Vegetation structural change and CO2 fertilization more than offset gross primary production decline caused by reduced solar radiation in China

•A computationally efficient method for large scale GPP estimation is proposed•Vegetation structural change in forest contributed most to the GPP increase in China•Afforestation enhanced GPP significantly in China•Solar radiation decline dominated the negative effect of climate variation on China's GPP•CO2 fertilization offset the negative effect of climate variation on China's GPP during 2001-2016 Terrestrial gross primary production (GPP) is the largest carbon flux from the atmosphere to the terrestrial ecosystems. However, how GPP dynamics respond to vegetation structural change (VSC), climate change, and rising CO2 concentration are still unclear. In this study, we developed a process-based model (i.e., Farquhar GPP Model) to characterize GPP dynamics in China from 2001 to 2016, and further identify the dominant drivers for GPP variation related to VSC, climate change, and rising atmospheric CO2 through model scenario design. During the study period, VSC showed an overwhelmingly positive impact on annual total GPP (i.e., 39.2 Tg C yr−1, P