2000-2020年闽东南地区土地利用变化及生境质量时空演变

Land Use Change and Spatiotemporal Evolution of Habitat Quality in Southeastern Fujian from 2000 to 2020

[目的]探究土地利用变化背景下生境质量的格局分布特征和时空演变规律,为促进区域生态安全及土地资源可持续利用提供决策参考。[方法]基于2000年、2010年、2020年3期土地利用数据,利用InVEST模型及空间自相关和热点分析方法,评估闽东南地区生境质量状况,分析了其时空演变特征。[结果]闽东南地区具有不低于67%的高植被覆盖度,但建设用地大量侵占以耕地、林地及草地为主的非建设用地,面积增幅达112.74%,加剧了区域景观破碎化程度,使景观空间形态趋向复杂。生境退化指数极值和均值分别上升23.44%,43.94%,退化强度持续提高,退化高值区域由东南沿海向内陆蔓延,退化水平表现出圈层式演化的空间形态。生境质量水平整体较好,中等以上等级区域占比保持在63%左右,但城市建成区的较低等级区域及城镇交界处的高等级区域易向下级转移且难以恢复,区域生境质量逐期降低,平均降幅达5.17%。生境质量分布带有明显空间聚集特征,集中于东南部、以市辖区为中心的生境质量冷点区逐步向周边乡镇扩散,分布于西北部、倚靠山地丘陵的生境质量热点区缓慢延展,生境质量冷点及热点区域乡镇分别增加11,6个,生境质量东西部差异趋于扩大。经济发展、产业调整、人口增长所带来的以建设用地爆发式扩张为主要表现的土地利用格局变动,是导致闽东南地区生境破碎、退化和质量下滑的首要原因。[结论]闽东南地区近20 a土地利用变化显著,对区域生境质量产生不利影响,未来应注重把控城镇空间扩张规模与速度,做好生态治理与恢复工作。

[Objective]The aims of this study are to explore the distribution characteristics and spatiotemporal evolution of habitat quality patterns under land use change,and to provide decision-making reference for promoting regional ecological security and sustainable use of land resources.[Methods]Based on the land use data in 2000,2010,and 2020,the InVEST model,spatial autocorrelation and hotspot analysis methods were used to evaluate habitat quality in southeastern Fujian,and to analyze its spatial-temporal evolution characteristics.[Results]Southeastern Fujian had a high vegetation cover of no less than 67%,but the construction land had encroached heavily on the non-construction land,mainly arable land,forest land and grassland,with an increase of 112.74%,which had intensified the degree of regional landscape fragmentation and made the landscape spatial pattern tend to be complex.The extreme and average values of habitat degradation index in southeastern Fujian increased by 23.44%and 43.94%,respectively,the intensity of degradation continued to increase,the high value area of degradation spread from southeast coast to inland,and the degradation level showed the spatial pattern of circling evolution.The overall level of habitat quality was good,and the proportion of areas above medium grade was about 63%.However,the lower grade areas in the built-up areas of cities and the higher grade areas at the junctions of cities and towns were easy to shift to the lower grade and difficult to recover,the regional habitat quality decreased gradually,with an average decrease of 5.17%.The habitat quality distribution presented the obvious spatial aggregation characteristics.The cold spots of habitat quality,which concentrated in the southeast and centered on municipal districts,gradually spread to surrounding townships.The hot spots of habitat quality,which distributed in the northwest and depend on mountains and hills,slowly extended.Townships in the cold and hot spot areas of habitat quality increased by 11 and 6,respectively,so that the regional habitat quality differences between the east and west tended to expand.Changes in land use patterns,mainly manifested by explosive expansion of construction land,brought about by economic development,industrial restructuring and population growth,were the primary causes of habitat fragmentation,degradation and quality decline in southeastern Fujian.[Conclusion]In the past 20 years,the significant land use changes in Southeastern Fujian had a negative impact on the regional habitat quality.The region should focus on controlling the scale and speed of urban spatial expansion,and do a good job in ecological governance and restoration in the future.