pose the question how the future of these forests may look like. To assess the current state of spruce forests in Eastern Europe, we established a tree-ring network consisting of 157 Norway spruce chronologies (from >3000 trees) of different ages distributed along elevational transects in the Eastern Carpathians, Romania. We evaluated early warning signals of climate change-induced stress, i.e. (1) growth decline, (2) increased sensitivity of tree growth (assessed over the statistics first-order autocorrelation and standard deviation), and (3) increased growth synchrony. A pronounced growth decline was observed over the last two decades, which was strongest in younger stands and at lower elevations. However, growth sensitivity and synchrony did not show consistent patterns, suggesting that forest decline may not be immediately imminent. Overall, our findings highlight an increased vulnerability of spruce in the Eastern Carpathians. With ongoing climate change, spruce dieback may be expected in this part of Europe as well.
Collapse
Affiliation(s)
- Andrei Popa
- National Institute for Research and Development in Forestry 'Marin Dracea', Bucharest, Romania; Faculty of Silviculture and Forest Engineering, Transilvania University of Brasov, Brasov, Romania.
| | | | - Ionel Popa
- National Institute for Research and Development in Forestry 'Marin Dracea', Bucharest, Romania; Center for Mountain Economy (CE-MONT), Vatra Dornei, Romania
| | | |
Collapse
|
3
|
Paligi SS, Link RM, Isasa E, Bittencourt P, Cabral JS, Jansen S, Oliveira RS, Pereira L, Schuldt B. Assessing the agreement between the pneumatic and the flow-centrifuge method for estimating xylem safety in temperate diffuse-porous tree species. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:1171-1185. [PMID: 37703535 DOI: 10.1111/plb.13573] [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: 03/16/2023] [Accepted: 07/06/2023] [Indexed: 09/15/2023]
Abstract
The increasing frequency of global change-type droughts has created a need for fast, accurate and widely applicable techniques for estimating xylem embolism resistance to improve forecasts of future forest changes. We used data from 12 diffuse-porous temperate tree species covering a wide range of xylem safety to compare the pneumatic and flow-centrifuge method, two rapid methods used for constructing xylem vulnerability curves. We evaluated the agreement between parameters estimated with both methods and the sensitivity of pneumatic measurements to the duration of air discharge (AD) measurements. There was close agreement between xylem water potentials at 50% air discharged (PAD), estimated with the Pneumatron, and 50% loss of hydraulic conductivity (PLC), estimated with the flow-centrifuge method (mean signed deviation: 0.12 MPa, Pearson correlation: 0.96 after 15 s of gas extraction). However, the relationship between the estimated slopes was more variable, resulting in lower agreement in the xylem water potential at 12% and 88% PAD/PLC. The agreement between the two methods was not affected by species-specific vessel length distributions. All pneumatic parameters were sensitive to AD time. Overall agreement was highest at relatively short AD times, with an optimum at 16 s. Our results highlight the value of the Pneumatron as an easy and reliable tool to estimate 50% embolism thresholds for a wide range of diffuse-porous temperate angiosperms. Further, our study provides a set of useful metrics for methodological comparisons of vulnerability curves in terms of systematic and random deviations, as well as overall agreement.
Collapse
Affiliation(s)
- S S Paligi
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - R M Link
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| | - E Isasa
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
| | - P Bittencourt
- College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - J S Cabral
- Ecosystem Modeling Group, Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - S Jansen
- Institute of Botany, Ulm University, Ulm, Germany
| | - R S Oliveira
- Department of Plant Biology, Instituto de Biologia, University of Campinas, Campinas, SP, Brazil
| | - L Pereira
- Institute of Botany, Ulm University, Ulm, Germany
| | - B Schuldt
- Chair of Ecophysiology and Vegetation Ecology, Julius-von-Sachs Institute of Biological Sciences, University of Würzburg, Würzburg, Germany
- Chair of Forest Botany, Institute of Forest Botany and Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| |
Collapse
|
4
|
Ping J, Cui E, Du Y, Wei N, Zhou J, Wang J, Niu S, Luo Y, Xia J. Enhanced causal effect of ecosystem photosynthesis on respiration during heatwaves. SCIENCE ADVANCES 2023; 9:eadi6395. [PMID: 37878695 PMCID: PMC10599625 DOI: 10.1126/sciadv.adi6395] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/21/2023] [Indexed: 10/27/2023]
Abstract
Because of global warming, Earth's ecosystems have been experiencing more frequent and severe heatwaves. Heatwaves are expected to tip terrestrial carbon sequestration by elevating ecosystem respiration and suppressing gross primary productivity (GPP). Here, using the convergent cross-mapping technique, this study detected positive bidirectional causal effects between GPP and respiration in two unprecedented European heatwaves. Heatwaves enhanced the causal effect strength of GPP on respiration rather than respiration on GPP across 40 site-years of observations. Further analyses and global simulations revealed spatial heterogeneity in the heatwave response of the causal link strength between GPP and respiration, which was jointly driven by the local climate and vegetation properties. However, the causal effect strength of GPP on respiration showed considerable uncertainties in CMIP6 models. This study reveals an enhanced causal link strength between GPP and respiration during heatwaves, shedding light on improving projections for terrestrial carbon sink dynamics under future climate extremes.
Collapse
Affiliation(s)
- Jiaye Ping
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Erqian Cui
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Ying Du
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Ning Wei
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Jian Zhou
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- School of Integrative Plant Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Jing Wang
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| | - Shuli Niu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Yiqi Luo
- School of Integrative Plant Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14850, USA
| | - Jianyang Xia
- Zhejiang Tiantong Forest Ecosystem National Observation and Research Station, State Key Laboratory of Estuarine and Coastal Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
- Research Center for Global Change and Complex Ecosystems, Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Bi MH, Jiang C, Brodribb T, Yang YJ, Yao GQ, Jiang H, Fang XW. Ethylene constrains stomatal reopening in Fraxinus chinensis post moderate drought. TREE PHYSIOLOGY 2023; 43:883-892. [PMID: 36547259 DOI: 10.1093/treephys/tpac144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 12/01/2022] [Accepted: 12/11/2022] [Indexed: 06/11/2023]
Abstract
Clarifying the mechanisms underlying the recovery of gas exchange following drought is the key to providing insights into plant drought adaptation and habitat distribution. However, the mechanisms are still largely unknown. Targeting processes known to inhibit gas exchange during drought recovery, we measured leaf water potential, the leaf hydraulic conductance, stomatal reopening, abscisic acid (ABA) and the ethylene emission rate (EER) following moderate drought stress in seedlings of the globally pervasive woody tree Fraxinus chinensis. We found strong evidence that the slow stomatal reopening after rehydration is regulated by a slow decrease in EER, rather than changes in leaf hydraulics or foliar ABA levels. This was supported by evidence of rapid gas exchange recovery in plants after treatment with the ethylene antagonist 1-methylcyclopropene. These findings provide evidence to rigorously support ethylene as a key factor constraining stomatal reopening from moderate drought directly, thereby potentially opening new windows for understanding species drought adaptation.
Collapse
Affiliation(s)
- Min-Hui Bi
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Chao Jiang
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Timothy Brodribb
- School of Biological Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Yu-Jie Yang
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Guang-Qian Yao
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Hui Jiang
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| | - Xiang-Wen Fang
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China
| |
Collapse
|
7
|
Férriz M, Martin-Benito D, Fernández-de-Simón MB, Conde M, García-Cervigón AI, Aranda I, Gea-Izquierdo G. Functional phenotypic plasticity mediated by water stress and [CO2] explains differences in drought tolerance of two phylogenetically close conifers. TREE PHYSIOLOGY 2023; 43:909-924. [PMID: 36809504 PMCID: PMC10255776 DOI: 10.1093/treephys/tpad021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/15/2023] [Indexed: 06/11/2023]
Abstract
Forests are threatened globally by increased recurrence and intensity of hot droughts. Functionally close coexisting species may exhibit differences in drought vulnerability large enough to cause niche differentiation and affect forest dynamics. The effect of rising atmospheric [CO2], which could partly alleviate the negative effects of drought, may also differ between species. We analysed functional plasticity in seedlings of two taxonomically close pine species (Pinus pinaster Ait., Pinus pinea L.) under different [CO2] and water stress levels. The multidimensional functional trait variability was more influenced by water stress (preferentially xylem traits) and [CO2] (mostly leaf traits) than by differences between species. However, we observed differences between species in the strategies followed to coordinate their hydraulic and structural traits under stress. Leaf 13C discrimination decreased with water stress and increased under elevated [CO2]. Under water stress both species increased their sapwood area to leaf area ratios, tracheid density and xylem cavitation, whereas they reduced tracheid lumen area and xylem conductivity. Pinus pinea was more anisohydric than P. pinaster. Pinus pinaster produced larger conduits under well-watered conditions than P. pinea. Pinus pinea was more tolerant to water stress and more resistant to xylem cavitation under low water potentials. The higher xylem plasticity in P. pinea, particularly in tracheid lumen area, expressed a higher capacity of acclimation to water stress than P. pinaster. In contrast, P. pinaster coped with water stress comparatively more by increasing plasticity of leaf hydraulic traits. Despite the small differences observed in the functional response to water stress and drought tolerance between species, these interspecific differences agreed with ongoing substitution of P. pinaster by P. pinea in forests where both species co-occur. Increased [CO2] had little effect on the species-specific relative performance. Thus, a competitive advantage under moderate water stress of P. pinea compared with P. pinaster is expected to continue in the future.
Collapse
Affiliation(s)
- M Férriz
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - D Martin-Benito
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | | | - M Conde
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - A I García-Cervigón
- Department of Biology and Geology, Physics and Inorganic Chemistry Rey Juan Carlos University, c/Tulipán s/n, 28933 Móstoles, Spain
| | - I Aranda
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| | - G Gea-Izquierdo
- ICIFOR-INIA, CSIC. Ctra La Coruña km 7.5, 28040 Madrid, Spain
| |
Collapse
|
8
|
Pinto JR, Sloan JL, Ervan G, Burney OT. Physiological and morphological responses of Pinus ponderosa seedlings to moisture limitations in the nursery and their implications for restoration. FRONTIERS IN PLANT SCIENCE 2023; 14:1127656. [PMID: 37235020 PMCID: PMC10206177 DOI: 10.3389/fpls.2023.1127656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/31/2023] [Indexed: 05/28/2023]
Abstract
Successful establishment of Pinus ponderosa seedlings in the southwestern United States is often limited by stressful and harsh site conditions related to drought severity and severe disturbances such as wildfire and mining operations. Seedling quality has an important influence on outplanting performance, but nursery practices that typically employ optimal growing environments may also be limiting seedling morphological and physiological performance on stressful outplanting sites. To address this, a study was established to test alterations in seedling characteristics subjected to irrigation limitations during nursery culture and their subsequent outplanting performance. This study was conducted as two separate experiments: (1) a nursery conditioning experiment examined seedling development of three New Mexico seed sources exposed to three irrigation levels (low, moderate, and high); (2) a simulated outplanting experiment examined a subset of the seedlings from experiment 1 in a controlled outplanting environment consisting of two soil moisture conditions (mesic, maintained via irrigation and dry, irrigated only once). In the nursery study, the lack of interactions between seed source and irrigation main effects for most response variables indicate that low irrigation treatment level responses were consistent across a range of sources. Irrigation treatment levels from the nursery resulted in few morphological differences; however, the low irrigation level increased physiological parameters such as net photosynthetic rate and water use efficiency. In the simulated outplanting experiment, seedlings subjected to less irrigation in the nursery had greater mean height, diameter, needle dry mass, and stem dry mass; additionally, low irrigation levels in the nursery increased the amount of hydraulically active xylem and xylem flow velocity. Overall, this study shows that nursery culture irrigation limitations, regardless of the seed sources tested, can improve seedling morphology and physiological functioning under simulated dry outplanting conditions. This may ultimately translate to increased survival and growth performance on harsh outplanting sites.
Collapse
Affiliation(s)
- Jeremiah R. Pinto
- Rocky Mountain Research Station, United States Forest Service, Moscow, ID, United States
| | - Joshua L. Sloan
- Department of Forestry, New Mexico Highlands University, Las Vegas, NM, United States
| | - Gokhan Ervan
- John T. Harrington Forestry Research Center, New Mexico State University, Mora, NM, United States
| | - Owen T. Burney
- John T. Harrington Forestry Research Center, New Mexico State University, Mora, NM, United States
| |
Collapse
|
9
|
Xu H, Zhang Z, Oren R, Wu X. Hyposensitive canopy conductance renders ecosystems vulnerable to meteorological droughts. GLOBAL CHANGE BIOLOGY 2023; 29:1890-1904. [PMID: 36655411 DOI: 10.1111/gcb.16607] [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: 05/31/2022] [Revised: 01/07/2023] [Accepted: 01/11/2023] [Indexed: 05/28/2023]
Abstract
Increased meteorological drought intensity with rising atmospheric demand for water (hereafter vapor pressure deficit [VPD]) increases the risk of tree mortality and ecosystem dysfunction worldwide. Ecosystem-scale water-use strategy is increasingly recognized as a key factor in regulating drought-related ecosystem responses. However, the link between water-use strategy and ecosystem vulnerability to meteorological droughts is poorly established. Using the global flux observations, historic hydroclimatic data, remote-sensing products, and plant functional-trait archive, we identified potentially vulnerable ecosystems, examining how ecosystem water-use strategy, quantified by the percentage bias (δ) of the empirical canopy conductance sensitivity to VPD relative to the theoretical value, mediated ecosystem responses to droughts. We found that prevailing soil water availability substantially impacted δ in dryland regions where ecosystems with insufficient soil moisture usually showed conservative water-use strategy, while ecosystems in humid regions exhibited more pronounced climatic adaptability. Hyposensitive and hypersensitive ecosystems, classified based on δ falling below or above the theoretical sensitivity, respectively, achieved similar net ecosystem productivity during droughts, employing different structural and functional strategies. However, hyposensitive ecosystems, risking their hydraulic system with a permissive water-use strategy, were unable to recover from droughts as quickly as hypersensitive ones. Our findings highlight that processed-based models predicting current functions and future performance of vegetation should account for the greater vulnerability of hyposensitive ecosystems to intensifying atmospheric and soil droughts.
Collapse
Affiliation(s)
- Hang Xu
- Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Zhiqiang Zhang
- Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| | - Ram Oren
- Nicholas School of the Environment and Pratt School of Engineering, Duke University, North Carolina, Durham, USA
- Department of Forest Science, University of Helsinki, Helsinki, Finland
| | - Xiaoyun Wu
- Jixian National Forest Ecosystem Observation and Research Station, CNERN, School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
- Key Laboratory of Soil and Water Conservation and Desertification Combating, State Forestry and Grassland Administration, Beijing Forestry University, Beijing, China
| |
Collapse
|
10
|
Li Z, Wang C, Luo D, Hou E, Ibrahim MM. Leaf-branch vulnerability segmentation occurs all year round for three temperate evergreen tree species. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 197:107658. [PMID: 37001301 DOI: 10.1016/j.plaphy.2023.107658] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/01/2023] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
Vulnerability segmentation (VS) and Hydraulic segmentation (HS) hypotheses propose higher hydraulic resistance and vulnerability to embolism in leaves than in branches, respectively. The VS and HS are suggested as an acclimation strategy of trees to drought stress, but whether they occur during freezing stress has rarely been explored. We measured the leaf and branch hydraulic traits of three temperate evergreen tree species [Picea koraiensis (Korean spruce), Pinus koraiensis (Korean pine), and Pinus sylvestris var. mongolica (Mongolian pine)] during four seasons (winter, spring, summer, and autumn) across the year. We assessed the applicability of VS and HS all year round, particularly in winter. The water potential at which leaf hydraulic conductance lost 50% (P50L), was more negative in winter than in summer, while higher leaf mass per area was obtained in winter. These results suggest that these species invest more carbon into leaf (including hydraulic systems) to acclimate to winter frost drought. Leaf and branch hydraulic conductance (KmL and KmB) were lower, and the percentage loss of branch hydraulic conductance (PLCB) was higher in spring than in autumn. These results were probably because of more freeze-thaw cycles in spring (69 cycles) than in autumn (37 cycles). The water potential at which branch hydraulic conductance lost 50%, P50B, was more negative than P50L across the year. The values of VS (P50L minus P50B) were positive, i.e. leaf was more vulnerable than the branch in all species and across seasons, with higher values occurring in spring or autumn. However, KmL positively correlated with KmB, suggesting hydraulic coordination between leaf and branch, but did not support HS. Our findings indicate that leaf-branch vulnerability segmentation can occur all year round, including freezing stress, to protect branches from hydraulic failure in temperate evergreen conifers.
Collapse
Affiliation(s)
- Zhimin Li
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China; Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
| | - Chuankuan Wang
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China
| | - Dandan Luo
- Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, 150040, China
| | - Enqing Hou
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Muhammed Mustapha Ibrahim
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Tai X, Trugman AT, Anderegg WRL. Linking remotely sensed ecosystem resilience with forest mortality across the continental United States. GLOBAL CHANGE BIOLOGY 2023; 29:1096-1105. [PMID: 36468232 DOI: 10.1111/gcb.16529] [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: 08/13/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 06/17/2023]
Abstract
Episodes of forest mortality have been observed worldwide associated with climate change, impacting species composition and ecosystem services such as water resources and carbon sequestration. Yet our ability to predict forest mortality remains limited, especially across large scales. Time series of satellite imagery has been used to document ecosystem resilience globally, but it is not clear how well remotely sensed resilience can inform the prediction of forest mortality across continental, multi-biome scales. Here, we leverage forest inventories across the continental United States to systematically assess the potential of ecosystem resilience derived using different data sets and methods to predict forest mortality. We found high resilience was associated with low mortality in eastern forests but was associated with high mortality in western regions. The unexpected resilience-mortality relation in western United States may be due to several factors including plant trait acclimation, insect population dynamics, or resource competition. Overall, our results not only supported the opportunity to use remotely sensed ecosystem resilience to predict forest mortality but also highlighted that ecological factors may have crucial influences because they can reverse the sign of the resilience-mortality relationships.
Collapse
Affiliation(s)
- Xiaonan Tai
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, New Jersey, USA
| | - Anna T Trugman
- Department of Geography, University of California Santa Barbara, Santa Barbara, California, USA
| | - William R L Anderegg
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA
- Wilkes Center for Climate Science and Policy, University of Utah, Salt Lake City, Utah, USA
| |
Collapse
|
13
|
Losso A, Challis A, Gauthey A, Nolan RH, Hislop S, Roff A, Boer MM, Jiang M, Medlyn BE, Choat B. Canopy dieback and recovery in Australian native forests following extreme drought. Sci Rep 2022; 12:21608. [PMID: 36517498 PMCID: PMC9751299 DOI: 10.1038/s41598-022-24833-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 11/21/2022] [Indexed: 12/15/2022] Open
Abstract
In 2019, south-eastern Australia experienced its driest and hottest year on record, resulting in massive canopy dieback events in eucalypt dominated forests. A subsequent period of high precipitation in 2020 provided a rare opportunity to quantify the impacts of extreme drought and consequent recovery. We quantified canopy health and hydraulic impairment (native percent loss of hydraulic conductivity, PLC) of 18 native tree species growing at 15 sites that were heavily impacted by the drought both during and 8-10 months after the drought. Most species exhibited high PLC during drought (PLC:65.1 ± 3.3%), with no clear patterns across sites or species. Heavily impaired trees (PLC > 70%) showed extensive canopy browning. In the post-drought period, most surviving trees exhibited hydraulic recovery (PLC:26.1 ± 5.1%), although PLC remained high in some trees (50-70%). Regained hydraulic function (PLC < 50%) corresponded to decreased canopy browning indicating improved tree health. Similar drought (37.1 ± 4.2%) and post-drought (35.1 ± 4.4%) percentages of basal area with dead canopy suggested that trees with severely compromised canopies immediately after drought were not able to recover. This dataset provides insights into the impacts of severe natural drought on the health of mature trees, where hydraulic failure is a major contributor in canopy dieback and tree mortality during extreme drought events.
Collapse
Affiliation(s)
- Adriano Losso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
- Department of Botany, University of Innsbruck, Sternwartestraße 15, 6020, Innsbruck, Austria.
| | - Anthea Challis
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Plant Ecology Research Laboratory PERL, Ecole Polytechnique Fédérale de Lausanne EPFL, 1015, Lausanne, Switzerland
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
| | - Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Samuel Hislop
- Forest Science, NSW Department of Primary Industries, Parramatta, NSW, 2150, Australia
| | - Adam Roff
- Department of Planning, Industry and Environment, Remote Sensing and Landscape Science, 26 Honeysuckle Drive, Newcastle, NSW, 2302, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- NSW Bushfire Risk Management Research Hub, Wollongong, NSW, Australia
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- College of Life Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou, Zhejiang, China
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
| |
Collapse
|
14
|
McDowell NG, Ball M, Bond‐Lamberty B, Kirwan ML, Krauss KW, Megonigal JP, Mencuccini M, Ward ND, Weintraub MN, Bailey V. Processes and mechanisms of coastal woody-plant mortality. GLOBAL CHANGE BIOLOGY 2022; 28:5881-5900. [PMID: 35689431 PMCID: PMC9544010 DOI: 10.1111/gcb.16297] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 05/24/2022] [Indexed: 05/26/2023]
Abstract
Observations of woody plant mortality in coastal ecosystems are globally widespread, but the overarching processes and underlying mechanisms are poorly understood. This knowledge deficiency, combined with rapidly changing water levels, storm surges, atmospheric CO2 , and vapor pressure deficit, creates large predictive uncertainty regarding how coastal ecosystems will respond to global change. Here, we synthesize the literature on the mechanisms that underlie coastal woody-plant mortality, with the goal of producing a testable hypothesis framework. The key emergent mechanisms underlying mortality include hypoxic, osmotic, and ionic-driven reductions in whole-plant hydraulic conductance and photosynthesis that ultimately drive the coupled processes of hydraulic failure and carbon starvation. The relative importance of these processes in driving mortality, their order of progression, and their degree of coupling depends on the characteristics of the anomalous water exposure, on topographic effects, and on taxa-specific variation in traits and trait acclimation. Greater inundation exposure could accelerate mortality globally; however, the interaction of changing inundation exposure with elevated CO2 , drought, and rising vapor pressure deficit could influence mortality likelihood. Models of coastal forests that incorporate the frequency and duration of inundation, the role of climatic drivers, and the processes of hydraulic failure and carbon starvation can yield improved estimates of inundation-induced woody-plant mortality.
Collapse
Affiliation(s)
- Nate G. McDowell
- Atmospheric Sciences and Global Change DivisionPacific Northwest National LabRichlandWashingtonUSA
- School of Biological SciencesWashington State UniversityPullmanWashingtonUSA
| | - Marilyn Ball
- Plant Science Division, Research School of BiologyThe Australian National UniversityActonAustralian Capital TerritoryAustralia
| | - Ben Bond‐Lamberty
- Joint Global Change Research Institute, Pacific Northwest National LaboratoryCollege ParkMarylandUSA
| | - Matthew L. Kirwan
- Virginia Institute of Marine Science, William & MaryGloucester PointVirginiaUSA
| | - Ken W. Krauss
- U.S. Geological Survey, Wetland and Aquatic Research CenterLafayetteLouisianaUSA
| | | | - Maurizio Mencuccini
- ICREA, Passeig Lluís Companys 23BarcelonaSpain
- CREAFCampus UAB, BellaterraBarcelonaSpain
| | - Nicholas D. Ward
- Marine and Coastal Research LaboratoryPacific Northwest National LaboratorySequimWashingtonUSA
- School of OceanographyUniversity of WashingtonSeattleWashingtonUSA
| | - Michael N. Weintraub
- Department of Environmental SciencesUniversity of ToledoToledoOhioUSA
- Biological Sciences DivisionPacific Northwest National LaboratoryWashingtonUSA
| | - Vanessa Bailey
- Biological Sciences DivisionPacific Northwest National LaboratoryWashingtonUSA
| |
Collapse
|
15
|
Gersony JT, Holbrook NM. Phloem turgor is maintained during severe drought in Ricinus communis. PLANT, CELL & ENVIRONMENT 2022; 45:2898-2905. [PMID: 35854434 DOI: 10.1111/pce.14401] [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: 05/04/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
The phloem is a key player in whole plant functioning-transporting carbon from sites of production to sites of demand-and is likely influenced by drought due to its dependence on water for generating pressure-driven bulk flow transport. Yet, phloem functioning during drought remains largely unknown due to a lack of experimental studies. Here, we use a phloem-bleeding species, Ricinus communis, to investigate phloem loss-of-function in the context of leaf physiological processes, the mechanisms of phloem turgor maintenance during drought, and the role of turgor in phloem loss-of-function. We found that the solute concentration in the phloem sap doubled over the drought, which allowed phloem turgor to be maintained past the point at which leaves have reached permanent stomatal closure. We also found that phloem turgor did not decline before bleeding ceased, which suggests that phloem bleeding ceassation (interpreted as the cessation of transport) occurred when the phloem still had turgor. In sum, our findings highlight the robustness of phloem functioning, with important implications for forecasting whole-plant carbon dynamics and drought-induced tree mortality.
Collapse
Affiliation(s)
- Jess Toby Gersony
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, USA
| | - Noel M Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
| |
Collapse
|
16
|
Li W, McDowell NG, Zhang H, Wang W, Mackay DS, Leff R, Zhang P, Ward ND, Norwood M, Yabusaki S, Myers-Pigg AN, Pennington SC, Pivovaroff AL, Waichler S, Xu C, Bond-Lamberty B, Bailey VL. The influence of increasing atmospheric CO 2 , temperature, and vapor pressure deficit on seawater-induced tree mortality. THE NEW PHYTOLOGIST 2022; 235:1767-1779. [PMID: 35644021 DOI: 10.1111/nph.18275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Increasing seawater exposure is killing coastal trees globally, with expectations of accelerating mortality with rising sea levels. However, the impact of concomitant changes in atmospheric CO2 concentration, temperature, and vapor pressure deficit (VPD) on seawater-induced tree mortality is uncertain. We examined the mechanisms of seawater-induced mortality under varying climate scenarios using a photosynthetic gain and hydraulic cost optimization model validated against observations in a mature stand of Sitka spruce (Picea sitchensis) trees in the Pacific Northwest, USA, that were dying from recent seawater exposure. The simulations matched well with observations of photosynthesis, transpiration, nonstructural carbohydrates concentrations, leaf water potential, the percentage loss of xylem conductivity, and stand-level mortality rates. The simulations suggest that seawater-induced mortality could decrease by c. 16.7% with increasing atmospheric CO2 levels due to reduced risk of carbon starvation. Conversely, rising VPD could increase mortality by c. 5.6% because of increasing risk of hydraulic failure. Across all scenarios, seawater-induced mortality was driven by hydraulic failure in the first 2 yr after seawater exposure began, with carbon starvation becoming more important in subsequent years. Changing CO2 and climate appear unlikely to have a significant impact on coastal tree mortality under rising sea levels.
Collapse
Affiliation(s)
- Weibin Li
- State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Nate G McDowell
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- School of Biological Sciences, Washington State University, Pullman, WA, 99164-4236, USA
| | - Hongxia Zhang
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Wenzhi Wang
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- The Key Laboratory of Mountain Environment Evolution and Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu, 610041, China
| | - D Scott Mackay
- Department of Geography and Department of Environment & Sustainability, University at Buffalo, Buffalo, NY, 14261, USA
| | - Riley Leff
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Peipei Zhang
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- CAS Key Laboratory of Mountain Ecological Restoration, Bioresource Utilization & Ecological Restoration, Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China
| | - Nicholas D Ward
- Marine and Coastal Research Laboratory, Pacific Northwest National Laboratory, Sequim, WA, 98382, USA
- School of Oceanography, University of Washington, Seattle, WA, 98105, USA
| | - Matt Norwood
- Marine and Coastal Research Laboratory, Pacific Northwest National Laboratory, Sequim, WA, 98382, USA
| | - Steve Yabusaki
- Earth Systems Science, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Allison N Myers-Pigg
- Marine and Coastal Research Laboratory, Pacific Northwest National Laboratory, Sequim, WA, 98382, USA
- Department of Environmental Sciences, University of Toledo, Toledo, OH, 43606, USA
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Stephanie C Pennington
- Pacific Northwest National Laboratory, Joint Global Change Research Institute, College Park, MD, 20740, USA
| | - Alexandria L Pivovaroff
- Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Scott Waichler
- Earth Systems Science, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Chonggang Xu
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Ben Bond-Lamberty
- Pacific Northwest National Laboratory, Joint Global Change Research Institute, College Park, MD, 20740, USA
| | - Vanessa L Bailey
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| |
Collapse
|
17
|
Zlobin IE. Linking the growth patterns of coniferous species with their performance under climate aridization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 831:154971. [PMID: 35367548 DOI: 10.1016/j.scitotenv.2022.154971] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/19/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Tree growth is highly sensitive to water deficit. At the same time, growth processes substantially influence tree performance under water stress by changing the root-absorbing surface, leaf-transpiring surface, amount of conducting xylem, etc. Drought-induced growth suppression is often higher in conifers than in broadleaf species. This review is devoted to the relations between the growth of coniferous plants and their performance under increasing climate aridization in the temperate and boreal zones of the Northern Hemisphere. For adult trees, available evidence suggests that increasing the frequency and severity of water deficit would be more detrimental to those plants that have higher growth in favorable conditions but decrease growth more prominently under water shortage, compared to trees whose growth is less sensitive to moisture availability. Not only the overall sensitivity of growth processes to water supply but also the asymmetry in response to lower-than-average and higher-than-average moisture conditions can be important for the performance of coniferous trees under upcoming adverse climate change. To fully understand the tree response under future climate change, the responses to both drier and wetter years need to be analyzed separately. In coniferous seedlings, more active growth is usually linked with better drought survival, although physiological reasons for such a link can be different. Growth stability under exacerbating summer water deficit in coniferous plants can be maintained by more active spring growth and/or by a bimodal growth pattern; each strategy has specific advantages and drawbacks. The optimal choice of growth strategy would be critical for future reforestation programs.
Collapse
Affiliation(s)
- Ilya E Zlobin
- K.A. Timiryazev Institute of Plant Physiology, RAS, 35 Botanicheskaya St., Moscow 127276, Russia.
| |
Collapse
|
18
|
Hajek P, Link RM, Nock CA, Bauhus J, Gebauer T, Gessler A, Kovach K, Messier C, Paquette A, Saurer M, Scherer-Lorenzen M, Rose L, Schuldt B. Mutually inclusive mechanisms of drought-induced tree mortality. GLOBAL CHANGE BIOLOGY 2022; 28:3365-3378. [PMID: 35246895 DOI: 10.1101/2020.12.17.423038] [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: 11/03/2021] [Accepted: 12/16/2021] [Indexed: 05/22/2023]
Abstract
Unprecedented tree dieback across Central Europe caused by recent global change-type drought events highlights the need for a better mechanistic understanding of drought-induced tree mortality. Although numerous physiological risk factors have been identified, the importance of two principal mechanisms, hydraulic failure and carbon starvation, is still debated. It further remains largely unresolved how the local neighborhood composition affects individual mortality risk. We studied 9435 young trees of 12 temperate species planted in a diversity experiment in 2013 to assess how hydraulic traits, carbon dynamics, pest infestation, tree height and neighborhood competition influence individual mortality risk. Following the most extreme global change-type drought since record in 2018, one third of these trees died. Across species, hydraulic safety margins (HSMs) were negatively and a shift towards a higher sugar fraction in the non-structural carbohydrate (NSC) pool positively associated with mortality risk. Moreover, trees infested by bark beetles had a higher mortality risk, and taller trees a lower mortality risk. Most neighborhood interactions were beneficial, although neighborhood effects were highly species-specific. Species that suffered more from drought, especially Larix spp. and Betula spp., tended to increase the survival probability of their neighbors and vice versa. While severe tissue dehydration marks the final stage of drought-induced tree mortality, we show that hydraulic failure is interrelated with a series of other, mutually inclusive processes. These include shifts in NSC pools driven by osmotic adjustment and/or starch depletion as well as pest infestation and are modulated by the size and species identity of a tree and its neighbors. A more holistic view that accounts for multiple causes of drought-induced tree mortality is required to improve predictions of trends in global forest dynamics and to identify mutually beneficial species combinations.
Collapse
Affiliation(s)
- Peter Hajek
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Roman M Link
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
| | - Charles A Nock
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Jürgen Bauhus
- Chair of Silviculture, University of Freiburg, Freiburg, Germany
| | - Tobias Gebauer
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arthur Gessler
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
- ETH Zurich, Institute of Terrestrial Ecosystems, Zurich, Switzerland
| | - Kyle Kovach
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Christian Messier
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
- University of Quebec in Outaouais (UQO), Institut des Sciences de la Forêt Tempérée (ISFORT), Gatineau, Quebec, Canada
| | - Alain Paquette
- Center for Forest Research, Université du Québec à Montréal, Montréal, Quebec, Canada
| | - Matthias Saurer
- Forest Dynamics, Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf, Switzerland
| | | | - Laura Rose
- Geobotany, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Bernhard Schuldt
- Chair of Ecophysiology and Vegetation Ecology, University of Würzburg, Julius-von-Sachs-Institute of Biological Sciences, Würzburg, Germany
| |
Collapse
|
19
|
Li X, Xi B, Wu X, Choat B, Feng J, Jiang M, Tissue D. Unlocking Drought-Induced Tree Mortality: Physiological Mechanisms to Modeling. FRONTIERS IN PLANT SCIENCE 2022; 13:835921. [PMID: 35444681 PMCID: PMC9015645 DOI: 10.3389/fpls.2022.835921] [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: 12/15/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
Drought-related tree mortality has become a major concern worldwide due to its pronounced negative impacts on the functioning and sustainability of forest ecosystems. However, our ability to identify the species that are most vulnerable to drought, and to pinpoint the spatial and temporal patterns of mortality events, is still limited. Model is useful tools to capture the dynamics of vegetation at spatiotemporal scales, yet contemporary land surface models (LSMs) are often incapable of predicting the response of vegetation to environmental perturbations with sufficient accuracy, especially under stressful conditions such as drought. Significant progress has been made regarding the physiological mechanisms underpinning plant drought response in the past decade, and plant hydraulic dysfunction has emerged as a key determinant for tree death due to water shortage. The identification of pivotal physiological events and relevant plant traits may facilitate forecasting tree mortality through a mechanistic approach, with improved precision. In this review, we (1) summarize current understanding of physiological mechanisms leading to tree death, (2) describe the functionality of key hydraulic traits that are involved in the process of hydraulic dysfunction, and (3) outline their roles in improving the representation of hydraulic function in LSMs. We urge potential future research on detailed hydraulic processes under drought, pinpointing corresponding functional traits, as well as understanding traits variation across and within species, for a better representation of drought-induced tree mortality in models.
Collapse
Affiliation(s)
- Ximeng Li
- College of Life and Environmental Science, Minzu University of China, Beijing, China
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Benye Xi
- Ministry of Education Key Laboratory of Silviculture and Conservation, Beijing Forestry University, Beijing, China
| | - Xiuchen Wu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
| | - Jinchao Feng
- College of Life and Environmental Science, Minzu University of China, Beijing, China
| | - Mingkai Jiang
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia
- Global Centre for Land-based Innovation, Western Sydney University, Richmond, NSW, Australia
| |
Collapse
|
20
|
Wang Z, Ding X, Li Y, Xie J. The compensation effect between safety and efficiency in xylem and role in photosynthesis of gymnosperms. PHYSIOLOGIA PLANTARUM 2022; 174:e13617. [PMID: 35199364 DOI: 10.1111/ppl.13617] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 12/18/2021] [Indexed: 06/14/2023]
Abstract
The classical theory of safety-efficiency trade-off is a common theme in plant sciences. Despite safety and efficiency partly compensating for each other physiologically (namely, there is a compensation effect, CE, among traits from the "whole" organism perspective), they are always mathematically described as a trade-off against one another. However, the compensation effect has never been defined and quantified, let alone its role in the xylem water transport and subsequently photosynthesis. Here, we developed an alternative theory to define the CE as a positive relationship between safety and efficiency, and further define a new trade-off index, SETO, that is expressed as CE multiplied by a trade-off factor (differing from the classical average trade-off value). Then, we tested SETO- and CE-photosynthetic rate relationships across different levels based on a common garden experiment using nine conifers and published data for gymnosperms. The results demonstrated that the compensation effect in xylem functions was the dominant force in facilitating photosynthetic rates from species- to phylum-scale. By integrating the compensation effect into the xylem hydraulic functional strategy, our study clearly indicated that the compensation effect is the evolutionary basis for the coordination of xylem hydraulic and photosynthesis physiology.
Collapse
Affiliation(s)
- Zhongyuan Wang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Xiaoran Ding
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| | - Yan Li
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
- Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang, China
| | - Jiangbo Xie
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, China
- College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China
| |
Collapse
|
21
|
Robbins ZJ, Xu C, Aukema BH, Buotte PC, Chitra-Tarak R, Fettig CJ, Goulden ML, Goodsman DW, Hall AD, Koven CD, Kueppers LM, Madakumbura GD, Mortenson LA, Powell JA, Scheller RM. Warming increased bark beetle-induced tree mortality by 30% during an extreme drought in California. GLOBAL CHANGE BIOLOGY 2022; 28:509-523. [PMID: 34713535 DOI: 10.1111/gcb.15927] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Quantifying the responses of forest disturbances to climate warming is critical to our understanding of carbon cycles and energy balances of the Earth system. The impact of warming on bark beetle outbreaks is complex as multiple drivers of these events may respond differently to warming. Using a novel model of bark beetle biology and host tree interactions, we assessed how contemporary warming affected western pine beetle (Dendroctonus brevicomis) populations and mortality of its host, ponderosa pine (Pinus ponderosa), during an extreme drought in the Sierra Nevada, California, United States. When compared with the field data, our model captured the western pine beetle flight timing and rates of ponderosa pine mortality observed during the drought. In assessing the influence of temperature on western pine beetles, we found that contemporary warming increased the development rate of the western pine beetle and decreased the overwinter mortality rate of western pine beetle larvae leading to increased population growth during periods of lowered tree defense. We attribute a 29.9% (95% CI: 29.4%-30.2%) increase in ponderosa pine mortality during drought directly to increases in western pine beetle voltinism (i.e., associated with increased development rates of western pine beetle) and, to a much lesser extent, reductions in overwintering mortality. These findings, along with other studies, suggest each degree (°C) increase in temperature may have increased the number of ponderosa pine killed by upwards of 35%-40% °C-1 if the effects of compromised tree defenses (15%-20%) and increased western pine beetle populations (20%) are additive. Due to the warming ability to considerably increase mortality through the mechanism of bark beetle populations, models need to consider climate's influence on both host tree stress and the bark beetle population dynamics when determining future levels of tree mortality.
Collapse
Affiliation(s)
- Zachary J Robbins
- Earth and Environmental Sciences Division (EES-14), Los Alamos National Laboratory, Los Alamos, New Mexico, USA
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
| | - Chonggang Xu
- Earth and Environmental Sciences Division (EES-14), Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Brian H Aukema
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, USA
| | - Polly C Buotte
- Energy and Resources Group, University of California Berkeley, Berkeley, California, USA
| | - Rutuja Chitra-Tarak
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
| | | | - Michael L Goulden
- Department of Earth System Science, University of California, Irvine, California, USA
| | - Devin W Goodsman
- Canadian Forest Service, Natural Resources Canada, Victoria, British Columbia, Canada
| | - Alexander D Hall
- Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA
| | - Charles D Koven
- Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Lara M Kueppers
- Energy and Resources Group, University of California Berkeley, Berkeley, California, USA
| | - Gavin D Madakumbura
- Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA
| | - Leif A Mortenson
- Pacific Southwest Research Station, USDA Forest Service, Davis, California, USA
| | - James A Powell
- Mathematics and Statistics Department, Utah State University, Logan, Utah, USA
| | - Robert M Scheller
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina, USA
| |
Collapse
|
22
|
Lintunen A, Preisler Y, Oz I, Yakir D, Vesala T, Hölttä T. Bark Transpiration Rates Can Reach Needle Transpiration Rates Under Dry Conditions in a Semi-arid Forest. FRONTIERS IN PLANT SCIENCE 2021; 12:790684. [PMID: 34987535 PMCID: PMC8721219 DOI: 10.3389/fpls.2021.790684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/17/2021] [Indexed: 05/25/2023]
Abstract
Drought can cause tree mortality through hydraulic failure and carbon starvation. To prevent excess water loss, plants typically close their stomata before massive embolism formation occurs. However, unregulated water loss through leaf cuticles and bark continues after stomatal closure. Here, we studied the diurnal and seasonal dynamics of bark transpiration and how it is affected by tree water availability. We measured continuously for six months water loss and CO2 efflux from branch segments and needle-bearing shoots in Pinus halepensis growing in a control and an irrigation plot in a semi-arid forest in Israel. Our aim was to find out how much passive bark transpiration is affected by tree water status in comparison with shoot transpiration and bark CO2 emission that involve active plant processes, and what is the role of bark transpiration in total tree water use during dry summer conditions. Maximum daily water loss rate per bark area was 0.03-0.14 mmol m-2 s-1, which was typically ~76% of the shoot transpiration rate (on leaf area basis) but could even surpass the shoot transpiration rate during the highest evaporative demand in the control plot. Irrigation did not affect bark transpiration rate. Bark transpiration was estimated to account for 64-78% of total water loss in drought-stressed trees, but only for 6-11% of the irrigated trees, due to differences in stomatal control between the treatments. Water uptake through bark was observed during most nights, but it was not high enough to replenish the lost water during the day. Unlike bark transpiration, branch CO2 efflux decreased during drought due to decreased metabolic activity. Our results demonstrate that although bark transpiration represents a small fraction of the total water loss through transpiration from foliage in non-stressed trees, it may have a large impact during drought.
Collapse
Affiliation(s)
- Anna Lintunen
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki, Finland
| | - Yakir Preisler
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot,Israel
| | - Itay Oz
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot,Israel
| | - Dan Yakir
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot,Israel
| | - Timo Vesala
- Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki, Finland
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki, Finland
- Laboratory of Ecosystem-Atmospheric Interactions of Forest - Mire Complexes, Yugra State University, Khanty-Mansiysk, Russia
| | - Teemu Hölttä
- Institute for Atmospheric and Earth System Research/Forest Sciences, University of Helsinki, Helsinki, Finland
| |
Collapse
|
23
|
Hotter droughts alter resource allocation to chemical defenses in piñon pine. Oecologia 2021; 197:921-938. [PMID: 34657177 PMCID: PMC8591002 DOI: 10.1007/s00442-021-05058-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 10/04/2021] [Indexed: 01/11/2023]
Abstract
Heat and drought affect plant chemical defenses and thereby plant susceptibility to pests and pathogens. Monoterpenes are of particular importance for conifers as they play critical roles in defense against bark beetles. To date, work seeking to understand the impacts of heat and drought on monoterpenes has primarily focused on young potted seedlings, leaving it unclear how older age classes that are more vulnerable to bark beetles might respond to stress. Furthermore, we lack a clear picture of what carbon resources might be prioritized to support monoterpene synthesis under drought stress. To address this, we measured needle and woody tissue monoterpene concentrations and physiological variables simultaneously from mature piñon pines (Pinus edulis) from a unique temperature and drought manipulation field experiment. While heat had no effect on total monoterpene concentrations, trees under combined heat and drought stress exhibited ~ 85% and 35% increases in needle and woody tissue, respectively, over multiple years. Plant physiological variables like maximum photosynthesis each explained less than 10% of the variation in total monoterpenes for both tissue types while starch and glucose + fructose measured 1-month prior explained ~ 45% and 60% of the variation in woody tissue total monoterpene concentrations. Although total monoterpenes increased under combined stress, some key monoterpenes with known roles in bark beetle ecology decreased. These shifts may make trees more favorable for bark beetle attack rather than well defended, which one might conclude if only considering total monoterpene concentrations. Our results point to cumulative and synergistic effects of heat and drought that may reprioritize carbon allocation of specific non-structural carbohydrates toward defense.
Collapse
|
24
|
Thrippleton T, Hülsmann L, Cailleret M, Bugmann H. An evaluation of multi-species empirical tree mortality algorithms for dynamic vegetation modelling. Sci Rep 2021; 11:19845. [PMID: 34615895 PMCID: PMC8494886 DOI: 10.1038/s41598-021-98880-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/08/2021] [Indexed: 12/04/2022] Open
Abstract
Tree mortality is key for projecting forest dynamics, but difficult to portray in dynamic vegetation models (DVMs). Empirical mortality algorithms (MAs) are often considered promising, but little is known about DVM robustness when employing MAs of various structures and origins for multiple species. We analysed empirical MAs for a suite of European tree species within a consistent DVM framework under present and future climates in two climatically different study areas in Switzerland and evaluated their performance using empirical data from old-growth forests across Europe. DVM projections under present climate showed substantial variations when using alternative empirical MAs for the same species. Under climate change, DVM projections showed partly contrasting mortality responses for the same species. These opposing patterns were associated with MA structures (i.e. explanatory variables) and occurred independent of species ecological characteristics. When comparing simulated forest structure with data from old-growth forests, we found frequent overestimations of basal area, which can lead to flawed projections of carbon sequestration and other ecosystem services. While using empirical MAs in DVMs may appear promising, our results emphasize the importance of selecting them cautiously. We therefore synthesize our insights into a guideline for the appropriate use of empirical MAs in DVM applications.
Collapse
Affiliation(s)
- Timothy Thrippleton
- Department of Environmental Systems Science, Forest Ecology, Swiss Federal Institute of Technology (ETH Zurich), Universitätstrasse 16, 8092, Zürich, Switzerland.
- Forest Resources and Management, Sustainable Forestry, Swiss Federal Research Institute (WSL), Zürcherstrasse 111, 8903, Birmensdorf, Switzerland.
| | - Lisa Hülsmann
- Theoretical Ecology Lab, Faculty of Biology and Pre-Clinical Medicine, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Maxime Cailleret
- INRAE, Aix-Marseille University, UMR RECOVER, 3275 Route de Cézanne, CS 40061, Aix-en-Provence Cedex 5, France
| | - Harald Bugmann
- Department of Environmental Systems Science, Forest Ecology, Swiss Federal Institute of Technology (ETH Zurich), Universitätstrasse 16, 8092, Zürich, Switzerland
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Gersony JT, McClelland A, Holbrook NM. Raman spectroscopy reveals high phloem sugar content in leaves of canopy red oak trees. THE NEW PHYTOLOGIST 2021; 232:418-424. [PMID: 33991343 DOI: 10.1111/nph.17465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
A robust understanding of phloem functioning in tall trees evades us because current methods for collecting phloem sap do not lend themselves to measuring actively photosynthesizing canopy leaves. We show that Raman spectroscopy can be used as a quantitative tool to assess sucrose concentration in leaf samples. Specifically, we found that Raman spectroscopy can predict physiologically relevant sucrose concentrations (adjusted R2 of 0.9) in frozen leaf extract spiked with sucrose. We then apply this method to estimate sieve element sucrose concentration in rapidly frozen petioles of canopy red oak (Quercus rubra) trees and found that sucrose concentrations are > 1100 mM at midday and midnight. This concentration is predicted to generate a sieve element turgor pressure high enough to generate bulk flow through the phloem, but is potentially too high to allow for sucrose diffusion from photosynthetic cells. Our findings support the Münch hypothesis for phloem transport once the carbon is in the phloem and challenge the passive-loading hypothesis for carbon movement into the phloem for red oak. This study provides the first ˜in-situ (frozen in the functioning state) source sieve element sucrose concentration characterization in any plant, opening a new avenue for investigation of phloem functioning.
Collapse
Affiliation(s)
- Jess T Gersony
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Arthur McClelland
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, 02138, USA
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| |
Collapse
|
27
|
Liu Q, Peng C, Schneider R, Cyr D, Liu Z, Zhou X, Kneeshaw D. TRIPLEX-Mortality model for simulating drought-induced tree mortality in boreal forests: Model development and evaluation. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
28
|
Feng X, Fu B, Zhang Y, Pan N, Zeng Z, Tian H, Lyu Y, Chen Y, Ciais P, Wang Y, Zhang L, Cheng L, Maestre FT, Fernández-Martínez M, Sardans J, Peñuelas J. Recent leveling off of vegetation greenness and primary production reveals the increasing soil water limitations on the greening Earth. Sci Bull (Beijing) 2021; 66:1462-1471. [PMID: 36654372 DOI: 10.1016/j.scib.2021.02.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/25/2020] [Accepted: 12/29/2020] [Indexed: 01/20/2023]
Abstract
Global vegetation photosynthesis and productivity have increased substantially since the 1980s, but this trend is heterogeneous in both time and space. Here, we categorize the secular trend in global vegetation greenness into sustained greening, sustained browning and greening-to-browning. We found that by 2016, increased global vegetation greenness had begun to level off, with the area of browning increasing in the last decade, reaching 39.0 million km2 (35.9% of the world's vegetated area). This area is larger than the area with sustained increasing growth (27.8 million km2, 26.4%); thus, 12.0% ± 3.1% (0.019 ± 0.004 NDVI a-1) of the previous earlier increase has been offset since 2010 (2010-2016, P < 0.05). Global gross primary production also leveled off, following the trend in vegetation greenness in time and space. This leveling off was caused by increasing soil water limitations due to the spatial expansion of drought, whose impact dominated over the impacts of temperature and solar radiation. This response of global gross primary production to soil water limitation was not identified by land submodels within Earth system models. Our results provide empirical evidence that global vegetation greenness and primary production are offset by water stress and suggest that as global warming continues, land submodels may overestimate the world's capacity to take up carbon with global vegetation greening.
Collapse
Affiliation(s)
- Xiaoming Feng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Bojie Fu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
| | - Yuan Zhang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Naiqing Pan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36832, USA
| | - Zhenzhong Zeng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hanqin Tian
- International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36832, USA
| | - Yihe Lyu
- Global Ecology Unit CREAF-CEAB-UAB, Spanish National Research Council, Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Yongzhe Chen
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, CEA CNRS UVSQ, Gif-sur-Yvette 91191, France
| | - Yingping Wang
- Oceans and Atmosphere, Commonwealth Scientific and Industrial Research Organisation, Aspendale, Victoria 3195, Australia; South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Lu Zhang
- Land and Water, Commonwealth Scientific and Industrial Research Organisation, Black Mountain, Canberra, ACT 2601, Australia
| | - Lei Cheng
- School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 430072, China
| | - Fernando T Maestre
- Departamento de Ecología and Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef", Universidad de Alicante, Alicante 03690, Spain
| | - Marcos Fernández-Martínez
- Global Ecology Unit CREAF-CEAB-UAB, Spanish National Research Council, Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Jordi Sardans
- Global Ecology Unit CREAF-CEAB-UAB, Spanish National Research Council, Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Josep Peñuelas
- Global Ecology Unit CREAF-CEAB-UAB, Spanish National Research Council, Cerdanyola del Vallès, Catalonia 08193, Spain
| |
Collapse
|
29
|
Sebald J, Thrippleton T, Rammer W, Bugmann H, Seidl R. Mixing tree species at different spatial scales: The effect of alpha, beta and gamma diversity on disturbance impacts under climate change. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13912] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Julius Sebald
- Department of Forest‐ and Soil Sciences Institute of SilvicultureUniversity of Natural Resources and Life Sciences (BOKU) Vienna Vienna Austria
- Ecosystem Dynamics and Forest Management Group School of Life Sciences Technical University of Munich Freising Germany
| | - Timothy Thrippleton
- Department of Environmental Systems Science, Forest Ecology Swiss Federal Institute of Technology (ETH Zurich) Zürich Switzerland
- Forest Resources and Management Sustainable Forestry Swiss Federal Research Institute WSL Birmensdorf Switzerland
| | - Werner Rammer
- Ecosystem Dynamics and Forest Management Group School of Life Sciences Technical University of Munich Freising Germany
| | - Harald Bugmann
- Department of Environmental Systems Science, Forest Ecology Swiss Federal Institute of Technology (ETH Zurich) Zürich Switzerland
| | - Rupert Seidl
- Department of Forest‐ and Soil Sciences Institute of SilvicultureUniversity of Natural Resources and Life Sciences (BOKU) Vienna Vienna Austria
- Ecosystem Dynamics and Forest Management Group School of Life Sciences Technical University of Munich Freising Germany
- Berchtesgaden National Park Berchtesgaden Germany
| |
Collapse
|
30
|
Venturas MD, Todd HN, Trugman AT, Anderegg WRL. Understanding and predicting forest mortality in the western United States using long-term forest inventory data and modeled hydraulic damage. THE NEW PHYTOLOGIST 2021; 230:1896-1910. [PMID: 33112415 DOI: 10.1111/nph.17043] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
Global warming is expected to exacerbate the duration and intensity of droughts in the western United States, which may lead to increased tree mortality. A prevailing proximal mechanism of drought-induced tree mortality is hydraulic damage, but predicting tree mortality from hydraulic theory and climate data still remains a major scientific challenge. We used forest inventory data and a plant hydraulic model (HM) to address three questions: can we capture regional patterns of drought-induced tree mortality with HM-predicted damage thresholds; do HM metrics improve predictions of mortality across broad spatial areas; and what are the dominant controls of forest mortality when considering stand characteristics, climate metrics, and simulated hydraulic stress? We found that the amount of variance explained by models predicting mortality was limited (R2 median = 0.10, R2 range: 0.00-0.52). HM outputs, including hydraulic damage and carbon assimilation diagnostics, moderately improve mortality prediction across the western US compared with models using stand and climate predictors alone. Among factors considered, metrics of stand density and tree size tended to be some of the most critical factors explaining mortality, probably highlighting the important roles of structural overshoot, stand development, and biotic agent host selection and outbreaks in mortality patterns.
Collapse
Affiliation(s)
- Martin D Venturas
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Henry N Todd
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| | - Anna T Trugman
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - William R L Anderegg
- School of Biological Sciences, University of Utah, Salt Lake City, UT, 84112, USA
| |
Collapse
|
31
|
Rowland L, Martínez-Vilalta J, Mencuccini M. Hard times for high expectations from hydraulics: predicting drought-induced forest mortality at landscape scales remains a challenge. THE NEW PHYTOLOGIST 2021; 230:1685-1687. [PMID: 33797779 DOI: 10.1111/nph.17317] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Lucy Rowland
- College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4QE, UK
| | - Jordi Martínez-Vilalta
- CREAF, Bellaterra (Cerdanyola del Vallès), 08193, Spain
- Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), 08193, Spain
| | - Maurizio Mencuccini
- CREAF, Bellaterra (Cerdanyola del Vallès), 08193, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, 08010, Spain
| |
Collapse
|
32
|
Nolan RH, Gauthey A, Losso A, Medlyn BE, Smith R, Chhajed SS, Fuller K, Song M, Li X, Beaumont LJ, Boer MM, Wright IJ, Choat B. Hydraulic failure and tree size linked with canopy die-back in eucalypt forest during extreme drought. THE NEW PHYTOLOGIST 2021; 230:1354-1365. [PMID: 33629360 DOI: 10.1111/nph.17298] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
Eastern Australia was subject to its hottest and driest year on record in 2019. This extreme drought resulted in massive canopy die-back in eucalypt forests. The role of hydraulic failure and tree size on canopy die-back in three eucalypt tree species during this drought was examined. We measured pre-dawn and midday leaf water potential (Ψleaf ), per cent loss of stem hydraulic conductivity and quantified hydraulic vulnerability to drought-induced xylem embolism. Tree size and tree health was also surveyed. Trees with most, or all, of their foliage dead exhibited high rates of native embolism (78-100%). This is in contrast to trees with partial canopy die-back (30-70% canopy die-back: 72-78% native embolism), or relatively healthy trees (little evidence of canopy die-back: 25-31% native embolism). Midday Ψleaf was significantly more negative in trees exhibiting partial canopy die-back (-2.7 to -6.3 MPa), compared with relatively healthy trees (-2.1 to -4.5 MPa). In two of the species the majority of individuals showing complete canopy die-back were in the small size classes. Our results indicate that hydraulic failure is strongly associated with canopy die-back during drought in eucalypt forests. Our study provides valuable field data to help constrain models predicting mortality risk.
Collapse
Affiliation(s)
- Rachael H Nolan
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, 2522, Australia
| | - Alice Gauthey
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Adriano Losso
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Department of Botany, University of Innsbruck, Sternwartestraße 15, Innsbruck, 6020, Austria
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Rhiannon Smith
- Ecosystem Management, University of New England, Armidale, NSW, 2351, Australia
| | - Shubham S Chhajed
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Kathryn Fuller
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, 2522, Australia
| | - Magnolia Song
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Xine Li
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
- Department of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Linda J Beaumont
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Matthias M Boer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Bushfire Risk Management Research Hub, Wollongong, NSW, 2522, Australia
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| |
Collapse
|
33
|
Matallana-Ramirez LP, Whetten RW, Sanchez GM, Payn KG. Breeding for Climate Change Resilience: A Case Study of Loblolly Pine ( Pinus taeda L.) in North America. FRONTIERS IN PLANT SCIENCE 2021; 12:606908. [PMID: 33995428 PMCID: PMC8119900 DOI: 10.3389/fpls.2021.606908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 04/08/2021] [Indexed: 05/25/2023]
Abstract
Earth's atmosphere is warming and the effects of climate change are becoming evident. A key observation is that both the average levels and the variability of temperature and precipitation are changing. Information and data from new technologies are developing in parallel to provide multidisciplinary opportunities to address and overcome the consequences of these changes in forest ecosystems. Changes in temperature and water availability impose multidimensional environmental constraints that trigger changes from the molecular to the forest stand level. These can represent a threat for the normal development of the tree from early seedling recruitment to adulthood both through direct mortality, and by increasing susceptibility to pathogens, insect attack, and fire damage. This review summarizes the strengths and shortcomings of previous work in the areas of genetic variation related to cold and drought stress in forest species with particular emphasis on loblolly pine (Pinus taeda L.), the most-planted tree species in North America. We describe and discuss the implementation of management and breeding strategies to increase resilience and adaptation, and discuss how new technologies in the areas of engineering and genomics are shaping the future of phenotype-genotype studies. Lessons learned from the study of species important in intensively-managed forest ecosystems may also prove to be of value in helping less-intensively managed forest ecosystems adapt to climate change, thereby increasing the sustainability and resilience of forestlands for the future.
Collapse
Affiliation(s)
- Lilian P. Matallana-Ramirez
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, Raleigh, NC, United States
| | - Ross W. Whetten
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, Raleigh, NC, United States
| | - Georgina M. Sanchez
- Center for Geospatial Analytics, North Carolina State University, Raleigh, Raleigh, NC, United States
| | - Kitt G. Payn
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, Raleigh, NC, United States
| |
Collapse
|
34
|
Why is Tree Drought Mortality so Hard to Predict? Trends Ecol Evol 2021; 36:520-532. [PMID: 33674131 DOI: 10.1016/j.tree.2021.02.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 01/18/2023]
Abstract
Widespread tree mortality following droughts has emerged as an environmentally and economically devastating 'ecological surprise'. It is well established that tree physiology is important in understanding drought-driven mortality; however, the accuracy of predictions based on physiology alone has been limited. We propose that complicating factors at two levels stymie predictions of drought-driven mortality: (i) organismal-level physiological and site factors that obscure understanding of drought exposure and vulnerability and (ii) community-level ecological interactions, particularly with biotic agents whose effects on tree mortality may reverse expectations based on stress physiology. We conclude with a path forward that emphasizes the need for an integrative approach to stress physiology and biotic agent dynamics when assessing forest risk to drought-driven morality in a changing climate.
Collapse
|
35
|
Gattmann M, Birami B, Nadal Sala D, Ruehr NK. Dying by drying: Timing of physiological stress thresholds related to tree death is not significantly altered by highly elevated CO 2. PLANT, CELL & ENVIRONMENT 2021; 44:356-370. [PMID: 33150582 DOI: 10.1111/pce.13937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/13/2020] [Indexed: 05/03/2023]
Abstract
Drought-induced tree mortality is expected to occur more frequently under predicted climate change. However, the extent of a possibly mitigating effect of simultaneously rising atmospheric [CO2 ] on stress thresholds leading to tree death is not fully understood, yet. Here, we studied the drought response, the time until critical stress thresholds were reached and mortality occurrence of Pinus halepensis (Miller). In order to observe a large potential benefit from eCO2 , the seedlings were grown with ample of water and nutrient supply under either highly elevated [CO2 ] (eCO2 , c. 936 ppm) or ambient (aCO2 , c. 407 ppm) during 2 years. The subsequent exposure to a fast or a slow lethal drought was monitored using whole-tree gas exchange chambers, measured leaf water potential and non-structural carbohydrates. Using logistic regressions to derive probabilities for physiological parameters to reach critical drought stress thresholds, indicated a longer period for halving needle starch storage under eCO2 than aCO2 . Stomatal closure, turgor loss, the duration until the daily tree C balance turned negative, leaf water potential at thresholds and time-of-death were unaffected by eCO2 . Overall, our study provides for the first-time insights into the chronological interplay of physiological drought thresholds under long-term acclimation to elevated [CO2 ].
Collapse
Affiliation(s)
- Marielle Gattmann
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, Germany
| | - Benjamin Birami
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, Germany
| | - Daniel Nadal Sala
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, Germany
| | - Nadine Katrin Ruehr
- Institute of Meteorology and Climate Research - Atmospheric Environmental Research, Karlsruhe Institute of Technology KIT, Garmisch-Partenkirchen, Germany
| |
Collapse
|
36
|
Nardini A, Petruzzellis F, Marusig D, Tomasella M, Natale S, Altobelli A, Calligaris C, Floriddia G, Cucchi F, Forte E, Zini L. Water 'on the rocks': a summer drink for thirsty trees? THE NEW PHYTOLOGIST 2021; 229:199-212. [PMID: 32772381 DOI: 10.1111/nph.16859] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
Drought-induced tree mortality frequently occurs in patches with different spatial and temporal distributions, which is only partly explained by inter- and intraspecific variation in drought tolerance. We investigated whether bedrock properties, with special reference to rock water storage capacity, affects tree water status and drought response in a rock-dominated landscape. We measured primary porosity and available water content of breccia (B) and dolostone (D) rocks. Saplings of Fraxinus ornus were grown in pots filled with soil or soil mixed with B and D rocks, and subjected to an experimental drought. Finally, we measured seasonal changes in water status of trees in field sites overlying B or D bedrock. B rocks were more porous and stored more available water than D rocks. Potted saplings grown with D rocks had less biomass and suffered more severe water stress than those with B rocks. Trees in sites with B bedrock had more favourable water status than those on D bedrock which also suffered drought-induced canopy dieback. Bedrock represents an important water source for plants under drought. Different bedrock features translate into contrasting below-ground water availability, leading to landscape-level heterogeneity of the impact of drought on tree water status and dieback.
Collapse
Affiliation(s)
- Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italia
| | - Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italia
| | - Daniel Marusig
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italia
- Dipartimento di Scienze delle Produzioni Vegetali Sostenibili, Università Cattolica del Sacro Cuore, Via E. Parmense 84, Piacenza, 29122, Italia
| | - Martina Tomasella
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italia
| | - Sara Natale
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italia
| | - Alfredo Altobelli
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, Trieste, 34127, Italia
| | - Chiara Calligaris
- Dipartimento di Matematica e Geoscienze, Università di Trieste, Via E. Weiss 2, Trieste, 34128, Italia
| | - Gabriele Floriddia
- Dipartimento di Matematica e Geoscienze, Università di Trieste, Via E. Weiss 2, Trieste, 34128, Italia
| | - Franco Cucchi
- Dipartimento di Matematica e Geoscienze, Università di Trieste, Via E. Weiss 2, Trieste, 34128, Italia
| | - Emanuele Forte
- Dipartimento di Matematica e Geoscienze, Università di Trieste, Via E. Weiss 2, Trieste, 34128, Italia
| | - Luca Zini
- Dipartimento di Matematica e Geoscienze, Università di Trieste, Via E. Weiss 2, Trieste, 34128, Italia
| |
Collapse
|
37
|
Albrich K, Rammer W, Turner MG, Ratajczak Z, Braziunas KH, Hansen WD, Seidl R. Simulating forest resilience: A review. GLOBAL ECOLOGY AND BIOGEOGRAPHY : A JOURNAL OF MACROECOLOGY 2020; 29:2082-2096. [PMID: 33380902 PMCID: PMC7756463 DOI: 10.1111/geb.13197] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/18/2020] [Accepted: 09/10/2020] [Indexed: 06/02/2023]
Abstract
AIM Simulation models are important tools for quantifying the resilience (i.e., persistence under changed environmental conditions) of forest ecosystems to global change. We synthesized the modelling literature on forest resilience, summarizing common models and applications in resilience research, and scrutinizing the implementation of important resilience mechanisms in these models. Models applied to assess resilience are highly diverse, and our goal was to assess how well they account for important resilience mechanisms identified in experimental and empirical research. LOCATION Global. TIME PERIOD 1994 to 2019. MAJOR TAXA STUDIED Trees. METHODS We reviewed the forest resilience literature using online databases, selecting 119 simulation modelling studies for further analysis. We identified a set of resilience mechanisms from the general resilience literature and analysed models for their representation of these mechanisms. Analyses were grouped by investigated drivers (resilience to what) and responses (resilience of what), as well as by the type of model being used. RESULTS Models used to study forest resilience varied widely, from analytical approaches to complex landscape simulators. The most commonly addressed questions were associated with resilience of forest cover to fire. Important resilience mechanisms pertaining to regeneration, soil processes, and disturbance legacies were explicitly simulated in only 34 to 46% of the model applications. MAIN CONCLUSIONS We found a large gap between processes identified as underpinning forest resilience in the theoretical and empirical literature, and those represented in models used to assess forest resilience. Contemporary forest models developed for other goals may be poorly suited for studying forest resilience during an era of accelerating change. Our results highlight the need for a new wave of model development to enhance understanding of and management for resilient forests.
Collapse
Affiliation(s)
- Katharina Albrich
- Institute of SilvicultureUniversity of Natural Resources and Life Sciences (BOKU) ViennaWienAustria
- Ecosystem Dynamics and Forest Management GroupTechnical University of MunichFreisingGermany
| | - Werner Rammer
- Institute of SilvicultureUniversity of Natural Resources and Life Sciences (BOKU) ViennaWienAustria
- Ecosystem Dynamics and Forest Management GroupTechnical University of MunichFreisingGermany
| | - Monica G. Turner
- Department of Integrative BiologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Zak Ratajczak
- Department of Integrative BiologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Kristin H. Braziunas
- Department of Integrative BiologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | | | - Rupert Seidl
- Institute of SilvicultureUniversity of Natural Resources and Life Sciences (BOKU) ViennaWienAustria
- Ecosystem Dynamics and Forest Management GroupTechnical University of MunichFreisingGermany
| |
Collapse
|
38
|
Grossiord C. Having the right neighbors: how tree species diversity modulates drought impacts on forests. THE NEW PHYTOLOGIST 2020; 228:42-49. [PMID: 30585635 DOI: 10.1111/nph.15667] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/17/2018] [Indexed: 05/20/2023]
Abstract
Droughts are a rising concern for terrestrial ecosystems, particularly for forests where drought-induced reductions in tree growth and survival are reported. Biodiversity has long been acknowledged as an important component modulating ecosystem functions, including mitigating their vulnerability to climate-related stresses. Yet the impact of tree diversity on forest vulnerability to drought is unclear. In this review, consistent mechanisms are identified by which tree diversity could reduce vulnerability to drought and emerging evidence is revealed that tree diversity is not systematically positively related to drought resistance in forests. A path is suggested to further increase our knowledge on this subject in the face of climate change, proposing standardization of methods to quantitatively establish diversity impacts on the drought resistance of forests.
Collapse
Affiliation(s)
- Charlotte Grossiord
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| |
Collapse
|
39
|
De Kauwe MG, Medlyn BE, Ukkola AM, Mu M, Sabot MEB, Pitman AJ, Meir P, Cernusak LA, Rifai SW, Choat B, Tissue DT, Blackman CJ, Li X, Roderick M, Briggs PR. Identifying areas at risk of drought-induced tree mortality across South-Eastern Australia. GLOBAL CHANGE BIOLOGY 2020; 26:5716-5733. [PMID: 32512628 DOI: 10.1111/gcb.15215] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
South-East Australia has recently been subjected to two of the worst droughts in the historical record (Millennium Drought, 2000-2009 and Big Dry, 2017-2019). Unfortunately, a lack of forest monitoring has made it difficult to determine whether widespread tree mortality has resulted from these droughts. Anecdotal observations suggest the Big Dry may have led to more significant tree mortality than the Millennium drought. Critically, to be able to robustly project future expected climate change effects on Australian vegetation, we need to assess the vulnerability of Australian trees to drought. Here we implemented a model of plant hydraulics into the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model. We parameterized the drought response behaviour of five broad vegetation types, based on a common garden dry-down experiment with species originating across a rainfall gradient (188-1,125 mm/year) across South-East Australia. The new hydraulics model significantly improved (~35%-45% reduction in root mean square error) CABLE's previous predictions of latent heat fluxes during periods of water stress at two eddy covariance sites in Australia. Landscape-scale predictions of the greatest percentage loss of hydraulic conductivity (PLC) of about 40%-60%, were broadly consistent with satellite estimates of regions of the greatest change in both droughts. In neither drought did CABLE predict that trees would have reached critical PLC in widespread areas (i.e. it projected a low mortality risk), although the model highlighted critical levels near the desert regions of South-East Australia where few trees live. Overall, our experimentally constrained model results imply significant resilience to drought conferred by hydraulic function, but also highlight critical data and scientific gaps. Our approach presents a promising avenue to integrate experimental data and make regional-scale predictions of potential drought-induced hydraulic failure.
Collapse
Affiliation(s)
- Martin G De Kauwe
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Evolution & Ecology Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Anna M Ukkola
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | - Mengyuan Mu
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Manon E B Sabot
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- Evolution & Ecology Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Andrew J Pitman
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Patrick Meir
- Research School of Biology, The Australian National University, Acton, ACT, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Qld, Australia
| | - Sami W Rifai
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Michael Roderick
- ARC Centre of Excellence for Climate Extremes, Sydney, NSW, Australia
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | | |
Collapse
|
40
|
|
41
|
Wilson Rankin EE, Barney SK, Lozano GE. Reduced Water Negatively Impacts Social Bee Survival and Productivity Via Shifts in Floral Nutrition. JOURNAL OF INSECT SCIENCE (ONLINE) 2020; 20:5918281. [PMID: 33021636 PMCID: PMC7583269 DOI: 10.1093/jisesa/ieaa114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Indexed: 06/11/2023]
Abstract
Pollinators provide a key ecosystem service vital for the survival and stability of the biosphere. Identifying factors influencing the plant-pollinator mutualism and pollinator management is necessary for maintaining a healthy ecosystem. Since healthy beehives require substantial amounts of carbohydrates (nectar) and protein (pollen) from forage plants such as clover, we must assess how resources offered by plants change under limited water conditions in order to fully understand how drought modifies the pollination mutualism. Here we document how reduced water availability leads to decreased nectar quality and quantity and decreased protein quality of pollen. Furthermore, we provide conclusive evidence that these lower quality resources lead to decreased survival and productivity in both developing honey bees (Hymenoptera: Apidae) and bumble bees (Hymenoptera: Apidae). The results emphasize the importance of the nutritional effects of reduced water on bees when predicting shifts of pollination mutualisms under climate change.
Collapse
Affiliation(s)
| | - Sarah K Barney
- Department of Entomology, University of California, Riverside, CA
| | - Giselle E Lozano
- Department of Entomology, University of California, Riverside, CA
| |
Collapse
|
42
|
Guadagno C, Millar D, Lai R, Mackay D, Pleban J, McClung C, Weinig C, Wang D, Ewers B. Use of transcriptomic data to inform biophysical models via Bayesian networks. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
43
|
Li X, Piao S, Wang K, Wang X, Wang T, Ciais P, Chen A, Lian X, Peng S, Peñuelas J. Temporal trade-off between gymnosperm resistance and resilience increases forest sensitivity to extreme drought. Nat Ecol Evol 2020; 4:1075-1083. [DOI: 10.1038/s41559-020-1217-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 05/05/2020] [Indexed: 01/15/2023]
|
44
|
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.
Collapse
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
| |
Collapse
|
45
|
Paschalis A, Fatichi S, Zscheischler J, Ciais P, Bahn M, Boysen L, Chang J, De Kauwe M, Estiarte M, Goll D, Hanson PJ, Harper AB, Hou E, Kigel J, Knapp AK, Larsen KS, Li W, Lienert S, Luo Y, Meir P, Nabel JEMS, Ogaya R, Parolari AJ, Peng C, Peñuelas J, Pongratz J, Rambal S, Schmidt IK, Shi H, Sternberg M, Tian H, Tschumi E, Ukkola A, Vicca S, Viovy N, Wang YP, Wang Z, Williams K, Wu D, Zhu Q. Rainfall manipulation experiments as simulated by terrestrial biosphere models: Where do we stand? GLOBAL CHANGE BIOLOGY 2020; 26:3336-3355. [PMID: 32012402 DOI: 10.1111/gcb.15024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Changes in rainfall amounts and patterns have been observed and are expected to continue in the near future with potentially significant ecological and societal consequences. Modelling vegetation responses to changes in rainfall is thus crucial to project water and carbon cycles in the future. In this study, we present the results of a new model-data intercomparison project, where we tested the ability of 10 terrestrial biosphere models to reproduce the observed sensitivity of ecosystem productivity to rainfall changes at 10 sites across the globe, in nine of which, rainfall exclusion and/or irrigation experiments had been performed. The key results are as follows: (a) Inter-model variation is generally large and model agreement varies with timescales. In severely water-limited sites, models only agree on the interannual variability of evapotranspiration and to a smaller extent on gross primary productivity. In more mesic sites, model agreement for both water and carbon fluxes is typically higher on fine (daily-monthly) timescales and reduces on longer (seasonal-annual) scales. (b) Models on average overestimate the relationship between ecosystem productivity and mean rainfall amounts across sites (in space) and have a low capacity in reproducing the temporal (interannual) sensitivity of vegetation productivity to annual rainfall at a given site, even though observation uncertainty is comparable to inter-model variability. (c) Most models reproduced the sign of the observed patterns in productivity changes in rainfall manipulation experiments but had a low capacity in reproducing the observed magnitude of productivity changes. Models better reproduced the observed productivity responses due to rainfall exclusion than addition. (d) All models attribute ecosystem productivity changes to the intensity of vegetation stress and peak leaf area, whereas the impact of the change in growing season length is negligible. The relative contribution of the peak leaf area and vegetation stress intensity was highly variable among models.
Collapse
Affiliation(s)
- Athanasios Paschalis
- Department of Civil and Environmental Engineering, Imperial College London, London, UK
| | - Simone Fatichi
- Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
| | - Jakob Zscheischler
- Climate and Environmental Physics, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Philippe Ciais
- Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Lena Boysen
- Max Planck Institute for Meteorology, Hamburg, Germany
| | - Jinfeng Chang
- Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France
| | - Martin De Kauwe
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | - Marc Estiarte
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Catalonia, Spain
| | - Daniel Goll
- Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France
- Department of Geography, University of Augsburg, Augsburg, Germany
| | - Paul J Hanson
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Anna B Harper
- Department of Mathematics, University of Exeter, Exeter, UK
| | - Enqing Hou
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Jaime Kigel
- Institute for Plant Sciences and Genetics, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Alan K Knapp
- Graduate Degree Program in Ecology, Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Klaus S Larsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark
| | - Wei Li
- Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, China
| | - Sebastian Lienert
- Climate and Environmental Physics, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Yiqi Luo
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Patrick Meir
- Research School of Biology, Australian National University, Acton, ACT, Australia
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | | | - Romà Ogaya
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Catalonia, Spain
| | - Anthony J Parolari
- Department of Civil, Construction, and Environmental Engineering, Marquette University, Milwaukee, WI, USA
| | - Changhui Peng
- Department of Biology Sciences, University of Quebec at Montreal, Montreal, QC, Canada
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, Catalonia, Spain
| | - Julia Pongratz
- Department of Geography, Ludwig Maximilian University of Munich, Munchen, Germany
| | - Serge Rambal
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, Montpellier, France
| | - Inger K Schmidt
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark
| | - Hao Shi
- International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, USA
| | - Marcelo Sternberg
- School of Plant Sciences and Food Security, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Hanqin Tian
- International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, USA
| | - Elisabeth Tschumi
- Climate and Environmental Physics, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Anna Ukkola
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | - Sara Vicca
- Centre of Excellence PLECO (Plants and Ecosystems), Biology Department, University of Antwerp, Wilrijk, Belgium
| | - Nicolas Viovy
- Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France
| | - Ying-Ping Wang
- CSIRO Marine and Atmospheric Research and Centre for Australian Weather and Climate Research, Aspendale, Vic., Australia
| | - Zhuonan Wang
- International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL, USA
| | | | - Donghai Wu
- Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Qiuan Zhu
- Center for Ecological Forecasting and Global Change, College of Forestry, Northwest A&F University, Xianyang, China
| |
Collapse
|
46
|
Kiorapostolou N, Camarero JJ, Carrer M, Sterck F, Brigita B, Sangüesa-Barreda G, Petit G. Scots pine trees react to drought by increasing xylem and phloem conductivities. TREE PHYSIOLOGY 2020; 40:774-781. [PMID: 32186730 DOI: 10.1093/treephys/tpaa033] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 02/29/2020] [Accepted: 03/12/2020] [Indexed: 06/10/2023]
Abstract
Drought limits the long-distance transport of water in the xylem due to the reduced leaf-to-soil water potential difference and possible embolism-related losses of conductance and of sugars in the phloem due to the higher viscosity of the dehydrated sugary solution. This condition can have cascading effects in water and carbon (C) fluxes that may ultimately cause tree death. We hypothesize that the maintenance of xylem and phloem conductances is fundamental for survival also under reduced resource availability, when trees may produce effective and low C cost anatomical adjustments in the xylem and phloem close to the treetop where most of the hydraulic resistance is concentrated. We analyzed the treetop xylem and phloem anatomical characteristics in coexisting Scots pine trees, symptomatic and non-symptomatic of drought-induced dieback. We selected the topmost 55 cm of the main stem and selected several sampling positions at different distances from the stem apex to test for differences in the axial patterns between the two groups of trees. We measured the annual ring area, the tracheid hydraulic diameter (Dh) and cell wall thickness (CWT), the conductive phloem area and the average lumen diameter of the 20 largest phloem sieve cells (Dph). Declining trees grew less than the non-declining ones, and despite the similar axial scaling of anatomical traits, had larger Dh and lower CWT. Moreover, declining trees had wider Dph. Our results demonstrate that even under drought stress, maintenance of xylem and phloem efficiencies is of primary importance for survival, even if producing fewer larger tracheids may lead to a xylem more vulnerable to embolism formation.
Collapse
Affiliation(s)
- Natasa Kiorapostolou
- Dip. Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, Legnaro, PD 35020, Italy
| | - J Julio Camarero
- Depto. Conservación de Ecosistemas, Instituto Pirenaico de Ecologia (IPE-CSIC), Avda Montanana 1005, Zaragoza 50059, Spain
| | - Marco Carrer
- Dip. Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, Legnaro, PD 35020, Italy
| | - Frank Sterck
- Department of Environmental Sciences, Wageningen University, Droevendaalsesteeg 3, NL 6700 AA Wageningen, The Netherlands
| | - Brigita Brigita
- Department of Environmental Sciences, Wageningen University, Droevendaalsesteeg 3, NL 6700 AA Wageningen, The Netherlands
| | - Gabriel Sangüesa-Barreda
- Depto. Conservación de Ecosistemas, Instituto Pirenaico de Ecologia (IPE-CSIC), Avda Montanana 1005, Zaragoza 50059, Spain
- Depto Ciencias Agroforestales, iuFOR-EiFAB, University of Valladolid, Campus Duques de Soria s/n, Soria E-42004, Spain
| | - Giai Petit
- Dip. Territorio e Sistemi Agro-Forestali, Università di Padova, Viale dell'Università 16, Legnaro, PD 35020, Italy
| |
Collapse
|
47
|
McDowell NG, Allen CD, Anderson-Teixeira K, Aukema BH, Bond-Lamberty B, Chini L, Clark JS, Dietze M, Grossiord C, Hanbury-Brown A, Hurtt GC, Jackson RB, Johnson DJ, Kueppers L, Lichstein JW, Ogle K, Poulter B, Pugh TAM, Seidl R, Turner MG, Uriarte M, Walker AP, Xu C. Pervasive shifts in forest dynamics in a changing world. Science 2020; 368:368/6494/eaaz9463. [DOI: 10.1126/science.aaz9463] [Citation(s) in RCA: 301] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
| | - Craig D. Allen
- U.S. Geological Survey, Fort Collins Science Center, New Mexico Landscapes Field Station, Los Alamos, NM 87544, USA
| | - Kristina Anderson-Teixeira
- Conservation Ecology Center, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
- Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Republic of Panama
| | - Brian H. Aukema
- Department of Entomology, University of Minnesota, St. Paul, MN 55108, USA
| | - Ben Bond-Lamberty
- Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD 20740, USA
| | - Louise Chini
- Department of Geographical Sciences, University of Maryland, College Park, MD 20742, USA
| | - James S. Clark
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Michael Dietze
- Department of Earth and Environment, Boston University, Boston, MA 02215, USA
| | - Charlotte Grossiord
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, 8903 Birmensdorf, Switzerland
| | - Adam Hanbury-Brown
- Energy and Resources Group, University of California, Berkeley, Berkeley, CA 94720, USA
| | - George C. Hurtt
- Department of Geographical Sciences, University of Maryland, College Park, MD 20742, USA
| | - Robert B. Jackson
- Department of Earth System Science, Woods Institute for the Environment, and Precourt Institute for Energy, Stanford University, Stanford, CA 94305, USA
| | - Daniel J. Johnson
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611, USA
| | - Lara Kueppers
- Energy and Resources Group, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Climate and Ecosystem Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Kiona Ogle
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ 86001, USA
| | - Benjamin Poulter
- Biospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - Thomas A. M. Pugh
- School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT Birmingham, UK
- Birmingham Institute of Forest Research, University of Birmingham, B15 2TT Birmingham, UK
| | - Rupert Seidl
- Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences Vienna, 1180 Vienna, Austria
- School of Life Sciences, Technical University of Munich, 85354 Freising, Germany
| | - Monica G. Turner
- Department of Integrative Biology, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Maria Uriarte
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
| | - Anthony P. Walker
- Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Chonggang Xu
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| |
Collapse
|
48
|
Huber N, Bugmann H, Lafond V. Capturing ecological processes in dynamic forest models: why there is no silver bullet to cope with complexity. Ecosphere 2020. [DOI: 10.1002/ecs2.3109] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Nica Huber
- Forest Ecology Institute of Terrestrial Ecosystems Department of Environmental Systems Science ETH Zurich Zurich Switzerland
| | - Harald Bugmann
- Forest Ecology Institute of Terrestrial Ecosystems Department of Environmental Systems Science ETH Zurich Zurich Switzerland
| | - Valentine Lafond
- Forest Ecology Institute of Terrestrial Ecosystems Department of Environmental Systems Science ETH Zurich Zurich Switzerland
- Faculty of Forestry Department of Forest Resources Management University of British Columbia Vancouver British Columbia Canada
| |
Collapse
|
49
|
Turner MG, Calder WJ, Cumming GS, Hughes TP, Jentsch A, LaDeau SL, Lenton TM, Shuman BN, Turetsky MR, Ratajczak Z, Williams JW, Williams AP, Carpenter SR. Climate change, ecosystems and abrupt change: science priorities. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190105. [PMID: 31983326 PMCID: PMC7017767 DOI: 10.1098/rstb.2019.0105] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2019] [Indexed: 11/12/2022] Open
Abstract
Ecologists have long studied patterns, directions and tempos of change, but there is a pressing need to extend current understanding to empirical observations of abrupt changes as climate warming accelerates. Abrupt changes in ecological systems (ACES)-changes that are fast in time or fast relative to their drivers-are ubiquitous and increasing in frequency. Powerful theoretical frameworks exist, yet applications in real-world landscapes to detect, explain and anticipate ACES have lagged. We highlight five insights emerging from empirical studies of ACES across diverse ecosystems: (i) ecological systems show ACES in some dimensions but not others; (ii) climate extremes may be more important than mean climate in generating ACES; (iii) interactions among multiple drivers often produce ACES; (iv) contingencies, such as ecological memory, frequency and sequence of disturbances, and spatial context are important; and (v) tipping points are often (but not always) associated with ACES. We suggest research priorities to advance understanding of ACES in the face of climate change. Progress in understanding ACES requires strong integration of scientific approaches (theory, observations, experiments and process-based models) and high-quality empirical data drawn from a diverse array of ecosystems. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.
Collapse
Affiliation(s)
- Monica G. Turner
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - W. John Calder
- Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, USA
| | - Graeme S. Cumming
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Terry P. Hughes
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Anke Jentsch
- Department of Disturbance Ecology, BayCEER, University of Bayreuth, 95440 Bayreuth, Germany
| | | | | | - Bryan N. Shuman
- Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, USA
| | - Merritt R. Turetsky
- Department of Integrative Biology, University of Guelph, Guelph, CanadaN1G 2W1
| | - Zak Ratajczak
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - John W. Williams
- Department of Geography, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - A. Park Williams
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
| | | |
Collapse
|
50
|
Bardgett RD, Caruso T. Soil microbial community responses to climate extremes: resistance, resilience and transitions to alternative states. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190112. [PMID: 31983338 DOI: 10.1098/rstb.2019.0112] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A major challenge for advancing our understanding of the functional role of soil microbial communities is to link changes in their structure and function under climate change. To address this challenge requires new understanding of the mechanisms that underlie the capacity of soil microbial communities to resist and recover from climate extremes. Here, we synthesize emerging understanding of the intrinsic and extrinsic factors that influence the resistance and resilience of soil microbial communities to climate extremes, with a focus on drought, and identify drivers that might trigger abrupt changes to alternative states. We highlight research challenges and propose a path for advancing our understanding of the resistance and resilience of soil microbial communities to climate extremes, and of their vulnerability to transitions to alternative states, including the use of trait-based approaches. We identify a need for new approaches to quantify resistance and resilience of soil microbial communities, and to identify thresholds for transitions to alternative states. We show how high-resolution time series coupled with gradient designs will enable detecting response patterns to interacting drivers. Finally, to account for extrinsic factors, we suggest that future studies should use environmental gradients to track soil microbial community responses to climate extremes in space and time. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.
Collapse
Affiliation(s)
- Richard D Bardgett
- Department of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Tancredi Caruso
- School of Biological Sciences and Institute for Global Food Security, Queen's University of Belfast, Belfast BT9 5DL, UK.,School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| |
Collapse
|