图2. 植物叶片碳(C)、氮(N)、磷(P)计量特征对N和P添加的响应(改自Yuan和Chen (2015))。圆圈表示自然环境中的样本, 灰色和绿色分别表示ln (响应比)与0差异不显著(p > 0.05)和差异显著(p? ≤ 0.05); 三角形表示控制环境中的样本, 灰色和红色分别表示ln (响应比)与0差异不显著(p > 0.05)和差异显著(p? ≤ 0.05)。误差线显示的是平均值的95%置信区间。括号外和括号内的数字分别代表自然环境和控制环境中的样本量。

Fig. 2. Natural log response ratios of plant carbon (C), nitrogen (N), phosphorus (P) and their stoichiometric ratios to N and P additions, respectively (replotted based on Yuan & Chen (2015)). Circles are for results in natural environments with grey and green representing insignificant (p > 0.05) and significant (p ≤ 0.05) difference between the log response ratio and zero, respectively. Triangles are for results in controlled environments with grey and red representing insignificant (p > 0.05) and significant (p ≤ 0.05) difference between the log response ratio and zero, respectively. Error bars are the 95% confidence intervals for the mean. The numbers out- and inside parentheses represent the numbers of observations for experiments in natural and controlled environments, respectively.