Fig. 4
Changes of WUELT (a–f) of the six studied species under N addition and drought. Data are shown as mean ± SE. Among them, a and d show the changes in grasses, b and e show the changes the leguminous forb, c and f show the changes in non-leguminous forbs. “N–C” and “ND–D” represent the relative changes of RUE caused by N addition without and with drought, respectively; “D–C” and “ND–N” represent the relative changes of RUE caused by drought without and with N addition, respectively. ^0.05 < p < 0.1, *0.01 < p < 0.05, **0.001 < p < 0.01, ***p < 0.001