Fig. 1From: Nitrogen use efficiency of terrestrial plants in China: geographic patterns, evolution, and determinantsChanges in NUE with latitude (a) and longitude (b). The latitudinal and longitudinal patterns of NUE were fitted by a linear function. These figures are drawn with 1° latitudinal/longitudinal resolution. Dots are the mean NUE values and the bars represent the standard errors (SE)Back to article page