橡胶树立木材积是全国林业常用数表体系的重要组成部分，目前由于多方面原因，我国无省级尺度以上的橡胶树立木材积表。海南省是我国橡胶树的主要种植区域，编制橡胶树立木材积表，将填补海南乃至全国基础林业数表的空白。编制二元立木材积表通常采用以胸径（D）、树高（H）为变量的山本材积式方程，未考虑区域分布、经营状况及品系等因素影响。由于橡胶树在经营中普遍采取了截干分枝措施，不同区域范围的立地条件、经营状况也不尽相同，加之橡胶树品系较多，均会给橡胶树材积带来一定程度的差异。为综合考虑这些因素的影响，以山本材积式方程为基础，分析了橡胶树分枝数、区域、品系对立木材积方程的影响，利用混合模型方法建立考虑上述因素为随机效应的立木材积混合模型。研究结果表明：橡胶树品系对立木材积的影响不显著，而分枝数、区域对立木材积的影响显著；建立考虑分枝数、区域及分枝数与区域交互作用为随机效应的混合模型明显优于山本材积式模型，其拟合优度、预估精度更高，适应性更强。%The standing rubber tree volume is an important part of the national standing forestry volume table system. Due to multiple aspects, the provincial scale above standing rubber tree volume hasn’t been established yet. Hainan province is the major rubber tree planting area in china, to establish the standing rubber tree volume would fill the gap of basic standing forestry volumes in Hainan, even in the whole country. The principle method to establish the standing volume is Yamamoto volume equation with tree diameter(D)and height(H)as variables,without considering the influence of regional distribution, site conditions, the strains of rubber tree and other aspects. Due to the fact that rubber trees are generally taken cut stem measures, the diverse of site conditions and management status in different regions, and the variety strains of rubber tree, which will bring a certain degree of difference to standing rubber tree volume. Taken these factors into consideration, this paper analyzed these factors’ influence upon the standing rubber tree volume in Hainan province based on Yamamoto volume equation, to establish nonlinear mixed effects models for standing volume by using factors above as random effects variables. The results showed that: the strains of rubber tree does not have a significant impact on the parameters of Yamamoto volume equation, but the branch numbers and the planting region have a significantly affection; the nonlinear mixed effects standing volume model has better fitting results, higher accuracy, and better adequacy than the Yamamoto standard volume model.
展开▼
