3.2.1. Spatial Distribution of Four LAI Climatologies

Figure 5 shows the spatial distribution of LAI climatology (11 years averaged LAI from 2001 to 2011) for each product. Generally, the four products are consistent in their patterns: a high LAI in the southeast and a low LAI in the northwest. Note that the pixels perennially at zero were set to null, which mainly occurs in the northwest of China. Considering the LAI values, four products show agreement in some regions: for example, in the northwest part of China (an arid or cold climate zone with mainly grassland land cover type), the LAI values are all in the range from 0 to 2. However, in the Sichuan basin in central China (red rectangles in Figure 5), with a cold climate and mainly covered with grassland in the west and a temperate climate and forest cover in the east, GLASS and GLOBMAP LAI mainly range from 2 to 4 at the edge of basin; GLOBALBNU LAI ranges from 0 to 2 in the western basin and 2 to 4 in the eastern basin, and MODIS LAI ranges from 0 to 2 in the whole basin. For southeast coastal regions located in a temperate climate and mainly covered with forest, GLOBMAP has a higher LAI than the other three products, while MODIS has the lowest LAI.

**Figure 5.** Spatial distributions of four LAI climatologies: (**a**) GLASS (**b**) GLOBALBNU; (**c**) GLOBMAP; (**d**) MODIS.

Figure 6 shows the boxplot of the overall LAI pixel values over China; the lines (from top to bottom) represent the maximum LAI value, 75% quartile value, median value, 25% quartile value, and minimum value, and the black spot represents the mean value. The results show that the four

products have the same minimum LAI, while the GLOBMAP product has the highest maximum value (9.25), followed by GLOBALBNU (6.20), MODIS (5.74), and GLASS (5.45). The mean values are almost the same for the four products (around 1.0), but GLOBMAP has the highest mean value (1.12). The interquartile range is lowest for MODIS (0.89), and the total spread is highest for GLOBMAP (9.25), which means GLOBMAP has the highest variation (1.19).

**Figure 6.** Boxplot of each LAI climatology. The lines (from top to bottom) represent the maximum LAI value, 75% quartile value, median value, 25% quartile value, and minimum value, respectively, and the black spot represents the mean value.
