Impact of diurnal unsymmetrical warming on soil respiration in an agroecological system of the Lhasa region

PURPOSE: The impact of diurnal unsymmetrical rise in temperature on soil respiration (R(s)) is not fully understood; thus, we explored such a warming influence on R(s) in an agroecological system of the Lhasa. MATERIALS AND METHODS: A field warming experiment (C: control; DW: daytime warming; NW: nighttime warming; DW+NW: daytime plus nighttime warming) was carried out in a naked barley ecological system. RESULTS AND DISCUSSION: The DW, NW and DW+NW treatments dramatically increased soil temperature and decreased soil moisture but did not markedly modify R(s). The effects of DW and NW on soil respiration sensitivity (Q(10)) during the daytime and nighttime were different; they had no effects on daytime Q(10) of R(s), but a significant inhibitory effect on nighttime Q(10) of R(s). CONCLUSIONS: A diurnal unsymmetrical rise in temperature brought about different results for the Q(10) of R(s) but did not cause changes in R(s) under different experimental treatments in agroecological systems of the Lhasa.