Effects Of Changing The Litter Input On Soil Organic Carbon And Enzyme Activities Of Dendrocalamus Affinnis

With the development of the global economy, the greenhouse effect gradually intensifies.The environment is deteriorating,.So,it becomes a hotspot that how to mitigate the greenhouse effect. Afforestation has become one of the effective means to solve this problem.But it makes the forestland ecological stability and the site quality decline that creating large area of pure forests.A variety of ecological problems happened after several rounds of planting.Mixed forests with relatively stable ecological structure and function become an important way to nurture. We selected Dendrocalamus qffinnis pure forests of West rain screen for the study.For constructing mixed forests and providing the basic data of soil carbon sink function,we changed and reducted the amount and kind of litter,then reaserched the response of soil organic carbon content, urease, invertase, phosphatase and catalase activity.The composition of the Litter were.Bambusa intermedia:Dendrocalamus affinnis=1:1(M1), Bambusa intermedia:Dendrocalamus affinnis=1:3(M3), Bambusa intermedia:Dendrocalamus affinnis=1:5(M5)Cunninghamia lanceolata:Dendrocalamus affinnis=1:1(S1), Cunninghamia lanceolata:Dendrocalamus affinnis=1:3(S3), Cunninghamia lanceolata:Dendrocalamus affinnis=1:5(S5) and pure Dendrocalamus affinnis (CK)The removal of litterfall levels were10%(L10),50%(L50) and70%(L70) and pure Dendrocalamus affinnis (CK)The results show that:(1) It significantly increased the organic carbon content of the0-20cm soil layer of the Dendrocalamus affinnis forest with adding the Bambusa intermedia litter(P<0.05),so was the20-40cm soil organic carbon content in the beginning(P<0.05).Later it showed two cases:inhibition and increasing. It increased the organic carbon content of the0-20cm soil layer of the Dendrocalamus affinnis forest in the first with adding the Cunninghamia lanceolata litter.After that,it showed inhibition. Among the different treatments of soil organic carbon content of the overall trend was M5>M3>M1,S5>S3>S1,M was higher than S on the whole. It showed that adding the Bambusa intermedia or Cunninghamia lanceolata litter to the Dendrocalamus affinnis litter, seriously affected the soil carbon sequestration capacity.The data showed that the main effect happened in the topsoil.It also showed that the impact on litter composition change of soil organic carbon did not only depend on litter, but also on the litter types. It means that the appropriate species and proportion of the mixed plays an important role on improving soil carbon sequestration capacity of bamboo mixed forests.(2) After adding Bambusa intermedia litter,it increased the soil urease, invertase activity of0-20and20-40cm soil layer on the overall(P<0.05).Significantly increased the phosphatase activity of0-20cm soil layer (P<0.05), M1and M5treatments promoted the phosphatase activity of20-40cm soil layer overall,but M3treatment significantly increased phosphatase activity in the early period(P<0.05),and inhibited it in the middle period; the catalase acticity was facilitated in the early and suppressed in the late on the whole (P<0.05).After adding Cunninghamia lanceolata litter,it significantly increased the soil urease of0-20cm soil layer on the overall(P<0.05),in the later it significantly inhibited activity (S1and S3treatment) and significantly increased activity (S5treatment)(P<0.05), the soil urease activity of20-40cm soil layer inhibited (S1and S5treatment) in the early and increased in the later, S3treatment significantly increased during the early and middle period,then significantly inhibited in the later period(P<0.05);The soil invertase and phosphatase acticity had not obviously changed; The soil catalase acticity had performance inhibited early and increased later overall(P<0.05). It means that the litter composition changed have the complex relativity on the soil enzyme activity.The exogenous litter to join to influence of the soil enzyme activity based on the exogenous litter species,decomposition stage and different layer.Research also showed that, while the lower percentage of change coudle improved the soil enzyme activity. And the influence of soil enzyme activity on litter composition changed depending on the kind of litter.(3) Dendrocalamus affinnis forest soil organic carbon content and soil enzyme activity decreased significantly after removing the Dendrocalamus affinnis litter in different proportions (P<0.05). It showed that the litter removed greater,the amount of organic carbon content and enzyme activity reduced greater. However, changes in litter producted by human, therefore, it is important to reduce human interference of forest ecosystems, strengthen the protection of the litter layer of forest litters.It is also important to maintain and increase soil carbon fixation capacity and improve soil fertility.