三江源兴海地区西北针茅产量影响因子的主成分分析

利用主成分分析法和多元逐步回归法分析影响三江源兴海地区西北针茅（Stipa sareptana Beckervat．krylovii）牧草产量的因子。结果表明，影响西北针茅牧草产量的主成分因子以水分因子为主，温度和光照因子其次；以各因子为自变量，西北针茅牧草产量为因变量，进行多元逐步回归分析，建立产量回归方程，方程的相关系数达0．9873，各因子影响牧草产量的大小为4月降水量＞4～8月降水量＞7月降水量＞8月日照时数＞6月日照时数。

Study on the Main Components of the Influential Factors on the Output of Stipa sareptana Becker var.krylovii in the Xinghai of Three Rivers' Head Source Area

By dint of main component analysis method and multivariate gradual regression method,factors that influenced the output of Stipa sareptana Becker var.krylovii in Xinghai of three rivers head sources area were expounded.Results suggested that moistures were the principle factors that influenced the output of stipa sareptana,followed by temperature,sunlight factors;taking each factor as independent variances,the output of Stipa sareptana Becker var.krylovii as dependent variances,output regression equation wa...