Spatiotemporal variations of soil CO2 in Chenqi, Puding, SW China: The effects of weather and LUCC

Abstract

Long-term monitoring of soil CO2 dynamic was applied under different weather conditions and land uses to investigate the influences of weather and LUCC on soil CO2 variations as well as its potential carbon sink. Observation results demonstrate that seasonal variations of soil CO2 are mainly controlled by temperature-water combined effect, rising to the peak in wet–hot season and declining to the valley during dry–cold time. In spatial scale, soil CO2 concentration is largely regulated by LUCC and follows the descending order of forest, shrubbery, dry land, and paddy land except for rice growing season, but with an ascending sequence for coefficient of variations (C.V.s), among which the highest C.V. and the abrupt changes of CO2 in paddy land are mainly due to the alternate cultivation, flooding irrigation, and draining mechanism. Furthermore, by means of modeling calculations, wet–hot weather conditions and land uses as forests are provided with higher dissolved inorganic carbon (DIC) equilibrium concentration than the other sites, reflecting stronger karst process as well as larger potential carbon sink.