基于最小累积阻力模型的山地石漠化地区生态安全格局构建:以重庆市南川区为例

Construction of Ecological Security Pattern in Mountain Rocky Desertification Area Based on MCR Model:A Case Study of Nanchuan,Chongqing

基于源地-廊道模式构建生态安全格局,对提升区域生态安全水平意义重大。从生态本底与人类需求的视角出发,以典型山地石漠化地区重庆市南川区为例,基于生态系统服务功能重要性、生态环境敏感性以及居民生态需求程度进行核心型生态源地识别;采用多因素综合决策法,从自然环境因素、人为干扰因素以及生物因素方面构建生态源地扩张综合阻力评价指标体系;将最小累积阻力模型和水文分析相结合识别生态廊道,进而构建全区生态安全格局。结果表明:(1)核心型生态源地以林地景观为主,面积达389.25 km 2,总体呈现出由中部向南北方向递减的趋势;(2)生态廊道表现为以关键生态廊道为主,潜在生态廊道为辅的特征,并呈“渔网状”分布,中部密集,两极稀疏,关键生态廊道呈“三横三纵”格局,“三横”贯穿东西,“三纵”连接南北,潜在生态廊道沿生态环境较好的山地丘陵地区分布,与关键生态廊道共同构成了区域物种迁移和能量流通的网络;(3)建议搭建“一轴连两翼”的生态网络框架,加强区域生态安全格局的构建。

The construction of ecological security pattern based on the"source-corridor"model is of great significance for improving regional ecological security.Nanchuan District,a typical desertification mountainous area,was taken as an example to construct the ecological security pattern.The core ecological source area was firstly identified based on the importance of ecosystem services,the eco-environmental sensitivity and the degree of inhabitants′ecological demands from ecological and human well-being perspective.The multi-factor comprehensive analysis method was then applied to detect the resistance surface of ecological source expansion using natural environmental factors,human interference factors and biological factors as evaluation indicators.Finally,the least cumulative resistance model and the hydrological analysis method were applied to identify the ecological corridors,so as to construct the regional ecological security pattern.It was found that the core ecological source area is dominated by forest with an area of 389.25 km 2,and the forest area decreases from the central to the north and the south in space.Six key corridors and a series of potential corridors were also successfully identified.In the key corridors,three of them traverse from west to east,and the others traverse from north to west.The potential corridors mainly distribute in hilly area with good environment,and form a network of regional species migration and energy circulation together with the key corridors.It is suggested that to construct an ecological network framework with one vertical and two horizonal ecological corridors to strengthen the regional ecological security pattern in Nanchuan District.