Fig 1.
(a). Different regions of the study area according to the elevation and annual precipitation. The pink circles are 839 meteorological stations. (b). Land use of China. The 23 stars represent the observed-NPP stations from published papers, and these stations located in the temperate forest are mainly used to verify the potential productivity.
Fig 2.
The spatial distribution of multi-year MOD17A3-NPP average from 2000 to 2015.
Fig 3.
Flowchart of the methodology employed in this study.
Light green represents the process of this study; Light orange represents data used in this study; Gray represents the output; Light blue represents the methods.
Fig 4.
Validation of NPP (a). The range of NPP of three models and measured data in Luo’s [35] study in 27 provincial administrative regions (b). The correlation of NPP between three models and Luo’s measured data in 27 provincial administrative regions (c). The correlation of NPP between three models and MODIS NPP in 23 observed stations (d). The correlation of NPP between three models and MODIS NPP in 23 observed stations.
Table 1.
Comparison of annual average NPP between this study and other studies.
Fig 5.
The spatial pattern of NPP calculated by three models (Abbreviation: TW represents Thornthwaite Memorial model, ZGS represents the synthetic model).
Table 2.
RB for the results of three models comparable with reference data (Note: TW represents Thornthwaite Memorial model).
Fig 6.
The spatial distribution of NSE of three models compared with MODIS NPP product.
Fig 7.
The spatial distribution of RMSE of three models compared with MODIS NPP product.
Table 3.
RMSE of three models comparable with MODIS NPP product.
Fig 8.
CC of three models compared with MODIS NPP product.
Fig 9.
The spatial distribution of CC in three models compared with MODIS NPP product.