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Holocene temperature variation recorded by branched glycerol dialkyl glycerol tetraethers in a loess-paleosol sequence from the north-eastern Tibetan Plateau

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Frontiers of Earth Science 2023年第4期17卷 1012-1025页

作者： Tianxiao WANG Duo WU Tao WANG Lin CHEN Shilong GUO Youmo LI Chenbin ZHANG Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Alpine Paleoecology and Human Adaptation group(ALPHA) Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Reconstructing Holocene temperature evolution is important for understanding present temperature variations and for predicting future climate change,in the context of global *** evolution of Holocene global temperature remains disputed,due to differences between proxy reconstructions and model simulations,a discrepancy known as the῾Holocene temperature conundrum᾽.More reliable and quantitative terrestrial temperature records are needed to resolve the spatial heterogeneity of existing *** this study,based on the analysis of branched glycerol dialkyl glycerol tetraethers(brGDGTs)from a loess-paleosol sequence from the Ganjia Basin in the north-eastern Tibetan Plateau(NETP),we quantitatively reconstructed the mean annual air temperature(MAAT)over the past 12 *** MAAT reconstruction shows that the temperature remained low during the early Holocene(12−8 ka),followed by a rapid warming at around 8 *** 8 to 4 ka,the MAAT record reached its highest level,followed by a cooling trend from the late Holocene(4−0 ka).The variability of the reconstructed MAAT is consistent with trends of annual temperature records from the Tibetan Plateau(TP)during the *** attribute the relatively low temperatures during the early Holocene to the existence of ice sheets at high-latitude regions in the Northern Hemisphere and the weaker annual mean insolation at 35°*** the mid to late Holocene,the long-term cooling trend in the annual temperature record was primarily driven by declining summer *** study provides key geological evidence for clarifying Holocene temperature change in the TP.

关键词： sHolocene Ganjia Basin loess temperature variation BrGDGTs

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Geospatial analysis of forest fragmentation in Uttara Kannada District, India

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Forest Ecosystems 2016年第3期3卷 206-220页

作者： Ramachandra T V Bharath Setturu Subash Chandran Energy & Wetlands research group Center for Ecological Sciences（CES） Indian Institute of Science Centre for Sustainable Technologies (astra) Bangalore Karnataka 560 012 India Centre for infrastructure Sustainable Transportation and Urban Planning（CiSTUP） Indian Institute of Science Bangalore Karnataka 560 012 India

Background： Landscapes consist of heterogeneous interacting dynamic elements with complex ecological, economic and cultural attributes. These complex interactions help in the sustenance of natural resources through bio-geochemical and hydrological cycling. The ecosystem functions are altered with changes in the landscape structure, Fragmentation of large contiguous forests to small and isolated forest patches either by natural phenomena or anthropogenic activities leads to drastic changes in forest patch sizes, shape, connectivity and internal heterogeneity, which restrict the movement leading to inbreeding among Meta populations with extirpation of species. Methods： Landscape dynamics are assessed through land use analysis by way of remote sensing data acquired at different time periods. Forest fragmentation is assessed at the pixel level through computation of two indicators, i.e., Pf （the ratio of pixels that are forested to the total non-water pixels in the window） and P~ （the proportion of all adjacent （cardinal directions only） pixel pairs that include at least one forest pixel, for which both pixels are forested）. Results： Uttara Kannada District has the distinction of having the highest forest cover in Karnataka State, India. This region has been experiencing changes in its forest cover and consequent alterations in functional abilities of its ecosystem. Temporal land use analyses show the trend of deforestation, evident from the reduction of evergreen - semi evergreen forest cover from 57.31% （1979） to 32.08 % （2013） Forest fragmentation at the landscape level shows a decline of interior forests 64.42 % （1979） to 25.62 % （20] 3） and transition of non-forest categories such as crop land, plantations and built-up areas, amounting now to 47.29 %. PCA prioritized geophysical and socio variables responsible for changes in the landscape structure at local levels. Conclusion： terrestrial forest ecosystems in Uttara Kannada District of Central Western Ghats have be

关键词： Land use dynamics Forest fraqmentation Interior forests Biodiversity Geophysical variables

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Observations of the solar corona during the total solar eclipse on 21 August 2017

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Earth and Planetary Physics 2017年第1期1卷 68-71页

作者： Hui Tian ZhongQuan Qu YaJie Chen LinHua Deng ZhengHua Huang Hao Li Yue Zhong Yu Liang JingWen Zhang YiGong Zhang BaoLi Lun XiangMing Cheng XiaoLi Yan ZhiKe Xue YuXin Xin ZhiMing Song YingJie Zhu Tanmoy Samanta School of Earth and Space Sciences Peking University Yunnan Observatories Chinese Academy of Sciences Shandong Provincial Key Laboratory of Optical Astronomy and Solar-terrestrial Environment Institute of Space Sciences Shandong University

The Sun’s tenuous outer atmosphere,the corona,emits only about one-millionth as much light as the solar *** ancient times the corona was observed by human beings only during total solar eclipses,when the strong emiss... 详细信息

关键词： solar corona solar eclipse solar magnetic fields coronal heating

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A RARE CENTIMETRIC SPIKE EVENT ON 10 MARCH 2002

A RARE CENTIMETRIC SPIKE EVENT ON 10 MARCH 2002

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第十一届全国日地空间物理学术讨论会

作者： R.A.Sych Institute of Solar-terrestrial Physics 126 Lermontov Street Irkutsk Russia 664033

＜正＞A group of centimetric spikes was detected during the burst of 10 March 2002 with the spectrometer of NAOC （National Astronomical Observatories of China）. These centimetric spikes are resolved clearly in the time and frequency panels. A statistical analysis shows that these spikes have very short durations （5-10 ms）, narrow bandwidths （20-40 MHz）, very high polarization degrees （90%）, and relatively weak flux densities （10-40 sfu）. The simultaneous 2D image observations of NoRH （Nobeyama Radioheliograph） and SSRT （Siberian Solar Radio Telescope） imply that the spikes should come from a small source region, which was located in an area with a complex magnetic field. It is also found that the spikes are polarized in the X-mode. These observations suggest that the electron cyclotron maser （ECM） is the most likely mechanism of these centimetric spikes.

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Strategies towards robust interpretations of in situ zircon oxygen isotopes

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Geoscience Frontiers 2023年第2期14卷 241-255页

作者： Janne Liebmann Christopher L.Kirkland John B.Cliff Christopher J.Spencer Aaron J.Cavosie Timescales of Mineral Systems group The Institute for Geoscience Research(TIGeR)School of Earth and Planetary SciencesCurtin UniversityPerthAustralia Pacific Northwest National Laboratory RichlandWashington 99354United States Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonONCanada Space Science and Technology Centre The Institute for Geoscience Research(TIGeR)School of Earth and Planetary ScienceCurtin UniversityPerthAustralia

Oxygen isotopes are a versatile tool to address a wide range of questions in the Earth *** include geothermometry,paleoclimatology,tracing of geochemical reservoirs,fluid-rock interaction,magmatic petrogenesis,and identification of extra-terrestrial *** arguably provides one of the most robust records of primary magmatic O isotope ratio due to low diffusion rates in crystalline *** ability to correlate zircon O isotopes with temporal and petrogenetic information(e.g.U-Pb geochronology,Lu-Hf isotopes,and trace elements)makes this mineral a key archive for understanding Earth’s crustal ***,zircon O isotope geochemistry has found widespread usage to address fundamental questions across the earth and planetary *** general apparent ease of O isotopic acquisition through the advancement of rapid in situ techniques(*** ion mass spectrometry;SIMS)and associated dedicated national laboratories has led to the generation of large O isotopic data sets of variable quality,highlighting the importance of a coherent workflow for data collection,reduction,and *** paper presents a set of approaches for measurement,assessment,and reporting of zircon O isotope *** focus in this contribution is on in situ analysis via secondary ion mass spectrometry using large geometry instruments,but other commonly used techniques are briefly reviewed for *** work aims to provide an analytical framework necessary for geologically meaningful interpretation of O isotope *** addition,we describe inherent geological(***-induced disturbance of the zircon O isotopic system)and analytical(*** due to sample topography effects)challenges and outline means to identify and avoid such issues as a prerequisite to the generation of robust primary O isotopic signatures for geological interpretation.

关键词： In situ Oxygen isotopes Zircon SIMS Secondary ion mass spectrometry Off-mount standard

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Worldwide impacts of atmospheric vapor pressure deficit on the interannual variability of terrestrial carbon sinks

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National Science Review 2022年第4期9卷 33-40页

作者： Bin He Chen Chen Shangrong Lin Wenping Yuan Hans W.Chen Deliang Chen Yafeng Zhang Lanlan Guo Xiang Zhao Xuebang Liu Shilong Piao Ziqian Zhong Rui Wang Rui Tang State Key Laboratory of Earth Surface Processes and Resource ecology College of Global Change and Earth System ScienceBeijing Normal University Department of Application research Twenty First Century Aerospace Technology Co.Ltd. School of Atmospheric Sciences Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)Sun Yat-sen University Department of Physical Geography and Ecosystem Science Lund University Regional Climate group Department of Earth SciencesUniversity of Gothenburg Academy of Disaster Reduction and Emergency Management School of GeographyBeijing Normal University State Key Laboratory of Remote Sensing Science Faculty of Geographical ScienceBeijing Normal University Sino-French Institute for Earth System Science College of Urban and Environmental SciencesPeking University

Interannual variability of the terrestrial ecosystem carbon sink is substantially regulated by various environmental variables and highly dominates the interannual variation of atmospheric carbon dioxide(CO2) ***,it is necessary to determine dominating factors affecting the interannual variability of the carbon sink to improve our capability of predicting future terrestrial carbon *** global datasets derived from machine-learning methods and process-based ecosystem models,this study reveals that the inter annual variability of the atmospheric vapor pressure deficit(VPD) was significantly negatively correlated with net ecosystem production(NEP) and substantially impacted the inter annual variability of the atmospheric CO2growth rate(CGR).Further analyses found widespread constraints of VPD interannual variability on terrestrial gross primary production(GPP),causing VPD to impact NEP and *** correlation analysis confirms the persistent and widespread impacts of VPD on terrestrial carbon sinks compared to other environmental *** Earth system models underestimate the interannual variability in VPD and its impacts on GPP and *** results highlight the importance of VPD for terrestrial carbon sinks in assessing ecosystems’ responses to future climate conditions.

关键词： vapor pressure deficit net ecosystem production gross vegetation production carbon dioxide concentration

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Eff ects of stand condition and root density on fi ne-root dynamics across root functional groups in a subtropical montane forest

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Journal of Forestry research 2023年第3期34卷 665-675页

作者： Lin Huang Rudong Zhao Xiaoxiang Zhao Qiuxiang Tian Pengyun Yue Feng Liu CAS Key Laboratory of Aquatic Botany and Watershed ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074People’s Republic of China University of the Chinese Academy of Sciences Beijing 100049People’s Republic of China

Fine roots play key roles in belowground C cycling in terrestrial *** on their distinct functions,fi ne roots are either absorptive fi ne roots(AFRs)or transport fi ne roots(TFRs).However,the function-based fi ne root dynamics of trees and their responses to forest stand properties remain ***,we studied the dynamics of AFRs and TFRs and their responses to stand conditions and root density in a subtropical montane mixed forest based on a 2-a root window ***(±SE)annual production,mortality,and turnover rate of AFRs were 7.87±0.17 m m^(−2)a^(−1),8.13±0.20 m m^(−2)a^(−1)and 2.96±0.24 a^(−1),respectively,compared with 7.09±0.17 m m^(−2)a^(−1),4.59±0.17 m m^(−2)a^(−1),and 2.01±0.22 a^(−1),respectively,for *** production and mortality of fi ne roots were signifi cantly higher in high root-density sites than in low-root density sites,whereas the turnover of fi ne roots was faster in the low root-density ***,root density had a larger positive eff ect than other environmental factors on TFR production but had no obvious impact on AFR *** species diversity had an apparent positive eff ect on AFR production and was the crucial driver of AFR production,probably due to a complementary eff ect,but had no evident impact on *** tree density and tree species diversity were positively correlated with the mortality of AFRs and negatively related to the turnover of TFRs,suggesting that higher root density caused stronger competition for rooting space and that plants tend to reduce maintenance costs by decreasing TFR *** fi ndings illustrated the importance of root functional groups in understanding root dynamics and their responses to changes in environmental conditions.

关键词： Root functional group Root production Root mortality Root turnover Stand condition Badagongshan mountain

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A systems perspective on national prioritisation of sustainable development goals:Insights from Australia

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Geography and Sustainability 2023年第3期4卷 255-267页

作者： Atie Asadikia Abbas Rajabifard Mohsen Kalantari SDGs research group Centre for Spatial Data Infrastructures and Land AdministrationFaculty of Engineering and ITThe University of MelbourneParkvilleVIC 3010Australia School of Civil and Environmental Engineering University of New South WalesSydneyNSW 2052Australia

Achieving the Sustainable Development Goals(SDGs)requires effective national initiatives and resource ***,the simultaneous attainment of all goals is hindered by constraints such as limited budgets and resources,varied national priorities,and the intricate nature of the *** we approach 2030 and beyond,an urgent need for an effective,data-driven prioritisation system exists to optimise what can be accomplished.A considerable knowledge gap persists in identifying the priority areas that demand concentrated attention and how their improvement would propel overall sustainability *** bridge this gap,our study presents a priori-tisation approach that identifies significant SDG indicators based on urgency and impact,utilising Benchmarking,Bivariate,and Network ***,we introduce an innovative Impact Index(IMIN)to assess an indi-cator’s extensive effect on the SDG *** system carries significant international relevance by establishing a robust framework to identify key,potent,and interconnected *** supports decision-makers worldwide in comprehending their nation’s SDG performance and promotes efficient resource *** the specific con-text of Australia,our analysis spotlights several impactful,yet underperforming SDG *** include the protection of Freshwater,terrestrial,and Mountain Key Biodiversity Areas(KBAs),the share of renewable energy and energy intensity level of primary energy,targeted research and development,gender equality in national parliaments,and carbon-efficient manufacturing,amongst others.

关键词： Sustainable development SDGs National prioritisation SDGs prioritisation Network analysis Australia’s SDGs

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Morphological evolution from aquatic to terrestrial in the genus Oreolalax(Amphibia,Anura,Megophryidae)

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Progress in Natural Science:Materials International 2009年第10期19卷 1403-1408页

作者： Gang Wei a,b,c,Bin Wang c,Ning Xu b,Zizhong Lia,Jianping Jiang c,a Institute of Entomology,Guizhou University,Guiyang 550025,China b Centre of ecology,Guiyang College,Guiyang 550005,China c Chengdu Institute of Biology,Chinese Academy of Sciences,Chengdu 610041,China Institute of Entomology Guizhou University Guiyang 550025 China Centre of ecology Guiyang College Guiyang 550005 China Chengdu Institute of Biology Chinese Academy of Sciences Chengdu 610041 China

A phylogeny of 17 species in the genus Oreolalax is reconstructed based on 21 morphological characters from adult specimens,skeleton specimens,tadpoles and *** species groups are recognized,of which the *** species group is the most primitive,the *** species group is the second,the *** species group is the third and the *** species group is the most recently *** on the evolutional tendency of the morphological characters on the phylogenetic tree,it is proposed that the evolution of tympanum,tympanic annulus,columella,spoon-like cartilage and the web between toes reflect the habit changes from aquatic to ***,Oreolalax is regarded as one important representative genus to study further the evolution of morphological characters from aquatic to terrestrial.

关键词： Aquatic terrestrial Morphology Evolution Oreolalax

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The History of Hydrocarbon Analyses: Whence Has Forensic Geochemical Hydrocarbon Fingerprinting Come

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Journal of Environmental Protection 2016年第3期7卷 303-311页

作者： Michael J. Wade Dennis Stainken Wade research Inc. Marshfield USA Princeton-Somerset group Inc. Hillsborough USA

The current techniques used in forensic geochemical hydrocarbon fingerprinting have their genesis along with the evolution of gas chromatography as it applies to hydrocarbon research. In the United States, a small group of government and academic chemists and marine scientists pioneered the use of gas chromatography in the identification of both natural and petroleum-derived hydrocarbons. Natural products were a primary focus until the research direction was altered somewhat by marine oil spills, accidents releasing crude oil and refined petroleum products to the world’s coastal marine environment, giving rise to concerns regarding biogeochemical impacts. Application of oil spill research continued from that point so that the geochemical research begun in the late 1960s and early 1970s now forms a major component of investigations of petroleum releases both in the aquatic and terrestrial environments. As the capabilities for the identification of individual hydrocarbons in a variety of petroleum products improved with basic advances in chromatographic technology, new applied sciences in forensic geochemical hydrocarbon fingerprinting have emerged. While in the beginning the identification of bulk petroleum products received primary emphasis, current techniques are now capable of distinguishing among a variety of potential sources including those derived from natural processes, undetected individual releases, chronic releases and obvious catastrophic releases. However, a review of the techniques employed in the late 1960s and early 1970s will show that the basic approaches pioneered at that time are still in use today, albeit with a higher level, with concomitant advances in chromatographic technology as the questions grow in complexity.

关键词： Hydrocarbon Fingerprinting Forensic Geochemistry Gas Chromatography

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