Phosphorus Limitation on Carbon Sequestration in China under RCP8.5

Currently, there is a lack of understanding regarding carbon (C) sequestration in China arising as a result of phosphorus (P) limitation. In this study, a global land surface model (CABLE) was used to investigate the response of C uptake to P limitation after 1901. In China, P limitation resulted in reduced net primary production (NPP), heterotrophic respiration, and net ecosystem production (NEP) in both the 2030s and the 2060s. The reductions in NEP in the period 2061–70 varied from 0.32 Pg C yr −1 in China to 5.50 Pg C yr −1 at the global scale, translating to a decrease of 15.0% for China and 7.6% globally in the period 2061–70, relative to the changes including C and nitrogen cycles. These ranges reflect variations in the magnitude of P limitation on C uptake (or storage) at the regional and global scales. Both in China and at the global scale, these differences can be attributed to differences in soil nutrient controls on C uptake, or positive feedback between NPP and soil decomposition rates, or both. Our results highlight the strong ability of P limitation to influence the pattern, response, and magnitude of C uptake under future conditions (2030s–2060s), which may help to clarify the potential influence of P limitation when projecting C uptake in China.