Fig. 4

Decomposition of changes in community trait values with nitrogen addition (N) and mowing (M) into inter-group, intra-group, and co-variation effects for concentrations and stocks of nutrients in forage. Red bars represent the total variation of each part. The positioning of an asterisk within the −/−/− graphic represents the significance of inter-group variation/intra-group variation/total variation, respectively. Relative height between the bar and the top of column determines the effects of co-variation. Height of bar that is higher than the top of column indicates positive co-variation, and the height of bar that is lower than the top of column indicates negative co-variation. N, nitrogen addition; M, mowing; N^*M, interaction between nitrogen addition and mowing; Res., residuals; Total, total variation. ^***P < 0.001, ^**P < 0.01, ^*P < 0.05, ⁻P > 0.05