绵阳官司河流域长江防护林的群落高度级结构分析

 对绵阳市官司河流域11个长江防护林模式径流场植被类型作了高度级个体数、盖度、种数结构统计；并提出了以高度级(年龄级或相对年龄级)为参考坐标，衡量种群及群落结构动态的失稳率，群落垂直空间盖度分布的均匀度种类的分享度等指标和公式；应用这些指标和公式对系列模式径流场植被类型的高度级结构动态，作了定量分析评价。

THE PLANT COMMUNITY HIGHNESS CLASS CONSTRUCTION OF YANGTZE RIVER SHELTER FOREST IN GUANSI RIVER VALLEY, MIANYANG CITY

In order to understand how the Yangtze River shelter forest community highness class construction be made of, we investigated plant community highness class number of plants, cover degree and number of species in 11 model of run-off plots of vegetation types in this area. The plant community highness class was regarded as coordinate axis. A series of new targets and equations, e. g. lost stable rate of plant number, cover degree fluctuative rate and species sharing degree, were put forward, for examining plant population or community dynamics and community construction. With this targets and equations, we quantitatively analyzed this series of highness class constructions of run-off plots of vegetation types and compared these models′advantages and shorters for their soil and water conservation effect.