Precipitation Pulses and Soil CO 2 Emission in Desert Shrubland of Artemisia ordosica on the Ordos Plateau of Inner Mongolia, China

• Published in: Pedosphere Vol. 19; no. 6; pp. 799 - 807
• Main Authors: JIN, Zhao, DONG, Yun-She, QI, Yu-Chun, DOMROES, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2009; Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101 China; State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi'an 710075 China%Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101 China%Institute of Geography,Mainz University,Mainz 55099 Germany
• Subjects: desert shrub ecosystem; Mu Us sand land; soil respiration response; water addition; desert shrub ecosystem; water addition; soil respiration response; Mu Us sand land
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(09)60175-2

Precipitation is the major driver of ecosystem functions and processes in semiarid and arid regions. In such water-limited ecosystems, pulsed water inputs directly control the belowground processes through a series of soil drying and rewetting cycles. To investigate the effects of sporadic addition of water on soil CO 2 efflux, an artificial precipitation event (3 mm) was applied to a desert shrub ecosystem in the Mu Us Sand Land of the Ordos Plateau in China. Soil respiration rate increased 2.8–4.1 times immediately after adding water in the field, and then it returned to background level within 48 h. During the experiment, soil CO 2 production was between 2 047.0 and 7 383.0 mg m −2. In the shrubland, soil respiration responses showed spatial variations, having stronger pulse effects beneath the shrubs than in the interplant spaces. The spatial variation of the soil respiration responses was closely related with the heterogeneity of soil substrate availability. Apart from precipitation, soil organic carbon and total nitrogen pool were also identified as determinants of soil CO 2 loss in desert ecosystems.