Abstract: To evaluate the impact of actual vegetative propagation ability (AVPA) of clones on population growth,an experimental cohort of Leymus secalinus was established under common-garden conditions. AVPA was estimated by using the vegetative reproductive indexes of a single clone. This phased and continuous growth patterns of module production and growth based on two-year experimental observations of the cohort of L. secalinus were analyzed. A bud flow model was also constructed based on the findings of the experiment. The vegetative reproductive indexes such as total length of rhizomes,number of rhizomes,and number of buds in the experimental cohort clone of L. secalinus in the same year and the following year all had significant plasticity,with coefficients of variation greater than 74%. The increase in AVPA between years was greater than that of vegetative propagation ability in the experimental cohort clones of L. secalinus. In the rhizome growth sequence,the total length of rhizomes,number of rhizomes,number of ramets,total number of active buds,and total number of live modules all follow a classic exponential growth pattern during the phased and continuous growth processes. In the bud flow,the failure rate of vegetative propagation of the experimental cohort in the two years was less than 1%. The success probability of vegetative reproductive was relatively high,with 40.6% in the first year of transplantation and 58.1% in the second year. Among them,the output rates of ramets were 4.3 times and 5.5 times that of the rhizome,respectively. The actual vegetative fecundity plasticity variations of AVPA within the experimental cohort clones of L. secalinus reflects survival strategies of population,while small clones prioritize occupying more above ground space.

Key words: Clone growth, Module, Experimental cohort, Allometric growth, Dormant bud bank, Active bud bank, Reproductive strategy, Plant ecology

摘要： 为了评估无性系实际营养繁殖力对植物种群增长的影响，本文基于同质园建立的赖草(Leymus secalinus)实验同生群，以单个无性系营养繁殖指标衡量实际营养繁殖力，分析了两个年份赖草单个无性系构件生产和生长的阶段性和连续性增长规律，并构建芽流模型。结果表明，赖草无性系在当年和翌年根茎总长度、根茎数、芽数等营养繁殖指标均具有较大可塑性，变异系数均大于74%。在年份间，实际营养繁殖力的增长大于营养繁殖力的增长。在根茎生长序列中，根茎总长度、根茎数、分株数、活芽总数、活构件总数的阶段性和连续性增长过程均符合指数模式。在芽流中，两个年份赖草无性系营养繁殖失败率均低于1%，而成功率均较高，当年为40.6%，翌年为58.1%，其中，分株输出率分别是根茎的4.3倍和5.5倍。无性系实际营养繁殖力的可塑性体现了植物种群生存对策，小无性系采取优先占据更多地上空间的策略。

关键词: 无性系生长, 构件, 实验同生群, 异速生长, 休眠芽库, 活动芽库, 繁殖策略, 植物生态学