Global aboveground and belowground Net Primary Productivity grids with 0.05° resolution from 1981 to 2018 using the Deep Learning model

Net primary productivity (NPP) in global ecosystems is a critical component of terrestrial carbon cycling and an essential indicator of ecosystem carbon sequestration capacity. However, the size and spatial patterns of NPP across global ecosystems remain uncertain, particularly for the divided estimation of above- and below-ground net primary productivity (ANPP and BNPP), which limits our understanding of global NPP carbon cycling and the sustainability of carbon sequestration. Here, an updated database was compiled with 5,184 filed observations to estimate the spatial patterns of ANPP and BNPP using a modified multilayer perceptron neural network (MLP) method. Based on the 10-fold cross-validation,<i> </i>the model performance<i> </i>of ANPP and BNPP were 0.74 (<i>R</i>^<em>2</em><i>, RMSE</i>: 138.37 g C m^-2 yr^-1) and 0.73 (<i>R</i>^<em>2</em><i>, RMSE</i>: 76.33 g C m^-2 yr^-1), respectively. The total ANPP and BNPP were 33.4 ± 0.5 and 19.2 ± 0.73 Pg C yr^-1, respectively. ANPP and BNPP exhibited decreasing trends from low latitudes toward the poles. Over the last 38 years, global 65.38% and 60.83% areas of the ANPP and BNPP showed a growth trend, and annual total ANPP and BNPP were significant positive growth trends (<i>p</i> &lt; 0.01), about 0.02 and 0.05 Pg C yr^-1, respectively. Our findings suggest that field data-driven prediction of NPP using the MLP model could be a useful approach for obtaining spatially explicit NPP of ecosystems, particularly BNPP. This study contributes to the understanding of the dynamics of terrestrial carbon sequestration in the context of global change and may provide a new method and basis for making climate change response proposals.Filename: ANPP_MLP_1981_2018_0.05.zip; BNPP_MLP_1981_2018_0.05.zipFile information：‘ANPP_MLP_1981_2018_0.05.zip’ is the predicted global ANPP grid with 0.05° spatial resolution from 1981 to 2018; ‘BNPP_MLP_1981_2018_0.05.zip’ is the predicted global BNPP grid with 0.05° spatial resolution from 1981 to 2018. The unit for these data is 'g C m^-2a^-1'. Besides, both zip files contain 38 grid images, and each grid image is named according to the following convention: 'data type' _ 'model type' _ 'year' _ 'spatial resolution'.tif. For example, the ANPP data for the year 1981 would be named:' ANPP_MLP_1981_0.05.tif'.<b>Corresponding author</b>: Xiaolu Tang ([e-mail])