山西太岳山杨桦林动态与空间格局分析

《山西太岳山杨桦林动态与空间格局分析》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、·山西师范大学学位论文analysisofthesurvivalfunction,cumulativemortalityratefunction,mortalitydensityfunctionandhazardratefunction,tostudythepopulationofstructureanddynamics.TheresultsshowedPopulusdavidianapopulationmostindividualsconcentratedintheageⅡandⅢclass(70.91%

2、),indicatingthatthepopulationwasinthedeclinestage.ThepeakofmortalitywasfromⅡtoⅢdiameterclass,andthedeathrateofthepopulationwashigherinthelaterstagethanintheformerstage.BetulaplatyphyllapopulationmostindividualsconcentratedintheageⅡandⅢclass(60.39%),indicat

3、ingthatthepopulationwasinthedeclinestage.ThepeakofmortalitywasfromⅡtoⅢdiameterclass,andthedeathrateofthepopulationwashigherinthelaterstagethanintheformerstage.Thepopulationwasstableinthewholecommunityatthepresentstage.Thefunctionsusedinthestaticlifetableco

4、uldwellexplainthestructureanddynamicsofpolar-birchforest.Theregenerationofthepopulationwasofdeclinestageandunstableatoldstage.（2）ThesurvivorshipcurveofPopulusdavidianapopulationgenerallymatchesaDeeveyTypeⅠ,althoughseedlingsarerareandhavealowsurvivalratedue

5、tohighcrowndensity.Thespatialdistributionpatternsofthepopulationdifferamongplotsandgrowthperiods.ThedistributionpatterntendstobeclumpedontheeasternslopeofTaiyueMountainpeakwhereinterspecificcompetitionisnotintense.Thespatialdistributionindifferentgrowthper

6、iodsisclumpedorrandom.Clusteringismorepronouncedforadulttreesthanoldtreesasaresultofbiologicalandenvironmentalfactors.Populationstendtoclumpwheninterspecificcompetitionisnotsevereinawet,cold,sunnyhabitatinTaiyueMountain.Intraspecific···4万方数据···Abstractcomp

7、etitionalsoaffectstheclusteringintensityofdifferentgrowthperiods.Theresultsshowedthat:Betulaplatyphyllapopulationswereallaggregateddistributionsinthethreehabitats,DifferenttypesofBetulaplatyphyllapopulationsonthethreeslopesshowedsignificantlyaggregateddist

8、ributionsatrelativelysmallerscalesandthedegreeofaggregationdecreasedwithincreasingspatialscales，andittendedtouniformdistributionsatlargerscalesinthegentleslope;Seedlingshadmoreobviouslyaggregateddistributiona