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Soil Organic C:N vs. Water-Extractable Organic C:N

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Open Journal of Soil Science 2012年第3期2卷 269-274页

作者： Richard L. Haney Alan. J. Franzluebbers Virginia. L. Jin Mari-Vaughn. Johnson Elizabeth. B. Haney Mike. J. White Robert. D. Harmel Texas AgriLife Research Blackland Research & Extension Center Temple TX usda-Agricultural Research Service (ARS) Grassland Soil & Water Research Laboratory Temple TX USA usda-ARS Agroecosystem Management Research Unit Lincoln NE 4usda-nrcs Resources Inventory and Assessment Division Temple TX usda-ARS J. Phil Campbell Sr. Natural Resource Conservation Center Watkinsville GA usda-nrcs Resources Inventory and Assessment Division Temple TX

Traditionally, soil-testing laboratories have used a variety of methods to determine soil organic matter, yet they lack a practical method to predict potential N mineralization/immobilization from soil organic matter. Soils with high micro-bial activity may experience N immobilization (or reduced net N mineralization), and this issue remains unresolved in how to predict these conditions of net mineralization or net immobilization. Prediction may become possible with the use of a more sensitive method to determine soil C:N ratios stemming from the water-extractable C and N pools that can be readily adapted by both commercial and university soil testing labs. Soil microbial activity is highly related to soil organic C and N, as well as to water-extractable organic C (WEOC) and water-extractable organic N (WEON). The relationship between soil respiration and WEOC and WEON is stronger than between respiration and soil organic C (SOC) and total organic N (TON). We explored the relationship between soil organic C:N and water-extractable organic C:N, as well as their relationship to soil microbial activity as measured by the flush of CO2 following rewetting of dried soil. In 50 different soils, the relationship between soil microbial activity and water-extractable organic C:N was much stronger than for soil organic C: N. We concluded that the water-extractable organic C:N was a more sensitive measurement of the soil substrate which drives soil microbial activity. We also suggest that a water-extractable organic C:N level > 20 be used as a practical threshold to separate those soils that may have immobilized N with high microbial activity.

关键词： Soil Microbial Activity C:N Ratios Soil Organic C N Mineralization N Immobilization Soil Testing

Simulation and analysis of the long-term impacts of 1.5°C global climate pledges on China's land systems

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Science China Earth Sciences 2025年

作者： Jiaying LV Changqing SONG Yifan GAO Sijing YE Peichao GAO State Key Laboratory of Earth Surface Processes and resource Ecology Beijing Normal University Center for GeoData and Analysis Beijing Normal University

Global warming has become a shared issue for humanity. At the 26th Conference of the Parties to the United Nations Framework Convention on Climate Change in 2021, participating countries reached climate pledges aimed at making more proactive contributions to limit the global average temperature rise within 1.5°C by 2100. Land system changes are significant responses of land to climate change. As one of the contracting parties, China has proposed climate targets such as carbon peaking and carbon neutrality goals in recent years to support the global pledges of limiting global warming to1.5°C, which will profoundly impact China's future land system changes. This study focuses on China as the study area,produces data with a thematic resolution of 27 types of land systems, integrates the output of various land types by the Global Change assessment Model(GCAM) into four categories of land service demand, and combines these with the improved CLUMondo model to simulate China's land system changes in 2100 under a 1.5°C global warming scenario and a reference scenario without updated emission reduction measures. The conclusions of this study are as follows:(1) The method of integrating the GCAM and improved CLUMondo model demonstrates high validation accuracy in simulating China's land system changes, effectively predicting the changes.(2) Under the 1.5°C global warming scenario, the quality of ecosystems related to mountains, water, forests, farmland, lakes, and grasslands in China improved. The areas of shrubland, wetland, and forest are projected to increase by 185%, 79%, and 33%, respectively, with low-density shrubland, high-density wetland, and high-density forest showing the most significant increases.(3) Compared with the reference scenario, the 1.5°C climate pledges drive greater changes in future land systems, with wetland and forest area growth levels exceeding those of the reference scenario by 20% and 10%, respectively. Notably, the changes in cropland, grasslan

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Developing individual tree-based models for estimating aboveground biomass of five key coniferous species in China

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Journal of Forestry Research 2018年第5期29卷 1251-1261页

作者： Weisheng Zeng Liyong Fu Ming Xu Xuejun Wang Zhenxiong Chen Shunbin Yao Academy of Forest inventory and Planning State Forestry Administration Research Institute of Forest resource Information Techniques Chinese Academy of Forestry Department of Ecology Evolution & Natural ResourcesRutgers University Central South Forest inventory and Planning Institute State Forestry Administration East China Forest inventory and Planning Institute State Forestry Administration

Estimating individual tree biomass is critical to forest carbon accounting and ecosystem service *** this study,we developed one-（tree diameter only） and two-variable（tree diameter and height） biomass equations,biomass conversion factor（BCF） models,and an integrated simultaneous equation system（ISES） to estimate the aboveground biomass for five conifer species in China,i.e.,Cunninghamia lanceolata（Lamb.） Hook.,Pinus massoniana Lamb.,*** Faranch,*** *** *** Engelm.,based on the field measurement data of aboveground biomass and stem volumes from 1055 destructive sample trees across the *** found that all three methods,including the one-and two-variable equations,could adequately estimate aboveground biomass with a mean prediction error less than 5%,except for Pinus yunnanensis which yielded an error of about 6%.The BCF method was slightly poorer than the biomass equation and the ISES *** average coefficients of determination（R^2） were 0.944,0.938 and 0.943 and the mean prediction errors were 4.26,4.49 and 4.29% for the biomass equation method,the BCF method and the ISES method,*** ISES method was the best approach for estimating aboveground biomass,which not only had high accuracy but also could estimate stocking volumes simultaneously that was compatible with aboveground *** addition,we found that it is possible to develop a species-invariant one-variable allometric model for estimating aboveground biomass of all the five coniferous *** model had an exponent parameter of 7/3 and the intercept parameter a_0 could be estimated indirectly from stem basic density（a_0= 0.294 q）.

关键词： Biomass models Allometric equations Biomass conversion factor Error-in-variable simultaneous equations

Re-Os Isotopic Dating of a W-Be Polymetallic Deposit in the Southern Qinling Region, China

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Acta Geologica Sinica(English Edition) 2018年第1期92卷 414-415页

作者： DAI Hongzhang WANG Denghong WANG Chenghui HUANG Fan Key Laboratory of Metallogeny and Mineral resource assessment Ministry of Land and ResourcesInstitute of Mineral Resource Chinese Academy of Geological Sciences

Objective In recent years, a series of tungsten prospecting breakthroughs have been made in the southern Qinling Mountains. Especially, a new deposit type with a scheelite -beryl-molybdenite assemblage in the Zhen＇an area of Shaanxi Province was firstly discovered. This deposit is currently in a detailed investigation stage, and no detailed study has been yet conducted. This work selected one molybdenite sample from the Be （W） ores in this deposit for Re-Os isotope measurements to define the time limit of tungsten and beryllium mineralization, and to further reveal the ore-forming geological setting of rare metals in the southern Qinling region.

关键词： Re-Os Isotopic Dating Re-Os Isotopic Dating of a W-Be Polymetallic Deposit the Southern Qinling Region

Distribution and mapping of temperate savanna in the sandy lands of eastern China

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Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya LI Feng WANG Tao DUAN Kaijie YANG Bin YANG Chunmei WANG Xin TIAN Qi LU Institute of Ecological Conservation and Restoration Institute of Desertification Studies Chinese Academy of Forestry Institute of Desertification Institute of Desertification Studies Chinese Academy of Forestry Institute of Great Green Wall Satellite Application Centre for Ecology and Environment MEE Institute of Microelectronics Chinese Academy of Sciences Aerospace Information Research Institute Chinese Academy of Sciences Institute of Forest resource Information Techniques Chinese Academy of Forestry

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution （VHR） unmanned aerial vehicle （UAV） and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover （FWVC） and fractional herbaceous vegetation cover （FHVC） in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the FWVC and FHVC models were 10.69% and 11.67%,and the R2values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10～6 *** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

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Constraints on the Archean atmospheric oxygen and sulfur cycle from mass-independent sulfur records from Anshan-Benxi BIFs, Liaoning Province, China

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Science China Earth Sciences 2007年第10期50卷 1471-1478页

作者： HOU KeJun1,2, LI YanHe1,2? & WAN DeFang1,2 1 Key Laboratory of Metallogeny and Mineral resource assessment, Institute of Mineral resource, Chinese Academy of Geological Sciences (CAGS), Beijing 100037, China 2 Key Laboratory of Isotope Geology, CAGS, Beijing 100037, China Key Laboratory of Metallogeny and Mineral resource assessment Institute of Mineral Resource Chinese Academy of Geological Sciences (CAGS) Beijing China Key Laboratory of Isotope Geology CAGS Beijing China

The Archean atmospheric oxygen concentration and sulfur cycle was long debated. The banded iron formation (BIF) is a special type of the sedimentary formation, which has truly recorded the atmospheric and oceanic conditions at that time. In this study, the composition of multiple sulfur isotope (δ 34S/δ 33S/δ 32S) for sulfides bedded in the Archean (~2.7 Ga) BIFs, in Anshan-Benxi area of Liaoning Province has been measured. The value of △33S varies from -0.89‰ to +1.21‰, which shows very obvious mass-independent fractionation (MIF) signatures. These non-zero △33S values indicate that the Archean sulfur cycles are different from what it is today, which have been deeply influenced by gas phase photochemical reactions. Algoma-type BIFs which are closely related to the volcanic activity have negative △33S value, however, Superior-type BIFs which are far away from the volcanic center have positive △33S value. The δ 34S varies in a large range from -22.0‰ to +11.8‰, which indicates that the bacteria reduction activity has already existed at that time, and that the oceanic sulfate concentration has at least reached 1 mmol/L in local areas. Combined with the contemporaneous existence of the hematite, magnetite and the occurrence and preservation of the sulfur MIF, it can be inferred that the Archean atmospheric oxygen level must be at 10-2―10-3 of the present atmospheric level (PAL).

关键词： sulfur mass-independent fractionation, Anshan-Benxi area, BIF, Archean atmospheric oxygen level, Archean sulfur cycle

Apatite Fission Track Ages in the Duolong Ore District and the Uplift Time of the Qiangtang Terrrane, Tibet

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Acta Geologica Sinica(English Edition) 2018年第1期92卷 408-409页

作者： YANG Huanhuan TANG Juxing SONG Yang LIU Zhibo LIN Bin MLR Key Laboratory of Metallogeny and Mineral resource assessment Institute of Mineral Resources Chinese Academy of Geological Sciences

Objective Fission track （FT） analysis has developed into one of the most useful techniques throughout the geologic community to reconstruct low-temperature thermal historyof rocks over geological time （Reiners et al., 2005）. The FT method is based on the accumulation of narrow damage trails （i.e., fission tracks） in uranium-rich mineral grains （e.g., apatite, zircon, titanite） and natural glasses, which form as a result of spontaneous nuclear fission decay of 238U in nature. Apatite Fission Track （AFT） has been used in many places in Tibet to study the Qinghai- Tibetan Plateanuplifl-exhumation history. However, few AFT studies have been reported in the Duolong ore district. The Duolong ore district is one of the most important ore districts in the Bangong Co-Nujiang metallogenic belt, Tibet （Lin Bin et al., 2017） and the uplift-exhumation of the Duolong ore district is closely related to the evolution of the Qiangtang Basin. Therefore, AFT of the Duolong ore district will provide important information about the uplift-exhumation history of the Duolong ore district and the Qiangtang Basin.

关键词： Apatite Fission Track Ages the Duolong Ore District the Uplift Time of the Qiangtang Terrrane

The Metallogenetic Regularities of Lithium Deposits in China

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Acta Geologica Sinica(English Edition) 2015年第2期89卷 652-670页

作者： LI Jiankang ZOU Tianren LIU Xifang WANG Denghong DING Xin Key Laboratory of Metallogeny and Mineral resource assessment Institute of Mineral ResourcesChinese Academy of Geological Sciences China University of Geosciences

Lithium resources support the development of high-technology industries. China has abundant lithium resources which are mainly distributed in Tibet, Qinghai, Sichuan and Jiangxi. Salt lakes in China have significant lithium reserves, but lithium is mainly produced from hard rock lithium deposits because the extraction from salt lakes requires further improvements. The hard rock lithium deposits mainly occur in granitic pegmatite in the Altay region of Xinjiang and the Jiajika deposit in western Sichuan Province; they mainly formed in the Mesozoic and occurred in a relatively stable stage during orogenic processes. On the basis of the information from 151 lithium deposits or spots, 14 lithium metallogenic series were identified, and granitic pegmatite, granite, and sedimentary types were considered to be the main prediction types of lithium resources. Twelve lithium mineralization belts were divided and a series of maps showing the lithium metallogenetic regularity in China were drawn. We conclude that the hard rock and brine type of lithium resources possibly have a similar lithium source related to magmatism. The mctallogenic features of the lithium in China were related with the distinct history of tectonic-magmatic activity in China. This study benefits the assessment of, and prospecting for, lithium resources in China.

关键词： lithium deposit prediction type of lithium resources metallogenetic regularity metallogenic series pegmatite

A century of National Forest inventory in Norway–informing past,present,and future decisions

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Forest Ecosystems 2020年第4期7卷 602-620页

作者： Johannes Breidenbach Aksel Granhus Gro Hylen Rune Eriksen Rasmus Astrup National Forest inventory Norwegian Institute of Bioeconomy ResearchÅsNorway

Past:In the early twentieth century,forestry was one of the most important sectors in Norway and an agitateddiscussion about the perceived decline of forest resources due to over-exploitation was *** base thediscussion on facts,the young state of Norway established Landsskogtakseringen–the world’s first National Forestinventory(NFI).Field work started in 1919 and was carried out by *** were recorded on 10m wide stripswith 1–5 km *** quality and land cover categories were recorded along each *** for the firstcounty were published in 1920,and by 1930 most forests below the coniferous tree line were *** 2ndto 5th inventories followed in the years 1937–*** of 1954,temporary sample plot clusters on a 3 km×3 kmgrid were used as sampling ***:The current NFI grid was implemented in the 6th NFI from 1986 to 1993,when permanent plots ona 3 km×3 km grid were established below the coniferous tree *** of the 7th inventory in 1994,the NFIis continuous,and 1/5 of the plots are measured *** trees with a diameter≥5 cm are recorded oncircular,250 m2 *** NFI grid was expanded in 2005 to cover alpine regions with 3 km×9 km and 9km×9 km *** 2012,the NFI grid within forest reserves was doubled along the cardinal *** temporary plots are used periodically to facilitate county-level *** of today,more than 120variables are recorded in the NFI including bilberry cover,drainage status,deadwood,and forest *** are monitored and trees outside forests are ***:Considerable research efforts towards the integration of remote sensing technologies enable thepublication of the Norwegian Forest resource Map since 2015,which is also used for small area estimation atthe municipality *** the analysis side,capacity and software for long term growth and yield prognosisare being ***,we foresee the inclusion of further variables for monitoring ec

关键词： Forest forest annually