LAUSR

Abstract The freeze-thaw phenomenon will occur more frequently in mid-high latitude ecosystems under climate change which has a remarkable effect on biogeochemical processes in wetland soils. Here, we used a wet sieving procedure and a barometric process separation (BaPS) technique to examine the responses of wetland soil aggregates and related carbon and nitrogen turnover affected by the freeze-thaw treatment. Wetland soil samples were divided into a treatment group and a control group. The treatment group was incubated at temperatures fluctuating from 10 °C to −10 °C, whereas the control group was incubated at the constant temperature of 10 °C. A 24 h process was set as the total freeze-thaw cycle, and the experiment had 20 continuous freeze-thaw cycles. In our results, the freeze-thaw process caused great destruction to the >2 mm water-stable aggregates (WSA) fraction and increased the 2 mm WSA fraction and the gross nitrification rate can be stimulated at the initial freeze-thaw cycles, nutrients and substrates may play a leading role in the freeze-thaw treatment regardless of the minimal influences on microbial biomass pools.