Abstract: A field investigation of the Phalaris arundinacea ramet height, ramet biomass, and biomass of leaves, sheaths, and stems was conducted in two different habitats of the natural grassland of Xiliao-River Plains. Significant differences were shown among the statistical figures of the five items compiled. The ramets’ increasing height and weight marked a regular pattern of heterogeneous speed growth; and with the ramets’ gaining height, their increasing weight was mainly attained by their stems. The increase of the ramets’ weight corresponded to the augmented weight of the biomass of leaves, sheaths, and stems in a stable regular pattern of heterogeneous speed growth. A large allocation of the biomass of both Phalaris arundinacea populations was in the leaves, which accounted for 42.98% to 50.47% of the total. The non-equative rate of increase between the ramets’ height and biomass weight relfected the growth plasticity of the Phalaris arundinacea population’s adaptability to the environment.

Key words: Population ecology, Phalaris arundinacea, Ramets, Heterogeneous speed growth, Biomass allocations, Growth plasticity

摘要： 对西辽河平原天然草地两个生境草芦种群分株的高度、分株生物量、叶生物量、叶鞘生物量、茎生物量5个数量性状调查统计结果表明,不同生境间存在着极显著差异,分株在增高和增重上呈异速生长规律,且分株高度较高的草芦种群随高度的增加以茎增重为主,分株增重与各器官增重之间也呈较为稳定的异速生长规律;两个生境分株生物量分配均以叶的比重最大,在42.98%～50.47%之间。分株的高度与生物量之间非等比例增长的相关性规律是草芦种群适应环境的一种生长可塑性反应。

关键词: 种群生态, 草芦, 分株, 异速生长, 生物量分配, 生长可塑性