The Initial Of Soil Carbon And Dynamics Of Artificial Cryptomeria Fortunei With Different Cutting Intensity And Land Use Types

The human activity is increasing so dramatically,inculding deforestation and land use and land cover change,that the concentration of atmospheric CO₂,followed by global warming which has profound impact on the survival and development of mankind. Therefore,the global climate change of mitigation has become the hot issues among the world's governments and scientists by forestry management.At present,the roles of carbon sink plantation have been considered to slow global climate change and a possible mechanism to choose the most promising global change of mitigation,which has become the core of the study.Plantation soils play an important role in producing,gathering and storing carbon source in the global carbon cycle.Therefore,the results have been concluded by doing research on the initial storage and dynamics of soil organic carbon the Cryptomeria fortunei plantation of different cutting intensity and the changed land use types after its clear-cut.(一) The impact on soil organic carbon storage and dynamics in the Cryptomeria fortunei plantation of different cutting intensity(1) The significant differences are showed in soil profile organic carbon storage of CP30,CP50,CP70,CP100(P＜0.05) as follows:CP30(268.1±15.4 tC/hm²)＞CP50 (254.0±13.2 tC/hm²)＞CP70(238.0±11.0 tC/hm²)＞CP100(209.1±9.1 tC/hm² ).Compared with CP(Soil profile carbon storage 274.3±25.4 tC/hm²),the difference is so significant(P＜0.05) and it has respectively reduced by 2.0%,7.0%,13.0%,24.0%.It can be showed that the soil profile organic carbon storage will reduce after its different cutting intensity and the reduce span depends on the size of cutting intensity.(2) The soil organic carbon storage increase along with the soil layer depth reduces in four kinds cut the intensity Cryptomeria fortunei plantation and.Compares with CP, Besides CP30,the soil organic carbon storage of CP50,CP70 and CP100 difference remarkable or extremely remarkable(P＜0.05) in 0～10 cm soil layers;The soil organic carbon storage in four kinds cut the intensity the Cryptomeria fortunei plantation and CP difference are not remarkable in 50～100 cm soil layers.This indicated that the Cryptomeria fortunei plantation Clear-cut the intensity differently,the initial period soil profile organic carbon storage wills reduces quickly,its speed with cuts the intensity the size correlation,but the first floor reduces slowly.(3) Compared with the CP soil organic carbon storage,the soil organic carbon storage of CP30,CP50,CP 70,CP100 are changing season by season.There are changes as follows:from spring to summer there shows upward trend and from summer to winter its storage is reducing gradually;the storage peak appears in summer and winter shows the smallest one.The significant difference(P＜0.05) of storage reduce is showed in these fours types compared with CP in the spring,summer,fall,winter.(二) The impact on soil organic carbon storage and dynamics after clear-cut in the initial different land use types of Cryptomeria fortunei plantation.(1) It changed by IP,EF,NU,CC,FL after clear-cut in the initial different land use types of CP,these soil profile organic carbon storage of five kinds land use types from the size to sort as follows:CC(214.2±17.0 tC/hm²)＞EF(191.13±13.4 tC/hm²)＞IP(173.5±15.1 tC/hm²)＞NU(171.9±9.2 tC/hm²)＞FL(132.7±12.1 tC/hm²).Compared with CP(272.9±21.8 tC/hm²),it is quite significantly(P＜0.05) and reduced by 21.5%,29.9%,36.4%,37.0%, 51.4%.It can be seen that soil organic carbon storage would be reduced after clear-cut in the initial different land use types of CP,which the extent of man-made and measures taken immediately relevant.(2) Compare with CP(soil profile carbon storage 272.9±21.8 tC/hm²),the soil profile carbon storage will reduce in five kinds different land use types.The initial period of soil profile carbon storage,which reduces along with the soil layer deepening in IP,NU,CC, EF and FL.This indicated that different land use types,its surface layer soil carbon storage will rapidly reduce,but the change land use types will influence on the soil first layer than soil bottom layer carbon storage.(3) Compared with the CP soil profile organic carbon storage,five kinds different land use types were reduce in the spring,summer,fall and winter.The soil organic carbon storage of five kinds different land use types and CP with the seasonal changes as follows: from spring to summer,the rise soil organic carbon storage of EF and CC,from summer to winter was a gradual downward trend in summer soil organic carbon storage have peaked.The soil organic carbon storage of NU and FL from spring to summer,decreasing in summer to the fall of the rise,fall into a downward trend in winter and spring,the soil organic carbon storage have peaked.Compared with CP,the soil organic carbon storage of five kinds different land use types were significantly(P＜0.05)in spring,summer,fall and winter.This can be showed that forest into other land use types,the soil organic carbon storage of various land use types will be a significant drop in throughout the year.