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1、生态学杂志ChineseJournalofEcology摇2010,29(6):1075-1080摇摇摇摇摇摇摇摇摇摇摇摇摇民勤绿洲鄄荒漠过渡带植被梯度特征*及其土壤水环境12**1222马摇瑞摇王继和摇屈建军摇刘虎俊摇孙摇涛摇魏林源12(中国科学院寒区旱区环境与工程研究所沙漠与沙漠化重点实验室,兰州730000;甘肃省治沙研究所,兰州730000)摘摇要摇民勤绿洲鄄荒漠过渡带的植被和土壤水环境随着与绿洲距离的增加具有明显的空间异质性,在景观分异角度沿绿洲至荒漠方向可划分为4个区段。本文研究了各景观区段上的植被特征以及各区段丘间地及灌丛沙包土壤水分特征。结果表明:过
2、渡带植被总盖度约为36%,灌木盖度为18郾7%,草本盖度为18郾0%,物种丰富度为19。区段1至区段4,物种组成、植被盖度、优势种、建群种均表现出与各区段立地条件相适应的特征,呈现出大灌木寅草本寅小灌木寅草本的格局,对应的地貌呈现出固定寅半流动寅半固定寅流动的格局。各区段丘间地土壤含水量垂直分布差异较大,5~60cm为降水主要持水层;因弱透水层的出现,区段1至区段3在60~180cm含水量出现了第二次波动,水分在弱透水层上的积累为地上植物的生存提供了重要的补给。沙包内土壤含水量从区段1到区段3显著减少。关键词摇内陆河流域;绿洲鄄荒漠过渡带;景观;区段;梯度分析中图分
3、类号摇P941;Q948摇文献标识码摇A摇文章编号摇1000-4890(2010)6-1075-06Vegetationgradientcharacteristicsandsoilwaterenvironmentofoasis鄄deserttransitional12122zoneinMinqin.MARui,WANGJi鄄he,QUJian鄄jun,LIUHu鄄jun,SUNTao,WEILin鄄21yuan(KeyLaboratoryofDesertandDesertification,ColdandAridRegionsEnvironmentand2Engin
4、eeringResearchInstitute,ChineseAcademyofSciences,Lanzhou730000,China;GansuDesertControlResearchInstitute,Lanzhou730000,China).ChineseJournalofEcology,2010,29(6):1075-1080.Abstract:ThevegetationandsoilwaterenvironmentinMinqinoasis鄄deserttransitionalzonehaveobviousspatialheterogeneitywit
5、htheincreasingdistancefromoasis,andcanbedividedinto4sections,accordingtothedifferentiationoflandscapes.Thispaperstudiedthevegetationfeaturesineachofthesections,andthesoilwaterfeaturesintheinter鄄dunesandshrubislandsinthesections.Inthetransitionalzone,thetotalcoveragewasabout36%,shrubcov
6、eragewas18郾7%,andherbalcoveragewas18.0%.Thespeciesrichnesswas19.Fromsection1tosec鄄tion4,thespeciescomposition,vegetationcoverage,dominantspecies,andconstructivespeciesallexhibitedthefeaturescorrespondingtothestandconditionsofeachsection,withapatternoflargeshrub寅herb寅shrub寅herb.Accordin
7、gly,thegeomorphologyshowedthepatternoffixed寅semi鄄shifting寅semi鄄fixed寅shifting.Therewereobviousdifferencesintheverticaldistribu鄄tionofsoilwatercontentamongthesections,and5-60cmsoillayerwasthemainrainwaterre鄄tentionlayer.Duetotheoccurrenceofaquiclude,thesoilwatercontentappearedasecondf
