Simulation Studies On Temperate Forest Soil CO₂ And N₂O Emissions And Nitrogen Net Mineralization After Water And Thermal Changes

This work was conducted under different soil depth of broadleaved Korean pine forest, secondary YangHuaLin and ginseng gardens located in Changbai Mountain on November 2009, to study the influence of water and thermal changes to activated carbon nitrogen content of soil,carbon dioxide(CO2) and nitric oxide (N2O)emissions and nitrogen net mineralization. This paper includes three aspects. First, it studied influence of the frequent freeze-thaw processes, dry soil wet again on activated soil carbon nitrogen content. Second, it used the soil after thawing process of frequent to research the influence of acetylene gas to activated carbon nitrogen content of soil, carbon dioxide(CO2) and nitric oxide (N2O)emissions and nitrogen net mineralization in with or without adding C,N,P circumstances. Third,it studied the influence of different wet strength and temperature of dry soil on above soil properties. We conclude the main results presented here as follows:(1)Through frequent thawing process, soil organic carbon and microbial carbon, nitrogen content is reduced the content of TN elevated. Different vegetation types of soil net mineralization content:Korean pine forest>YangHuaLin>ginseng gardens. Along with the increase of soil depth,soil net mineralization content gradually reduced.(2) After rewetted process, TNand DOC of Soil increased microbial carbon and microbial nitrogen content decreased. KCL system of net nitrogen mineralization content: when Water content was 60% YangHuaLin and Korean pine forest reached maximum. Ginseng reached maximumwhen moisture was80%. Nitrogen net mineralization content: YangHuaLin>Korean pine forest>ginseng gardens.(3)Acetylene did not influence of CO2 emissions of soil without C,N,P adding. The acetylene gas makes emissions of CO2 to decline significantly of soil with C,N,P. Acetylene inhibitory effect on soil autotrophic nitrification was more obvious to the soil without C,N,P adding. And acetylene gases make nitrogen net mineralization content reduced.(4)At the same humidity, DOC, TN and CO2 emissions content increases with the increasing of temperature, microbial carbon,nitrogen content reduced significantly. N2O emissions are not consistent regularity.At 15℃and 25℃, the temperature is the main influence factors of CO2 emissions qCO2, Q10 value. When the temperature rised to 35℃, water has important implications on aboved index.