不同栽杉代数林分生物量的研究

Stand Biomass in Different Rotations of Chinese Fir

文章采用设标准地进行实验测定的方法．研究了南平溪后２９年生杉木林不同连栽代数林分的生物量．结果表明：２９年生单株杉木各组成所占比例大小顺序为干＞根＞皮＞枝。２代和３代林分中实生平均木的生物量、于皮占总生物量的比例随连栽代数增加均下降．而枝叶和根系所占比例则上升。２代和３代林中实生的生物量、枝叶所占的比重均分别大于相应萌芽的．而根系所占比重则比萌芽的小。２代和３代林分中杉木子皮生物量、林分枝叶生物量、林分根系的生物量、乔木层总生物量均呈下降趋势。说明随连栽代数增加．林分总生物量明显下降．生产力严重衰退。

Through studying stand biomass in different rotations of 29-year-old Chinese fir in Xihuo.' Nanping. the result indicated that the proportions of tree composition were in the sequence of trunk>root>bark>branch; the average tree biomass and the proportion of trunk and bark in total biomass ofChinese fir seedling stand of the second and the third planting both declined along with the increasingcontinuous plantations. while the proportions of branches and leaves. root system increased; the biomassand proportion of branches and leaves of the second and the third plantation were both higher thanthose of corresponding sprout forest; comparing with the first planting. the biomass of trunk and bark.branches and leaves. root system. tree stratum all declined. It is proved that the total biomass andproductivity of Chinese fir seedling stand decline distinctly with the increasing continuous plantations.