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Zhang Y, Gou X, Wang T, Zhang F, Wang K, Yang H, Yang K. Response of tree growth to drought variability in arid areas: Local hydroclimate and large-scale precipitation. ENVIRONMENTAL RESEARCH 2024; 249:118417. [PMID: 38316385 DOI: 10.1016/j.envres.2024.118417] [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: 10/06/2023] [Revised: 01/21/2024] [Accepted: 02/02/2024] [Indexed: 02/07/2024]
Abstract
The impact of drought on terrestrial ecosystems is increasing, and the spatiotemporal heterogeneity of drought changes exacerbates the difficulty of determining ecosystem responses, especially in arid regions far from oceans. Tree rings have been widely used to understand how forest ecosystems respond to drought. However, the link between local hydroclimate variations related to tree rings and large-scale climate changes is not clear in the Qilian Mountains. Here, we used the tree ring width index to analyze the trend of Picea crassifolia growth and its relationship with climate in the middle Qilian Mountains. The results showed that the radial growth trend of Picea crassifolia is synchronized in the middle Qilian Mountains by calculating the Gleichläufigkeit index (GLK). Our analyses indicated that tree radial growth is positively correlated with drought during the growing season. Tree growth responds stably to drought (scPDSI and SPEI) and precipitation but unstably to temperature during 1950-2019. We further traced the meteorological factors that cause regional drought changes associated with radial growth. An increased total precipitation and decreased evaporation contribute to drought alleviation, favoring an increased tree radial growth. The increased total precipitation is mainly due to increased large-scale precipitation, which is related to water vapor transport changes. This study attempts to explore the influence of large-scale meteorology on regional drought change and its related tree radial growth response, which helps us to better understand the changes in forest ecosystems under climate change.
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Affiliation(s)
- Yiran Zhang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Xiaohua Gou
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China.
| | - Tao Wang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Fen Zhang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Kai Wang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Haijiang Yang
- MOE Key Laboratory of Western China's Environmental Systems, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou, China
| | - Kaixuan Yang
- College of Geographic Sciences, Qinghai Normal University, Xining, 810016, China; Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Xining, 810016, China
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Pernicová N, Urban O, Čáslavský J, Kolář T, Rybníček M, Sochová I, Peñuelas J, Bošeľa M, Trnka M. Impacts of elevated CO 2 levels and temperature on photosynthesis and stomatal closure along an altitudinal gradient are counteracted by the rising atmospheric vapor pressure deficit. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:171173. [PMID: 38401718 DOI: 10.1016/j.scitotenv.2024.171173] [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: 12/04/2023] [Revised: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
The efficiency of water use in plants, a critical ecophysiological parameter closely related to water and carbon cycles, is essential for understanding the interactions between plants and their environment. This study investigates the effects of ongoing climate change and increasing atmospheric CO2 concentration on intrinsic (stomata-based; iWUE) and evaporative (transpiration-based; eWUE) water use efficiency in oak trees along a naturally small altitudinal gradient (130-630 m a.s.l.) of Vihorlat Mountains (eastern Slovakia, Central Europe). To assess changes in iWUE and eWUE values over the past 60 years (1961-2020), stable carbon isotope ratios in latewood cellulose (δ13Ccell) of annually resolved tree rings were analyzed. Such an approach was sensitive enough to distinguish tree responses to growth environments at different altitudes. Our findings revealed a rising trend in iWUE, particularly in oak trees at low and middle altitudes. However, this increase was negligible at high altitudes. Warmer and drier conditions at lower altitudes likely led to significant stomatal closure and enhanced efficiency in photosynthetic CO2 uptake due to rising CO2 concentration. Conversely, the increasing intracellular-to-ambient CO2 ratio (Ci/Ca) at higher altitudes indicated lower efficiency in photosynthetic CO2 uptake. In contrast to iWUE, eWUE showed no increasing trends over the last 60 years. This suggests that the positive impacts of elevated CO2 concentrations and temperature on photosynthesis and stomatal closure are counteracted by the rising atmospheric vapor pressure deficit (VPD). These differences underscore the importance of the correct interpretation of stomata-based and transpiration-based WUEs and highlight the necessity of atmospheric VPD correction when applying tree-ring δ13C-derived WUE at ecosystem and global levels.
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Affiliation(s)
- Natálie Pernicová
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic; Mendel University in Brno, Department of Agrosystems and Bioclimatology, Faculty of AgriSciences, Zemědělská 1, CZ-613 00 Brno, Czech Republic
| | - Otmar Urban
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic.
| | - Josef Čáslavský
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic
| | - Tomáš Kolář
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic; Mendel University in Brno, Department of Wood Science and Technology, Faculty of Forestry and Wood Technology, Zemědělská 1, CZ-613 00 Brno, Czech Republic
| | - Michal Rybníček
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic; Mendel University in Brno, Department of Wood Science and Technology, Faculty of Forestry and Wood Technology, Zemědělská 1, CZ-613 00 Brno, Czech Republic
| | - Irena Sochová
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic; Mendel University in Brno, Department of Wood Science and Technology, Faculty of Forestry and Wood Technology, Zemědělská 1, CZ-613 00 Brno, Czech Republic
| | - Josep Peñuelas
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic; CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra 08193, Catalonia, Spain; CREAF, Cerdanyola del Vallès 08193, Catalonia, Spain
| | - Michal Bošeľa
- Faculty of Forestry, Technical University in Zvolen, T. G. Masaryka 24, SK-960 01 Zvolen, Slovakia
| | - Miroslav Trnka
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, CZ-603 00 Brno, Czech Republic; Mendel University in Brno, Department of Agrosystems and Bioclimatology, Faculty of AgriSciences, Zemědělská 1, CZ-613 00 Brno, Czech Republic
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Dastigerdi M, Nadi M, Sarjaz MR, Kiapasha K. Trend analysis of MODIS NDVI time series and its relationship to temperature and precipitation in Northeastern of Iran. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:346. [PMID: 38443602 DOI: 10.1007/s10661-024-12463-y] [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: 06/06/2023] [Accepted: 02/17/2024] [Indexed: 03/07/2024]
Abstract
Vegetation plays a crucial role in providing organic matter and regulating energy exchange on the Earth's surface. This study investigates the changes in vegetation cover, temperature, and precipitation in northeastern Iran during 2001-2020. MODIS-NDVI time series data and climatic data from 11 synoptic stations were utilized. The nonparametric Mann-Kendall method was employed to detect trends in vegetation cover and climatic variables. Additionally, the correlation between climatic parameters and vegetation was examined. Trend analysis revealed significant increases/decreases in vegetation cover in 32%/26% of the region, respectively. The increasing trend in vegetation cover was predominantly observed in highlands, suggesting that a warmer climate has enhanced the living conditions for plants in these regions. The vegetation trend map indicates an expansion of vegetation cover in the northern and central parts of Iran during the past 20 years, whereas the southern and eastern portions experienced declines. The relationship between vegetation and elevation revealed that vegetation increased above 1,850 m and decreased below 850 m. Trend analysis showed no significant trend in precipitation data since the beginning of the twenty-first century, but an increasing trend in temperature was observed in 82% of the region's area, excluding the western strip. Correlation coefficients between temperature, precipitation, and vegetation indicated that declining temperatures are the limiting factors for vegetation in the highlands, while in lowland areas, the decrease in precipitation significantly diminishes vegetation growth.
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Affiliation(s)
- Morteza Dastigerdi
- Department of Water Engineering, Sari Agricultural sciences and Natural Resources University, Sari, Iran
| | - Mehdi Nadi
- Department of Water Engineering, Sari Agricultural sciences and Natural Resources University, Sari, Iran.
| | - Mahmoud Raeini Sarjaz
- Department of Water Engineering, Sari Agricultural sciences and Natural Resources University, Sari, Iran
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Zhai B, Hu Z, Sun S, Tang Z, Wang G. Characteristics of photosynthetic rates in different vegetation types at high-altitude in mountainous regions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:168071. [PMID: 37898202 DOI: 10.1016/j.scitotenv.2023.168071] [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: 07/03/2023] [Revised: 10/20/2023] [Accepted: 10/21/2023] [Indexed: 10/30/2023]
Abstract
Mountains play an important role in the carbon cycle of the terrestrial ecosystem and are one of the most sensitive ecosystems to climate change. However, our current knowledge regarding the physiological responses of alpine plants to environmental changes remains limited due to the severe climatic conditions prevailing in these high-altitude regions. Therefore, this study quantified the variations in photosynthetic rates (An) and identified their driving factors of herbaceous plants, shrubs, and trees along an elevation gradient (2200 m asl to 3200 m asl) on Mount Gongga. Elevation emerged as a significant determinant of An, with a general increase observed, albeit followed by a decline above 3000 m asl. In high-altitude regions, trees displayed more significant fluctuations in An compared to herbaceous plants and shrubs. The lower levels of atmospheric carbon dioxide concentration (eCO2) and temperature in high-altitude regions resulted in a 16 % increase in An for herbaceous plants, 60 % increase for shrubs, and 43 % increase for trees compared to the low-altitude areas. Structural equation modeling (SEM) analyses underscored the considerable impact of environmental factors on An. Notably, photosynthetically active radiation, eCO2, and stomatal conductance were identified as positive influencers, while other factors exerted negative effects. Our results further highlighted that trees were subject to greater constraints from multiple factors compared to herbs and shrubs, aligning with the outcomes of our variance analysis. In summary, our study presents a comprehensive assessment of vegetation responses to environmental factors along elevational gradients. The significance of An in plants at high altitude to external factors suggests the potential adaptability of alpine plants, and also indicates that changes in photosynthetic physiological functions at high altitude should be paid more attention to in the study of climate change.
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Affiliation(s)
- Biying Zhai
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China
| | - Zhaoyong Hu
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China.
| | - Shouqin Sun
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China.
| | - Zishu Tang
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China
| | - Genxu Wang
- State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource and Hydropower, Sichuan University, Chengdu 610044, China
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Cao Z, Zhang J, Gou X, Wang Y, Sun Q, Yang J, Manzanedo RD, Pederson N. Increasing forest carbon sinks in cold and arid northeastern Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167168. [PMID: 37730072 DOI: 10.1016/j.scitotenv.2023.167168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/21/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023]
Abstract
Arid forest lands account for 6 % of the world's forest area, but their carbon density and carbon storage capacity have rarely been assessed. Forest inventories provide estimates of forest stock and biomass carbon density, improve our understanding of the carbon cycle, and help us develop sustainable forest management policies in the face of climate change. Here, we carried out three forest inventories at five-year intervals from 2006 to 2016 in 104 permanent sample plots covering the Qinghai spruce (Picea crassifolia) distribution in the north slope of Qilian Mountains, northeastern Tibetan Plateau. Results shows that mean biomasses for Qinghai spruce were 133.80, 144.89, and 157.01 Mg ha-1 while biomass carbon densities were 65.52, 70.92, and 76.88 Mg C ha-1, in 2006, 2011, and 2016, respectively. This shows an increase in the Qinghai spruce carbon density of 17.34 % from 2006 to 2016. Both the precipitation and temperature play crucial roles on the increase of aboveground carbon density. The average carbon densities were different among forests with different ages and were higher for older forests. Our results show that the carbon sequestration rate for Qinghai spruce in the Qilian Mountains is significantly higher than the average rates of national forest parks in China, suggesting that this spruce forest has the potential to sequester a significant amount of carbon despite the general harsh growing conditions of cold and arid ecoregions. Our findings provide important insights that are helpful for the assessment of forest carbon for cold and arid lands.
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Affiliation(s)
- Zongying Cao
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou University, Lanzhou 730333, China
| | - Junzhou Zhang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou University, Lanzhou 730333, China.
| | - Xiaohua Gou
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou University, Lanzhou 730333, China.
| | - Yuetong Wang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou University, Lanzhou 730333, China
| | - Qipeng Sun
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou University, Lanzhou 730333, China
| | - Jiqin Yang
- Key Laboratory of Western China's Environmental Systems (Ministry of Education), College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China; Gansu Liancheng Forest Ecosystem Field Observation and Research Station, Lanzhou University, Lanzhou 730333, China; Liancheng National Nature Reserve in Gansu, Lanzhou 730300, China
| | - Rubén D Manzanedo
- Plant Ecology, Institute of Integrative Biology, D-USYS, ETH-Zürich, 8006 Zürich, Switzerland
| | - Neil Pederson
- Harvard Forest, Harvard University, Petersham, MA 01366, USA
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Seyedin SMV, Mojtahedi M, Farhangfar SH, Ghavipanje N. Partial substitution of alfalfa hay by Berberis vulgaris leaf modulated the growth performance, meat quality and antioxidant status of fattening lambs. Vet Med Sci 2022; 8:2605-2615. [PMID: 36112758 PMCID: PMC9677374 DOI: 10.1002/vms3.934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Undoubtedly, global warming has caused a decrease in the production of agricultural commodities. This problem has increased the price of animal feed due to competition with human consumption. Meanwhile, the physiology of ruminants gives them the ability to use by-products and agricultural waste and supply their requirements for growth, maintenance and even production. Berberis vulgaris is a plant native to Iran, and after separating the fruit, its waste (mainly leaf) is unused and causes environmental pollution. The leaves of this plant contain significant amounts of phenolic compounds, alkaloids and anthocyanins that have antioxidant properties. OBJECTIVES This experiment was conducted with the aim of determining the chemical properties of barberry leaves, such as crude protein, phenolic compounds, tannins and alkaloids. The effects of substituting of B. vulgaris leaf (BVL) in the diet on performance characteristics of fattening Baluchi lambs were evaluated. The quality and antioxidant status of meat and blood parameters such as glucose, cholesterol, blood urea nitrogen and liver enzymes were investigated. MATERIAL AND METHODS A total of 21 male of 5-6 months old lambs with a mean body weight of 30.60 ± 1.28 kg were randomly assigned to one of three dietary treatments with different levels of BVL: 1-diet without BVL (control), 2-diet containing 7.5% BVL (BVL7.5), and 3-diet containing 15% BVL (BVL15; dry matter [DM] basis). Blood samples were harvested after overnight fasting from the jugular vein at 0, 28, 56 and 84 days. The lambs were slaughtered after 84 days of feeding trial and longissimus dorsi (LD) muscle was dissected. Meat quality and antioxidant stability status were measured. RESULTS 15% substitution of alfalfa hay by BVL (BVL15) increased DM intake) and decreased average daily gain (p ≤ 0.05). The LD muscle (p ≤ 0.05), liver (p ≤ 0.01) and plasma (p ≤ 0.05) samples of lambs fed either BVL7.5 or BVL15 displayed a greater total antioxidant capacity than that of lambs fed the control diet. Also, malondialdehyde concentration was decreased in plasma (p ≤ 0.01) and LD muscle of lambs (p ≤ 0.05) fed both BVL7.5 and BVL15. In addition, higher a* and C* values (p ≤ 0.05) were observed in the meat of lambs fed BVL15 than those fed with the control, while the lightness (L*) in BVL15 was lower, compared to other experimental diets CONCLUSIONS: Overall, our results indicated that 7.5% substitution of alfalfa hay by BVL may positively modulate the antioxidant status of fattening lambs and improve the colour stability of meat without negative effects on performance characteristics.
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Affiliation(s)
| | - Mohsen Mojtahedi
- Department of Animal ScienceFaculty of AgricultureUniversity of BirjandBirjandIran
| | | | - Navid Ghavipanje
- Department of Animal ScienceFaculty of AgricultureUniversity of BirjandBirjandIran
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Jia H, Guan C, Zhang J, He C, Yin C, Meng P. Drought effects on tree growth, water use efficiency, vulnerability and canopy health of Quercus variabilis-Robinia pseudoacacia mixed plantation. FRONTIERS IN PLANT SCIENCE 2022; 13:1018405. [PMID: 36311079 PMCID: PMC9597382 DOI: 10.3389/fpls.2022.1018405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Drought-induced forest canopy die-back and tree mortality have been commonly recorded in the lithoid mountainous regions of northern China. However, the capacity of trees to regulate their carbon and water balance in response to drought remains inadequately understood. We measured tree growth, intrinsic water use efficiency (iWUE), vulnerability, and canopy health during drought events using dendrochronology, C isotope measurements, and a tree canopy health survey in a mixed plantation of Quercus variabilis and Robinia pseudoacacia. Resistance (Rt), recovery (Rc), resilience (Rs), and increased amplitude in iWUE compared to the indices 3 years before drought (iWUEr) were calculated for each species across the dominant tree (D), co-dominant tree (CD), and suppressed tree (S). Our results revealed that D and CD showed lower Rt, higher Rc, and higher iWUEr than S. After exposure to multiple sequential drought events, Q. variabilis showed an increasing trend in Rt, and R. pseudoacacia showed a decreasing trend in Rc. R. pseudoacacia exhibited a more conservative strategy towards drought, resulting in a negative SRt-iWUEr (slope of the linear model fitted to capture the trend between Rt and iWUEr) during drought events than Q. variabilis. For individual trees, lower Rc or positive SRt-iWUEr Q. variabilis and negative SRt-iWUEr R. pseudoacacia were more susceptible to canopy die-back. In conclusion, our study offers a new perspective for improved management practices in the design of silvicultural actions for forestry plantations in lithoid mountainous areas with increasing drought risk.
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Affiliation(s)
- HanSen Jia
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing, China
- Henan Xiaolangdi Earth Critical Zone National Research Station on the Middle Yellow River, Jiyuan, China
| | - ChongFan Guan
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing, China
- Henan Xiaolangdi Earth Critical Zone National Research Station on the Middle Yellow River, Jiyuan, China
| | - JinSong Zhang
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing, China
- Henan Xiaolangdi Earth Critical Zone National Research Station on the Middle Yellow River, Jiyuan, China
| | - ChunXia He
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing, China
- Henan Xiaolangdi Earth Critical Zone National Research Station on the Middle Yellow River, Jiyuan, China
| | - ChangJun Yin
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing, China
- Henan Xiaolangdi Earth Critical Zone National Research Station on the Middle Yellow River, Jiyuan, China
| | - Ping Meng
- Key Laboratory of Tree Breeding and Cultivation, National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forest University, Nanjing, China
- Henan Xiaolangdi Earth Critical Zone National Research Station on the Middle Yellow River, Jiyuan, China
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Fan B, Ma Z, Gao P, Lu J, Ding N, Sun K. Functional Traits of Male and Female Leaves of Hippophae tibetana on the Eastern Edge of the Tibetan Plateau and Their Altitudinal Variability. PLANTS (BASEL, SWITZERLAND) 2022; 11:2484. [PMID: 36235349 PMCID: PMC9573225 DOI: 10.3390/plants11192484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
To date, there have been few studies of the functional traits of the dioecious Hippophae tibetana Schlecht leaves, either male or female, in response to ecological factors such as altitude. Elucidating these relationships will establish an important scientific basis for vegetation restoration and reconstruction of the Tibetan Plateau ecosystem. The natural populations of H. tibetana, distributed across three field sites, at 2868 m, 3012 m and 3244 m, in Tianzhu, Gansu, were studied by field survey sampling and laboratory analysis. In particular, the adaptions of leaf functional traits to elevation in these dioecious plants were analyzed. The results show that: (1) there is no “midday depression” of photosynthetic activity in either male or female plants. Over a one-day period, the net photosynthetic rate (Pn) and transpiration rate (Tr) of H. tibetana female plants were higher than those of male plants (p < 0.05). This correlated to the period of vigorous fruit growth in the female plant. The measured Pn and Tr were maximal at the intermediate altitude (3012 m). The light compensation point (LCP) of the leaves of male and female plants were 57.6 and 43.2 μmol·m−2·s−1, respectively, and the light saturation points (LSP) of the leaves were 1857.6 and 1596.8 μmol·m−2·s−1. (2) Altitude had a significant effect on plant and leaf functional traits of male and female H. tibetana (p < 0.05), and no significant difference was noted between plants at the same altitude. The values for leaf area (LA), specific leaf weight (LMA), leaf phosphorus content per unit mass (Pmass) and leaf phosphorus content per unit area (Parea) were also maximal at the intermediate altitude. Leaf nitrogen content per unit area (Narea) and leaf nitrogen content per unit mass (Nmass) increased with altitude. This indicated that the functional traits of male and female plants and leaves of H. tibetana showed a strong “trade-off relationship” with altitude. (3) Pearson correlation analysis showed that there were significant correlations among functional traits of H. tibetana leaves. Redundancy analysis (RDA) showed that soil water content (SWC), altitude (Alt) and soil organic carbon (SOC) had significant effects on the functional traits of H. tibetana leaves (p < 0.05).
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Moradi E, Darabi H, Heydari E, Karimi M, Kløve B. Vegetation vulnerability to hydrometeorological stresses in water-scarce areas using machine learning and remote sensing techniques. ECOL INFORM 2022. [DOI: 10.1016/j.ecoinf.2022.101838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Jia G, Chen L, Yu X, Liu Z. Soil water stress overrides the benefit of water-use efficiency from rising CO 2 and temperature in a cold semi-arid poplar plantation. PLANT, CELL & ENVIRONMENT 2022; 45:1172-1186. [PMID: 35037279 DOI: 10.1111/pce.14260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 09/15/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
The counteractive effect of atmospheric CO2 (ca ) enrichment and drought stress on tree growth results in great uncertainty in the growth patterns of forest plantations in cold semi-arid regions. We analysed tree ring chronologies and carbon isotopes in Populus simonii plantations in cold semi-arid areas in northern China over the past four decades. We hypothesized that the hydraulic stress from drought would override the stimulating effect of increasing ca and temperature (T) on stem growth (basal area increment [BAI]). We found the stimulating effect of rising ca and T on the growth, indicated by continuous increase of intrinsic water-use efficiency in all stands and a positive correlation between T and BAI. However, these effects failed to alleviate the negative impacts of drought on tree growth. Concurrent acceleration of BAI reversed during the intensive drought episodes. Water stress resulted from inaccessibility of roots to deep soil water rather than from lack of precipitation, suggested by the decoupling of BAI from precipitation and vapour pressure deficit. Local soil water limitation might also cause greater stomatal regulation in declining trees, indicated by lower intercellular CO2 concentration. Thus, site-specific soil moisture conditions growth sensitivity to global warming resulting in site-specific decline episodes in drought-prone areas.
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Affiliation(s)
- Guodong Jia
- Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Lixin Chen
- Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Xinxiao Yu
- Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Forestry University, Beijing, China
- School of Soil and Water Conservation, Beijing Forestry University, Beijing, China
| | - Ziqiang Liu
- School of Forestry, Nanjing Forestry University, Nanjing, China
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11
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Li Y, Zhang X, Shao Q, Fan J, Chen Z, Dong J, Hu Z, Zhan Y. Community Composition and Structure Affect Ecosystem and Canopy Water Use Efficiency Across Three Typical Alpine Ecosystems. FRONTIERS IN PLANT SCIENCE 2022; 12:771424. [PMID: 35126410 PMCID: PMC8810523 DOI: 10.3389/fpls.2021.771424] [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: 09/06/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
Unique ecosystems distributed in alpine areas of the Qinghai-Tibetan Plateau play important roles in climate change mitigation, local food supply, and conservation of species diversity. To understand the water use efficiency (WUE) of this fragile and sensitive region, this study combined observed data from the eddy covariance system and the Shuttleworth-Wallace (S-W) model to measure the continuous mass exchange, including gross primary productivity (GPP), evapotranspiration (ET), and canopy transpiration (T) throughout 2 or 3 years (2016-2018) in three common alpine ecosystems (i.e., alpine steppe, alpine meadow, and alpine swamp). These ecosystems represent a water availability gradient and thus provide the opportunity to quantify environmental and biological controls on WUE at various spatiotemporal scales. We analyzed the ecosystem WUE (WUEe; defined as the ratio of GPP to ET) and canopy WUE (WUEc; defined as the ratio of GPP and canopy T). It was found that the yearly WUEe was 1.40, 1.63, and 2.16 g C kg-1 H2O, and the yearly WUEc was 8.93, 2.46, and 5.19 g C kg-1 H2O in the three typical ecosystems, respectively. The controlling factors of yearly WUE diverged between WUEe and WUEc. We found that plant functional group proportion (e.g., gramineous and Cyperaceae) highly explained the yearly WUEe variation across sites, and a good correlation was observed between community species diversity and WUEc. These findings suggest that community composition and trait change are critical in regulating WUEe and WUEc across different alpine ecosystems and that the regulation mechanisms may differ fundamentally between WUEe and WUEc.
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Affiliation(s)
- Yuzhe Li
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Xinyuan Zhang
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
- School of Earth Sciences and Resources, China University of Geosciences, Beijing, China
| | - Quanqin Shao
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Jiangwen Fan
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Zhi Chen
- Key Laboratory of Ecosystem Network Observation and Modeling, Synthesis Research Center of Chinese Ecosystem Research Network, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Jinwei Dong
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Zhongmin Hu
- School of Geography, South China Normal University, Guangzhou, China
| | - Yue Zhan
- College of Forestry, Nanjing Forestry University, Nanjing, China
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12
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Liu X, Ziaco E, Biondi F. Water-Use Efficiency of Co-occurring Sky-Island Pine Species in the North American Great Basin. FRONTIERS IN PLANT SCIENCE 2021; 12:787297. [PMID: 34925427 PMCID: PMC8678526 DOI: 10.3389/fpls.2021.787297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/02/2021] [Indexed: 06/14/2023]
Abstract
Water-use efficiency (WUE), weighing the balance between plant transpiration and growth, is a key characteristic of ecosystem functioning and a component of tree drought resistance. Seasonal dynamics of tree-level WUE and its connections with drought variability have not been previously explored in sky-island montane forests. We investigated whole-tree transpiration and stem growth of bristlecone (Pinus longaeva) and limber pine (Pinus flexilis) within a high-elevation stand in central-eastern Nevada, United States, using sub-hourly measurements over 5 years (2013-2017). A moderate drought was generally observed early in the growing season, whereas interannual variability of summer rains determined drought levels between years, i.e., reducing drought stress in 2013-2014 while enhancing it in 2015-2017. Transpiration and basal area increment (BAI) of both pines were coupled throughout June-July, resulting in a high but relatively constant early season WUE. In contrast, both pines showed high interannual plasticity in late-season WUE, with a predominant role of stem growth in driving WUE. Overall, bristlecone pine was characterized by a lower WUE compared to limber pine. Dry or wet episodes in the late growing season overrode species differences. Our results suggested thresholds of vapor pressure deficit and soil moisture that would lead to opposite responses of WUE to late-season dry or wet conditions. These findings provide novel insights and clarify potential mechanisms modulating tree-level WUE in sky-island ecosystems of semi-arid regions, thereby helping land managers to design appropriate science-based strategies and reduce uncertainties associated with the impact of future climatic changes.
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Affiliation(s)
- Xinsheng Liu
- School of Geography and Tourism, Anhui Normal University, Wuhu, China
- DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, United States
- College of Tourism and Geography, Jiujiang University, Jiujiang, China
| | - Emanuele Ziaco
- Department of Ecology and Genetics, Plant Ecology and Evolution, University of Uppsala, Uppsala, Sweden
| | - Franco Biondi
- DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, United States
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Beaulne J, Boucher É, Garneau M, Magnan G. Paludification reduces black spruce growth rate but does not alter tree water use efficiency in Canadian boreal forested peatlands. FOREST ECOSYSTEMS 2021; 8:28. [PMID: 34721933 PMCID: PMC8550502 DOI: 10.1186/s40663-021-00307-x] [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: 08/10/2020] [Accepted: 04/15/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Black spruce (Picea mariana (Mill.) BSP)-forested peatlands are widespread ecosystems in boreal North America in which peat accumulation, known as the paludification process, has been shown to induce forest growth decline. The continuously evolving environmental conditions (e.g., water table rise, increasing peat thickness) in paludified forests may require tree growth mechanism adjustments over time. In this study, we investigate tree ecophysiological mechanisms along a paludification gradient in a boreal forested peatland of eastern Canada by combining peat-based and tree-ring analyses. Carbon and oxygen stable isotopes in tree rings are used to document changes in carbon assimilation rates, stomatal conductance, and water use efficiency. In addition, paleohydrological analyses are performed to evaluate the dynamical ecophysiological adjustments of black spruce trees to site-specific water table variations. RESULTS Increasing peat accumulation considerably impacts forest growth, but no significant differences in tree water use efficiency (iWUE) are found between the study sites. Tree-ring isotopic analysis indicates no iWUE decrease over the last 100 years, but rather an important increase at each site up to the 1980s, before iWUE stabilized. Surprisingly, inferred basal area increments do not reflect such trends. Therefore, iWUE variations do not reflect tree ecophysiological adjustments required by changes in growing conditions. Local water table variations induce no changes in ecophysiological mechanisms, but a synchronous shift in iWUE is observed at all sites in the mid-1980s. CONCLUSIONS Our study shows that paludification induces black spruce growth decline without altering tree water use efficiency in boreal forested peatlands. These findings highlight that failing to account for paludification-related carbon use and allocation could result in the overestimation of aboveground biomass production in paludified sites. Further research on carbon allocation strategies is of utmost importance to understand the carbon sink capacity of these widespread ecosystems in the context of climate change, and to make appropriate forest management decisions in the boreal biome. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s40663-021-00307-x.
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Affiliation(s)
- Joannie Beaulne
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- GRIL-UQAM, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
| | - Étienne Boucher
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Centre d’études nordiques, Université Laval, Montréal, Québec G1V 0A6 Canada
| | - Michelle Garneau
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- GRIL-UQAM, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Centre d’études nordiques, Université Laval, Montréal, Québec G1V 0A6 Canada
| | - Gabriel Magnan
- Geotop Research Center, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- Department of Geography, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
- GRIL-UQAM, Université du Québec à Montréal, Montréal, Québec H3C 3P8 Canada
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14
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Rayback SA, Belmecheri S, Gagen MH, Lini A, Gregory R, Jenkins C. North American temperate conifer (Tsuga canadensis) reveals a complex physiological response to climatic and anthropogenic stressors. THE NEW PHYTOLOGIST 2020; 228:1781-1795. [PMID: 33439504 DOI: 10.1111/nph.16811] [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: 03/16/2020] [Accepted: 07/03/2020] [Indexed: 05/08/2023]
Abstract
Rising atmospheric CO2 (ca) is expected to promote tree growth and lower water loss via changes in leaf gas exchange. However, uncertainties remain if gas-exchange regulation strategies are homeostatic or dynamical in response to increasing ca, as well as evolving climate and pollution inputs. Using a suite of tree ring-based δ13C-derived physiological parameters (Δ13C, ci, iWUE) and tree growth from a mesic, low elevation stand of canopy-dominant Tsuga canadensis in north-eastern USA, we investigated the influence of rising ca, climate and pollution on, and characterised the dynamical regulation strategy of, leaf gas exchange at multidecadal scales. Isotopic and growth time series revealed an evolving physiological response in which the species shifted its leaf gas-exchange strategy dynamically (constant ci; constant ci/ca; constant ca - ci) in response to rising ca, moisture availability and site conditions over 111 yr. Tree iWUE plateaued after 1975, driven by greater moisture availability and a changing soil biogeochemistry that may have impaired a stomatal response. Results suggested that trees may exhibit more complex physiological responses to the changing environmental conditions over multidecadal periods, and complicating the parameterisation of Earth system models and the estimation of future carbon sink capacity and water balance in midlatitude forests and elsewhere.
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Affiliation(s)
- Shelly A Rayback
- Department of Geography, University of Vermont, 207 Old Mill Building, 94 University Place, Burlington, VT, 05405, USA
| | - Soumaya Belmecheri
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, 85721, USA
| | - Mary H Gagen
- Department of Geography, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Andrea Lini
- Department of Geology, University of Vermont, 319 Delehanty Hall, 180 Colchester Avenue, Burlington, VT, 05405, USA
| | - Rachel Gregory
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK
| | - Catherine Jenkins
- School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, UK
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15
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Marchand W, Girardin MP, Hartmann H, Depardieu C, Isabel N, Gauthier S, Boucher É, Bergeron Y. Strong overestimation of water-use efficiency responses to rising CO 2 in tree-ring studies. GLOBAL CHANGE BIOLOGY 2020; 26:4538-4558. [PMID: 32421921 DOI: 10.1111/gcb.15166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/25/2020] [Indexed: 06/11/2023]
Abstract
The carbon isotope ratio (δ13 C) in tree rings is commonly used to derive estimates of the assimilation-to-stomatal conductance rate of trees, that is, intrinsic water-use efficiency (iWUE). Recent studies have observed increased iWUE in response to rising atmospheric CO2 concentrations (Ca ), in many different species, genera and biomes. However, increasing rates of iWUE vary widely from one study to another, likely because numerous covarying factors are involved. Here, we quantified changes in iWUE of two widely distributed boreal conifers using tree samples from a forest inventory network that were collected across a wide range of growing conditions (assessed using the site index, SI), developmental stages and stand histories. Using tree-ring isotopes analysis, we assessed the magnitude of increase in iWUE after accounting for the effects of tree size, stand age, nitrogen deposition, climate and SI. We also estimated how growth conditions have modulated tree physiological responses to rising Ca . We found that increases in tree size and stand age greatly influenced iWUE. The effect of Ca on iWUE was strongly reduced after accounting for these two variables. iWUE increased in response to Ca , mostly in trees growing on fertile stands, whereas iWUE remained almost unchanged on poor sites. Our results suggest that past studies could have overestimated the CO2 effect on iWUE, potentially leading to biased inferences about the future net carbon balance of the boreal forest. We also observed that this CO2 effect is weakening, which could affect the future capacity of trees to resist and recover from drought episodes.
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Affiliation(s)
- William Marchand
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn Noranda, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Martin P Girardin
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn Noranda, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Henrik Hartmann
- Department of Biogeochemical Processes, Max-Planck Institute for Biogeochemistry, Jena, Germany
| | - Claire Depardieu
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
- Chaire de recherche du Canada en génomique forestière, Université Laval, Sainte-Foy, QC, Canada
| | - Nathalie Isabel
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
- Chaire de recherche du Canada en génomique forestière, Université Laval, Sainte-Foy, QC, Canada
| | - Sylvie Gauthier
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Quebec City, QC, Canada
| | - Étienne Boucher
- GEOTOP, Université du Québec à Montréal, Montreal, QC, Canada
- Department of Geography, Université du Québec à Montréal, Montreal, QC, Canada
- Centre d'Études Nordiques, Université Laval, Quebec City, QC, Canada
| | - Yves Bergeron
- Centre d'étude de la forêt, Université du Québec à Montréal, Montreal, QC, Canada
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn Noranda, QC, Canada
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16
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Retrospective Analysis of Tree Decline Based on Intrinsic Water-Use Efficiency in Semi-Arid Areas of North China. ATMOSPHERE 2020. [DOI: 10.3390/atmos11060577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Long-term tree growth is significantly affected by climate change, which have become a global concern. Tree-ring width and isotopic information can show how trees respond to climate change on a long-term scale and reveal some phenomena of tree decline or death. In this study, we used isotopic techniques and investigated annual changes in carbon isotope composition and tree-ring width of Populus simonii Carr. in Zhangbei, as well as trends in tree-ring carbon discrimination (Δ13C) and iWUE in normal, mildly declining and severely declining trees, in order to make a retrospective analysis and further understand the process of tree decline. We found that there were significant differences (p < 0.01 **) in δ13C, Δ13C, ci and iWUE at different decline stages, meaning that the δ13C and iWUE could be new indicators of tree health. The iWUE of all groups increased significantly, while the growth rate of declined P. simonii was much higher than that of normal growth P. simonii. According to the analysis, there may be a threshold of iWUE for healthy trees, which once the threshold value is exceeded, it indicates that trees are resistant to adversity and their growth is under stress. Similarly, the changing trend of BAI supports our conclusion with its changes showed that tree growth became slower and slower as degradation progressed. iWUE inferred from tree-ring stable carbon isotope composition is a strong modulator of adaptation capacity in response to environmental stressors under climate change. Elevated annual temperatures and increased groundwater depth are all contributing to the decline of P. simonii in north China.
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17
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Weiwei LU, Xinxiao YU, Guodong JIA, Hanzhi LI, Ziqiang LIU. Responses of Intrinsic Water-use Efficiency and Tree Growth to Climate Change in Semi-Arid Areas of North China. Sci Rep 2018; 8:308. [PMID: 29321679 PMCID: PMC5762888 DOI: 10.1038/s41598-017-18694-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/13/2017] [Indexed: 11/19/2022] Open
Abstract
Tree-level intrinsic water-use efficiency (iWUE) is derived from the tree-ring 13C isotope composition (δ13C) and is an important indicator of the adaptability for trees to climate change. However, there is still uncertainty regarding the relationship between long-term forest ecosystem carbon sequestration capacity and iWUE. To determine whether elevated atmospheric CO2 concentration (Ca) increase iWUE and tree growth (basal area increment, BAI), dendrochronological methods and stable isotope analyses were used to examine annual changes in the tree-ring width and carbon isotope composition (δ13C) of Platycladus orientalis in northern China. The iWUE derived from δ13C has increased significantly (p < 0.01). Long-term iWUE trend was largely and positively driven by the elevated atmospheric CO2 concentration and temperature. We observed a general increase in averaged BAI, which had significant positive correlation with iWUE (R2 = 0.3186, p < 0.01). Increases in iWUE indeed translated into enhanced P. orientalis growth in semi-arid areas of northern China. Elevated atmospheric CO2 concentration significantly (p < 0.01) stimulated P. orientalis biomass accumulation when Ca was less than approximately 320 ppm in the early phase; however, this effect was not pronounced when Ca exceeded 320 ppm.
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Affiliation(s)
- L U Weiwei
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
| | - Y U Xinxiao
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China.
| | - J I A Guodong
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
| | - L I Hanzhi
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
| | - L I U Ziqiang
- Beijing Forestry University, Key Laboratory of State Forestry Administration on Soil and Water Conservation, Beijing Engineering Research Center of Soil and Water Conservation, Beijing, 100083, China
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18
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Fu PL, Grießinger J, Gebrekirstos A, Fan ZX, Bräuning A. Earlywood and Latewood Stable Carbon and Oxygen Isotope Variations in Two Pine Species in Southwestern China during the Recent Decades. FRONTIERS IN PLANT SCIENCE 2017; 7:2050. [PMID: 28119725 PMCID: PMC5223062 DOI: 10.3389/fpls.2016.02050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 12/21/2016] [Indexed: 06/06/2023]
Abstract
Stable isotopes in wood cellulose of tree rings provide a high-resolution record of environmental conditions, yet intra-annual analysis of carbon and oxygen isotopes and their associations with physiological responses to seasonal environmental changes are still lacking. We analyzed tree-ring stable carbon (δ13C) and oxygen (δ18O) isotope variations in the earlywood (EW) and latewood (LW) of pines from a secondary forest (Pinus kesiya) and from a natural forest (Pinus armandii) in southwestern China. There was no significant difference between δ13CEW and δ13CLW in P. kesiya, while δ13CEW was significantly higher than δ13CLW in P. armandii. For both P. kesiya and P. armandii, δ13CEW was highly correlated with previous year's δ13CLW, indicating a strong carbon carry-over effect for both pines. The intrinsic water use efficiency (iWUE) in the earlywood of P. armandii was slightly higher than that of P. kesiya, and iWUE of both pine species showed an increasing trend, but at a considerably higher rate in P. kesiya. Respective δ13CEW and δ13CLW series were not correlated between the two pine species and could be influenced by local environmental factors. δ13CEW of P. kesiya was positively correlated with July to September monthly mean temperature (MMT), whereas δ13CEW of P. armandii was positively correlated with February to May MMT. Respective δ18OEW and δ18OLW in P. kesiya were positively correlated with those in P. armandii, indicating a strong common climatic forcing in δ18O for both pine species. δ18OEW of both pine species was negatively correlated with May relative humidity and δ18OEW in P. armandii was negatively correlated with May precipitation, whereas δ18OLW in both pine species was negatively correlated with precipitation during autumn months, showing a high potential for climate reconstruction. Our results reveal slightly higher iWUE in natural forest pine species than in secondary forest pine species, and separating earlywood and latewood of for δ18O analyses could provide seasonally distinct climate signals in southwestern China.
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Affiliation(s)
- Pei-Li Fu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of SciencesMenglun, China
| | - Jussi Grießinger
- Institute of Geography, University of Erlangen-NürnbergErlangen, Germany
| | - Aster Gebrekirstos
- Institute of Geography, University of Erlangen-NürnbergErlangen, Germany
- World Agroforestry CentreNairobi, Kenya
| | - Ze-Xin Fan
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of SciencesMenglun, China
| | - Achim Bräuning
- Institute of Geography, University of Erlangen-NürnbergErlangen, Germany
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19
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Lyu L, Deng X, Zhang QB. Elevation Pattern in Growth Coherency on the Southeastern Tibetan Plateau. PLoS One 2016; 11:e0163201. [PMID: 27685668 PMCID: PMC5042441 DOI: 10.1371/journal.pone.0163201] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/06/2016] [Indexed: 11/30/2022] Open
Abstract
It is generally expected that inter-annual changes in radial growth among trees would be similar to the increase in altitude due to the limitation of increasingly harsher climatic factors. Here, we examine whether this pattern exists in alpine forests on the southeastern Tibetan Plateau. Increment cores were collected from mature trees at the lower, middle and upper limits of balfour spruce (Picea likiangensis var. balfouriana (Rehd. et Wils.) Hillier ex Slsvin) forests at the Buze and Yela Mountains in Basu County, Changdu Prefecture of Tibet, China. The treeline elevations are 4320 m and 4510 m a.s.l. for Buze and Yela, respectively. Tree-ring widths were measured, crossdated, and detrended to obtain a sequence of ring-width indices for each individual sample. Annual growth rate, climate sensitivity, growth-climate relationships, and growth synchrony among trees were calculated and compared across altitudes. In Buze Mountain, the annual growth rate of trees has no significant difference across altitudes. The mean sensitivity of trees is lower at the treelines than at lower elevations. Tree growth has stronger correlation with winter temperature at upper elevations than at lower elevations, has significant correlation with moisture, not temperature, in the growing season, and the growth response to moisture is lower at the treeline than at lower elevations. The correlation among individual tree-ring sequences is lower at the treeline than at sites at lower elevation. In Yela Mountain, the characterisitics of annual growth rate, mean sensitivity, tree growth-climate relationships, and inter-serial correlation are similar to those in Buze, but their differences along altitudinal gradients are less significant as those in Buze. Our data do not support the general expectation of growth convergence among individuals with increasing altitude. We conclude that individual heterogeneity and microhabitat diversity are important features for treeline trees that may dampen the growth synchrony in trees. The results obtained in this study expand our knowledge about the pattern of forest growth along altitudinal gradients in high-elevation regions and demonstrate the importance of checking the growth of tree individuals before analyzing the average signal.
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Affiliation(s)
- Lixin Lyu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xu Deng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- Graduate School of the Chinese Academy of Sciences, Beijing, 100093, China
| | - Qi-Bin Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- * E-mail:
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20
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Wieser G, Oberhuber W, Gruber A, Leo M, Matyssek R, Grams TEE. Stable Water Use Efficiency under Climate Change of Three Sympatric Conifer Species at the Alpine Treeline. FRONTIERS IN PLANT SCIENCE 2016; 7:799. [PMID: 27375653 PMCID: PMC4894875 DOI: 10.3389/fpls.2016.00799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 05/22/2016] [Indexed: 05/23/2023]
Abstract
The ability of treeline associated conifers in the Central Alps to cope with recent climate warming and increasing CO2 concentration is still poorly understood. We determined tree ring stable carbon and oxygen isotope ratios of Pinus cembra, Picea abies, and Larix decidua trees from 1975 to 2010. Stable isotope ratios were compared with leaf level gas exchange measurements carried out in situ between 1979 and 2007. Results indicate that tree ring derived intrinsic water-use efficiency (iWUE) of P. cembra, P. abies and L. decidua remained constant during the last 36 years despite climate warming and rising atmospheric CO2. Temporal patterns in Δ(13)C and Δ(18)O mirrored leaf level gas exchange assessments, suggesting parallel increases of CO2-fixation and stomatal conductance of treeline conifer species. As at the study site soil water availability was not a limiting factor iWUE remained largely stable throughout the study period. The stability in iWUE was accompanied by an increase in basal area increment (BAI) suggesting that treeline trees benefit from both recent climate warming and CO2 fertilization. Finally, our results suggest that iWUE may not change species composition at treeline in the Austrian Alps due to similar ecophysiological responses to climatic changes of the three sympatric study species.
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Affiliation(s)
- Gerhard Wieser
- Department of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and LandscapeInnsbruck, Austria
| | - Walter Oberhuber
- Institute of Botany, Leopold-Franzens-Universität InnsbruckInnsbruck, Austria
| | - Andreas Gruber
- Institute of Botany, Leopold-Franzens-Universität InnsbruckInnsbruck, Austria
| | - Marco Leo
- Department of Alpine Timberline Ecophysiology, Federal Research and Training Centre for Forests, Natural Hazards and LandscapeInnsbruck, Austria
| | - Rainer Matyssek
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
| | - Thorsten Erhard Edgar Grams
- Ecophysiology of Plants, Department of Ecology and Ecosystem Management, Technische Universität MünchenFreising, Germany
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