海口市海岸带生态网络演变趋势

基于GIS和RS技术,利用最小阻力距离法构建研究区4个时期(1988、2000、2009和2017年)的生态网络,结合重力模型、斑块中心度指数评价网络完善度,探讨海口市海岸带生态网络的演变趋势。结果显示:(1)1988—2017年间研究区内生态源地由18个减少为10个,生态廊道数目由43条减少到15条。从空间角度看,核心斑块未发生变化,但四级斑块的大量减少对生态网络产生直接影响;从时间角度看,各斑块间相互作用力呈减弱态势。(2)生态网络踏脚石斑块多分布于园林地和湿地,在整个生态网络中具有重要的连接性作用,同时又具有保护生物多样性的重要生态功能。(3)1988到2017年生态网络质量显著下降,网络模型趋于单一化。(4)快速城市化及高强度人类活动是网络状态弱化的主要胁迫因素。研究结果对海口市海岸带地区生态网络的构建具有重要的指导意义和实践价值,同时亦可为其他地区生态网络的构建提供借鉴与参考。

Study on the evolution of ecological network in Haikou coastal zone

Based on four high-resolution remote sensing images in 1988,2000,2009 and 2017, the ecological network in Haikou coastal zone was built by using minimum resistance distance methods. Combined with gravity model and Patch Center Index, the change trends of ecological network in the past 30 years are discussed. The results indicate that:(1) the number of ecological source region has decreased from 18 to 8, and ecological corridor has decreased from 43 to 15. Though less changes happened in core patches, the obvious effects caused by rapid reducing of grade 4 patches could be found. The interactivity between patches has weakened in the temporal dimensions. (2)Most of the ecological network stepping-stone patches, which play important roles in connectivity and biodiversity protection, distributed in gardens and wetlands. (3) The quality of ecological network has been declined, and the network model tended to be simplified. (4) Rapid urbanization and high intensity of human activities are the main driving factors for the weakening of the network state. The results provide scientific and practical guidance for building ecological network in Haikou City and, other areas with the similar situation.