三江源国家公园NPP长时序时空变化多模型集成分析

Spatio-temporal variation of net primary productivity in Three-River-Source National Park using a multi-model integration method

三江源国家公园位于青藏高原腹地,拥有独特气候和丰富物种基因,在生态系统中具有特殊地位。然而,气候变化和人类活动的影响使其面临生态挑战。准确监测三江源国家公园植被净初级生产力(NPP)的时空变化对于促进生态环境的保护和改善至关重要。模型模拟是陆地生态系统研究的重要方法,但模拟结果存在不确定性。多模型集成技术能够综合不同模型的优点,提高NPP模拟的准确性,为研究NPP长时序变化提供思路,同时为环境治理提供科学支持。本文应用多模型集成分析方法,结合4种生态系统过程模型CLM、DALEC、CEVSA和GLOPEM-CEVSA,分析三江源国家公园2000—2018年NPP的时空变化,并探讨气候因子对NPP变化的影响。结果表明:①2000—2018年三江源国家公园年均NPP为251.17 g C m^(-2)a^(-1),澜沧江源园区最大(267.24 g C m^(-2)a^(-1)),长江源园区最小(121.88 g C m^(-2)a^(-1)),黄河源园区居中(198.81 g C m^(-2)a^(-1)),NPP呈现自东南向西北递减的空间分布。②2000—2018年三江源平均NPP为222.00~298.02 g C m^(-2)a^(-1),年际变化呈显著增加趋势,增速为9.8 g C m^(-2)10a^(-1)。③气候因子对三江源NPP的影响存在区域差异性,长江源园区和黄河源园区主要受到气温和辐射的影响,澜沧江源园区还受降水的显著影响。本文研究结果将为三江源国家公园生态保护成效评估和科学管理提供技术支撑与决策依据。

The Three-River-Source National Park,located in the hinterland of the Qinghai-Tibet Plateau,possesses unique climate and abundant genetic species.However,this region is facing serious ecological problems due to climate change and human activities.Accurate monitoring of spatiotemporal variations in net primary productivity(NPP)in the Three-River-Source region is crucial for promoting ecological conservation and environment improvement.Model simulation is an important approach in terrestrial ecosystem research,but it inherently remains uncertain.Multi-model integration techniques can enhance the accuracy of NPP simulation and provide a better estimation of NPP variations for environmental governance.In this study,we used four process-based ecosystem models(i.e.,CLM,DALEC,CEVSA,and GLOPEM-CEVSA)and a multi-model integration analysis method to examine the spatiotemporal changes in NPP in the Three-River-Source National Park from 2000 to 2018 and to investigate the effect of climatic factors on NPP variations.The results show that NPP exhibited a decreasing trend from southeast to northwest,with an average annual NPP of 251.17 gC m^(-2) a^(-1) during 2000-2018.Ecosystems in the Lancang River Source Park had the highest NPP(267.24 gC m^(-2) a^(-1)),followed by the Yellow River Source Park(198.81 gC m^(-2) a^(-1))and Yangtze River Source Park(121.88 gC m^(-2) a^(-1)).The average NPP in the Three-River-Source region ranged from 222.00 to 298.02 gC m^(-2) a^(-1) and had a significant increasing trend with the rate of 9.8 gC m^(-2)10a^(-1).The attributions of NPP variation to climatic factors were far different among regions.It was primarily affected by temperature and radiation in the Yangtze River Source Park and Yellow River Source Park,but was also significantly influenced by precipitation in the Lancang River Source Park.The findings of this study could provide technical support and decision-making basis for assessing the effectiveness of ecological conservation and ecological management in the Three-River-Source National Park.