Modelling Soil Greenhouse Gas Fluxes from a Broad-Leaved Korean Pine Forest in Changbai Mountain: Forest-DNDC Model Validation
Modelling Soil Greenhouse Gas Fluxes from a Broad-Leaved Korean Pine Forest in Changbai Mountain: Forest-DNDC Model Validation
复制标题
DOI：
10.5814/j.issn.1674-764x.2019.02.003
复制
发表时间：
2019-04
影响因子：
--
通讯作者：
Ye Shu;Gu Chuying;Han Jiayin;Zhang Leiming;Dai Guanhua;Wen Xuefa;Y. Guirui
中科院分区：
文献类型：
--
作者：
Ye Shu;Gu Chuying;Han Jiayin;Zhang Leiming;Dai Guanhua;Wen Xuefa;Y. Guirui
摘要：土壤温室气体(GHG)的波动是陆地生态系统碳-氮循环的重要组成部分，但土壤温室气体通量的动态变化和收支评估仍存在不确定性。利用自动动态小室系统测量的高频和连续土壤温室气体通量，检验了现有的森林-DNDC模型对长白山温带阔叶红松林土壤CH4、CO2和N2O通量的模拟适用性。结果表明，森林-DNDC模型再现了环境变量的一般模式，但模拟的土壤温度、融雪过程和土壤水分的季节变化部分偏离了测量变量，特别是在非生长季。模拟的CH4通量与实测值接近，主要受土壤温度和积雪的影响。模拟的土壤CO2通量随温度的变化与观测值具有相同的季节变化趋势，但模拟的生长季CO2通量被低估。由于温度的影响，模拟的N2O通量在夏季达到峰值，这与冻融期观测到的N2O通量峰值明显不同。同时，模拟的CO2通量和N2O通量都受到降雨事件的抑制。除了对年土壤CH4通量的一致估计外，CO2和N2O的年累积量被低估了。仍有必要利用长期高频观测数据，特别是土壤中热量和水分的迁移以及温室气体的产生机制，进一步优化模型参数和过程。继续开展的工作将改进建模、生态系统碳氮平衡评估和土壤温室气体从场地到区域通量的估算。
Abstract: Fluctuations in soil greenhouse gas (GHG) are an important part of the terrestrial ecosystem carbon-nitrogen cycle, but uncertainties remain about the dynamic change and budget assessment of soil GHG flux. Using high frequency and consecutive soil GHG fluxes measured with an automatic dynamic chamber system, we tested the applicability of the current Forest-DNDC model in simulating soil CH4, CO2 and N2O fluxes in a temperate broad-leaved Korean pine forest at Changbai Mountain. The results showed that the Forest-DNDC model reproduced general patterns of environmental variables, however, simulated seasonal variation in soil temperature, snow melt processes and soil moisture partly deviated from measured variables, especially during the non-growing season. The modeled CH4 flux was close to the field measurement and co-varied mainly with soil temperature and snowpack. The modeled soil CO2 flux had the same seasonal trend to that of the observation along with variation in temperature, however, simulated CO2 flux in the growing season was underestimated. The modeled N2O flux attained a peak in summer due to the influence of temperature, which was apparently different from the observed peak of N2O flux in the freeze-thaw period. Meanwhile, both modeled CO2 flux and N2O flux were dampened by rainfall events. Apart from consistent estimation of annual soil CH4 flux, the annual accumulation of CO2 and N2O was underestimated. It is still necessary to further optimize model parameters and processes using long-term high-frequency observation data, especially transference of heat and water in soil and GHG producing mechanism. Continues work will improve modeling, ecosystem carbon-nitrogen budget assessment and estimation of soil GHGs flux from the site to the region.