气候敏感的马尾松生物量相容性方程系统研建

【目的】构建气候敏感的马尾松生物量相容性方程系统,分析气候因子对马尾松各分项生物量的影响,为森林碳汇监测和森林可持续经营提供技术支撑。【方法】基于150株马尾松单木生物量数据,采用非线性联立方程组法构建气候敏感的马尾松生物量相容性方程系统,各分项生物量(干材、干皮、树枝、树叶和地上总生物量)选用以直径和树高为自变量的二元生物量方程作为基础模型,利用一阶交叉验证法对所构建的生物量相容性方程系统进行评价。【结果】与传统未考虑气候因子的各分项生物量模型相比,气候敏感的马尾松生物量相容性方程系统预测精度明显提高,且该生物量相容性方程系统可定量描述不同气候带亚区生物量的差异程度,保证干材、干皮、树枝和树叶与地上总生物量相容。【结论】气候敏感的马尾松生物量相容性方程系统能有效分析气候因子对各分项生物量的影响,可应用于其他树种的生物量预估。

Developing a System Climate Sensitive Biomass Compatible Equations for Masson Pine

【Objective】 Masson pine ( Pinus massoniana ) is an important species which is widely distributed in the subtropical zone in China.According to the national climate change assessment report,the temperature in China has raised by 0.5-0.8 ℃.The mean ground temperature in China might be raised by 3.9-6.0 ℃ to the end 2100.The method for detecting the response of biomass of Masson pine to climate change are the foundation for estimating forest biomass accurately.However,the effects of climate change on each component (wood,bark,branch and foliage) biomass in traditional systems of biomass equations without being considered.Therefore,in this study,the prediction accuracy of biomass was improved by developing a system of climate-sensitive biomass compatible equations.【Method】 In this study,the method on developing systems of climate-sensitive biomass compatible equations using nonlinear simultaneous equations were proposed in detail based on the biomass data from 150 individual trees of Masson pine.The two-predictor equations with independent variables including diameter at breast height and total tree height were selected as base models for each components to develop the system of climate-sensitive biomass compatible equations.The one-fold cross validation was applied for model evaluation.【Result】 Compared with the traditional biomass models without including climate factors,the prediction accuracy of the system of climate sensitive biomass compatible equations was substantially increased.In addition,the differences of biomass among different subtropical zones were also explained by the proposed system of climate sensitive biomass compatible equations,which ensured the sum of wood,bark,branch and foliage biomass equal to the total biomass.【Conclusion】 The system of climate sensitive biomass compatible equations proposed in this study could be used as an effective tool to analyze the effects of climate change on each component biomass.