Temporal-spatial variations of soil respiration and the controlling factors on global scale (1991-2015)

Temporal-spatial variations of soil respiration and the controlling factors is important for understanding the global carbon cycle process. In this research, the Global Soil Respiration Database (SRDB) and Global Geochemical Baseline (GGB) dataset were used, temporal-spatial variations of soil respiration from 1991 to 2015 and the controlling factors in soils developed from different soil parent materials were analyzed. We found, for the first time, soil respiration was significantly varied in soils developed from different soil parent materials on a global scale, which was mainly controlled by geochemical indexes such as Al/Si, MnO, CaO and P2O5. We also found that temporal variations of soil respiration during 1991-2015 in acidic plutonic rocks, acidic volcanic rocks, metamorphic rocks, siliciclastic sedimentary rocks and unconsolidated sediments-developed soils was significantly controlled by temperature, while that of basic plutonic rocks, basic volcanic rocks, intermediate volcanic rocks, mixed sedimentary rocks and carbonate rocks-developed soils was less sensitive to temperature relatively. We conclude that temporal-spatial variations of soil respiration were correlated with soil geochemistry, which mainly depends on the stability difference caused by the bonding between soil organic carbon and soil minerals. The findings may be helpful to understand the temporal-spatial pattern of global soil respiration, moreover reveal the importance of soil geochemistry in influencing soil respiration on global scale.