Coupling Of Landscape Pattern And Water Use Efficiency Based On Biome-BGC Model

The objectives of this study are to explore the coupling relationship between multi-scale landscape pattern and ecological process and its response to climate change,and provide a theoretical basis for the study of ecosystem carbon-water coupling.Auther used the PEST model combined with eddy covariance flux data to optimize the physiological parameters of the Biome-BGC model.The parameter-optimized Biome-BGC model was used to simulate water use efficiency in different climate change scenarios of forest ecosystems(Changbai Mountain,Qianyanzhou and Dinghu Mountain),grassland ecosystems(Inner Mongolia and Dangxiong)and shrub ecosystem(Habei).Auther analyzed the variation of the relationship between landscape pattern and water use efficiency,gross primary productivity at different amplitudes.The results showed:(1)Water use efficiency was significantly affected by precipitation,temperature,leaf area index,evapotranspiration and gross primary productivity.There was a significant positive correlation between water use efficiency and temperature,leaf area index and total primary productivity of Changbai Mountain,Qianyanzhou,Dinghu Mountain,Inner Mongolia,Haibei and Dangxiong(The water use efficiency of Dinghu Mountain was not significantly affected by temperature).The water use efficiency of Changbai Mountain and Dangxiong was significantly negatively correlated with precipitation.The water use efficiency of Changbai Mountain,Qianyanzhou,Dinghu Mountain and Dangxiong was significantly negatively correlated with evapotranspiration.(2)The water use efficiency of forest ecosystems such as Changbai Mountain,Qianyanzhou and Dinghu Mountain was significantly affected by landscape fragmentation,landscape shape,adjacent and agglomeration of the landscape,the diversity and uniformity of the landscape.And this relationship was obviously affected by the scale.(3)Climate change had a significant impact on the water use efficiency of forest and shrub ecosystems.PTC scenario,TC scenario,T scenario(The impact on water use efficiency of Qianyanzhou,Dinghu Mountain were not significant),C scenario,PT scenario(The impact on water use efficiency of Changbai Mountain,Dinghu Mountain was not significant)and PC scenario(The impact on water use efficiency of Inner Mongolia was not significant)had significant effects on water use efficiency in Changbai Mountain,Qianyanzhou,Dinghu Mountain,Inner Mongolia and Haibei.P scenario only had a significant impact on the water use efficiency of Haibei.Dangxiong's water use efficiency were only affected by T scenario and TC scenario.