中文摘要：

本实验研究了3个盐分梯度对盐地碱蓬株高、生物量、种群密度以及种内竞争的影响，并通过所得数据建立了一种计算生态位的新方法用以分析盐地植物群落中盐地碱蓬的分布特点。结果表明，低土壤盐分梯度的环境虽然适合盐地碱蓬个体的生长，表现为株高较高，生物量较大，但并不适合盐地碱蓬种群的生活，表现为种内竞争激烈，种内生态位很小，所以当与其他物种共存时并无明显优势；而在中高土壤盐分的环境中，盐地碱蓬由于受到盐分胁迫而使个体生长受到了一定的限制，但同时这种环境胁迫也降低了种内竞争，所以最终结果是种内生态位比低土壤盐分时要大，也就是当与其他物种竞争时很可能会形成单优势种群落或盐地碱蓬的纯群落。

英文摘要：

This experiment studied the effect of height, biomass, population density and intraspecific competition of Suae- da salsa in three different salt treatments and established a new calculation method of niche based on the data that we obtained from the experiment. The results showed that S. salsa grew pretty well in the environment of low soil salinity with high plant height and biomass. In compared with the performance of the individuals, the population performed fierce intraspecific competi- tion and small intraspecific niche. It indicates that there are no obvious advantages for S. salsa when coexisting with other spe- cies in low stress of salinity. In the high soil salinity environment, the individuals of S. salsa were inhibited by salt stress, whereas the intraspecific competition was reduced. So the intraspecific niche was bigger than that in the lower soil salt environ- ment, which means that it is likely to form the dominant species in the community or pure community of S. salsa when compe- ting with other species.