北京地区侧柏人工林标准木生长过程研究

从北京地区的6个郊区县设置侧柏人工林样地17块,获取了34株标准木,进行树干解析,建立胸径和树高生长模型,对其生长过程进行分析研究。结果表明:所建立的北京侧柏人工林标准木的胸径和树高生长模型均具有较高的预估精度,其精度分别为98.992 1和93.073 4;胸径的最优生长模型为Gompertz模型,树高的最优生长模型为Richards模型,可用于北京地区侧柏人工林生长过程的预测。在树龄<48a时,胸径生长的增长速度较快,在48a<树龄<81a期间,胸径的生长维持在较高的水平;胸径连年生长量出现3次较明显的生长高峰,且每隔一定年限发生1次,可用于指导间伐抚育期。树高生长在24a以内都维持在一个较高的水平,连年生长量和平均生长量的最大值均出现在9～18a,第15年时,平均和连年生长量相等,在树龄大于24a后,平均和连年生长量一直处于下降水平,维持在0.04～0.16m。

Standard Tree Growth of Platycluadus orientalis Plantation in Beijing

In order to find out the growth regularity of Platycladus orientalis plantations in Beijing,we established 17 sample plots in six counties around Beijing and obtained 34 sample trees to carry out stem analysis.The results showed that the Gompertz model was the optimum one for the growth process of DBH,while the Richards model was suitable for tree height.Moreover,two growth models displayed good prediction accuracy,and with the values of prediction accuracy of 98.992 1 and 93.073 4,respectively,indicating the models could be applied in estimating the growth process of P.orientalis growing in Beijing The growth rate of DBH increased rapidly before the age of 48 years,and it kept at a high level during the age of 48 to 81 years.The growth process of DBH also showed three pronounced peaks every several years,from which the thinning and tending,therefore,could be guided.Although the growth of tree height kept a comparatively high level within 24 years,its maximum value of annual growth and average growth were found during the age of 9 to 18 years,and both the values became equal in the 15th year.However annual growth and the average growth maintained a falling trend after 24 years,with the values from 0.04~0.16 m.