松嫩平原全叶马兰种群无性系分株的建成及其年龄结构

全叶马兰（Kalimeris integrifolia Turcz.)为根蘖型多年生草本菊种植物。在生长季后期，新生肉质细根向地表生长形成根蘖芽，根蘖芽成株后形成主根。经过对大量样本观察。创建了按形态特征对根蘖型草本植物种群无性系分株和芽的年龄划分方法，以及对主根生活年限的估计方法。分株年龄是按主根芽再生的次数划分，新根蘖芽成株为1a,1a分株死亡后从主根再萌生的分株为2a,2a分株死亡后从主根再萌生的分株为3a。新根蘖芽为0a芽，其它龄级与分株的龄级相一致，即1a分株主根芽为1a芽，2a分株主根芽为2a芽，在松嫩平原割草草场，全叶马兰种群由3个龄级无性系分株组成，呈稳定型年龄结构。分株主根的生活年限最多为4年，分株的生产力种群水平以2a最高，个体水平以1a最低，并随着龄级的增加呈增长趋势，其中，在生长季初期以3a分株的生产力最高，进入中期以后则1a最低，并随着龄级的增加呈增长趋势。其中，在生长季初期以3a分株的生产力最高，进入中期以后则1a分株的相对生长速率最大，用秋末新生根蘖数量和现时种群数量可以较准确预报翌年种群数量和年龄结构。芽库中潜在种群数量是现时种群数量的2倍以上，但不意味着种群将发生疯长，而是为替补所做的充分准备。

Development and Age Structure of Ramets of Kalimeris integrifolia Populations in the Songnen Plains, Northeast China

Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In the late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root_borne buds, which in turn grow into ramets and taproot. On the basis of observation on numerous samples, methods to classify the age of ramets and buds for the root sucker herbaceous plant population and to estimate the ages of taproots were established according to their morphology. The age of ramets was classified based on the regeneration times of taproot buds. Ramets developed from new root sucker buds were classified as 1 a. After 1 a ramets died, the ramets reproduced from the taproots were 2 a, and so on. New buds from a root sucker were 0 a buds, other age classes of buds were consistent with that of ramets, i.e. buds produced from taproots of 1 a ramets were 1 a buds, and so on. In the hay clipping meadows of the Songnen Plains, for K. integrifolia population, there are three age classes of ramets, representing a steady age structure. The maximal age of taproots of ramets is 4 a. Among all age classes, the population productivity of 2 a ramets was the highest, and that of 1 a ramets was the lowest. The ramet productivity increased with ramet age. During the early period of growing season, the productivity of 3 a ramets was the highest, but after the middle of growing season, 1 a ramets showed the greatest relative growth rate. The population size and age structure in the next year could be accurately forecasted by the number of fresh roots with budlet and present population in late autumn. The potential population in the bud banks was more than two times of the present population, which may provide sufficient substitution in the future.