Response of soil respiration to hydrothermal factors under different land cover types in a desert – oasis ecotone, northwest China

For the study of soil carbon cycling, it is important to investigate the effects of hydrothermal factors on soil respiration under different land cover types in arid areas. In this study, soil respiration during the growing season under three land cover types (Haloxylon ammodendron plantation, oasis field, and poplar plantation) was measured in a desert-oasis ecotone in Northwest China. The response of soil respiration to hydrothermal factors under the three land cover types was analyzed. There were differences in monthly soil respiration among the three land cover types. From April to September in 2016, soil respiration was 0.59 μmol·(m²·s)^–1 in the H. ammodendron plantation, 2.67 μmol·(m²·s)^–1 in the oasis field, and 3.16 μmol·(m²·s)^–1 in the poplar plantation. The monthly variation in soil respiration was influenced by both soil temperature and soil moisture. The relationship between soil temperature and soil respiration can be simulated by linear and exponential equations, whereas the relationship between soil moisture and soil respiration was more complex and had a quadratic function. For all three land-cover types, the diurnal variation in soil respiration showed a single-peak curve, which was mainly affected by soil temperature.