Soil Respiration In Response To Changing Of Avenues Carbon Input In Secondary Forest Southern Of Daxinganling

As one of the important ways to circulate the global carbon cycle, forest soil respiration’s dynamic changes will directly influence the global C balance, so it is necessary to discuss the dynamic changes in forest soil respiration.We selected a typical populus davidiana secondary forest to conduct a set carbon input change treatments of removing litter, two-fold litter, removing root, removing litterxremoving root, control (one-fold litter). They were conducted to investigate effects of carbon input on soil respiration, soil temperature at10cm soil layer and soil content at5cm soil layer. The main results are as follows:(1) Except that the dynamic of control soil respiration showed double-peak curve on August, it showed a single peak curve on May, June, July. During the. growing season, the ranking for the monthly average control soil respiration rate is July4.65umol·m-2·s-1> Aug-ust3.87u mol·m-2-s-1> June3.27u mol·m-2·s-1> September2.33u mol·m-2·s-1> May2.06u mol·m-2·s-1. The control soil respiration rate had a significant exponential relationship with the soil temperature in10cm soil layer and a significant linear relationship with soil content in5cm soil layer. These results suggested that soil respiration in populus davidiana secondary forest was controlled by the koinonia of soil temperature and soil content.(2) The change range of removing root respiration was-0.14, namely soil respiration declined by14percent after removal of roots; The removing root respiration rate were exponentially related to the soil temperature in10cm soil layer, the Q10value of removing root respiration calculated based on the soil temperature was2.46. It had a significant linea-r relationship with soil content in5cm soil layer.(3) The proportion relation of soil respiration among two-fold litter, one-fold litter, and removing litter was1.19:1.12:1. Two-fold litter had a larger influence on the soil respiration than one-fold litter. The soil respiration of removing litter, one-fold litter and two-fold litter were exponentially related to the soil temperature in10cm soil layer and soil content in5cm soil layer(P<0.0001). The Q10values of removing litter respiration, one-fold litter respiration and two-fold litter respiration calculated based on the soil temperature were3.23,3.32and3,48.