Response ratios of fine root and soil variables to N and P treatments.

Values are Ln(treatment mean/control mean). A positive response ratio indicates positive effects of fertilization, whereas a negative one indicates negative effects. * indicates significant difference at P数值为处理组均值与对照组均值比值的自然对数（Ln）。响应比值为正时表明施肥具有正向效应，为负时则表明施肥具有负向效应。* 表示在P水平下存在显著差异。