不同栽杉代数29年生林分生产力变化

对一代、二代及三代杉木人工林林分生产力变化的比较分析结果表明：随着杉木栽植代数增加，林分生产力明显下降，不同代数间胸径、树高和蓄积量差异均达到极显著水平，但多重比较显示一代与二代平均胸径、二代和三代平均树高差异不显著．利用调查数据建立的立地指数与立地指数衰退量数学模型，能较好反映了连栽后杉木生长的实际情况．

Change on the Stand Productivity of 29-Year-Old Chinese Fir Plantation in Different Rotations

The productivity of the Chinese fir stands of the first,the second,the third planting were comparatively studied The results showed that,with the increasing of the Chinese fir different rotations,the first and second stand productivity declined distinctly,the variance analysis showed that the difference of mean stand DBH,mean tree height,average tree volume and stand stock between the Chinese fir plantations in different rotations were remarkable,but the multiple comparison showed that the differences of the mean stand DBH between the stands of the first and the second,the mean tree height between the stands of the second and the third rotation were not clear.The simulation model of the site indexes and the degrade quantity on different site indexes indicated the changes of stand productivity of Chinese fir plantation on different rotations well.