Effects of thinning intensity on the carbon dynamics in mixed coniferous forests
[Objective]Thinning effect on litter decomposition,the dynamic changes of litter and soil carbon,the response of litter decomposition to temperature cycle times in different thinning intensities,and the effect of thinning intensity on carbon dynamics in mixed coniferous forests are all investigated.[Method]We characterized thinning in the residual rate and mass-loss rate of litter,as well as the carbon release dynamics of litter and soil,in mixed coniferous forests in the Xiaoxinganling region by controlling temperature cycle times.The carbon release rate and mass-loss rate of litter at two levels of decomposition(undecomposed and semi-decomposed)were measured.According to the thinning intensity,6 levels of treatments had been set as 10%,15%,20%,25%,30%,35%and control.The two temperatures were alternated for 12 hours for a total of 90 cycles,with the boxes being removed at the 0,3rd,7th,15th,30th,60th,and 90th cycles.Under different summer fostering thinning intensities,the decomposition rate,mass loss rate,and response of organic carbon and soil organic carbon to temperature were investigated in two different levels of decomposition:the undecomposed layer and the semi-decomposed layer.We investigated the mass residue rate,mass loss rate,and organic carbon release dynamics of litter in the treatments,starting with the factors affecting the decomposition of litter,such as the intensity of thinning and the degree.[Result]The semi-decomposed litter decomposed more quickly than undecomposed litter.With the residual rate of undecomposed litter being the lowest at 35%thinning intensity,whereas the decomposition rate of semi-decomposed litter increased and then decreased with increasing thinning intensity,with the residual rate of semi-decomposed litter being the lowest at 20%thinning intensity.After the end of summer,the organic carbon of litter increased from 0%-15%and 35%,while the organic carbon of both litter and soil decreased 25%and 30%,and the organic carbon of undecomposed litter decreased and semi-decomposed increased at 20%,while the soil organic carbon of undecomposed litter decreased and semi-decomposed increased at 15%,and the soil organic carbon increased.The litter decomposition was highest at 20%of the thinning,and the organic carbon in the undecomposed litter was discharged into the semi-decomposed litter and soil.Decomposition of the litter released 25%and 30%of the carbon in the litter to the surrounding environment,and both the litter and soil organic carbon decreased.It served as a reference for enhancing forest stand quality,enriching and improving the theory of fostering thinning,and establishing a foundation for the carbon dynamics process in summer forests.[Conclusion]At the conclusion of the summer,semi-decomposable litter decomposes more quickly than non-decomposable litter.In general,faster decomposition occurs in the early stages of decomposition(more readily decomposable materials)and slower decomposition occurs in the later stages(consumption of easily decomposable materials and accumulation of difficult decomposable materials).Thinning care not only promotes litter decomposition but also aids in soil and litter carbon storage.According to studies,stands with a 35%thinning intensity have a high potential for carbon sequestration in the soil and litter during the summer.
NETL
NSTL
万方数据
