白龙江林区3种桦木次生林种群结构与动态特征OA

Taking three secondary forest types of Betula albosinensis,Betula platyphylla,and Betula utilis in the Bailongjiang Forest Area of southern Gansu as the research object,this study employed community ecology research methods.Permanent sample plots of 20 m × 30 m were established in the study area to measure structural data.Using population dynamic indices and survival analysis meth-ods,the survival rate,mortality,and population structure characteristics of the three birch species across different age classes in the Bailongjiang Forest Area were revealed,and future population dy-namics were predicted.The results showed that:(1)The population size distribution of Betula al-bosinensis was relatively uniform across age classes,with a high survival rate,particularly showing strong adaptability at young age classes and relatively stable population structure.(2)The population sizes of Betula platyphylla and Betula utilis decreased significantly in older age classes,with a nota-ble decline in survival rates and considerable fluctuation in population structure,indicating greater survival pressure at advanced age classes.(3)Static life table analysis further confirmed that Betula albosinensis had a higher life expectancy and lower mortality,while Betula platyphylla and Betula utilis exhibited significantly increased mortality in older age classes.(4)The individual numbers of all three birch populations showed an increasing trend after 2,4,6,and 8 age classes in the future.This study reveals the structural characteristics and adaptation strategies of the three birch populations in the Bailongjiang Forest Area,providing a scientific basis for precise management and conservation(e.g.,thinning of mature Betula platy phylla,protection of high-altitude habitats for Betula utilis)and maintenance of ecological functions in birch secondary forests in the region.