Fig. 5

Spatial distribution of significant correlations between annual WUE and PREP in the SRB (a) and the heatmap of correlations between WUE and PREP in different ecological functional areas (b) (WUE 1/2/3/4 are the same as in Fig. 4; Prep 1/2/3/4 represent the annual precipitation in Zones I/II/III/IV, respectively).