老铁山自然保护区景观格局与生境质量时空变化

由于人口数量的增长和日益频繁的人类活动促进了城市扩张,自然生态系统面积逐渐缩小,一些自然保护区内部生态环境和物种栖息地随之受到影响。因此以辽宁蛇岛老铁山国家级自然保护区中的老铁山自然保护区为研究区,以1997年、2007年和2017年该地区的遥感影像为数据源,解译出15种景观类型,分析景观格局变化趋势。再选取3个景观指数作为衡量人类干扰强度的指标,生成人类干扰强度空间分布图。InVEST模型由美国自然资本项目组开发,能够定量分析生态系统服务功能,因此采用InVEST模型计算生境质量,并探讨该地区20年来人类干扰强度与生境质量的时空变化,并分析二者的相关性。结果表明:(1)1997—2017年,老铁山自然保护区建筑用地、园地面积增加最多,林地、草地略有减少;耕地向园地的转移面积最大。(2)1997—2017年,研究区内试验区和缓冲区人类干扰强度逐年增强,而核心区部分呈现先减弱再增强的趋势,保护区整体呈现出干扰逐渐增强的趋势。(3)1997—2017年该地区的生境质量整体呈现逐渐下降的趋势,生境质量时空变化的热点集中在研究区核心区的周边地带。(4)生境质量与代表人类干扰强度的景观指数呈现出较强的负相关。

Temporal-spatial changes of landscape pattern and habitat quality in Laotieshan nature reserve

Rapid population growth and irrational human activities have led to dramatic changes in land use, urban expansion, shrinking natural ecosystems, and landscape patterns, further leading to a decline of habitat quality. The landscape pattern is the arrangement of landscape patches with different shapes and sizes in the landscape space, which reflects the heterogeneity of the landscape and is the final result of many natural and human factors acting on different spatial and temporal scales. Habitat quality refers to the ability of ecosystems to provide sustainable development to individuals and populations within a certain time and space. It is the premise and basis for all ecosystem services. In recent years, with the development of the economy, the rapid growth of the population, and the changes of the urban landscape pattern, the regional habitat quality have also been affected to varying degrees. For the nature reserves, the changes of the landscape pattern in their peripheral area will profoundly affect the resources, environment, and ecology. Laotieshan part in the Liaoning Snake Island and Laotieshan National Nature Reserve was selected as the study area. Based on remote sensing images of the study area in 1997, 2007 and 2017, 15 types of landscape pattern were interpreted by ENVI. The views of the landscape pattern change network derived from the visualization tool NetDraw were used to analyze landscape pattern change trend. Then the Fragstats software was used to calculate the landscape pattern index and 3 indices were selected to show the human disturbance intensity. The spatial distribution map of human disturbance intensity was produced by ArcGIS10.2. The InVEST model was used to calculate the habitat quality. Based on them, the temporal and spatial changes of human disturbance intensity and habitat quality in Laotieshan over the past 20 years were discussed, and the correlation between the two was analyzed. The results showed that:(1) From 1997 to 2017, the construction land and garden area increased at most; the forest land and grassland decreased slightly and the transfer area of cultivated land to the garden was the largest in the landscape pattern change of the Laotieshan Nature Reserve.(2) From 1997 to 2017, the intensity of human disturbance in the experimental area and buffer zone in the study area increased year by year, while the core area showed a trend of weakening and then enhancing. (3)The habitat quality in the study area from 1997 to 2017 showed a trend of persistently decreasing. The hotspots of temporal and spatial changes in habitat quality are concentrated in the surrounding areas of the core area of the study area. (4) The habitat quality was significantly and negatively correlated with the human disturbance intensity represented by landscape index.