To understand the effects of erosion on soil respiration(Rs)

we analyzed temporal variations of Rs on the slope lands and its relationship with soil temperature and moisture under artificial stimulated erosion conditions(top soils removed at the depths of 0

5

10 cm

referred to as E0

E5 and E10)with a dynamic closed chamber. Two type of lands in which the fertility levels differed distinctly were chosen to deploy the experiments. The results indicate that with similar temperature and rainfall

the rates of Rs were affected sig-nificantly by erosion and the affecting degree was related closely to the fertility level of the land. Comparing to the control(original soil without removal of top soil)

the Rs rates of the soils with the erosion level of E5 decreased by 32%and 14%in the fertile and poor soils

respectively. The rainfall stimulated the Rs rates and amplified the effects of erosion on the Rs rates. Soil moisture contents were closely correlated with the Rs rates

and conversely

the soil temperature was not. Soil moisture was the main controlling factor responsi-ble for the variations of soil respiration rates during water erosion events. The results suggested that the effects of erosion on Rs rates should be considered in understanding and estimating carbon loss in the loess hilly region. Soil erosion may alter the carbon balance through dynamic changes of Rs in these ecosystems

which could have important negative consequences for ecosystem functions and sustainability.