西南桦人工林的林木分化研究

对4、7和16年生西南桦人工林林木的胸径、树高和材积的分析结果表明:其林分林木个体间胸径的极差分别达8.30 cm、13.60 cm和15.00 cm;7年生林分林木个体间的材积极差为0.13692 m3。聚类分级结果,4、7和16年生林分林木的组间胸径极差分别达6.17 cm、12.82 cm和12.90 cm;7年生林分林木的组间活立木蓄积量极差达45.86012 m3/hm2。揭示了用实生苗营造的西南桦人工林其林木个体间强烈分化及其早期表现的客观存在,据此提供了对西南桦进行遗传改良和早期优良无性系选育的信息,同时也预示着西南桦无性系林业发展的重要性。

Study on Differentiation of Betula alnoides Plantation

The DBH,height and stand volume of Betula alnoides individuals in the plantations of 4,7 and 16 years old were analyzed,the result showed that the extreme differences of DBH among individuals of 4,7 and 16 years old were 6.17 cm,12.82 cm and 15.00 cm respectively,the rangs of stand volume of stand 7-year-old individuals reached 0.136 92 m3.The results of hierarchical cluster analysis indicated that the DBH subset ranges were 6.17 cm,12.82 cm and 12.90 cm for the 4,7 and 16-year-old B.alnoides plantations,respectively;the volume subset range for the 7-year-old stand was 45.860 12 m3/hm2.These results revealed that intrinsic properties of great growth differentiation between stand individuals involving the properties presented in juvenile stands within B.alnoides plantations established by seeding seedlings.The study was also showed the information of feasibilities on tree improvement and early selection,which suggests the significance of developing B.alnoides clonal forestry.