Abstract: A study of the Stipa krylovii and Artemisia frigida populations reproductive tiller numbers and weight, and the relationship between water and the two species’reproductive allocation, pupulation densities and aboveground biomass showed that appropriate water supply could stimulate the sexual reproduction for the S.krylovii population, but not for the A.frigida one. When more water was supplied, the ratio of the reproductive allocation of S.krylovii rose with the increase of the population density and biomass, while A.frigida decreased with more water supply. However, with the growth of biomass ,there showed no significant difference between the two. Water supply, population density, and biomass affected both species in their reproductive allocation indicating that their reproductive allocations are deeply affected by the phenotypic plasticity, but not by the genetic factors.

Key words: Water supply, Stipa krylovii, Artemisia frigida, Reproductive allocation

摘要： 研究克氏针茅(Stipa krylovii)和冷蒿(Artemisia frigida)的生殖枝数量、重量以及水分对繁殖分配与种群密度、地上生物量之间的关系。结果表明:增加水分有利于克氏针茅的生殖生长,而不利于冷蒿;增加水分时,克氏针茅繁殖分配比例随着密度和生物量的增加而呈增加趋势,但冷蒿则呈降低趋势,但随着生物量的增加二者变化不大;水分、密度和生物量的变化对克氏针茅和冷蒿繁殖分配比例均产生影响,表明两者的繁殖分配是与表型可塑性的变化密切相关,而不受遗传控制。

关键词: 水分, 克氏针茅, 冷蒿, 繁殖分配