Population dynamics of Betula ermanii associated with soil change on treeline of northern slope of Changbai Mountains
长白山北坡林线岳桦种群与土壤关系

This paper, taking the treeline of northern slope of Changbai Mountains as the research object, selected 4 plots (83 quadrats) to study diameter-class structure of Betula ermanii population and soil physical and chemical properties. Four indices of soil properties (SOM, TN, AN and gravel contents) and diameter-class structure of two life forms (shrub and single-trunk) were analyzed by ANOVA, correlation analysis and other statistical analysis. The relationships between population dynamics and soil change were investigated by correlation analyses. The results showed soil physical and chemical properties on different quadrats had obvious difference with different expansion of Betula ermanii population. Soil factor had a certain restrictive effect on population dynamics. However, soil factor did not play a crucial role in treeline shifts and population expansion. The gradual weakening of soil properties has an effect on treeline shifts with the passage of time. The Betula ermanii population tended to continuously adjust its life forms to adapt air temperature change in order to overcome soil restrictions.