"双碳"目标下主要粮食作物生产净碳汇时空演变特征及其驱动因素OACHSSCD

Grain production exhibits the dual attributes of being both a carbon source and a carbon sink.Clarifying the spatiotemporal evolution characteristics of the net carbon sink of major grain crop production in the Yangtze River Delta region,as well as its driving factors,is of great importance for promoting emission reduction and carbon sequestration policies within China's grain industry under the national"dual carbon"goals.From the dual perspective of carbon sources and carbon sinks,this study takes the Yangtze River Delta region as its research area.It estimates the carbon emissions,carbon absorption,and total net carbon sink of major grain crop production in 41 prefecture-level cities from 2011 to 2022,employing the carbon emission coefficient method and the parameter estimation method.ArcGIS visualization,standard deviation ellipse analysis,and trend surface analysis were comprehensively applied to describe the spatiotemporal evolution of the net carbon sink of grain production.Furthermore,the optimal parameter geographic detector and the geographically and temporally weighted regression methods were used to identify the primary driving factors affecting the net carbon sink.The results indicate the following:(1)During the study period,the total net carbon sink of major grain crop production in the Yangtze River Delta region exhibited an overall upward trend,increasing from 4151.38 × 104 tons in 2011 to 4279.64 × 104 tons in 2022,with a cumulative growth rate of 3.09 percent.This suggests a continuous strengthening of the carbon sink function in grain production systems.(2)In terms of spatial distribution,the high-value areas of the net carbon sink were mainly concentrated in the northern parts of Jiangsu Province and Anhui Province,while the low-value areas were located in the southern parts of Zhejiang Province and Anhui Province.(3)The main axis of the standard deviation ellipse consistently displayed a northwest-southeast orientation,with the spatial centroid primarily concentrated near the border area between Chuzhou City and Huai'an City.Moreover,the core area of the net carbon sink gradually extended northward over time.(4)Sunshine duration,effective irrigation rate,average temperature,and fertilizer application intensity were identified as the main driving factors influencing the net carbon sink of major grain crop production.Each of these factors exhibited an explanatory power exceeding 53 percent,and significant interactive effects were observed among them.(5)The geographically and temporally weighted regression results revealed pronounced spatiotemporal heterogeneity in the effects of different driving factors on the net carbon sink.The impacts of climatic factors and agricultural input variables demonstrated distinct spatial differentiation and temporal variation patterns,reflecting the complex and dynamic mechanisms underlying agricultural carbon balance.In conclusion,to further enhance the carbon sequestration capacity of grain production in the Yangtze River Delta region,it is essential to optimize the regional allocation of agricultural production elements,deepen the structural reform of the agricultural supply side,and develop an integrated low-carbon grain production technology and policy system.Such measures will help achieve the synergistic goals of ensuring national food security and advancing carbon neutrality.This research provides both theoretical and empirical support for constructing sustainable,low-carbon agricultural development pathways in China and offers valuable insights for regional agricultural carbon management and policy-making.