基于县域尺度的福建省土地利用碳排放效应分析

Investigation on County-Scale Carbon Emission Effect of Land Use in Fujian Province

土地利用碳排放核算及效应分析是土地覆被变化研究领域的热点问题,也是落实碳达峰、碳中和决策部署的核心主题之一.福建省是全国首批生态文明示范区,如何系统优化土地利用格局,发挥生态本底优势,成为福建省低碳土地利用规划的重要课题.本文融合空间数据和统计数据,构建福建省自下而上的县域耕地、林地、草地、建设用地碳排放及其变化的科学核算体系,核算2005-2020年福建省县域尺度土地利用碳排放,并结合空间马尔科夫链、地理探测器、随机森林等多种方法分析土地利用碳排放的空间格局、时空演变和影响机理.结果表明:①2005-2020年,福建省土地利用碳排放呈增长趋势,从6587.20×10^(4) t增至12008.03×10^(4) t,但增速逐年放缓,从27.04%降至17.19%.②建设用地碳排放占比逐渐增大,从72.64%增至98.23%.林地碳汇量逐年增长,从307.49×10^(4) t增至432.10×10^(4) t.③福建省土地利用碳排放总体呈从闽东南向西北递减的分布特征,逐步形成以福州都市圈和厦漳泉都市圈为两极的高碳排放区的空间格局.④福建省土地利用碳排放呈现明显的空间正相关.LISA聚类结果表明,碳排放的空间集聚存在路径依赖和空间锁定特征.⑤福建省土地利用碳排放存在空间溢出效应,并且低低集聚区碳排放类型跨级转移活跃.⑥地理探测器结果表明,各影响因素的解释力(q值)范围为0.01~0.69,其中人口规模(0.47~0.69)和土地利用程度指数(0.30~0.34)是对区域土地利用碳排放量影响程度较大的因素,其余因素影响力较弱(q值均在0.2以下).研究显示,福建省土地利用碳排放总量增长趋势已经放缓,但是其空间分布仍然存在显著差异.因此,应结合不同地区的特点,制定针对性的减排政策,对于工业化和城镇化比较发达的闽东南地区,应该合理控制碳排放;而对于生态资源相对丰富的闽西北地区,则应该发挥其绿色发展优势.

The accounting and analysis of carbon emissions resulting from land use are crucial issues in the research of land cover change,and is essential to the decision-making and deployment of‘carbon peak,carbon neutrality’.In Fujian Province,as the first batch of ecological civilization demonstration areas in China,optimizing the land use pattern and leveraging the advantages of ecological background have become critical issues in low-carbon land use planning.This study presents a scientific accounting system for carbon emissions and changes in cultivated land,forest land,grassland,and construction land in Fujian Province from 2005 to 2020,using integrated spatial and statistical data.The spatial pattern,spatial and temporal evolution,and influence mechanism of land use carbon emissions were analyzed through various methods,including spatial Markov chain,geographical detector,and random forest.The results indicate that from 2005 to 2020,the carbon emissions of land use in Fujian Province increased from 6,587.20×10^(4) t to 12,008.03×10^(4) t,with a slowing growth rate from 27.04%to 17.19%.The proportion of carbon emissions from construction land gradually increased from 72.64%to 98.23%and from 307.49×10^(4) t to 432.10×10^(4) t.The carbon emissions of land use in Fujian Province generally decreased from southeast to northwest,forming a spatial pattern of high carbon emission areas with Fuzhou metropolitan area and Xiamen-Zhangzhou-Quanzhou metropolitan area as poles.The spatial positive correlation was evident,with carbon emissions showing path dependence and spatial locking characteristics.The spatial spillover effects on carbon emissions were observed,with the cross-level transfer of carbon emission types in low agglomeration areas being active.The influence of each factor on carbon emissions ranged from 0.01 to 0.69,as indicated by the geographical detector analysis.Overall,the growth trend of total land use carbon emissions in Fujian Province has slowed down significantly,but significant spatial differences still exist,calling for region-specific emission reduction policies.For the southeast of Fujian,where industrialization and urbanization are relatively developed,carbon emissions should be reasonably controlled.For Northwest Fujian with relatively rich ecological resources,its green development advantages should be brought into play.