简介：INTRODUCTIONSoilacidificationduetoaciddepositionhasbeenoneofthemajorenvironmentalprob-lemsconcernedbysoilscientistsandecologistsfortherecent20years(vanBreemen,1990).SoilacidificationwithamarkedpHdecreaseofforestsoilswithinvarioustimeintervalshasbeenreportedinGermany,Sweden,theNetherlands,AustraliaandtheUnitedStates(van

简介：陆地使用变化影响地下的生态系统。在过去几十年期间，在东北中国的陆地使用更加变化了，并且稻地的区域从高地很快增加了。在这研究，土壤特征和土壤，有大米耕作的不同的年的稻地里的关於生命的社区被测量在土壤上从高地检验土地使用变化的效果到稻地微食物的网。当控制和微生物引起的社区作文用phospholipid被描绘，高地玉米领域被选择丰满的酸(PLFA)分析。微生物引起的生物资源(全部的PLFA)，细菌生物资源，和真菌生物资源在20-40-year是更高的(迟了阶段)比1-10-year(早阶段)稻领域。许多总数线虫和bacterivores是更低的在比迟了阶段的稻地早阶段。许多草食动物在早阶段的稻领域里是最高的，但是不偏食的人食肉动物的在迟了阶段的稻领域里是最高的。结构的方程模型显示那张土壤食物网在20以后被发展并且组织稻耕作的年。我们的结果建议了微食物的网可以是的那土壤为土壤开发和稻的稳定的好指示物回答后面的土地使用变化。

简介：Theannualseriesofδ13CweremeasuredintreeringsofthreeCryptomeriafortuneidisks(CF-1,CF-2,andCF-3)collectedfromWestTianmuMountain,ZhejiangProvince,China,accordingtocross-datingtreeringages.Therewasnoobviousdecreasingtrendoftheδ13CannualtimeseriesofCF-2before1835.However,from1835to1982thethreetreeringδ13Cannualseriesexhibitedsimilardecreasingtrendsthatweresignificantly(P≤0.001)correlated.Thedistributioncharacteristicsofascatterdiagrambetweenestimatedδ13CseriesofCF-2frommodelingandtheatmosphericCO2concentrationextractedfromtheLawDomeicecorefrom1840to1978wereanalyzedandacurvilinearregressionequationforreconstructingatmosphericCO2concentrationwasestablishedwithR2=0.98.Also,atestofindependentsamplesindicatedthatbetween1685and1839thereconstructedatmosphericCO2concentrationusingtheδ13CseriesofCF-2hadacloserelationshipwiththeLawDomeandSipleicecores,withastandarddeviationof1.98.ThegeneralincreasingtrendofthereconstructedatmosphericCO2concentrationcloselyreflectedthelong-termvariationofatmosphericCO2concentrationrecordedbothbeforeandaftertheIndustrialRevolution.Between1685and1840theevaluatedatmosphericCO2concentrationwasstable,butafter1840itexhibitedarapidincrease.Givenalongerδ13Cannualtimeseriesoftreerings,itwasfeasibletorebuildarepresentativetimeseriestodescribetheatmosphericCO2concentrationforanearlierperiodandforyearsthatwerenotintheicecorerecord.