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随着桉树人工林栽培面积的扩大,桉树人工林对生物多样性与土壤过程的影响,引发学术界的广泛讨论,更值得关注是的短论轮伐期桉树人工林对森林碳汇增加的贡献缺乏定量化的评估。因此,要合理评价桉树人工林对于生态系统碳吸存的影响,开展野外定位研究十分必要。正是基于这种考虑,项目组对闽南山区连续年龄序列(2a、3a、4a、5a、6a)的尾巨桉人工林碳库进行了分析,以空间替代时间的方法探讨了桉树人工林生长发育过程中的碳库动态,以期对桉树人工林可持续发展提供理论指导。研究结果显示:连续年龄序列桉树人工林生态系统碳库总量分别为152.88、199.97、241.67、221.94和210.95t·hm-2,表现为先期随年龄增加而增加,4年生后则出现下降趋势。其中乔木层C储量次为20.49、32.57、41.86、49.84和83.16 t·hm-2,占总贮量的13.54%～30.09%;林下植被C贮量分别为2.24、2.97、2.46、1.76和4.01 t·hm-2,占3.39%～9.74%;地被物C贮量分别为1.76、2.49、1.44、2.19和6.43 t·hm-2,占0.60%～3.05%;土壤C贮量所占比例最大(56.96%～84.17%),且主要分布在0-40 cm土层。各年龄段桉树人工林生态系统净初级生产力分别为22.86、26.07、32.64、32.71和46.69 t·hm-2.a-1,年固C量分别为10.37、11.72、14.98、15.02和21.51 t·hm-2.a-1,表现为固碳能力随林龄的增大而增大。由此可见,大力发展集约经营的桉树人工林,是解决大气中CO2浓度升高,缓解温室效应潜在的重要途径之一。
With the expansion of eucalyptus plantation area, the impact of Eucalyptus plantation on biodiversity and soil processes has aroused widespread discussion in academia. What deserves more attention is the brief comment on the contribution of Eucalyptus plantation to the increase of forest carbon sinks Lack of quantitative assessment. Therefore, it is necessary to carry out field mapping in order to evaluate the impact of Eucalyptus plantation on ecosystem carbon sequestration. Based on this consideration, the project team analyzed the carbon pools of Eucalyptus grandis plantations in successive age series (2 a, 3 a, 4 a, 5 a, 6 a) in the mountainous areas of southern Fujian Province, and explored the growth of Eucalyptus plantation forests Development of carbon pool dynamics, with a view to sustainable development of eucalyptus plantations provide a theoretical guidance. The results showed that the total carbon pool of continuous eucalyptus plantation ecosystems was 152.88, 199.97, 241.67, 221.94 and 210.95 t · hm-2, respectively. The results showed that the carbon stocks increased with increasing age and decreased after 4 years. Among them, the storage of C was 20.49, 32.57, 41.86, 49.84 and 83.16 t · hm-2, accounting for 13.54% ~ 30.09% of the total storage, respectively. The C stocks of understory vegetation were 2.24, 2.97, 2.46, 1.76 and 4.01 t · hm-2, accounting for 3.39% ~ 9.74%. The C stocks of ground cover were 1.76, 2.49, 1.44, 2.19 and 6.43 t · hm-2, accounting for 0.60% ~ 3.05% The largest (56.96% ~ 84.17%), and mainly distributed in 0-40 cm soil layer. The net primary productivity of Eucalyptus plantation ecosystem in each age group was 22.86, 26.07, 32.64, 32.71 and 46.69 t · hm-2.a-1, respectively. The annual solid C contents were 10.37, 11.72, 14.98, 15.02 and 21.51 t · hm -2.a-1, the performance of carbon sequestration increases with age. Thus, to develop intensively managed Eucalyptus plantations is one of the important ways to solve the potential of CO2 concentration in the atmosphere and mitigate the greenhouse effect.