兴安落叶松天然林单木高生长模型

Single tree height growth models of Larix gmelinii natural forest

根据31株解析木数据,利用Logistic方程和4参数的Richards方程拟合了兴安落叶松天然林优势木、平均木和被压木高生长模型,经检验,模型均在0.01水平上显著。对林木年龄(A)、胸径(D)、树高(H)、活枝下高(h1)、死枝下高(h2)进行相关性分析后,发现D、H、h1、h2等在0.01水平上有显著正相关,所拟合的活枝下高和死枝下高的模型在0.01水平上显著。研究表明:Logistic方程较4参数的Richards方程对兴安落叶松高生长的拟合效果好,它们对优势木、平均木和被压木高生长拟合所得模型的R2分别为0.829、0.758、0.807和0.771、0.668、0.824。以Logistic方程对优势木和被压木的拟合效果较对平均木的好。对优势木高生长模型精度检验发现,实测值与理论值无显著差异(p>0.05)。

According to the 31 analyzed trees,Logistic and four-parameter Richards equations were used to fit the height growth models of the dominating stems,the average stems and the overtopped stems of natural Larix gmelinii forests.All models were highly significant at 0.01 level.Correlations among the age（A）,the DBH（D）,the tree height（H）,the live height under branches（h1）,the dead height under branches（h2） were analyzed and verified that there was a significantly positive correlation among D,H,h1 and h2 at 0.01 level.Live height under branches and dead height under branches significantly fit the model at 0.01 level.Results indicated that Logistic equation was better than the four-parameter Richards equation when fitting the growth,logistic equation was evidenced by their corresponding model determinant coefficients R2 of 0.829,0.758,0.807 for the dominating stem,the average stem and the overtopped stem respectively.In contrast,0.771,0.668,0.824 were respectively derived by the four-parameter Richards equation.Obviously,two models were jointly well-performed when fitting the growth of the dominant trees and the overtopped trees compared to the average trees.After test,the measured values and the modeled values in terms of the growth of the dominant trees had statistically no significant difference（p0.05）,which indicated that the established models could be practical.