关键词: 红砂, 生境, 种群数量动态, 静态生命表, 动态指数, 谱分析, 兰州市南北两山

Abstract: The quantity dynamics of the natural Reaumuria soongorica populations from different habitats in the south-north hills in Lanzhou were studied. Using the age class structure regression by diameter class, the static life table and survival function curves were determined, the dynamic indexes were calculated and spectrum analysis was done. The results showed: in 4 habitats the Reaumuria soongorica populations all contained more young members and less middle-aged or old members; all populations had highest death rates at age class Ⅲ. As the age increased, the death rates reduced; because of the physiological senescence, the death rates of age class Ⅶ and Ⅷ increased. The survival curve of the populations approached to Deevey type Ⅲ. The populations all belonged to progressive type. The order of growth potential is: at the foot of shady slope (5.90%)> at the foot of sunny slope (5.62%)> at the top of shady slope (4.77%)> at the top of sunny slope (3.79%), and this order indicated obvious periodicity. The dynamic quantity of all Reaumuria soongorica populations were overall controlled by their biological characteristics of lifecycle. Due to the environmental heterogeneity caused by different slope situations and altitudes, Reaumuria soongorica populations at the foot of shady slope grew well, at the top of shady slope and at the foot of sunny slope took the second place. But Reaumuria soongorica populations at the top of sunny slope which were influenced significantly by both environment and intraspecific competition pressure, had the biggest danger coefficient. The Reaumuria soongorica populations should be protected by proper tending practices to enhance sustainable development.

Key words: Reaumuria soongorica, habitats, population quantity dynamics, static life table, dynamic index, spectral analysis, the south-north hills in Lanzhou