基于MSPA与MCR模型的三峡库区林地生态网络构建与评价研究

Research on Construction and Evaluation of Forest Land Ecological Network in Three Gorges Reservoir Area Based on MSPA and MCR Model

三峡库区是长江经济带上重要的生态屏障区,同时也是生态脆弱区。提取三峡库区重要生态源地、构建综合生态阻力面、识别重要生态廊道和生态节点,从而构建生态安全网络,对筑牢长江上游重要生态屏障具有十分重要的研究价值和意义。以三峡库区为研究区,利用形态学空间格局分析方法(MSPA)识别出林地生态源地斑块,通过景观连通性指数评价斑块重要性;结合土地利用类型、DEM、坡度、距河流距离、距道路距离和NDVI等阻力因子构建综合生态阻力面,运用最小累计阻力模型(MCR)构建生态廊道,提取生态廊道上重要生态节点,形成三峡库区林地生态安全网络;最后对三峡库区生态安全网络结构进行评价研究。研究结果表明:(1)三峡库区林地生态源地共38块,占林地面积的59.55%,占区域总面积的27.95%,主要分布在三峡库区湖北段的大巴山-巫山-武陵山区以及重庆段的缙云山-中梁山-铜锣山-明月山-云雾山区。(2)阻力高值区主要分布在城镇建设用地区,最高值位于重庆市主城区;阻力低值区主要分布在林地和水域,最低值位于湖北段巫山山脉。(3)生态廊道共79条,其中,3条重要廊道,76条一般廊道,廊道总长度为1326.37 km。(4)生态廊道的平均阻力为2.50,生态斑块间的廊道总累积阻力为197.36;α指数、β指数、γ指数分别为0.52、2.08、0.73;耕地、林地和草地是构成重要廊道的主要景观类型。研究结果呈现出“三屏多廊多点多斑块”的生态网络空间格局,对保护生物多样性、提升生态系统功能和维持区域生态安全格局提供科学指导。

The Three Gorges Reservoir Area(TGRA)is an important ecological barrier area and an ecologically fragile area on the Yangtze River Economic Belt.It is of great research value and significance to construct an ecological safety network by extracting important ecological sources,constructing comprehensive ecological resistance surface,identifying important ecological corridors and ecological nodes in the TGRA.Taking the TGRA as the study area,morphological spatial pattern analysis(MSPA)was used to identify forest ecological source patches,and the importance of patches was evaluated by landscape connectivity index.Combined with the resistance factors of land use type,DEM,slope,distance from river,distance from road and NDVI,the comprehensive ecological resistance surface was constructed.The minimum cumulative resistance model(MCR)was used to construct the ecological corridor,and the important ecological nodes were extracted to form the forest ecological safety network in the TGRA.The results of the study showed:(1)There are 38 ecological sources of forest land in the TGRA,accounting for 59.55%of the forest area and 27.95%of the total area of the region.They are mainly distributed among the Daba-Wushan-Wuling Mountains in Hubei and Jinyun-Zhongliang-Tongluo-Mingyue-Yunwu Mountains in Chongqing.(2)High resistance areas are mainly distributed in urban construction areas,the highest value of resistance is located in the main urban area of Chongqing;low resistance areas are mainly distributed in woodland and water areas,and the lowest value of resistance is located in the Wushan mountainous area in the Hubei section of the TGRA.(3)There are 79 ecological corridors,including 3 important corridors and 76 general corridors.The total length of the corridors is 1326.37 km.(4)The average resistance of ecological corridors is 2.50,and the total cumulative resistance of corridors between ecological patches is 197.36;αindex,βindex,andγindex are 0.52,2.08,and 0.73 respectively;cultivated land,woodland,and grassland are the main landscape type of corridors.The results of the research present an ecological network spatial pattern of“three screens,multiple corridors,multiple spots,and multiple patches”,providing scientific guidance for protecting biodiversity,improving ecosystem functions,and maintaining regional ecological security patterns.