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Jin Y, Hao G, Hammond WM, Yu K, Liu X, Ye Q, Zhou Z, Wang C. Aridity-dependent sequence of water potentials for stomatal closure and hydraulic dysfunctions in woody plants. GLOBAL CHANGE BIOLOGY 2023; 29:2030-2040. [PMID: 36655297 DOI: 10.1111/gcb.16605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/01/2023] [Indexed: 05/28/2023]
Abstract
The sequence of physiological events during drought strongly impacts plants' overall performance. Here, we synthesized the global data of stomatal and hydraulic traits in leaves and stems of 202 woody species to evaluate variations in the water potentials for key physiological events and their sequence along the climatic gradient. We found that the seasonal minimum water potential, turgor loss point, stomatal closure point, and leaf and stem xylem vulnerability to embolism were intercorrelated and decreased with aridity, indicating that water stress drives trait co-selection. In xeric regions, the seasonal minimum water potential occurred at lower water potential than turgor loss point, and the subsequent stomatal closure delayed embolism formation. In mesic regions, however, the seasonal minimum water potential did not pose a threat to the physiological functions, and stomatal closure occurred even at slightly more negative water potential than embolism. Our study demonstrates that the sequence of water potentials for physiological dysfunctions of woody plants varies with aridity, that is, xeric species adopt a more conservative sequence to prevent severe tissue damage through tighter stomatal regulation (isohydric strategy) and higher embolism resistance, while mesic species adopt a riskier sequence via looser stomatal regulation (anisohydric strategy) to maximize carbon uptake at the cost of hydraulic safety. Integrating both aridity-dependent sequence of water potentials for physiological dysfunctions and gap between these key traits into the hydraulic framework of process-based vegetation models would improve the prediction of woody plants' responses to drought under global climate change.
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Affiliation(s)
- Ying Jin
- Key Laboratory of Sustainable Forest Ecosystem Management, Center for Ecological Research, Ministry of Education, Northeast Forestry University, Harbin, China
| | - Guangyou Hao
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - William M Hammond
- Agronomy Department, University of Florida, Gainesville, Florida, USA
| | - Kailiang Yu
- Department of Ecology & Evolutionary Biology, High Meadows Environmental Institute, Princeton University, Princeton, New Jersey, USA
| | - Xiaorong Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Zhenghu Zhou
- Key Laboratory of Sustainable Forest Ecosystem Management, Center for Ecological Research, Ministry of Education, Northeast Forestry University, Harbin, China
| | - Chuankuan Wang
- Key Laboratory of Sustainable Forest Ecosystem Management, Center for Ecological Research, Ministry of Education, Northeast Forestry University, Harbin, China
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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.
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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
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Liu X, Li Q, Wang F, Sun X, Wang N, Song H, Cui R, Wu P, Du N, Wang H, Wang R. Weak Tradeoff and Strong Segmentation Among Plant Hydraulic Traits During Seasonal Variation in Four Woody Species. FRONTIERS IN PLANT SCIENCE 2020; 11:585674. [PMID: 33329647 PMCID: PMC7732674 DOI: 10.3389/fpls.2020.585674] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 11/03/2020] [Indexed: 05/08/2023]
Abstract
Plants may maintain long-term xylem function via efficiency-safety tradeoff and segmentation. Most studies focus on the growing season and community level. We studied species with different efficiency-safety tradeoff strategies, Quercus acutissima, Robinia pseudoacacia, Vitex negundo var. heterophylla, and Rhus typhina, to determine the seasonality of this mechanism. We separated their branches into perennial shoots and terminal twigs and monitored their midday water potential (Ψmd), relative water content (RWC), stem-specific hydraulic conductivity (Ks), loss of 12, 50, and 88% of maximum efficiency (i.e., P12, P50, P88) for 2 years. There were no correlations between water relations (Ψmd, RWC, Ks) and embolism resistance traits (P12, P50, P88) but they significantly differed between the perennial shoots and terminal twigs. All species had weak annual hydraulic efficiency-safety tradeoff but strong segmentation between the perennial shoots and the terminal twigs. R. pseudoacacia used a high-efficiency, low-safety strategy, whereas R. typhina used a high-safety, low-efficiency strategy. Q. acutissima and V. negundo var. heterophylla alternated these strategies. This mechanism provides a potential basis for habitat partitioning and niche divergence in the changing warm temperate zone environment.
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Affiliation(s)
- Xiao Liu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Qiang Li
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Feng Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Xiaohan Sun
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Huijia Song
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Rong Cui
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Pan Wu
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Ning Du
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
| | - Hui Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
- *Correspondence: Hui Wang,
| | - Renqing Wang
- School of Life Sciences, Institute of Ecology and Biodiversity, Shandong University, Qingdao, China
- Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China
- Qingdao Forest Ecology Research Station of National Forestry and Grassland Administration, Shandong University, Qingdao, China
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Drought-Induced Mortality Is Related to Hydraulic Vulnerability Segmentation of Tree Species in a Savanna Ecosystem. FORESTS 2019. [DOI: 10.3390/f10080697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vulnerability segmentation (VS) has been widely suggested to protect stems and trunks from hydraulic failure during drought events. In many ecosystems, some species have been shown to be non-segmented (NS species). However, it is unclear whether drought-induced mortality is related to VS. To understand this, we surveyed the mortality and recruitment rate and measured the hydraulic traits of leaves and stems as well as the photosynthesis of six tree species over five years (2012–2017) in a savanna ecosystem in Southwest China. Our results showed that the NS species exhibited a higher mortality rate than the co-occurring VS species. Across species, the mortality rate was not correlated with xylem tension at 50% loss of stem hydraulic conductivity (P50stem), but was rather significantly correlated with leaf water potential at 50% loss of leaf hydraulic conductance (P50leaf) and the difference in water potential at 50% loss of hydraulic conductance between the leaves and terminal stems (P50leaf-stem). The NS species had higher Huber values and maximum net photosynthetic rates based on leaf area, which compensated for a higher mortality rate and promoted rapid regeneration under the conditions of dry–wet cycles. To our knowledge, this study is the first to identify the difference in drought-induced mortality between NS species and VS species. Our results emphasize the importance of VS in maintaining hydraulic safety in VS species. Furthermore, the high mortality rate and fast regeneration in NS species may be another hydraulic strategy in regions where severe seasonal droughts are frequent.
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