沙坡头人工植被区中的油蒿种群动态与稳定性

利用种群生态学中的年龄结构、静态生命表和种群动态指数对沙坡头包兰铁路北侧1964年和1981年沙地人工植被区中的油蒿种群结构动态进行分析,发现1981年区和1964年区的油蒿种群都属于增长型,但1981年区的增长性大于1964年区,也就是说,随着人工植被建立的时间延长,油蒿种群结构由快增长型转向慢增长型.因此,沙地中的油蒿种群的动态趋势是由快增长向慢增长,以及衰退方向演变,最终有从人工植被区中消失的趋势.同时,油蒿种群结构的增长型是油蒿能长期存在的种群生态学原因,是它具有适应干旱、半干旱区的沙地生境的生物学特性所决定的.

Dynamics and Stability of Artemisia ordosica Population in Shapotou Area

The dynamics of %Artemisia ordosica% populations were analyzed through age|structure, static life table and population change index in two fields of artificially sown vegetations (established in 1964 and 1981) along northern side of Baotou-Lanzhou Railway in Shapotou section. The results showed that both of the populations in two fields were all in increasing trends. The population of 1981 plot was in faster growth type compared with that of 1964 plot. That is to say the growing of %A. ordosica% population will be gradually retarded with time going. So, the dynamic growth of %A. ordosica% population in artificial vegetation was from fast to low, and then to declining manner. The artificially sown vegetations of %A. ordosica% population had showed a disappearing trend. Meanwhile, the growing pattern of %A. ordosica% population is determined by biologic characters of %A. ordosica%, which enable the plant well adapted to live in arid and semi|arid desert.