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Potassium isotopic signatures of modern offshore detrital sediments from different climatic regimes and the implications

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Science China Earth Sciences 2024年第2期67卷 405-419页

作者： Jun MU Tianyu CHEN Qian YU Shichao AN Jianfang CHEN Xuefa SHI Weiqiang LI State Key Laboratory for Mineral Deposits Research School of Earth Sciences and EngineeringNanjing UniversityNanjing210023China Ministry of Education Key Laboratory for Coast and Island Development School of Geography and Ocean ScienceNanjing UniversityNanjing210023China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao266061China

Potassium isotopes are a novel tracer for continental *** K isotope studies on chemical weathering generally targeted weathering profiles under a particular climate region,yet the effects of chemical weathering on K isotopes under different climatic backgrounds remain ***,little is known about the K isotope signatures of modern unconsolidated detrital ***,we report K isotopic data of surficial seafloor sediments from continental shelves along the east coast of China(ECC),as well as those around the tropical Hainan island in the northern South China *** ECC sediments have a relatively narrow distribution ofδ^(41)K(with reference to NIST3141a)values,which range from(-0.40±0.01)‰to(-0.57±0.04)‰,with an average of(-0.51±0.09)‰.By contrast,δ^(41)K values of Hainan offshore sediments display a larger variation,ranging from(-0.28±0.07)‰to(-0.67±0.02)‰.Theδ^(41)K values of Hainan offshore sediments exhibit negative correlations with the chemical index of alteration(CIA),Al/K,Ti/K,and total iron(FeT),which underlines the control of chemical weathering on K isotopic signatures of detritus inputs into *** also measured Mg isotope compositions for the same samples;interestingly,the variability inδ^(26)Mg of the samples is small(~0.24‰)for all ECC and Hainan offshore sediments,andδ^(26)Mg values do not show clear correlations with indexes of chemical *** study demonstrates the link between K isotopic variability of detrital sediments and climatic conditions including rainfall intensity,which indicates that K isotopes of the detrital component of marine sediments could be applied to study Earth’s climate in deep ***δ^(41)K values of the offshore detrital sediments are significantly less variable than those of pelagic marine sediments,highlighting the importance of distinguishing the effects of diagenesis and neoformation of clay minerals from continental weathering in attempts to study deep-time climate-weathering

关键词： Potassium isotopes Magnesium isotopes Chemical weathering Detrital sediments Climatic regimes mean annual precipitation

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Spatial and temporal relationships between precipitation and ANPP of four types of grasslands in northern China

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Journal of Environmental Sciences 2006年第5期18卷 1024-1030页

作者： GUO Ran WANG Xlao-ke OUYANG Zhi-yun LI Ying-nian Key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Northwest Inst tute of Plateau Biology Ch nese Academy of Sciences Xining 810001 China

precipitation is considered to be the primary resource limiting terrestrial biological activity in water-limited regions. Its overriding effect on the production of grassland is complex. In this paper, field data of 48 sites （including temperate meadow steppe, temperate steppe, temperate desert steppe and alpine meadow） were gathered from 31 published papers and monographs to analyze the relationship between above-ground net primary productivity （ANPP） and precipitation by the method of regression analysis. The results indicated that there was a great difference between spatial pattern and temporal pattern by which precipitation influenced grassland ANPP. mean annual precipitation （MAP） was the main factor determining spatial distribution of grassland ANPP （r^2 = 0.61, P 〈 0.01）; while temporally, no significant relationship was found between the variance of AN PP and inter-annual precipitation for the four types of grassland. However, after dividing annual preeipitation into monthly value and taking time lag effect into account, the study found significant relationships between ANPP and precipitation. For the temperate meadow steppe, the key variable determining inter-annual change of ANPP was last August-May precipitation （r^2 = 0.47, P = 0.01）; for the temperate steppe, the key variable was July precipitation （r^2 = 0.36, P = 0.02）; for the temperate desert steppe, the key variable was April-June precipitation （r^2 = 0.51, P 〈 0.01）; for the alpine meadow, the key variable was last September-May precipitation （r^2 = 0.29, P 〈 0.05）. In comparison with analogous research, the study demonstrated that the key factor determining inter-annual changes of grassland ANPP was the cumulative precipitation in certain periods of that year or the previous year.

关键词： above-ground net primary productivity mean annual precipitation spatial sensitivity inter-annual changes

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The partitioning patterns of nutrients between pods and seeds of Zanthoxylum fruits impacted by environmental factors

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Acta Geochimica 2018年第5期37卷 676-683页

作者： Hechun Piao Siliang Li Zhifeng Yan State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Institute of Surface-Earth System Science Tianjin University

The nutritive quality in plant organs is related to the different partitioning patterns of nutrient resources among the organs under various environmental *** study examined the relationship between the nutritive quality of pods and seeds in Zanthoxylum and environmental factors, such as temperature and preciptation by using numerous samples collected from Southwest China to the East China of Shandong peninsula. The increasing accumulations of N, P and C in seeds implied that the nutritive quality in seeds was higher at the regions with relative higher mean annual temperature(MAT) and mean annual precipitation(MAP), while that in pods was on the contrary. By contrast, pod nutritive content was relatively high, but seed nutritive content was relatively low at the regions with relative high MAT and MAP. In addition, C:N ratio in pods was significantly and negatively correlated with MAT and MAP, while that in seed was significantly and positively correlated with MAT and MAP. The partitioning patterns of N-compounds between pods and seeds reflected different nitrogen translocations in the plant organs under various climate condition. The N:P ratios were negatively correlated with MAP, implying a higher proportional allocation of P to seeds than that of N in the areas with a relative high MAP. Therefore, the strategies to assess pod nutritional quality should be taken into accountfor nutritive translocation under various environmental conditions.

关键词： Partitioning pattern Nutritional quality C:Nratio Zanthoxylum fruits mean annual temperature mean annual precipitation

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Mismatch between species distribution and climatic niche optima in relation to functional traits

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Forest Ecosystems 2022年第6期9卷 813-822页

作者： Zhenghua Lian Juan Wang Chunyu Zhang Xiuhai Zhao Klaus von Gadow Research Center of Forest Management Engineering of State Forestry and Grassland Administration Beijing Forestry UniversityBeijing100083China Department of Forest Ecology School of Ecology and Nature ConservationBeijing Forestry UniversityBeijing100083China Faculty of Forestry and Forest Ecology Georg-August-University GottingenBüsgenweg 5D-37077GottingenGermany Department of Forest and Wood Science University of StellenboschStellenbosch7600South Africa

Background:Forecasts of climate change impacts on biodiversity often assume that the current geographical distributions of species match their niche ***,empirical evidence has challenged this assumption,suggesting a *** examine whether the mismatch is related to functional traits along temperature or precipitation ***:The observed distributions of 32 tree species in northeast China were evaluated to test this *** models were used to estimate the climatic niche optima,*** habitats where the highest species growth and density can be *** mismatch is defined as the difference between the actual species occurrence in an assumed niche optimum and the habitat with the highest probability of species ***’functional traits were used to explore the mechanisms that may have caused the ***:Contrasting these climatic niche optima with the observed species distributions,we found that the distribution-niche optima mismatch had high variability among species based on temperature and precipitation ***,these mismatches depended on functional traits associated with competition and migration lags only in temperature ***:We conclude that more relevant research is needed in the future to quantify the mismatch between species distribution and climatic niche optima,which may be crucial for future designs of forested landscapes,species conservation and dynamic forecasting of biodiversity under expected climate change.

关键词： Demography Functional traits mean annual temperature mean annual precipitation Niche theory Species distribution

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Changes in the relationship between species richness and belowground biomass among grassland types and along environmental gradients in Xinjiang, Northwest China

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Journal of Arid Land 2019年第6期11卷 855-865页

作者： YANG Yuling LI Minfei MA Jingjing CHENG Junhui LIU Yunhua JIA Hongtao LI Ning WU Hongqi SUN Zongjiu FAN Yanmin SHENG Jiandong JIANG Ping'an Xinjiang Key Laboratory of Soil and Plant Ecological Processes College of Grassland and Environmental SciencesXinjiang Agricultural UniversityUrumqi 830052China Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China

The association between biodiversity and belowground biomass(BGB) remains a central debate in *** this study, we compared the variations in species richness(SR) and BGB as well as their interaction in the top(0–20 cm), middle(20–50 cm) and deep(50–100 cm) soil depths among 8 grassland types(lowland meadow, temperate desert, temperate desert steppe, temperate steppe desert, temperate steppe, temperate meadow steppe, mountain meadow and alpine steppe) and along environmental gradients(elevation, energy condition(annual mean temperature(AMT) and potential evapotranspiration(PET)), and mean annual precipitation(MAP)) based on a 2011–2013 survey of 379 sites in Xinjiang, Northwest *** SR and BGB varied among the grassland *** alpine steppe had a medium level of SR but the highest BGB in the top soil depth, whereas the lowland meadow had the lowest SR but the highest BGB in the middle and deep soil *** SR and BGB in the different soil depths were tightly associated with elevation, MAP and energy condition;however, the particular forms of trends in SR and BGB depended on environmental factors and soil *** relationship between SR and BGB was unimodal in the top soil depth, but SR was positively related with BGB in the middle soil *** elevation, MAP, energy condition and SR had significant effects on BGB, the variations in BGB in the top soil depth were mostly determined by elevation, and those in the middle and deep soil depths were mainly affected by energy *** findings highlight the importance of environmental factors in the regulations of SR and BGB as well as their interaction in the grasslands in Xinjiang.

关键词： species richness belowground biomass unimodal pattern energy condition soil depths mean annual precipitation grasslands in Xinjiang

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Late Pleistocene spore-pollen record and climatic change at the Chongphadae Cave Site,Democratic People's Republic of Korea

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Journal of Palaeogeography 2023年第4期12卷 624-636页

作者： Se Chan Kim Rye Sun Choe Il Nam Kim Chol U Ryong Il Kang Institute of Human Evolution and Development History Faculty of HistoryKim Il Sung UniversityTaesong DistrictPyongyangDemocratic People's Republic of Korea

We present a detailed pollen record and interpretations of late Pleistocene climatic change at the Chongphadae Cave Site, Democratic People's Republic of Korea. The mean annual paleotemperature and mean annual paleoprecipitation of the site were calculated using the temperature index and precipitation index based on ecological features and geographical distribution of each taxon. Temperature index and precipitation index range from 8.8℃ to 10.4℃ and from 805.0 mm to 963.1 mm, respectively. Four dates(radiocarbon, uranium series, fission track, and paleomagnetic excursion dating) of the deposit profile investigated yield a range of ~21.3 ka BP to ~117 ka BP, geochronologically corresponding to the late Pleistocene, and extend from the last interglacial highstand through the Last Glacial Maximum. Our results are thus consistent with the climatic shift from interglacial to glacial conditions, provide evidence that the environments of the region, which was reconstructed from the paleoclimatic index, changed from a mild and humid to a cool and dry climate during the late Pleistocene, and suggest trends similar to those of several parts of the Northern Hemisphere which lie in the same latitudinal zone as our study area.

关键词： Chongphadae cave Pollen Climatic change Late Pleistocene mean annual temperature mean annual precipitation

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Carbon and Nitrogen Storage in Inner Mongolian Grasslands: Relationships with Climate and Soil Texture

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Pedosphere 2014年第3期24卷 391-398页

作者： HE Nian-Peng WANG Ruo-Meng ZHANG Yun-Hai CHEN Quan-Sheng Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences

Understanding the spatial variability of soil carbon （C） storage and its relationship with climate and soil texture is critical for developing regional C models and for predicting the potential impact of climate change on soil C storage. On the basis of soil data from a transect across the Inner Mongolian grasslands, we determined the quantitative relationships of C and nitrogen （N） in bulk soil and particle-size fractions （sand, silt, and clay） with climate and soil texture to evaluate the major factors controlling soil C and N storage and to predict the effect of climate changes on soil C and N storage. The contents of C and N in the bulk soil and the different fractions in the 0 20 and 20 40 cm soil layers were positively correlated with the mean annum precipitation （MAP） and negatively correlated with the mean annual temperature （MAT）. The responses of C storage in the soil and particle-size fractions to MAP and MAT were more sensitive in the 0-20 cm than in the 2（~40 cm soil layer. Although MAP and MAT were both important factors influencing soil C storage, the models that include only MAP could well explain the variation in soil C storage in the Inner Mongolian grasslands. Because of the high correlation between MAP and MAT in the region, the models including MAT did not significantly enhance the model precision. Moreover, the contribution of the fine fraction （silt and clay） to the variation in soil C storage was rather small because of the very low fine fraction content in the Inner Mongolian grasslands.

关键词： mean annual precipitation mean annual temperature native grassland particle-size fraction soil organic matter

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Variations of root and heterotrophic respiration along environmental gradients in China’s forests

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Journal of Plant Ecology 2013年第5期6卷 358-367页

作者： Pin Li Yuanhe Yang Jingyun Fang Department of Ecology and Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Aims Root and heterotrophic respiration may respond differently to environmental variability,but little evidence is available from largescale *** we aimed to examine variations of root and heterotrophic respiration across broad geographic,climatic,soil and biotic *** We conducted a synthesis of 59 field measurements on root and heterotrophic respiration across China’s *** Findings Root and heterotrophic respiration varied differently with forest types,of which evergreen broadleaf forest was significantly different from those in other forest types on heterotrophic respiration but without statistically significant differences on root *** results also indicated that root and heterotrophic respiration exhibited similar trends along gradients of precipitation,soil organic carbon and satellite-indicated vegetation ***,they exhibited different relationships with temperature:root respiration exhibited bimodal patterns along the temperature gradient,while heterotrophic respiration increased monotonically with ***,they showed different relationships with MOD17 GPP,with increasing trend observed for root respiration whereas insignificant change for heterotrophic *** addition,root and heterotrophic respiration exhibited different changes along the age sequence,with insignificant change for root respiration and decreasing trend for heterotrophic ***,these results suggest that root and heterotrophic respiration may respond differently to environmental *** findings could advance our understanding on the different environmental controls of root and heterotrophic respiration and also improve our ability to predict soil CO_(2) flux under a changing environment.

关键词： enhanced vegetation index forest age heterotrophic respiration latitude mean annual temperature mean annual precipitation root respiration GPP

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