Comparing the temperature sensitivity of organic matter decomposition in oxic and oxygen-deprived soils

No consistent variation was found in soil respiration Q10 under various O2 conditions.Substrate C quality had a strong effect on Q10 in oxic soils.N limitation had a large impact on Q10 in soils under O2 limitation.Current studies on the temperature sensitivity(Q10)of soil organic matter(SOM)decomposition mainly focus on aerobic conditions.However,varia-tions and determinants of Q10 in oxygen(O2)-deprived soils remain unclear.Here we incubated three grassland soils under oxic,suboxic,and anoxic conditions subjected to varying temperatures to compare variations in Q10 in relation to changing substrates.No consistent variation was found in Q10 under various O2 conditions.Further analysis of edaphic properties demon-strated that substrate carbon quality showed a strong influence on Q10 in oxic soils,whereas nitrogen limitation played a more important role in suboxic and anoxic soils.These results suggest that substrate carbon quality and nitrogen limitation may play roles of varying importance in determining the temperature sensitivity of SOM decomposition under various O2 conditions.