摘要 Knowledge of soil respiration and the influencing factors in desert ecosystems is essential to understanding carbon dynamics and responses of biotic and abiotic processes in soils to climate change. In this study, soil respiration rate (Rs) for three land-cover types (shifting sandy land, sandy land with straw checkerboard barriers, and shelter forest land) in the hinterland of the Taklimakan Desert was measured in May 2015 using an automated soil CO2 flux system. The effects of soil temperature (Ts) and soil water content (Ws) on Rs were also analyzed. The results showed that Rs values in shifting sandy land, sandy land with straw checkerboard barriers, and shelter forest land were all low and exhibited obvious diurnal fluctuations. The establishment of straw checkerboard barriers in sandy land had no significant effect on Rs, while the establishment of shelterbelts significantly increased Rs. Shifting sandy land and sandy land with straw checkerboard barriers were carbon sinks at night and early morning and were carbon sources in the daytime, while shelter forest land always acted as a carbon source during the whole day. The synergistic effect of Ts and Ws could better explain the diurnal dynamics in Rs than single factor. In shifting sandy land and sandy land with straw checkerboard barriers, Ws was identified as a limiting factor influencing the diurnal dynamics of Rs. Furthermore, a relatively strong hysteresis loop existed between Rs and Ts. In contrast, in shelter forest land, Rs was significantly influenced by Ts, and a relatively weaker hysteresis loop existed between Rs and Ws.
Abstract：
Knowledge of soil respiration and the influencing factors in desert ecosystems is essential to understanding carbon dynamics and responses of biotic and abiotic processes in soils to climate change. In this study, soil respiration rate (Rs) for three land-cover types (shifting sandy land, sandy land with straw checkerboard barriers, and shelter forest land) in the hinterland of the Taklimakan Desert was measured in May 2015 using an automated soil CO2 flux system. The effects of soil temperature (Ts) and soil water content (Ws) on Rs were also analyzed. The results showed that Rs values in shifting sandy land, sandy land with straw checkerboard barriers, and shelter forest land were all low and exhibited obvious diurnal fluctuations. The establishment of straw checkerboard barriers in sandy land had no significant effect on Rs, while the establishment of shelterbelts significantly increased Rs. Shifting sandy land and sandy land with straw checkerboard barriers were carbon sinks at night and early morning and were carbon sources in the daytime, while shelter forest land always acted as a carbon source during the whole day. The synergistic effect of Ts and Ws could better explain the diurnal dynamics in Rs than single factor. In shifting sandy land and sandy land with straw checkerboard barriers, Ws was identified as a limiting factor influencing the diurnal dynamics of Rs. Furthermore, a relatively strong hysteresis loop existed between Rs and Ts. In contrast, in shelter forest land, Rs was significantly influenced by Ts, and a relatively weaker hysteresis loop existed between Rs and Ws.
This study was funded by the National Natural Science Foundation of China (41175140) and the National Department of Public Benefit (Meteorology) Research Foundation (GYHY201306066).
通讯作者: YANG Fan
E-mail: yangfan309@yeah.net
引用本文:
YANG Fan,ALI Mamtimin,ZHENG Xinqian等. Diurnal dynamics of soil respiration and the influencing factors for three land-cover types in the hinterland of the Taklimakan Desert, China[J]. Journal of Arid Land, 2017, 9(4): 568-579.
YANG Fan,ALI Mamtimin,ZHENG Xinqian et al. Diurnal dynamics of soil respiration and the influencing factors for three land-cover types in the hinterland of the Taklimakan Desert, China[J]. Journal of Arid Land, 2017, 9(4): 568-579.
2017, Vol. 9 
