Synthesisofinformationonrapidlandcoverchange198120

February2005/Vol.55No.2•BioScience115ArticlesChangesinlandcoverandinthewaypeopleusethelandhavebecomerecognizedoverthelast15yearsasimportantglobalenvironmentalchangesintheirownright(Turner2002).Theyarealsointertwinedinmanywayswithotherenvironmentalissues,suchasclimatechangeandcarboncycle,lossofbiodiversity,sustainabilityofagriculture,andprovisionofsafedrinkingwater.Theinternationalsci-entificcommunityhascreatednewinterdisciplinaryresearchprogramstounderstandthemultiplecausesandconse-quencesofland-coverandland-usechange(Lambinetal.2003).Therehasbeenaconcomitantrapidexpansionintheavailabilityofdataandinformation.However,therehasnotyetbeenasystematicexamination,usingglobalandregionalobservations,ofthestatusandtrendsinterrestrialandcoastalland-coverorrelatedimportantecosystemprocesses.Theinformationneedsforsuchasynthesisarediverse.Remotesensinghasanimportantcontributiontomakeindocumentingtheactualchangeinlandcoveronregionalandglobalspatialscalesfromthemid-1970s(Achardetal.2002,DeFriesetal.2002,Lambinetal.2003).Italsohasaroletoplayinevaluatingindicesofchangeinecologicalprocesses,suchasnetprimaryproductionandrainfalluseefficiency(Princeetal.1998).Remotesensinginformationisfoundinawidelyscatteredliterature,someofitrefereed,someinthegrayliterature,andsomeunpublishedasyet.Thereisalsoanobviousneedforgoodinventorydataandstatisticsaboutlandcoverandland-coverchangeatsubnational,national,andin-ternationalscales,augmentedbyaneedforsubnationalandnationalindicatorsofcondition,status,andtrendsoftheglobalenvironment.Finally,thereisaneedtodeterminetheinterrelationshipsofremotelysensedandstatisticalinventorydata,tointegrateheterogenousdatasources.Thetremendousinvestmentinscientificanalysisofremotesensingdataoverthelastdecade,andtheprofusionofstud-iesbasedonotherdatasources,providesabasisforasynthesis.Althoughinformationisnotcompleteglobally,severalprod-uctsarenowavailablethatdepictthelandcoverofEarthglob-allyinthe1990sandin2000–2001.Thesameistrueforsnapshotsofmanyimportantregionswithsubstantialland-ErikaLepersandEricF.Lambin(e-mail:[e-mail])workintheDepartmentofGeography,UniversityofLouvain,3PlaceLouisPasteur,1348Louvain-la-Neuve,Belgium.AnthonyC.JanetosworksattheH.JohnHeinzIIICenterforScience,Economics,andtheEnvironment,1001PennsylvaniaAvenue,NW,Washington,DC20004.RuthDeFriesiswiththeDepartmentofGeographyandEarthSystemScienceInterdisciplinaryCenter,UniversityofMaryland,CollegePark,MD20742.FredericAchardworksattheInstituteforEnvironmentandSustainability,JointResearchCentre,TP440,21020Ispra,Italy.NavinRamankuttyiswiththeCenterforSustainabilityandtheGlobalEnvironment,NelsonInstituteforEnvironmentalStudies,UniversityofWisconsin,Madison,WI53726.RobertJ.ScholesworksattheCSIRDivi-sionofWater,EnvironmentandForestTechnology,POBox395,Pretoria0001,SouthAfrica.©2005AmericanInstituteofBiologicalSciences.ASynthesisofInformationonRapidLand-coverChangeforthePeriod1981–2000ERIKALEPERS,ERICF.LAMBIN,ANTHONYC.JANETOS,RUTHDEFRIES,FREDERICACHARD,NAVINRAMANKUTTY,ANDROBERTJ.SCHOLESThisarticlepresentsasynthesisofwhatisknownaboutareasofrapidland-coverchangearoundtheworldoverthepasttwodecades,basedondatacompiledfromremotesensingandcensuses,aswellasexpertopinion.Asiacurrentlyhasthegreatestconcentrationofareasofrapidland-coverchanges,anddrylanddegradationinparticular.TheAmazonbasinremainsamajorhotspotoftropicaldeforestation.Rapidcroplandin-crease,oftenassociatedwithlarge-scaledeforestation,isprominentinSoutheastAsia.ForestdegradationinSiberia,mostlyrelatedtologgingactivities,isincreasingrapidly.ThesoutheasternUnitedStatesandeasternChinaareexperiencingrapidcroplanddecrease.ExistingdatadonotsupporttheclaimthattheAfricanSahelisadesertificationhotspot.Manyofthemostpopulatedandrapidlychangingcitiesarefoundinthetropics.Keywords:landuse,cropland,deforestation,desertification,urbanizationcoverchange:EuropeanRussia,SouthAmericaandAfrica,partsofEastAsiaandSoutheastAsia,andthecontinentalUnitedStatesandCanada,forexample.Therearemultipleex-amplesofstudiesandresultantdatabasesofrapidland-coverchangeandecosystemdisturbancesinimportantregionsoftheworld:deforestationinthepantropicalforestbelt;firefre-quencygloballyandregionallyinSouthAmerica,SouthernAfrica,andpartsofRussia;andtheinfluenceofurbanizationinselectedcitiesaroundtheworld.Inadditiontothescientificneedsforasystematicdocu-mentationofchangesinlandcoveroverthepastseveraldecades,thereisapressingneedtounderstandthesechangesfromthestandpointoftheirconsequencesforhumanwelfare.TheMillenniumEcosystemAssessmenthasbeeninitiatedtoevaluatethedegreetowhichecosystemser-vices,onwhichhumansocietiesdepend,aresustainable,giventhemanyenvironmentalstressestheyface().AwidevarietyofstakeholdershaveidentifiedtheMillenniumEcosystemAssessmentasacriticalactivityforunderstandingthecurrentstateandpo-tentialfuturesofecosystemgoodsandservices:individualcountries,internationalnongovernmentalorganizations,governmentagenciesandministries,internationalgovern-mentalorganizations,andinternationalmultilateralen