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Zhao L, Liu X, Wang N, Barbeta A, Zhang Y, Cernusak LA, Wang L. The determining factors of hydrogen isotope offsets between plants and their source waters. New Phytol 2024; 241:2009-2024. [PMID: 38178796 DOI: 10.1111/nph.19492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/22/2023] [Indexed: 01/06/2024]
Abstract
A fundamental assumption when using hydrogen and oxygen stable isotopes to understand ecohydrological processes is that no isotope fractionation occurs during plant water uptake/transport/redistribution. A growing body of evidence has indicated that hydrogen isotope fractionation occurs in certain environments or for certain plant species. However, whether the plant water source hydrogen isotope offset (δ2 H offset) is a common phenomenon and how it varies among different climates and plant functional types remains unclear. Here, we demonstrated the presence of positive, negative, and zero offsets based on extensive observations of 12 plant species of 635 paired stable isotopic compositions along a strong climate gradient within an inland river basin. Both temperature and relative humidity affected δ2 H offsets. In cool and moist environments, temperature mainly affected δ2 H offsets negatively due to its role in physiological activity. In warm and dry environments, relative humidity mainly affected δ2 H offsets, likely by impacting plant leaf stomatal conductance. These δ2 H offsets also showed substantial linkages with leaf water 18 O enrichment, an indicator of transpiration and evaporative demand. Further studies focusing on the ecophysiological and biochemical understanding of plant δ2 H dynamics under specific environments are essential for understanding regional ecohydrological processes and for conducting paleoclimate reconstructions.
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Affiliation(s)
- Liangju Zhao
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an, 710069, China
| | - Xiaohong Liu
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
| | - Ninglian Wang
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an, 710069, China
| | - Adrià Barbeta
- BEECA, Department of Evolutionary Biology, Ecology and Environmental Sciences, Universitat de Barcelona, Barcelona, Catalonia, 08007, Spain
| | - Yu Zhang
- School of Geography and Tourism, Shaanxi Normal University, Xi'an, 710119, China
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, QLD, 4878, Australia
| | - Lixin Wang
- Department of Earth and Environmental Sciences, Indiana University Indianapolis (IUI), Indianapolis, IN, 46202, USA
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Tang X, Zhang L, Ren S, Zhao Y, Zhang Y. Temporal and geographic distribution of gut microbial enterotypes associated with host thermogenesis characteristics in plateau pikas. Microbiol Spectr 2023; 11:e0002023. [PMID: 37815332 PMCID: PMC10715161 DOI: 10.1128/spectrum.00020-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 08/28/2023] [Indexed: 10/11/2023] Open
Abstract
IMPORTANCE The gut microbiotas of small mammals play an important role in host energy homeostasis. However, it is still unknown whether small mammals with different enterotypes show differences in thermogenesis characteristics. Our study confirmed that plateau pikas with different bacterial enterotypes harbored distinct thermogenesis capabilities and employed various strategies against cold environments. Additionally, we also found that pikas with different fungal enterotypes may display differences in coprophagy.
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Affiliation(s)
- Xianjiang Tang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining, China
- University of Chinese Academy of Sciences, College of Life Sciences, Beijing, China
| | - Liangzhi Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining, China
| | - Shi'en Ren
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining, China
- University of Chinese Academy of Sciences, College of Life Sciences, Beijing, China
| | - Yaqi Zhao
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining, China
- University of Chinese Academy of Sciences, College of Life Sciences, Beijing, China
| | - Yanming Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Provincial Key Laboratory of Animal Ecological Genomics, Xining, China
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Zan J, Maher B, Yamazaki T, Fang X, Han W, Kang J, Hu Z. Mid-Pleistocene links between Asian dust, Tibetan glaciers, and Pacific iron fertilization. Proc Natl Acad Sci U S A 2023; 120:e2304773120. [PMID: 37279267 PMCID: PMC10268273 DOI: 10.1073/pnas.2304773120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 05/08/2023] [Indexed: 06/08/2023] Open
Abstract
Increasing Asian dust fluxes, associated with late Cenozoic cooling and intensified glaciations, are conventionally thought to drive iron fertilization of phytoplankton productivity in the North Pacific, contributing to ocean carbon storage and drawdown of atmospheric CO2. During the early Pleistocene glaciations, however, productivity remained low despite higher Asian dust fluxes, only displaying glacial stage increases after the mid-Pleistocene climate transition (~800 ka B.P.). We solve this paradox by analyzing an Asian dust sequence, spanning the last 3.6 My, from the Tarim Basin, identifying a major switch in the iron composition of the dust at ~800 ka, associated with expansion of Tibetan glaciers and enhanced production of freshly ground rock minerals. This compositional shift in the Asian dust was recorded synchronously in the downwind, deep sea sediments of the central North Pacific. The switch from desert dust, containing stable, highly oxidized iron, to glacial dust, richer in reactive reduced iron, coincided with increased populations of silica-producing phytoplankton in the equatorial North Pacific and increased primary productivity in more northerly locations, such as the South China Sea. We calculate that potentially bioavailable Fe2+ flux to the North Pacific was more than doubled after the switch to glacially- sourced dust. These findings indicate a positive feedback between Tibetan glaciations, glaciogenic production of dust with enhanced iron bioavailability, and changes in North Pacific iron fertilization. Notably, this strengthened link between climate and eolian dust coincided with the mid-Pleistocene transition to increased storage of C in the glacial North Pacific and more intense northern hemisphere glaciations.
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Affiliation(s)
- Jinbo Zan
- State Key Laboratory of Tibetan Plateau Earth System and Resources Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing100101China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing1000449China
| | - Barbara A. Maher
- Centre for Environmental Magnetism & Palaeomagnetism, Lancaster Environment Centre, University of Lancaster,LancasterLA1 4YQ, UK
| | - Toshitsugu Yamazaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa277-8564, Japan
| | - Xiaomin Fang
- State Key Laboratory of Tibetan Plateau Earth System and Resources Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing100101China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing1000449China
| | - Wenxia Han
- School of Resource and Environmental Sciences, Linyi University,276000Linyi, China
| | - Jian Kang
- State Key Laboratory of Tibetan Plateau Earth System and Resources Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing100101China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing1000449China
| | - Zhe Hu
- State Key Laboratory of Tibetan Plateau Earth System and Resources Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing100101China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing1000449China
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Meng F, Liu D, Wang Y, Wang S, Wang T. Negative relationship between photosynthesis and late-stage canopy development and senescence over Tibetan Plateau. Glob Chang Biol 2023; 29:3147-3158. [PMID: 36883758 DOI: 10.1111/gcb.16668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/24/2023] [Accepted: 03/01/2023] [Indexed: 05/03/2023]
Abstract
Canopy greening, which is associated with significant canopy structure changes, is the most notable signal of ecosystem changes in response to anthropogenic climate change. However, our knowledge of the changing pattern of canopy development and senescence, and its endogenous and climatic drivers is still limited. Here, we used the Normalized Difference Vegetation Index (NDVI) to quantify the changes in the speed of canopy development and senescence over the Tibetan Plateau (TP) during 2000-2018, and used a solar-induced chlorophyll fluorescence dataset as a proxy for photosynthesis, in combination with climate datasets to decipher the endogenous and climatic drivers of the interannual variation in canopy changes. We found that the canopy development during the early green-up stage (April-May) is accelerating at a rate of 0.45-0.8 × 10-3 month-1 year-1 . However, this accelerating canopy development was largely offset by a decelerating canopy development during June and July (-0.61 to -0.51 × 10-3 month-1 year-1 ), leading to the peak NDVI over the TP increasing at a rate of only one fifth of that in northern temperate regions, and less than one tenth of that in the Arctic and boreal regions. During the green-down period, we observed a significant accelerating canopy senescence during October. Photosynthesis was found to be the dominant driver for canopy changes over the TP. Increasing photosynthesis stimulates canopy development during the early green-up stage. However, slower canopy development and accelerated senescence was found with larger photosynthesis in late growth stages. This negative relationship between photosynthesis and canopy development is probably linked to the source-sink balance of plants and shifts in the allocation regime. These results suggest a sink limitation for plant growth over the TP. The impact of canopy greening on the carbon cycle may be more complicated than the source-oriented paradigm used in current ecosystem models.
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Affiliation(s)
- Fandong Meng
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Dan Liu
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Yilong Wang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Shiping Wang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Tao Wang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
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