[Population dynamics of endangered plant species Abies chensiensis].
In order to know the endangered status and causes of Abies chensiensis in Qinlin Mountains, a field investigation on 18 plots was conducted on its age structure, life table and fecundity, and its population dynamics were predicted by time sequence model. The analysis on the age structure of Abies chensiensis populations showed that there were fewer young individuals, but middle-aged and old individuals were relatively rich. The population D in Abies chensiensis-Indigofera amblyantha-Carex lanceolata association showed a relatively stable development tendency, while other four populations (A, B, C and E) in Abies chensiensis-Pinus tabulaeformis-Sinarundinaria nitida-Carex lanceolata association, Abies chensiensis-Quercus aliena var. acutserrata-Litsea pungens-Carex lanceolata association, Abies chensiensis-Betula albo-sinensis-Sinarundinaria nitida-Duchesnea indica association, and Abies chensiensis-Pinus tabulaeformis-Smilax stans-Carex lanceolata association all showed an obviously declining tendency. The analysis on the life tables and survival curves showed that the survival curve of Abies chensiensis populations belonged to Deevey III, and the death peak of different populations was in the period of 60--100 years old. The number difference among populations reflected the population habitat. Time sequence prediction indicated the numbers of old individuals would be increased at the beginning, and decreased finally in 20, 40, and 80 years. It was difficult to maintain the population stability. Analysis on 10 ecological factors showed that tree coverage, soil organisms and air humidity influenced population positively, and human disturbance and sunlight influenced population negatively. In situ conservation should be taken as the most important management countermeasure, and natural regeneration should be promoted. At the same time, artificial population should be expanded.
Zhang
Wenhui
W
Tianjin Normal University, Tianjin, China. zwhckh@163.com
Xu
Xiaobo
X
Zhou
Jianyun
J
Xie
Zongqiang
Z
D028202:Abies / Q000145:classification* / Q000254:growth & development*; D002681:China; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005544:Forecasting; D008962:Models, Theoretical; D011157:Population Dynamics