中林、中林23两个杨树无性系的生长特性

目的]通过对中林和中林232两个无性系人工林生长特性进行分析,为2个无性系人工林的集约经营及其木材的合理加工与利用提供理论依据。方法]分析2个无性系的树高、胸径和材积的生长模型和连年生长量和平均生长量的规律。结果]中林杨2个无性系的高生长与胸径生长同步,生长中后期单株之间差异明显;树高连年生长量最大值与平均生长量最大值几乎同步出现,胸径亦如此,树高连年生长量在接近第4～5年与平均生长量相交,胸径连年生长量和平均生长量在第4～6年相交。结论]从18年生的2个无性系生长过程来看,生长可分为3个时期:第0～5年为幼树期,树高、胸径生长比较快,第6～9年为速生期,树高、胸径生长急速上升,第10～18年为近熟期,树高、胸径生长趋缓。中林杨材积的平均生长量与连年生长量在第7～10年相交,达到数量成熟,此时可进行轮伐。

Growth Characteristic of Two Clones of Poplar Zhonglin and Zhonglin 23

Objective]The purpose of this program was to study the growth characteristic of Poplar Zhonglin and Zhonglin 23 plantation.It was expected to provide theoretical basics for planting in Ili Prefecture.Method]The height,the breast diameter and the volume was analyzed.Result]The results showed that the tree height growth of Poplar Zhonglin and Zhonglin 23 was the same time with the breast diameter growth,the competition for resources grew cruelly among the trees in later growth period;The maximum of current annual increment and mean annual increment of tree height appeared nearly synchronously,so did the breast diameter.But the maximum of current annual increment of timber volume appeared much earlier than the maximum of mean annual increment.The current annual increment and mean annual increment of tree height,breast diameter and timber volume were respectively intersected in about 4 to 6 years.Conclusion]The growth process of Poplar Zhonglin and Zhonglin 23 was divided into three periods; 0-5 years of time was the young stand period,6-9 years of time was the fast - growing period,10 -18 years of time was the near mature period.The rotation of Poplar Zhonglin and Zhonglin 23 was about between 7 and 10 years.