不同气象条件下Biome-BGC模型碳通量模拟精度评价

Evaluation on the Accuracy of Carbon Flux Simulation Based on Biome-BGC Model Under Different Meteorological Conditions

建立在植物生理生态机理上的过程模型Biome-BGC,能够较好地模拟陆地生态系统的行为和特征并被广泛采用。现有基于Biome-BGC的研究多侧重于模型季节和年尺度模拟精度的评价和应用,对不同气象条件下模型模拟精度的评价则较少。本研究利用全球长期通量观测网络Fluxnet验证了4个代表性针叶林站点——Lavarone(意大利)、Renon(意大利)、Loobos(荷兰)、Fyodorovskoye(俄罗斯),模拟了2011—2013年日总初级生产力(gross primary productivity,GPP),并着重分析该模型在上述研究区域不同气象条件下日GPP的模拟精度。结果表明:模拟值在整体趋势上较通量验证值偏小(4%~25%);有降水的条件下,Biome-BGC模型较无降水的条件下具有更好的模拟效果(相关系数rno rain为0.843~0.936和rrain为0.887~0.952,P<0.01),并且典型雨天的模拟精度高于典型晴天(rsun为0.830~0.915和rrain为0.887~0.952,P<0.01)。本文结果加深了Biome-BGC模型在不同气象条件对GPP模拟的不确定性理解,明确了不同气象条件下模拟碳通量的适用性,为进一步提高模型模拟精度提供了参考。

The biome-biogeochemical cycles(Biome-BGC)model based on plant physiological and ecological pro?cesses has been widely applied to describe the behaviors and characteristics of terrestrial ecosystems.Most previ?ous studies focused on the model evaluation or the model application at seasonal and annual scales,while daily scale performance of the model under different meteorological conditions has been less studied.In this study,flux data of the four needle-leaf fluxnet sites,Lavarone(Italy),Renon(Italy),Loobos(Holland),Fyodorovskoye(Russia)were used to evaluate the performance of the Biome-BGC model on daily gross primary productivity(GPP)in 2011—2013,and the accuracy of carbon flux simulation in those areas under different meteorological conditions were analyzed.The results show that the simulated daily GPP is generally smaller(varied from 4%to 25%)than the flux measurements;the Biome-BGC model in the rainy days has better performance than that without precipitation(rnorain=0.843~0.936 and rrain=0.887~0.952,P<0.01),and the simulation accuracy of typical rainy days was higher than that of typical sunny days(rsun=0.830~0.915 and rrain=0.887~0.952,P<0.01).The ob?tained results are helpful to understand the uncertainty of Biome-BGC model simulation under different meteorological conditions and to clarify the applicability of simulated carbon flux under different meteorological condi?tions,and provide a reference for further improving the accuracy of model simulations.