简介：Sandydesertificationislanddegradationcharacterizedbywinderosionmainlyresultedfromtheexcessivehumanactivitiesinarid,semiaridandpartofsub-humidregionsinnorthernChina.Theresearchonsandydesertificationhasexperiencedmorethan5decadesofarduouscourseofthestrugglealongwiththeestablishmentanddevelopmentofChina′sdesertscience.Researchesinthisfieldhavemadeagreatcontributiontothenationaleconomicconstruction,andenvironmentalprotection.Thispaperfocusesonpresentingthemajorprogressandachievementsinthesandydesertificationresearchduringthelast50years,includingthestagesofstudyonsandydesertification,backgroundenvironmentofsandydesertificationanditschanges,theconception,causes,process,monitoringandassessmentofsandydesertification,thevegetationsuccession,landscapeecology,plantphysiology,impactsonecosystem,high-effectiveuseofwaterandlandresourcesandsustainabledevelopmentinsandydesertifiedregions,sandydesertificationcontrolmodelsandtechniquesetc.

简介：TheGurbantunggutDesertisthelargeststableandsemi-stablesanddesertinChina,yetfewdataexistonvegetationpatternandspecies-environmentrelationshipsforthesediversedesertlandscapes.Thesanddunesofthesurveyareaaremainlyofthelongitudinalformfromnorthtosouth,butcheckerboard-shapedandhoneycomb-shapedformsarealsopresent,withtheheightof10-50m.Wemeasuredvegetationandsoildataonnorth-southtransectsandcomparedthemwithvegetationandsoildataoneast-westtransects.Analysisrevealedthatthevaryingtrendandstrengthofthespeciesdiversity,dominanceandcoveroftheplantcommunitiesinthelongitudinalandtransversedirectionsacrossthelandscapearesignificantlydifferent.TheresultsofCCAordinationshowthatthemicro-habitatsofsoilorganicmatter(OM),soilsalts(TS),sortingindex(σ),topsoilwater-content(SM)andpHrelatetothedifferencesinvegetationobservedasdifferencesinspeciesassemblagefromsalt-intolerantephemerals,micro-subshrubsandsubshrubstosalt-tolerantshrubsandmicro-arbors.Theterrain(alt.)andsoiltexture(thecontentsofMzandφ1)affectthespatialdifferentiationofmanyspecies.However,thisspatialdifferentiationisnotsomarkedontransectsrunninglongitudinallywiththelandscape,inthesamedirectionasthedunes.Thespeciesofthedesertvegetationhaveformedthreeassemblagesundertheactionofhabitatgradients,relatingtothreesectionsrunningtransverselyacrossthelandscape,atrightanglestothedirectionofthedunecrests.Inthemid-eastsectionofthestudyareathetopographyishigher,withsand-landsordune-slopeswithcoarseparticles.HerethedominantvegetationcomprisesshrubsandsubshrubsofSeriphidiumsantoliumandEphedradistachya,withlargenumbersofephemeralandephemeroidplantsofSeneciosubdentatus,andCarexphysodesinspringandsummer.Onthesoilofthedune-slopesinthemidwestofthestudyarea,withcoarseparticlesandabundantTK,theplantassemblageofHaloxylonpersicu

简介：利用航空摄影测量方法，讨论台风暴雨对台湾的砾岩地形的冲蚀作用；利用航空数值模型的量化比对地表的冲蚀作用力．研究结果显示，台风暴雨的巨大冲蚀力量，对砾岩地表的冲刷与搬运，具有极大的影响．3个时期（1991、1998、2002年）精度达2m的航空照片判读，都显示火炎山地区的地貌，受到公元2001年的桃芝与纳莉台风的影响，有非常大的改变．在1998和2002年之间，2号子集水区下游也呈现河道堆积的现象，厚度达5—6m．这些变迁也是桃芝台风与纳莉台风所带来的影响．

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简介：根据实地调研与张氏族谱资料，发现张谷英村落体系空间结构变迁过程具有明显的阶段变迁特点，可分为村落肇始、龙形村落、双核心村落体系等3个阶段；进一步分析发现，人口迁移、地缘、血缘与风水等是张谷英村落体系空间结构变迁的最主要影响因素，其影响的着力点在于张谷英村落的人地关系，土地的占有与利用是人地关系矛盾的焦点，传统农耕时期的村落活动半径决定张谷英村落必然由集中走向分散，最终形成双核心村落体系．