小兴安岭泥炭沼泽甸杜种群分株的年龄结构与生长分析

Age structure and growth analysis of ramets of Chamaedaphne calyculata populations in a mire of the Xiaoxing'an Mountains

甸杜(Chamaedaphnecalyculata)是常绿小灌木,为无性系植物,主要分布于贫营养泥炭沼泽中.通过对大量样本的观察,应用计数芽鳞痕的方法划分了甸杜分株的年龄结构.在小兴安岭泥炭沼泽生长季中期,沼泽中心与沼泽边缘的甸杜种群分株均由8个龄级组成,呈现稳定型年龄结构.分株平均高度和生物量沼泽中心低于沼泽边缘.不同养分条件是两种生境甸杜种群分株间的年龄结构、生物量和高度生长特征及其生态可塑性等出现差异的主要因素.生境的环境异质性决定了甸杜种群分株的生物量和高度的生态可塑性.

As a clonal evergreen dwarf shrub, Chamaedaphne calyculata is mainly distributed in oligotrophic mires. By virtue of observing a great deal of samples,classified age structure of ramets of Chamaedaphne calyculata clonal populations by way of counting bud scale traces on the ramets. In a mire of Xiaoxing'an Mountains in the middle of growing season, the ramets were classified as 8 age classes and showed a declining age structure. Both mean biomass and mean height per ramet in the center was lower than those in the margin. Different condition of nutrients was main factor to affect the differences of the age structure, growth characteristics of biomass and height and their ecological plasticity of Chamaedaphne calyculata ramets in the two habitats. Oligotrophic condition limited the biomass accumulation and height increment.Heterogenous environmental conditions determined ecological plasticity of ramet biomass and length in Chamaedaphne calyculata populations.