中国农业净碳汇时空演变及影响因素分析

ANALYSIS OF SPATIAL-TEMPORAL EVOLUTION AND INFLUENCING FACTORS OF AGRICULTURAL NET CARBON SINK IN CHINA

关键词:  农业净碳汇  时空演变  影响因素  空间马尔科夫链  地理探测器

Key words:  agricultural net carbon sink  spatial-temporal evolution  influencing factors  spatial Markov chain  Geodetector

摘要:

目的 探讨农业净碳汇时空演变规律及其驱动机制，为促进农业低碳发展提质增效提供重要支撑。方法 文章在测度2002—2021年中国31个省（市、区，不含港澳台）农业净碳汇的基础上，采用标准差椭圆和空间马尔科夫链分析其动态演变趋势，并利用地理探测器模型进一步识别农业净碳汇演变的影响因素。结果 （1）中国农业净碳汇总量整体呈现波动上升的趋势，由2002年的2.296 5亿 t C增至2021年的4.999 2亿 t C，年均增速4.19%；（2）农业净碳汇具有显著的空间分异特征，“东北—西南”空间分布格局稳定，椭圆面积与长短半轴均趋于分散化，呈现向西扩张趋势；净碳汇重心总体保持向北迁移的趋势，累积实现迁移距离638.09 km；（3）中国农业净碳汇的类型转移具有稳定性，且存在“俱乐部收敛”现象，邻域状态强化了低水平省份的空间集中和高水平省份的空间溢出，并带动了俱乐部收敛的空间扩散；（4）中国农业净碳汇的空间分异受到农业资源禀赋和社会经济等因素综合影响，灌溉条件、机械化秸秆还田和农业经营规模是驱动空间差异的主要影响因子且因子间交互作用会增强其空间分异。结论 建议通过优化保护性耕作技术的推广政策、改善农田灌溉技术条件和探索跨区域合作交流机制等措施促进农业减碳固汇，以推动农业绿色低碳发展。

Abstract:

Investigating the spatiotemporal evolution patterns and driving mechanisms of agricultural net carbon sinks (ANCS) is essential for advancing quality-efficiency synergies in low-carbon agricultural development. Based on measurements of ANCS in 31 provinces (municipalities, autonomous regions, excluding Hong Kong, Macao, and Taiwan of China) of China from 2002 to 2021, this study employed standard deviation ellipse and spatial Markov chain to analyze dynamic evolution trends, complemented by Geodetector modeling to identify determinant factors. The results were indicated as follows. (1) China's aggregate ANCS demonstrated a fluctuating upward trajectory, increasing from 229.65 million t C in 2002 to 499.92 million t C in 2021, with an annual growth rate of 4.19%. (2) ANCS exhibited pronounced spatial heterogeneity with a persistent northeast-southwest orientation. The ellipse area and semi-axes showed progressive dispersion, indicating a westward expansion trend, while the ANCS centroid shifted northward by 638.09 km. (3) Type transitions displayed stability with club convergence characteristics. Spatial autocorrelation intensified clustering among low-level provinces and spillover effects among high-level regions, facilitating convergence diffusion. (4) ANCS spatial differentiation stemmed from resource endowments and socioeconomic determinants, with irrigation infrastructure, mechanized straw incorporation, and operational scale emerging as primary drivers. Factor interactions significantly amplified regional disparities. Therefore, to enhance carbon reduction and sequestration, a multidimensional strategy is proposed, encompassing: optimization of conservation tillage policies, modernization of farmland irrigation infrastructure, and establishment of interregional collaboration frameworks. These measures aim to reconcile agricultural productivity with green, low-carbon development imperatives.