【摘要】 理解土地利用方式转变过程影响生态系统生物地球化学循环及温室气体排放的机理,并利用模型模拟土地利用方式转变过程对温室气体通量的影响是一项长期、艰巨的科学任务。本研究基于国际上广泛应用的生物地球化学过程模型（DNDC模型）,结合气象、土壤和管理措施等数据,模拟了旱田转水田土地利用方式转变后稻田CH₄、CO₂和N₂O三种温室气体的通量和常年种植水稻的稻田温室气体通量,并将模拟值与观测值进行比较。结果表明:DNDC模型能够较好地模拟新、老稻田温室气体通量的季节变化,但对老稻田温室气体的排放通量模拟效果（R²>0. 89,n=40,P<0. 01）优于新转稻田（R²>0.79,n=265,P<0.01）,且对CH₄和CO₂的模拟效果优于对N₂O的模拟效果;根据田间观测数据,改变模型模拟土地利用方式转换前后土壤SOC浓度和p H值,并不能完全模拟土地利用变化对温室气体的影响,微生物群落在土地利用方式转变过程中可能发生较大变化,需要在模型中进一步体现。通过模型模拟土地利用方式改变对温室气体排放的影响,可为国家温室气体、碳排放清单的编制及管理政策的制定提供参考依据。更多还原

【Abstract】 It is an arduous scientific task to understand the mechanism of land use change process affecting ecosystem biogeochemical cycles and to use models to simulate the impacts of land use change on greenhouse gas flux.Using the DNDC model,a biogeochemical process based modeling,and meteorological,soil and management data,we estimated the greenhouse gas fluxes of CH₄,CO₂,and N₂O in both new and old rice fields.Compared with the observed data,the DNDC model performed better in the old rice fields（R²>0.89,n=40,P<0.01） than in the new paddy fields（R²>0.79,n=265,P<0.01）,indicating that the model has limitations in capturing the land use change effects on greenhouse gas effluxes.The model performed better for CH₄ and CO₂ than for N₂O.Changing soil SOC concentration and p H value is not enough to fully capture the land use change effect on greenhouse gas emissions,suggesting that soil biota associated with land use change have to be considered in the future to improve the model.Using model to simulate the effects of land use change on greenhouse gas effluxes may contribute to the national greenhouse gas emission inventories and the formulation of greenhouse gas management policy.更多还原