关键词: 毛竹林, 经营措施, 土壤碳库, 植被碳库, 排放泄漏, 净碳汇量

Abstract: [Objective] Moso bamboo shows excellent carbon sequestration potential and plays an important role in combating climate change. Managing bamboo forests affects not only soil carbon pool, but also vegetation carbon pool, and there comes along with carbon emissions and carbon leakage problems. It is of vital significance to study the comprehensive effect of different management measures on the carbon in bamboo forest ecosystem.[Method] A two-way randomized block design was adopted to evaluate the effects of different management measures on net carbon sequestration capacity of moso bamboo forest ecosystem during 2010 to 2013. Excluding the effects of topographical factors, we chose fertilization intensity and harvesting model as the two factors, and each of them was set with three levels, coming to a total of nine treatments:high intensities of both fertilization and harvesting, high intensity of fertilization with intermediate intensity of harvesting, high intensity of fertilization with low intensity of harvesting, intermediate intensity of fertilization with high intensity of harvesting, intermediate intensities of both fertilization and harvesting, intermediate intensity of fertilization with low intensity of harvesting model, no fertilization with high intensity of harvesting model, no fertilization with intermediate intensity of cutting, no fertilization with low harvesting model.[Result] Results showed that between 2010 and 2013 there were no significant differences (P>0.05) in SOM storage in 0-10 cm soil layer but differences were significant (P<0.05) in SOM storage in 0-50 cm soil layer. Differences of carbon storage by under canopy vegetation was not significant (P>0.05) while differences of total carbon storage by vegetation and moso bamboo carbon storage were highly significant (P<0.01). The total transportation leakage from sample area accounted for only 7.32% of total fertilization emissions inside sample area. Differences of net carbon sequestration were significant (P<0.05) between treatments of A₂B₃ (intermediate fertilization intensity with low intensity of harvesting and high retention model) and treatments of A₁B₁ (high fertilization intensity with high intensity of harvesting and low retention model). The highest net carbon sequestration was 64.721 tC·hm^-2 in treatments A₂B₃, and the lowest was-14.237 tC·hm^-2 in treatments A₁B₁. It implies that excessive intensive management may cause carbon emissions in moso bamboo forest ecosystem, and a reasonable model of management will benefit carbon accumulation in moso bamboo forest ecosystem. The soil carbon pool changes accounted for 70.99%±12.30% of all carbon pool changes, the moso bamboo carbon pool for 23.37%±11.24%, the under canopy vegetation carbon pool for 0.63%±0.37%, the transportation leakage for 0.40%±0.16%, and fertilization emissions for 4.60%±4.85%. The sum of soil carbon pool changes and moso bamboo carbon pool changes accounted for 94.36% of all carbon pool changes.[Conclusion] When monitoring and measuring carbon sequestration, for cost saving, we may consider to ignore the under canopy vegetation carbon pool and transportation leakage. The study also showed that under the common management measure of moso bamboo forest, i.e., high fertilization intensity with high harvesting intensity, the total carbon storage by vegetation increases slowly, and soil carbon emission is significant, which goes against the accumulation of net carbon sequestration in moso bamboo forests. We suggest that intermediate fertilization intensity with low harvesting intensity be the best measure to increase carbon sequestration in moso bamboo forests, not only the total vegetation carbon storage increases most, but also soil carbon pool, it is a most favorable model of management for increasing carbon sequestration and reducing the emission of carbon dioxide.

Key words: moso bamboo forest, management measure, soil carbon pool, vegetation carbon pool, emission and leakage, net amount of carbon sequestration