基于主成分分析水稻植株CH4排放估算模型

估算稻田甲烷（CH4）排放量是开展稻田甲烷排放研究的重要内容之一．通过观测南方红黄壤稻田不同水稻品种甲烷排放通量，测定了16个早稻、20个晚稻品种的植株节间组织的数量特征．选取株高、茎秆长度、茎秆维管束面积／茎壁横切面积、茎壁横切面积／节间横切面积、叶鞘横切面积／节间横切面积、气腔面积／茎壁横切面积、维管束总面积／茎壁横切面积等相关因子进行了主成分分析，建立基于水稻植株的CHa排放估算模型，早、晚稻估算模型相关系数分别为0．827、0．853．同时构造了综合评价函数，得出了水稻品种CH4排放综合分值，与实测结果相比较，吻合度较高．利用估算模型进行模拟，比较模拟值与实测值，相对误差较小，证明模型具有有效性和可行性，为估算水稻CH4排放提供参考依据，为评价水稻品种CH4排放高低提供经验参考．

Rice Plant Methane Emission Estimated Model Based on Principal Component Analysis

Methane is one of the greenhouse gases, which contributed to the greenhouse effect. Estimate value of methane emission from paddy soil is one of the researches on the mechanism of methane emission. During 2005 double-season rice system, methane emission flux of 16 early varieties and 20 late rice varieties were measured and the quantitative characteristics of rice plants tissues were determined. Seven index were selected by the capital component analysis, which are plant height, stem length, the ratio for stem vascular bundles area to the stem wall section area, the ratio for the stem wall transverse section area to the internodal transverse section area, the ratio for leaf sheath transverse section area to the internodal transverse section area, the ratio for the gas chambers area to the stem wall transverse section area, the ratio for the total area of vascular bundles to the stem wall transverse section area, and the estimated model based on the plant tissues was established and the correlation coefficient of models on early rice and late rice were 0.827 and 0.853, respectively. At the same time, the integrative evaluation function was applied to available the integrative scores of rice methane emission. ＇Compared to the observed values, the identical degree was beyond 90%.The simulate value which proved the efficiency and feasibility of models and supposed the reference basis for estimates of rice methane emission and evaluated the grades of rice varieties methane emission.