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Millennial-scale hydroclimate control of tropical soil carbon storage 期刊论文
NATURE, 2020, 581 (7806) : 63-+
作者:  Lam, Tommy Tsan-Yuk;  Jia, Na;  Zhang, Ya-Wei;  Shum, Marcus Ho-Hin;  Jiang, Jia-Fu;  Zhu, Hua-Chen;  Tong, Yi-Gang;  Shi, Yong-Xia;  Ni, Xue-Bing;  Liao, Yun-Shi;  Li, Wen-Juan;  Jiang, Bao-Gui;  Wei, Wei;  Yuan, Ting-Ting;  Zheng, Kui;  Cui, Xiao-Ming;  Li, Jie;  Pei, Guang-Qian
收藏  |  浏览/下载:25/0  |  提交时间:2020/05/13

Over the past 18,000 years, the residence time and amount of soil carbon stored in the Ganges-Brahmaputra basin have been controlled by the intensity of Indian Summer Monsoon rainfall, with greater carbon destabilization during wetter, warmer conditions.


The storage of organic carbon in the terrestrial biosphere directly affects atmospheric concentrations of carbon dioxide over a wide range of timescales. Within the terrestrial biosphere, the magnitude of carbon storage can vary in response to environmental perturbations such as changing temperature or hydroclimate(1), potentially generating feedback on the atmospheric inventory of carbon dioxide. Although temperature controls the storage of soil organic carbon at mid and high latitudes(2,3), hydroclimate may be the dominant driver of soil carbon persistence in the tropics(4,5)  however, the sensitivity of tropical soil carbon turnover to large-scale hydroclimate variability remains poorly understood. Here we show that changes in Indian Summer Monsoon rainfall have controlled the residence time of soil carbon in the Ganges-Brahmaputra basin over the past 18,000 years. Comparison of radiocarbon ages of bulk organic carbon and terrestrial higher-plant biomarkers with co-located palaeohydrological records(6) reveals a negative relationship between monsoon rainfall and soil organic carbon stocks on a millennial timescale. Across the deglaciation period, a depletion of basin-wide soil carbon stocks was triggered by increasing rainfall and associated enhanced soil respiration rates. Our results suggest that future hydroclimate changes in tropical regions are likely to accelerate soil carbon destabilization, further increasing atmospheric carbon dioxide concentrations.


  
Femtosecond-to-millisecond structural changes in a light-driven sodium pump 期刊论文
NATURE, 2020, 583 (7815) : 314-+
作者:  Moore, Luiza;  Leongamornlert, Daniel;  Coorens, Tim H. H.;  Sanders, Mathijs A.;  Ellis, Peter;  Dentro, Stefan C.;  Dawson, Kevin J.;  Butler, Tim;  Rahbari, Raheleh;  Mitchell, Thomas J.;  Maura, Francesco;  Nangalia, Jyoti;  Tarpey, Patrick S.;  Brunner, Simon F.;  Lee-Six, Henry;  Hooks, Yvette;  Moody, Sarah;  Mahbubani, Krishnaa T.;  Jimenez-Linan, Mercedes;  Brosens, Jan J.;  Iacobuzio-Donahue, Christine A.;  Martincorena, Inigo;  Saeb-Parsy, Kourosh;  Campbell, Peter J.;  Stratton, Michael R.
收藏  |  浏览/下载:17/0  |  提交时间:2020/07/03

Light-driven sodium pumps actively transport small cations across cellular membranes(1). These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved(2,3), it is unclear how structural alterations overtime allow sodium to be translocated against a concentration gradient. Here, using the Swiss X-ray Free Electron Laser(4), we have collected serial crystallographic data at ten pump-probe delays from femtoseconds to milliseconds. High-resolution structural snapshots throughout the KR2 photocycle show how retinal isomerization is completed on the femtosecond timescale and changes the local structure of the binding pocket in the early nanoseconds. Subsequent rearrangements and deprotonation of the retinal Schiff base open an electrostatic gate in microseconds. Structural and spectroscopic data, in combination with quantum chemical calculations, indicate that a sodium ion bind stransiently close to the retinal within one millisecond. In the last structural intermediate, at 20 milliseconds after activation, we identified a potential second sodium-binding site close to the extracellular exit. These results provide direct molecular insight into the dynamics of active cation transport across biological membranes.


  
Extreme weather events recorded by daily to hourly resolution biogeochemical proxies of marine giant clam shells 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (13) : 7038-7043
作者:  Yan, Hong;  Liu, Chengcheng;  An, Zhisheng;  Yang, Wei;  Yang, Yuanjian;  Huang, Ping;  Qiu, Shican;  Zhou, Pengchao;  Zhao, Nanyu;  Fei, Haobai;  Ma, Xiaolin;  Shi, Ge;  Dodson, John;  Hao, Jialong;  Yu, Kefu;  Wei, Gangjian;  Yang, Yanan;  Jin, Zhangdong;  Zhou, Weijian
收藏  |  浏览/下载:14/0  |  提交时间:2020/05/13
Tridacna shell  daily growth bands  ultra-high resolution  biogeochemical proxies  weather-timescale extreme events  
The impact of Last Glacial climate variability in west-European loess revealed by radiocarbon dating of fossil earthworm granules 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2017, 114 (24) : 6209-6214
作者:  Moine, Olivier;  39;homme, Charlotte
收藏  |  浏览/下载:4/0  |  提交时间:2019/11/27
millennial-timescale climate change  radiocarbon dating  earthworm calcite granules  Last Glacial loess  Europe