兰州半荒漠植被区红砂(Reaumurta soongorica)种群数量动态

对兰州市永登县半荒漠植被区天然分布的红砂(Reaumurta soongorica)种群实地调查取样,利用红砂植株地径大小与相应年轮年龄的关系,得出回归方程,求出各地径对应年龄,编制静态生命表、分析动态指数、存活曲线、生存分析曲线。结果表明:各生境红砂种群均表现出新苗和幼株丰富,占种群株数的比例大;所有样地存活曲线均接近于Deevev-Ⅲ型(凹型);静态生命表显示,生境异质性,特别是水分差异,致使红砂种群表现出2种不同的环境适应策略;各生境种群动态指数均基本为正值,充分说明样地内的红砂种群基本处于发育状态,整体上是稳定增长的。

Preliminary Study on Reaumurta soongorica Population Dynamics in Lanzhou Semi-desert Vegetation Area

In this paper, we sampling surveyed on the Reaumurta soongorica populations naturally distributed in semi-desert vegetated area of Yongdeng, Lanzhou. Through analysised the relationship between R. soongorica stem basal diameter and age, the regression equation was established to get the age of the corresponding basal diameter. We made the static life table, analyzed the dynamics index, the survival curves and survival analysis curves. The results showed that: the R.soongorica populations in different habitats had lots of seedlings, the seedlings accounted for large proportion of the populations. The population survival curves in all plots were close to Deevey-Ⅲ type (concave). The static life tables showed the R. soongorica populations adopted two kinds of different strategy for the habitat heterogeneity, especially different water conditions. The population dynamics index V_n were positive value, fully illustrated the R. soongorica populations were in the developing state, and the overall populations kept on the tendency with steady increasing.