长白山北坡林线岳桦种群动态对气候变化响应的坡向分异

选取长白山北坡岳桦(Betula ermanii)苔原交错带3个不同坡向(东北坡、东南坡、东坡)的岳桦径级结构为研究对象,分析坡向在岳桦种群动态与气候变化之间关系的异同。结果表明:三坡向的岳桦种群扩张和气温高低存在明显差异。14个生态气候指标与对应年份内繁殖且存活下来的岳桦棵数的逐步回归分析和相关分析表明三坡向岳桦种群扩张是对气温变化的积极响应,但响应有差异:东坡>东南坡>东北坡。不同坡向岳桦种群扩张的差异是对气温变化差异的响应。

The Dynamics Response of Betula ermanii Population and Climate Change on Different Slopes Aspect of North Slope,Changbai Mountains

To discover the relation between Betula ermanii population dynamics and climate change on treeline ecotone of Changbai Mountains,53 plots were selected on three different slope aspects(northeast,southeast,east slopes) through treeline ecotone on north slope of Changbai Mountains.Distributing character of the diameter-class(diameter at breast height(DBH)) structure of shrub and single-trunk forms were described by four aggregation indices.Trend analysis of distributing character was carried through by unitary linearity equations.Different reflection of the dynamics response of Betula ermanii population to climate change on different slope aspects was analyzed by stepwise regression and correlation analysis.The results are as follows:the results of trend analysis of the diameter-class distributing(slopes of equations are negative) shows the capacity expansion rate of shrub form is east slopes>southeast slopes>northeast slopes and that of single trunk form is northeast slopes>east slopes>southeast slopes.The population expansion is leapfrog and pulsatile from low to high(p>0.01).The result of One-way ANOVA displays that daily mean temperature on three slopes are significant differences(p<0.05) and the temperature change has synchronism.The results of correlation analysis between annual stem recruitment of Betula ermanii population and 14 ecological preferences of air temperature(1953-2008) show that the different response of population dynamics to climate change caused by different temperature on three slopes.The difference of climate change lead to different expansion of Betula ermanii population on different positions.