森林资源连续清查中四种一元材积估计方法的对比分析

Comparison on Four Kinds of One-variable Volume Estimation Methods in Continuous Forest Inventory

国家森林资源连续清查中长期使用的一元立木材积表是否存在偏估,一直是值得关注的问题。利用第八次全国森林资源清查2012年广东省的杉木(Cunninghamia lanceolata)和马尾松(Pinus massoniana)样地调查数据,以二元材积估计结果为基础,对4种一元立木材积估计方法进行了对比分析。结果表明,杉木和马尾松现行一元立木材积表的相对误差均大大超出了±3%的允许范围,本文提出的3种一元材积估计方法都能有效消除材积估计偏差。建议各省参照本文提出的方法,对现行的一元立木材积表进行一次系统检验,对偏差过大者应当及时予以修正或更新。

Abstract ： Whether one-variable tree volume tables used in national forest inventory （NFI） for long- term are biased or not has been drawn attention. Using the mensuration data of sample plots from Chinese fir （Cunninghamia lanceolata） and Masson pine （Pinus massoniana） forests in 2012 Guangdong province of the 8^th NFI, four kinds of one-variable volume estimation methods were compared and analyzed, based on the volume estimate of two-variable model. The results showed that relative errors of the current one-variable tree volume tables for Chinese fir and Masson pine did exceed the allowance ＋ 3 %, and the others 3 kinds of one-vari- able volume estimation method spresented in this paper could effectively eliminate the bias in volume estimations. It is recommended that one-variable tree volume tables/models currently used in each province need to be systematically tested by using the methods provided here, and the significantly biased ones should be corrected or updated in time.