摘要
本文基于1992—2022年CCI-LC全球土地覆盖数据,选取中国东北、美国、乌克兰和阿根廷4个典型黑土区,系统分析了耕地变化的时空格局及其对NPP的影响。结果表明:①1992年以来四大黑土区耕地总面积呈增长趋势(平均增速为4.1×10^(4)hm^(2)/a),中国东北黑土区耕地面积持续增长,其他区域耕地扩张趋势减缓或呈负增长;②森林、草地和未利用地是耕地开垦的主要来源(占耕地开垦总面积的98.1%),耕地转出则主要表现为退耕还林和建设用地占用(分别占耕地转出总面积的30.9%和48.0%),中国和乌克兰以城镇扩张导致的耕地流失为主,美国和阿根廷则呈现多方向转出;③2001—2022年,除乌克兰外,其他黑土区稳定耕地NPP均呈显著增长趋势,表明这些区域农业生产力不断提高,但耕地开垦过程造成的NPP增速慢于退耕过程,意味着开垦可能降低黑土区的固碳能力。本研究表明了近年来中国东北黑土区耕地经历了更大规模的开垦,未来应聚焦于土地利用强度、耕地质量和作物种植结构等方向,开展更深入的区域间横向对比,为中国东北黑土地保护与利用提供参考依据。
Although black soil regions account for less than 7%of the global land surface,their high soil fertility and agricultural productivity make them vital for ensuring global food security.However,climate change and intensive agricultural activities have posed increasing threats of land degradation in these regions.It is crucial for understanding the mechanisms of black soil degradation and formulating sustainable development strategies to accurately characterize the spatiotemporal dynamics of cropland reclamation and abandonment,and their effects on net primary productivity(NPP).This study,based on CCI-LC global land cover data from 1992 to 2022,focuses on 4 representative black soil regions—Northeast China,the United States,Ukraine,and Argentina—to analyze the patterns of cropland change and their impact on NPP.The results show that:1)Since 1992,the total cropland area in the 4 regions has generally increased,with an average annual growth rate of 41000 hm^(2).The northeast China region has experienced continuous cropland expansion,while other regions have shown slower or even declining trends;2)Forests,grasslands,and unused lands were the primary sources of cropland expansion,accounting for 98.1%of total reclaimed area.In contrast,cropland abandonment mainly occurred through reforestation and conversion to construction land,comprising 30.9%and 48.0%of the total abandoned area,respectively.Urban expansion was the major driver of cropland loss in China and Ukraine,while cropland conversion in the United States and Argentina exhibited more diversified trajectories;3)From 2001 to 2022,except for Ukraine,stable croplands in the other black soil regions showed a significant increase in NPP,indicating enhanced agricultural productivity.However,NPP gains from cropland expansion were lower than those from cropland abandonment,suggesting that reclamation may reduce the carbon sequestration capacity of black soil ecosystems.This study highlights the extensive cropland expansion in northeast China’s black soil region in recent decades.Future research should focus on land-use intensity,cropland quality,and cropping structure,with deeper cross-regional comparisons to support the conservation and sustainable use of black soil resources in northeast China.
作者
吕滨雁
董金玮
张强
孟紫琪
李之超
廖晓勇
邓祥征
冷国勇
刘正佳
Lyu Binyan;Dong Jinwei;Zhang Qiang;Meng Ziqi;Li Zhichao;Liao Xiaoyong;Deng Xiangzheng;Leng Guoyong;Liu Zhengjia(Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Resources and Environment,Shandong Agricultural University,Tai’an 271018,Shandong,China)
出处
《地理科学》
北大核心
2026年第1期118-127,共10页
Geographical Science
基金
国家自然科学基金项目(42271375)
中国科学院战略性先导科技专项(A类)课题(XDA28060100)资助。
关键词
全球黑土区
耕地开垦
耕地退耕
耕地生产力
global black soil region
cropland reclamation
cropland abandonment
cropland productivity
