简介：Withpopulationgrowthandincreasingpressureonlandresources,landcarryingcapacity(LCC)andfoodsafetyhavebeenattractinggreatattentionworldwide.Fromthepointofman-grainrelationshipandbyestablishingLCCandlandcarryingcapacityindex(LCCI)models,thisarticlefirstlyanalyzesthespatial-temporaldynamicsofLCCofChinafrom1949to2005atcounty,provincialandnationallevels.Choosing2005asarepresentativeyear,thisarticlethenevaluatestheLCCof264pastoralregions(semipastoralregions),663urbanregionsand592povertystrickenregionsofthecountry.Theresultsshowthat:(1)from1949to2005,withtheincreaseofgrainproduction,theLCCofChinahasbeenimprovedconspicuously,butduetotherapidpopulationgrowth,theproductioncanonlymaintainalowlevelgrainconsumption;(2)overthepast25years(1980-2005),thenumberofpopulationoverloadingprovincesdecreasedfrom23to15andthemangrainrelationshiphasbeenimprovedgradually,butthereweremoreoverloadingprovincesthansurplusprovincesinChina;(3)atcountylevel,therewere1572overloadingcountiesin1980accountingfor68.26%ofthetotalcountiesofthecountryandwherewere649millionpeoplelived,whilein1990,2000and2005,thenumberofoverloadingcountieswere1066,1133and1087respectively,whichshowsthattheman-grainrelationshiphasbeenimprovedobviouslyduringthepast25years;asforspatialdistribution,thesurpluscountiesweremainlyconcentratedinagriculturedevelopedregions,suchasNortheastPlain,NorthChinaPlain,middleandlowerReachesoftheYangtzeRiverPlain,andoverloadingcountiesweremainlylocatedinregionswithpoornaturalenvironmentandlowgrainproductioncapacity,suchasNorthwestChina,TibetanPlateauandLoessPlateauandeconomicallydevelopedurbanregions,suchasBeijing,TianjinandShanghai;(4)animalhusbandryimprovedgreatlytheLCCofpastoralandsemi-pastoralregions,whileurbanregionswereoverloadingforincreasingpopulationpressureandmoreth

简介：Withtheincreaseofglobalpopulation,grain-populationrelationshiphasattractedgreatattentionworldwide.InChina,grain-populationrelationshiphasbecomeanincreasinglyimportanteconomicconcern.OfcentralimportancetothefoodsecuritydebateinChinaisthegeographyofgrainsupplyanddemand.Thispaperusesagraindemandandsupplyindex(DSR)toanalyzethespatial-temporalrelationshipbetweenpopulationandgraininChinafrom1949to2007atnationalandprovincialscales.Theresultsareexaminedinthreeperiods.(1)From1949to2007,withtheincreaseofgrainproduction,therelationshipbetweenpopulationandgrainofChinaimprovedconsiderably.(2)Overthepast35years(1970-2005),onthewholethegrainproducingareashavehadgrainsurplusandcontributedtothenationbyprovidinggrain,buttheabilitytoprovidesufficientgrainisnotstable.(3)Overthepast15years(1990-2005),decreasesinplantingareabroughtpressureonnationalgrainfoodsecurity.Thepaperconcludesthatthekeytoprovidingmorefoodforthemainfoodproducingprovincesisincreasingyieldonthebasisofsteadyplantarea.