《生态学》课程PPT教学课件（生态学原理与应用）05 interactions Competition

INTERACTIONSCOMPETITION

COMPETITION INTERACTIONS

ECOLOGECONCEPTSANDAPLUICAZONSCOPEZTOY以其无争，天下莫能与争《道德经》第六十六章

以其无争， 天下莫能与争。 《道德经》第六十六章

ECOLOGECONCEPTSANDAPLUICAZIONSCOPEZTO0-02+002-01+0+++++000+0

O1 O2 O2 O1 + - 0 + + + - + 0 + - + - - - 0 - 0 + 0 - 0 0 0

Damselfish, Territories guard, Im?Interference competition.Resource limitationIntraspecific competitionInterspecific competitionTerritorialreeffishsuchasthisthreespotdamselfishFIGUREIO.1Eum

Damselfish, Territories guard, 1m2 . Interference competition, Resource limitation, Intraspecific competition, Interspecific competition

White pine10times

White pine 10 times

ECOLOGECONCEPTSANDAPLUICAZONSCOPEZTOYStudies ofintraspecific competitionprovide evidence for resource limitation

❖ Studies of intraspecific competition provide evidence for resource limitation

ECOLOGECONCEPTSANDAPLUICAZIONSCOMPEZTOIntraspecific Competition Among Herbaceous Plants

➢ Intraspecific Competition Among Herbaceous Plants

S. natans was grown at highand low densities on a gradientAt lowdensitofnitrogen availabilityS.natans grer10to a large sizeDavid Tilman et al 1989sse8Sorghastrum nutans64S.natansremainedsmallat highdensities23009001,500Soil nitrogen (mg N perkg soil)FIGURE 10.3

David Tilman et al 1989 Sorghastrum nutans

The self-thinning rule predicts thatplants will decrease in populationdensity (self-thin)as the totalbiomass of the population increasesPopulations A,B, C.and D allconverge on a state of lowdensity and high total biomass.LargesseorgjouaoHighinitial numbermedium biomassCHigh initialLow initialMediuminitialAnumber,number,number,lowbiomassDlowbiomassLowlowbiomassHighLowLogarithm of numberof individualsm.WestobySelf-Thinningin Plant Population

• Self-Thinning in Plant Population

As plantings of altalfaMedicagosarw arew, ortality thinnedthe stands as surviving plantsfeached larnersiSelf-Thinning rule(K.Yoda 1963):Msariia population atend ot theexperinent consisted of largerM=KN-3/2plants growinp at lower densiry0.5uedsadaueaFinal densir0.01M,arwplantedathigh densiry ininiall0.05Imitaldensity5,0001.00010.000Density (plantsperm)Whiteand Harper(1970),AlfalfaFGURGTO.NSetfrhinninginpolonswfatata,Nleeeago sativahiieaaper1o7o)

Self-Thinning rule(K. Yoda 1963): M = KN-3/2 White and Harper(1970), Alfalfa