北京西部山区胡枝子种群研究:个体和构件生物量

通过对北京西部山区胡枝子(Lespedeza bicolor Turcz.)种群个体和构件地上生物量进行系统研究。结果表明,种群(总和)个体和各构件地上生物量积累与年龄的关系均可用方程式Y=axb表示。不同种群的植株个体和构件生物量有显著性不同(P<0.05),在海拔910-1100m的山脊林缘的种群个体和构件地上生物量较其它种群大,植株地上营养构件的生物量比率较小,而繁殖构件生物量比率较大;不适生境中的种群则反之。种群个体生长和各构件生物量动态与环境条件关系密切。构件生物量比率也随着年龄的增长而有所变化。叶生物量比率随年龄增加而减小;枝构件生物量比率随年龄增加而增大;繁殖构件的生物量比率随年龄增加先增后减。依据相关指数R2,筛选各构件生物量估计的最优模型:枝、枝叶生物量和地上生物量均为m(DW)=a(D2H1)b,叶生物量和花果生物量均为m(DW)=a(D)b。

Individual and Modular Biomass of Lespedeza bicolor Turcz. Populations in Western Mountain Areas of Beijing

We systematically studied the individual and modular biomass dynamics of Lespedeza bicolor Turcz. populations in western mountain areas of Beijing. Except for the biomass of reproductive modules, which followed the power function, the biomass accumulation of other modules could all be expressed by the equation Y=axb. The individual and modular aboveground biomass of different populations within different habitats significantly differed (P<0.05), and were greater for populations in the forest edge mountain ridge at 910-1 100 m than for other populations. The ratios of vegetative modular biomass were low and that of reproductive modules high in the most compatible habitat for L. bicolor Turcz. populations. The incompatible habitats had the opposite results. The individual growth and modular biomass accumulation were closely related to habitat conditions. The ratios of branch modules increased but that of leaf modules decreased with increasing age, whereas the ratios of reproductive modules first increased and then decreased. Depending on the relation index (R2), the model m(DW)= a(D2H1)b was selected for branch, vegetative modules and individual biomass and the model m(DW)=a(D)b for leaf and reproductive module biomass.