A dataset of observational key parameters in carbon and water fluxes in a semi-arid steppe, Inner Mongolia (2012 – 2020): based on a long-term manipulative experiment of precipitation pattern

Warming has led to remarkable changes in global precipitation pattern, which will significantly affect vegetation growth and ecosystem function of the semiarid grasslands in Northern China. As a key processe of ecosystem function, carbon and water flux determines the carbon sequestration capability and resource utilization strategies of ecosystems. Therefore, understanding the responses of ecosystem carbon and water fluxes to precipitation pattern changes and their controls will be helpful for the evaluation in the carbon sequestration capacity of grassland ecosystems. However, there is a lack of long-term experiments and observational data on the responses of carbon and water processes to precipitation pattern changes in grassland ecosystems. Based on the long-term precipitation pattern manipulative experiment (including seven precipitation amount and rain event frequency treatments), we collected seasonal dynamics of ecosystem carbon and water fluxes by the static chamber method connecting with infrared gas analyzer during 2012-2020 in Xilin Gol grassland, Inner Mongolia. The dataset consists of two data files, namely the meteorological environmental data file (including annual precipitation, air temperature, soil moisture, and soil temperature) and the carbon and water fluxes data file (including ecosystem gross primary productivity, ecosystem respiration, net ecosystem carbon exchange, evapotranspiration, carbon use efficiency, and water use efficiency). Preliminary data analysis has shown that the drought treatment could significantly reduce the carbon and water fluxes, while water addition treatment had no significant effect on them. All the parameters recovered to the control level in the first year after the treatment cessation. This dataset is expected to provide important data support for the understanding of the responses of carbon and water cycles and their coupling processes to future precipitation regime in grasslands of Northern China.