Site plays an important role in fitting height-diameter model in such a large scale as nation, whereas it is not known in most cases. Using the classified height method with double iteration algorithm, height-diameter model of six major tree species in china, including Quercus, Cunninghamia lanceolata, Pinus massoniana, Populus, Larix gmelinii and Pinus tabulaeformis ,were constructed. The data came from height-measurement file in 7th national consecutive forest inventory, total observations were 118 441, of which 79 095 observations used for model development and 39 346 observations used for model validation. Contrasting to ordinary method, the coefficients of determination reached 0. 942 8-0. 966 5 from 0. 520 3-0. 753 2. Parameter sensitivity analysis and model validation showed that models were robust in general and fitted parameters were statistically reliable. The classified height method is useful to construct height-diameter model for all tree species in china. Considering stand factors,the method is helpful to evaluate national forest site.%采用树高分级方法,通过双重迭代算法,建立栎类、杉木、马尾松、杨树、落叶松和油松6个全国主要树种的树高-胸径曲线模型.数据来自第7次全国森林资源连续清查的树高测定资料,总样本数118 441个,其中建模样本79 095个,验证样本39 346个.与未分级方法相比,分级后模型的决定系数从0.5203 ～0.7532提高到0.943 8～0.966 5;模型参数灵敏度分析和验证模型的应用表明:模型总体稳定,参数可靠,为构建全国所有树种的树高-胸径模型提供可行的方法,有较好的推广价值.进一步考虑林分特点,可以用来进行全国所有现有森林的立地评价.
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