河北省木兰林管局山杨天然次生林生长规律研究

目的]系统了解和掌握山杨天然次生林林木生长规律。方法]以河北省木兰林管局山杨天然次生林为研究对象,利用多年调查的临时样地资料,借助Excel、SPSS11.0和ForStat统计分析软件,对主要林分因子生长进行模拟以了解其生长规律。结果]抛物线方程拟合其立木株数生长过程效果最好,Logistic方程拟合其蓄积量、材积生长过程效果最好,对数方程拟合其胸径、树高生长过程效果最好;50年生山杨胸径年平均生长量为0.27 cm,速生期为0～5年;树高年平均生长量为0.29 m,速生期为0～10年;材积年平均生长量为0.003 65 m3/hm2,速生期为15～25年和30～40年2个阶段。结论]山杨天然次生林数量成熟龄为50年左右,此时可进行人工采伐。

Study on the Growth Rhythm of Pobulus davidiana Dode.Secondary Forest at Mulan Forestry Management Bureau in Hebei

Objective]Understand and grasp the forest growth rhythm of Pobulus davidiana Dode.secondary forest systematically.Method]Based on the data collected from experimental sample plots and analytical trees of Pobulus davidiana Dode.secondary forest at Mulan Forestry Management Bureau in Hebei,Excel,SPSS11.0 and Forstat were used to model the growth process of main stand factors for understanding forest growth rule.Result]Parabola equation was the best model for describing the number of Pobulus davidiana Dode..Logistic equation was the best model for describing the stand volume and volume.Loqarithm equation was the best model for describing the DBH and heigh.Mean annual DBH increment was 0.27 cm,and early 5 years were the speed period of DBH growth.Mean annual height increment was 0.29 m,and early 10 years were the speed growth period.Mean annual volume increment was 0.003 65 m3,15-20 and 30-40 years were the speed growth period.Conclusion]The quantitative maturity age of Pobulus davidiana Dode.secondary forest was 50.