松嫩平原杂类草草甸阿尔泰狗哇花无性系种群构件年龄结构

阿尔泰狗哇花为根蘖型菊科多年生无性系草本植物.采用主根芽区的繁殖世代数划分分株和芽龄级的方法，研究了松嫩平原杂类草草甸阿尔泰狗哇花无性系种群不同构件的年龄结构.结果表明:分株构件和芽构件均由4个龄级组成.在孕蕾期，分株构件中1龄级占22.6%、2龄级44.8%、3龄级28.8%、4龄级3.8%，呈稳定型年龄结构.在乳熟期，生殖分株构件以2龄级比重最大,占45.6%，4龄级最小，占0.8%，为稳定型年龄结构；而营养分株构件以1龄级比重最大,占47.5%，4龄级最小，占1.1%，为增长型年龄结构.分株主根的生活年限最多为5年.不同生育期分株构件的生产力均以2龄级最高.在乳熟期，1龄级分株具有较大的生产潜力，4龄级分株的生产力已普遍减弱.芽库中潜在种群呈增长型年龄结构.

Age structure of the modules of clonal Heteropappus altaicus population on weedy meadow steppe in Songnen Plain of China.

Heteropappus altaicus is a root sucker type perennial herbaceous clonal plant of compositae. The age structure of its modules on the weedy meadow in Songnen Plain of China was studied by a method, in which, age class was compartmentalized according to the propagared generations in bud section of taproot. The results showed that both ramets and buds of the clonal population consisted of 4 age classes. The modules of ramets showed stable age structure, with the age spectrum being 22.6%, 44.8%, 28.8% and 3.8% from 1st to 4th age classes at flowerbud stage, respectively. At milk stage, the modules of reproductive ramets showed a stable age structure, with the proportion of 2nd age class being the largest (45.6%) and of 4th age class being the least (0.8%), while those of vegetative ramets showed an expansive age structure, with the largest proportion (47.5%) of 1st age class and the least (1.1%) of 4th age class. The taproot of the ramets could survive for five years at most. The productivity of 2nd age class ramets was most vigorous at different growth stages. The ramets of 1st age class had the biggest productive potential, while the ramet productivity of 4th age class was generally weakened at milk stage. The potential population in the bud banks presented an expansive age structure.