不同林分密度指标在杉木单木直径年生长模型的应用

Annual Tree Diameter Growth Model of Chinese fir Plantations Including Different Stand Density Indices

[目的]分析不同林分密度指标在直径生长模型中的应用,对林分密度的精准管理具有重要意义。[方法]以福建邵武杉木(Cunninghamia lanceolata)人工林密度长期试验林28 a连续观测数据为研究对象,基于可变生长率法,对7种不同的林分密度指标在单木直径年生长模型中的应用进行了比较研究,共构建了8种杉木单木直径年生长模型。[结果]8种模型的拟合精度比较高,R^(2)均在0.96以上。相比较含有密度指标的杉木单木直径模型精度高于不含密度指标模型。在所有含有密度指标的模型中,决定系数最高的是以林分密度指数(SDI)为密度指标的模型,其次为以林分断面积BA和Nilson密度指数为密度指标的模型。[结论]基于SDI林分密度指数构建的杉木单木直径模型最优。

[Objective]To analyze the application value of stand density index in tree diameter growth model for accurate management of stand density.[Method]Based on the 28 years continuous observation data of the spacing trials of Chinese fir(Cunninghamia lanceolata)plantation in Shaowu,Fujian Province,the annual tree growth model was developed through variable rate method using seven density indices respectively.Also the model without stand density index was developed for comparing.[Result]All the eight models performed well,with R2 values more than 0.96.The models including the stand density indices were better than the model without stand density index.Among all the models with density indices,the model including stand density index(SDI)has the highest R2 value,followed by the model with stand basal area Ba and SD density index.[Conclusion]The model including SDI density index performed the best,which provides insights into density management in reason for Chinese fir plantations.