典型旅游城市黄山市森林景观时空动态变化遥感分析

森林景观动态监测是识别森林生态系统内部功能与结构变化驱动机制的基础。以典型旅游城市和国家森林城市黄山市为例，以1988、1997、2006、2018年遥感影像为数据源，采用景观转移矩阵、核密度分析、景观指数等方法对黄山市森林景观时空动态变化特征进行分析。结果表明:1）森林景观为黄山市主要景观类型，有林地为优势景观，1988-2018年，有林地面积占比逐渐上升；空间上形成林地亚类镶嵌分布格局；不同年份林地亚类转移以有林地与疏林地之间相互转移为主。2）不同年份海拔与森林覆盖率呈正相关；黄山市大多数乡镇森林覆盖率在75%以上，森林覆盖率<50%的乡镇聚集在以屯溪区、徽州区为核心的中部偏东南区域；1997-2006、2006-2018年林地变化核密度密集区分布广泛，而1988-1997、1988-2018年林地变化分布较为聚集。3）景观水平上，1997、2006年聚合指数呈下降趋势，景观分裂指数呈现升高趋势，景观破碎度增加。类型水平上，有林地1988-2006年破碎度增加，2018年有所下降；疏林地较有林地破碎度更高，且斑块边缘形状复杂化；灌木林地斑块密度较小，斑块凝聚度林地景观类型中最低，分离度最高，1997年后分布区域破碎化、零散化；近30 a非林地中建设用地斑块密度、景观形状指数呈下降趋势，分布更加集聚。多期森林景观时空变化分析可为黄山市森林资源保护提供理论基础。

Remote Sensing Analysis of Temporal and Spatial Dynamics of Forest Landscape:A Case Study of Huangshan City

Dynamic monitoring of forest landscape is the basis for identifying the driving mechanisms of internal functional and structural changes in forest ecosystems.Taking the typical tourist city and the national forest city of Huangshan as example,this paper analyzed the spatial and temporal dynamics of forest landscape in Huangshan city by using landscape transfer matrix,kernel density analysis and landscape index based on the remote sensing images of 1988,1997,2006 and 2018.The results showed that 1) the proportion of forest landscape in the city was about 80%,forestland was the dominant landscape,the proportion of forest land continued to rise from 1988 to 2018.In space,different types of forest landscapes formed a mosaic pattern,and the subtypes of forest land transfer between different years were mainly the mutual transfer between forestland and open forestland.2) The elevation and slope of different years were positively correlated with the forest coverage rate.In addition,the forest coverage rate of most towns and villages in Huangshan city was above 75%,and the townships with forest coverage below 50% were concentrated in the central and southeastern regions of Huangshan with the Tunxi district and Huizhou district as the core area.The concentrated area of kernel density between forest land and non-forest land was widely distributed from 1997-2006 and 2006-2018,while the distributions in 1988-1997 and 1988-2018 were more concentrated.3) At the landscape level,the aggregation index showed downward trends in 1997 and 2006,while the landscape division index showed increasing trends,which meant that the landscape fragmentation degree increased.Correspondingly,at the type level,there was an increase in the degree of fragmentation in forest land from 1988-2006,but it decreased in 2018.And compared with forest land,the values of patch density and landscape shape index of the open forest were higher,which meant that the degree of fragmentation was higher,and the edge shape of landscape patch was complicated.The patch density of shrub land was small,and the patch cohesion index was the lowest in the three forest landscape types,so the distribution of shrub land was very scattered,and the degree of fragmentation was high.The patch density and landscape shape index of construction land showed a downward trend in the past 30 years,indicating that the distribution of construction land was more concentrated.Analysis of temporal and spatial changes of multi-stage forest landscape can provide a theoretical basis for forest resource protection in Huangshan city.