Afforestation increases ecosystem productivity and carbon storage in China during the 2000s

Abstract

China is experiencing fast afforestation and sensible climate change in recent decades. However, their impacts on regional carbon cycle remain unclear. Here, we explore the effects of climate and land cover change (LCC) on ecosystem productivity and carbon storage in China during 2001-2012 by forcing a dynamic vegetation model with satellite-based land cover and two different climate datasets. The model predicts a significant increase of 0.065 m2 m−2 decade−1 in annual mean leaf area index, higher than the observed trend of 0.038 m2 m−2 decade−1. Meanwhile, national annual total gross primary productivity increases by 0.041 ± 0.007 Pg C yr−2, which is contributed by CO2 fertilization (0.035 ± 0.001 Pg C yr−2), LCC (0.036 ± 0.001 Pg C yr−2), and climate change (-0.032 ± 0.01 Pg C yr−2). Consequently, the total land carbon storage in China increases by 0.99 Pg C yr−1, to which the LCC alone contributes 0.77 Pg C yr−1. The maximum enhancement of >1 g C m−2 yr−1 in land carbon stock is found over the central west, where a large fraction of shrublands is converted to forests. Our results suggest that afforestation in China provides a strong mitigation to the regional carbon emissions during the 2000s.