Soil Respiration Characteristics in Three Shrublands along an Elevation Gradient in a Semiarid Loess Plateau Mountain Area

ABSTRACTShrub is one of the major vegetation types distributed mostly in the mountainous area in China, and its vegetation carbon storage is approximately one-third of both forests and grasslands. It is essential to investigate how soil temperature (Ts) and soil water content (Ws) affect soil respiration (Rs) in this ecosystem. The purpose of this study was to understand the correlations of Rs with Ts, Ws, and other factors in the shrubs. In the current study, Rs was characterized in three shrublands (hereafter, shrub 1, shrub 2, and shrub 3, respectively) located in different elevations over a 4-year period at a biweekly interval in the eastern Loess Plateau (Shanxi province) of China. Our results showed that the trend of seasonal change of Rs was controlled mainly by Ts and Ws. The measured mean Rs over 4 years was 3.64 ± 2.83 (mean ± S.D.), 2.69 ± 2.05, and 4.41 ± 3.28 μmol carbon dioxide (CO2) m−2 s−1 for shrubs 1, 2, and 3, respectively, exhibiting an increase trend with elevation increment. Over the...