世界人口分布.pptx

文档介绍：体停车设备电动葫芦管涂塑复合管钢塑复合管消防涂覆钢管WorldpopulationPopulationgrowthDefinition:howthenumberofindividualsinapopulationincreasesordecreaseswithtimeGrowthiscontrolledbyratesofbirth,:noimmigrationandemigration,orimmig.=,(t)(b)anddeathrate(d)dN/dt=(b-d)N=rNThedifferencebetweenbirthrateanddeathrateistheintrinsicgrowthrate(r)(instantaneouspercapitarateofgrowth).r=b-dInaclosedpopulation,populationsizechangeisrelatedtobirthrate(b)anddeathrate(d)Thedifferencebetweenbirthrateanddeathrateistheintrinsicgrowthrate(r)(instantaneouspercapitarateofgrowth).r=b-dPopulationgrowthisrelatedtothisintrinsicgrowthrate(r).ExponentialpopulationgrowthEquations:1)dN/dt=rN(differentialequationform)2)N(t)=N(0)exp(rt)(exponentialgrowthmodel)Conditions:InitialpopulationissmallNofoodorresourcelimitationAnexampleReindeer,,,therewerenearly2000Whoopingcrane,anendangeredspeciesrecoveredfromnearextinctionin1941Howtocalculater?Software,Excel(trendline)AransasNationalWildlifeRefugePropertiesofexponentialgrowth