The Natural Masson Pine Forest Soil Organic Carbon Storage And Its Carbon Fraction Of The Characteristic

With the in-depth development of the global carbon sink natural forests due to its large amount of carbon that can be stored and long duration of action, it gets more and more people’s attention. The soil carbon pool has historically been the irreplaceable carbon pool in the terrestrial ecosystem. And the natural forest soil organic carbon will play an increasingly important role. Therefore, this study has selected natural Mason pine forest as research object. And the paper preliminary has analysised the vertical distribution characteristics of China’s natural masson pine forest soil organic carbon content and organic carbond density and has estimated the soil organic carbon storage basing on the soil data collected on the results of previous studies. In order to further understand the soil organic carbon of the natural masson pine forest, this research also selected masson pine and broad-leaved mixed forest, masson pine and Chinese fir mixed forest and Masson pine pure forest. the study had used the method of double exponential fitting and multiple comparison to analyse the dynamic changes of soil carbon mineralization of the natural masson pine forest and its organic carbon fractions about change features with the soil depth. The study showed that like the following conclusions:1) The soil organic carbon content and density of China’s natural masson pine forest decline with the increase of soil depth. The average content of soil organic carbon of0～10cm,10～20cm,20～40cm,40～60cm,60～100cm are22.87±15.16g/kg,13.84±8.05g/kg,7.24±6.02g/kg,4.84±4.80g/kg、3.32±3.55g/kg.2) The China’s natural Masson pine soil organic carbon average density of0～IOcm、10～20cm、20～40cm、40～60cm and60～100cm are24.60±12.75t/hm2.16.66±6.94t/hm2、17.07±1.67t/hm2、12.22±10.93t/hm2、14.44±14.54t/hm2. The organic carbon density of China natural Masson pine forest soil of0～100cm is83.27±47.73t/hm2.3) The study has calculated the soil organic carbon storage of China’s natural masson pine forest that is72.25x107t/hm2according to China’s natural masson pine forest area.4) The organic carbon content and the activated carbon content of the three kinds of natural Masson pine forest had showed the trend of decrease with soil depth increasing. They had a relatively strong surface enrichment phenomenon.5) The vertical variation characteristics of three types of forest soil microbial biomass carbon content were different. Two kinds of mixed forest soil microbial biomass carbon mainly concentrated in the0-20cm soil layer and reached significant difference levels with the lower soil. But the pure masson pine forest soil microbial carbon content had the gradient characteristics of vertical distribution, difference between layers was not obvious.6) The soil organic carbon mineralization of three kinds of masson pine forest showed that the intensity were greater early, then the reaction intensity weaken with the reaction. Further analysis of the ratio (C/Co) of cumulative release of mineralization of carbon and activated carbon found that although the same soil layer of two kinds of mixed forest with soil organic carbon mineralization intensity of the difference was not significant,soil mineralization reaction was still significantly different in two mixed forests below10cm. Masson Pine and broad-leaved mixed forest below10cm soil remained a considerable number of active carbon (C/C0<1)in aged100days later, each layer soil mineralization reaction would still decompose labile organic carbon in a certain period of time, the mineralization intensity would continue to maintain at a higher level; The activated carbon in the soil of the mixed forest of masson pine and Chinese fir had be all basically decomposed (C/C0>1), the difficult decomposition of organic carbon had become the main decomposition. mineralization intensity would exhibit a decreasing tendency.7) The activated carbon, slow release carbon and inert carbon were very significant negative correlation with the soil density and clay and were significantly positive correlation with the soil total organic carbon, soil total nitrogen content and effective phosphorus content. Activated carbon and inert carbon also were positively related to the soil powders, the activated carbon and slow release carbon were significantly negative correlation with Ph.While inert soil carbon has significant positive correlation with soil moisture content.