中文摘要：

研究了土壤营养、土壤水分和种群密度等环境因素对沙米表型可塑性的影响．结果表明：土壤营养、土壤水分和种群密度对沙米的形态特性和生物量具有显著影响；随着土壤营养的增加，沙米的根冠比从0．135减小到0．073，但与土壤水分和种群密度无显著相关关系．对土壤营养和土壤水分变化响应的沙米繁殖分配可塑性是“真正的可塑性”；沙米繁殖分配与土壤营养呈负相关，与土壤水分呈正相关；在高土壤营养或低土壤水分条件下，沙米的繁殖分配随个体大小变化的速率较大；种群密度对沙米的繁殖分配无影响，其繁殖分配主要受个体大小的制约．在3个环境因素中，土壤营养对沙米形态特性和生物量特性的可塑性影响最大．

英文摘要：

However, soil moisture content and population density had less effect on the root/shoot ratio. The plasticity of reproductive allocation of A. squarrosum as responding to the changes of soil nutrient and moisture contents was a ＂real plasticity＂, and the allocation was negatively correlated with soil nutrient content but positively correlated with soil moisture content, wnen SOll nument colltvllt was high or moisture content was low, the reproductive allocation of A. squarrosura changed larger with plant size. Population density had no effects on the reproductive allocation, while plant size conditioned the allocation. Among the three test affecting factors, soil nutrient content had the greatest effects on the morphological characters and biomass of A. squarrosum.