Carbon storage in China's terrestrial ecosystems: A synthesis

It is important to accurately estimate terrestrial ecosystem carbon (C) storage. However, the spatial patterns of C storage and the driving factors remain unclear, due to lacking of data. Here, we collected data from literature published between 2004 and 2014 on C storage in China's terrestrial ecosystems, to explore variations in C storage across different ecosystems and evaluate factors that influence them. We estimated that total C storage was 99.15±8.71 PgC, with 14.60±3.24 PgC in vegetation C (Veg-C) and 84.55±8.09 PgC in soil organic C (SOC) storage. Furthermore, C storage in forest, grassland, wetland, shrub, and cropland ecosystems (excluding vegetation) was 34.08±5.43, 25.69±4.71, 3.62±0.80, 7.42±1.92, and 15.17±2.20 PgC, respectively. In addition to soil nutrients and texture, climate was the main factor regulating the spatial patterns of C storage. Climate regulated the spatial patterns of Veg-C and SOC density via different mechanisms, Veg-C was mainly positively influenced by mean annual precipitation (MAP), whereas SOC was negatively dependent on mean annual temperature (MAT). This systematic estimate of C storage in China provided new insights about how climate constrains C sequestration, demonstrating the contrasting effects of MAP and MAT on Veg-C and SOC; thus, these parameters should be considered in future reforestation strategies.