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1、JournalofBlackwellPublishingLtd.ESSAYREVIEWEcology200391,707–720IndicesofplantcompetitionALEXANDRAWEIGELTandPETERJOLLIFFE*ChairofExperimentalandSystemsEcology,UniversityofBielefeld,Universitätsstr.25,33615Bielefeld,Germany,and*FacultyofAgriculturalScience,Univ
2、ersityofBritishColumbia,2357MainMall,Vancouver,BCV6T1Z4,CanadaSummary1Mathematicalindices,formedbycombiningseveralprimarymeasures,canhelpresearcherssummarize,interpretanddisplayresultsfromplantcompetitionexperi-ments.Thisessaycompilesanddiscussesmorethan50indi
3、cesthathavebeenusedinstudiesofplantcompetition.2Indicesallowresearcherstoquantifyandexpressseveralattributesofplantcom-petition,includingcompetitionintensityandimportance,competitiveeffectsandresponses,andtheoutcomeofcompetition.3Severalqualitiesshouldbeconsid
4、eredwhenselectingacompetitionindexforuse.Theseincludespecificityandclarityofmeaning,mathematicalandstatisticalpro-perties,densitydependence,versatilityandfreedomfromsizebias.4Manyindicesarebasedoncomparisonsofplantperformanceinmixturescomparedwithpurestandsorco
5、ntrolplots.Additionalmeasuresofcompetitionarealsoavailablefromyield-densityfunctions,sizedistributionsandneighbourhoodanalysis.5Indicesreflecttheconsequencesofcompetition.Inordertoappreciatecompetitiveprocesses,indiceshavetobeusedinconjunctionwithstudiesofthech
6、ronology,circum-stancesandcompositionofplantassociations.Key-words:competitionindices,competitionintensity,competitiveeffects,competitiveresponses,outcomeofcompetitionJournalofEcology(2003)91,707–720facilitatethepresentationofresults.ByaggregatingIntroductions
7、everaldifferentmeasuresindicescanexpressand‘Theinterpretationoftheoutcomeofcompetitioncanquantifycompositeideasthatmaybettercharacterizedependcriticallyonthewaycompetitionismeasured’competitionthanispossiblethroughasimpleprimary(Freckleton&Watkinson1999,p.286)
8、.Thisstatementmeasure(Hunt1982).Bycondensingandorganizingisapplicabletoseveralaspectsof‘measurement’,includ-experimentalresultsindicescanhelpresearchersinter-ingexperimentaldesign,