共查询到20条相似文献，搜索用时 15 毫秒
1.
Comparative study on CO_2 emissions from different types of alpine meadows during grass exuberance period 总被引：1，自引：0，他引：1
1IntroductionTherisingatmosphericgreenhousegaseswerebelievedtobetheprimarycauseofglobalclimatechange(Tettetal.,1999;Crowley,2000).Amongthegreenhousegases,theconcentrationofatmosphericcarbondioxidehasincreasedfrom280ppmsincepre-industrialtimestocurrent355ppm,whichaccountedfor50%ofthetotalgreenhouseeffect(Nefteletal.,1985;Friedlietal.,1986;Rodhe,1990;Fanetal.,1998).ElevatedCO2hasamarkedeffectonterrestrialecosystemprocesses(Melilloetal.,1996).TheQinghai-TibetPlateau,thelargestgeomorphologica… 相似文献
2.
QIAN Yibing WU Zhaoning ZHANG Liyun SHI Qingdong JIANG Jin TANG Lisong 《地理学报(英文版)》2004,14(4):447-455
1IntroductionStudy on the interrelationship between vegetation patterns and their habitat heterogeneity is important to recover and rehabilitate the desert vegetation, stabilize the desert ecosystem and prevent desert expansion. Domestic and foreign researchers have carried out many studies on this topic (Archer etal., 2002; Bolling etal., 2000; Chen etal., 2003; Dasti etal., 1994; Gu etal., 2002, Li etal., 2001; Li etal., 2001; Liang etal., 2003), which have used and refined statistic tech… 相似文献
3.
土地利用变化时空模型的图谱方法--以黄河三角洲为例 总被引：12，自引：0，他引：12
Changesinlandcoverandland-usehaveimpactsandimplicationsatlocal,regionalandglobalscalesbecauseofthewaytheyalterbiophysical,biogeochemicalandhydrologicalstatesandprocesses(Alcamoetal.,1996;Li,1996).Since1990,scientistsathomeandabroadhavebeenpayingattentiontoresearchesonland-useandland-coverchange(LUCC)(Turneretal.,1990;MeyerandTurner,1994),butresearchisnotenoughon"spaceandprocess"ofLUCC(Turneretal.,1995).Spatialrelationshipbetweenvariablesyethasnotbeenestablished(Bockstael,1996).Soitispara… 相似文献
4.
SPATIAL VARIATION OF Zn GEOCHEMICAL FRACTIONS IN THE SURFACE SEDIMENTS OF THE STRAITS OF MALACCA: NATURAL OR ANTHROPOGENIC? 总被引：1，自引：1，他引：0
CheeKongYap AhmadIsmail SoonGuanTan 《湿地科学》2005,3(2):94-103
1INTRODUCTION Studiesonheavymetalcontaminationinsedi mentshavealwaysbeenfocusedonthecoastalandin tertidalareas(Sivalingam,etal.,1980;Ismail,1993;Ismail,etal.,1993;IsmailandRosniza,1997;Yap,etal.,2002a,2002b).Theheavymet alconcentrationsfoundinthesediments… 相似文献
5.
<正>Land is the basis for human survival and production, providing food, fuel, fiber, and other ecosystem services(Verburg et al., 2013; Jin et al., 2021). Land-use change is both a cause and consequence of many biophysical and socioeconomic changes(Van and Verburg, 2013). Human land-use activities have a great impact on biodiversity and the ecological environment by changing the ecosystem(Newbold et al., 2015; Asamoah et al., 2017; Tilman, 2017; 相似文献
6.
1IntroductionResearch results have shown that overland flow firstly removes fine particles of topsoil because the fine soil particles can be easily transported in runoff (Burwell etal., 1975; Alberts etal., 1983; Gregory 1991). The component differences of fine soil particles between the sediment resulting from soil erosion and the original soil were studied (Meyer etal., 1975; Loch etal., 1982; Cogo, 1983). Sediment was normally composed of soil aggregates and particles of different diamet… 相似文献
7.
G lobalw arm ing and its possible influences on hum an society have received increasing concernsfrom academ ic circles (Y ao et al.,1996; Chen, 1987; Zhang et al.,2004; Zhang et al.,2000).Som e scholars paid m uch m ore attention to clim atic changes duri… 相似文献
8.
长江河口营养物质输送的组成与通量 总被引：5，自引：0，他引：5
1IntroductionRiversplayanimportantroleintransportofnutrients(e.g.,NandP)andtheirbiogeochemicalcyclinginland-oceaninteractionsystem.Forexample,humanactivitieshaveresultedinaboutthesameamountofnitrogenfixation(140×106t)oncontinentsasthatofnaturethroughfertilizerproduction,energyproductionandcultivationofcrops,or30%ofthetotalamounttransportedtooceansbyrivers(Gallowayetal.,1995).Thefluxesofdissolvedphosphorusfromlandtoseasurfacecarriedbyriverrunoffasorthophosphateisabout2TgPyear-1(1Tg=1×1012g)… 相似文献
9.
基于多时相陆地卫星图像的锡林河流域土地覆盖类型特征 总被引：1，自引：0，他引：1
1IntroductionThe growing concern over the impact of changes in land use and land cover on environmental conditions and the increasing human impact on the natural resources has captured worldwide attention of the political and scientific community (Ojima etal., 1991; Smith etal., 2001). It is expected that the changing land use/land cover pattern will be one of the driving forces of environmental changes superimposed on the natural changes at regional scale (Fu etal., 1993; Bonan, 1995). Arid… 相似文献
10.
Maria Victoria Ortega Espaldon 《地理学报(英文版)》2012,22(3):575-576
Land system change has never been out of human concerns. It is always one of the hottest themes in global environmental change research (Seto et al., 2002; Gutman et al., 相似文献
11.
1IntroductionDistributed watershed hydrological model has become one of the hot topics in hydrology for its predominance in reflecting the influence of the spatial distributed features of terrains on hydrological processes (Wan etal., 2001; Abbott etal., 1986; Beven etal., 1992). However its demands on the spatio-temporal changeful surface elements such as solar radiation, precipitation, temperature etc. are strict. Being the limitations of observation techniques, data availability and study … 相似文献
12.
1 Introduction Wind erosion, which occurred in arid, semiarid and sub-humid areas, is a critical process in land desertification and degradation. It is a global environmental problem (Dong et al., 1996; Gomesa et al., 2003). Previous researches on process… 相似文献
13.
1GeneralsituationofstudyChina is one of the oldest civilized countries in the world. Human activities and the practice of agriculture date back nearly 10 thousands years when people began gaining an understanding and knowledge about soils. Records of these activities can be found in ancient or current Chinese references (Gong etal., 1999), and in non-Chinese literatures like those in English and Russian (Thorp, 1936; Kovda, 1960; Needham, 1986; Li and Cao, 1990; Gong etal., 2003). Soil cl… 相似文献
14.
WANG Zhi-Qiang CHEN Ming WANG Dan-Dan ZHANG Bai ZHANG Shu-Qing 《湿地科学》2005,3(3):176-182
1INTRODUCTION Thewetlandsystemhasbeencriticaltothede velopmentandsurvivalofhumancommunities(Yu Xing Xiu,etal.,2002;IGBPReportNo48,1999;Wiliam,1986).Itisnotonlyamongthemostimpor tantenvironmentsforhumanbeings'survivalbutalso amongtheimportantecologicallandscapeswhich serveasthemostdiversifiedhabitatsforlivingthings(LIXiu Bin,1996).Wetlandsperformfunctions whichothersystemscannotsupplantsuchasattenua tingfloods,regulatingsurfacerunoff,storingfreshwa terandpreventingdrought,adjustingcli… 相似文献
15.
黄土高原平凉地区中全新世以来的植硅体记录与古气候研究 总被引：1，自引：0，他引：1
通过黄土高原西部平凉剖面的植硅体分析,对黄土高原西部全新世中晚期气候进行研究,将研究时期的气候分为5个阶段:8.43～7.78KaB.P.,气候凉湿;7.78～7.17KaB.P.,气候暖湿;7.17～6.27KaB.P.,气候总体仍为暖湿,但较上带有变冷趋势;6.27～5.55KaB.P.,气候特征为凉湿;5.55～0KaB.P.,气候特征仍为凉湿,但具有偏凉干趋势。明显的气候波动与全新世中晚期全球变化可以对比,与相邻区域的孢粉、粒度、磁化率等研究工作结果较为一致。 相似文献
16.
Both land use/land cover change (LUCC) and the effects of nutrients cycles on terrestrial ecosystems and biodiversity are key environmental problems in the 21st century (Yang etal., 2002; Li, 1996; Bai and Bai, 1998). Land cover change is the accumulated result of land use, which includes three types, i.e., deterioration, transition and amelioration of land cover (Cai, 2001). The nutrient cycle is the main functional process to maintain stability and production of an ecosystem. Land cover … 相似文献
17.
《地理学报(英文版)》1990,(6)
AutranC.,4 13Bandemer,H.,147Bertrand,D.、413B lalkowski,5.E.,271Burdiek,D.5.,15MaeFie,H.J,H.,355MeGown,L.B.,15Meglen,R.R.,361Meritan,R.,413M illiean,D W.,15M iyashita,Y.,97Moret,1.,217CaPodaglio,G.,217Co一Iny,J.M.,36]Cotroneo,A.,379Coureoux,P.,413Crilly,P.B.,51,291CrisPoni,G.,123Nurehi,V.,123Ohman,J.,79,1 35Danzer,K.,1 95Duewer,D L.,299Dugo,G.,379Eekschlager,K.,195Esbensen,K.,337,389Pan,Z一X.,323Pell,R.J.,331Prada一S应nehez,J.M.,429Favretto,Favretto,L.,379L .G.,Fl… 相似文献
18.
典型岩溶农业区土地利用变化对土壤性质的影响——以云南小江流域为例 总被引：2，自引：0，他引：2
蒋勇军 《地理学报(英文版)》2006,16(1):69-77
1 Introduction Because of modifying land-cover (Turner et al., 1991) and management measures of soil (Dalal, 1986), land use changes can cause significant modifications in soil properties (Islam, 2000; Mcalister, 1998; Braimoh, 2004; Lal, 1996; Shepherd, … 相似文献
19.
《地理学报(英文版)》1989,(3)
A lonso,J.,249,285AParieio,R,175Armanino,C.,1 15Baeza,J J.,223Barrado,E.,315Bartroli,J.,249,285Baucells,M.,163Beltran,J一L.,209,217Berbellini,A.,293Bertrand,D.,397Bezemer,R.,81Brarehell,N,,579Burdiek,D.5.,431Carri6n,J.L.,193Casassas,E.,151,163Castril]ejo,Y.,315Ceeil,T.L.,21Centioni,G.,293C]ementi,S,499Colina,A.,323Contj,P.,293Cox,P.,81Crueiani,G.,499Curti,G.,499DasguPta,P.K.,601Deane,J.M.,359,477de la Guardia,M.,193del Valle,M.,249,285Derde,M.P.,375Devaux,M一F.,397Do… 相似文献
20.
《地理学报(英文版)》1991,(6)
Armanino,C.,435Arroy,G.,291Avila,F.,455Moezzi,M.,299Morat,J一L.,73Myers,D.E.,273,455Bertrand,D.,Bialkowski,5.B laekwood,LBrown,5.D.,211263Naes,T.,49,487N ilsson,G.,52373EGl4’503Clark,R.D.,Crilly,P.B.,85Deming,5.Doornbos,Drava,G.,Duewer,D181A.,345435L.,Edland,SEsbensen,O’Brien,R.,249Palasota,J.A.,181Palasota,J.M.,181Palmer,C.,455Pan,2.,193Pell,R.J.,375Perkins,R.,291Permutt,T.,29997Fitzgerald,K.E.,241Flatman,G.T.,309Forina,M.,435RajagoPal,R.,321Rayens,W.5.,227,361R… 相似文献