顾及石漠化敏感性的山地型城市生态网络构建——以云南省曲靖市为例

Ecological network construction of mountainous cities considering rocky desertification sensitivity:A case study of Qujing City,Yunnan Province

开展生态系统健康评价、构建生态安全网络是有效管理生态资本和保护生物多样性的重要举措,尤其对于石漠化广布、生态基底薄弱的滇东地区,其能够预防潜在生态风险和保障生态安全。将生态系统服务纳入到生态系统健康模型中,构建"活力-组织力-恢复力-生态系统服务"的生态安全评估体系,定量化地评估了曲靖市2000-2020年的生态系统健康状况,并据此识别生态源地,借助石漠化敏感性修正基于土地类型的基本阻力面,运用最小累积阻力模型和重力模型识别生态廊道,从而构建曲靖市生态安全网络。结果表明:(1)研究时段内,曲靖市的生态系统健康水平先上升后下降,整体呈下降趋势。除受人类活动影响较大的城镇建成区外,其余地区的健康状况总体稳定;(2)曲靖市生态源地共有8656.65 km2,占研究区总面积的29.92%,与自然保护区重合率达70.18%,由西北向东南呈不规则分布,集中分布于曲靖市北部及东南部地区;(3)潜在廊道143条,生态节点137处,生态断裂点82处,呈网状辐射分布,西南部未有源地和廊道分布,易形成生态孤岛,区域连通性亟待提升。顾及石漠化敏感性的生态网络能够更好地反映生物迁徙过程中受到的阻力,并可以通过生态廊道实现不同源地之间的连接。针对滇东喀斯特生态脆弱区的环境底质特征,构建顾及石漠化敏感性的山地生态网络格局,可为具有相似环境背景的中小型城市的生态网络优化提供新的思路。

Carrying out an ecosystem health assessment and building an ecological safety network are essential measures to effectively manage ecological capital and protect biodiversity,especially in eastern Yunnan,where rocky desertification is widespread,and the ecological base is weak.Besides,they can prevent potential ecological risks and ensure ecological safety.In this paper,ecosystem services were incorporated into the ecosystem health model,and an ecological security evaluation system of"vitality-organization-resilience-ecosystem services"was constructed and quantitatively evaluated the ecosystem health status of Qujing City from 2000 to 2020 and identified the core areas accordingly.With the help of the sensitivity of rocky desertification,the resistance surface based on the land type was modified.The minimum cumulative resistance model and gravity model were used to identify the ecological corridors and build the ecological security network of Qujing City.The results showed that:(1)during the study period,the ecosystem health status of Qujing City increased and then decreased,indicating a downward trend.Except for the urban built-up areas significantly affected by human activities,the ecosystem health status in the other regions was generally stable.(2)The core areas of Qujing City were 8656.65 km2,accounting for 29.92%of the study area,and the coincidence rate with the nature reserve was 70.18%,with an irregular distribution from northwest to southeast,and concentrated in the north and southeast of Qujing City.(3)There were 143 potential corridors,137 ecological nodes,and 82 ecological breakpoints distributed in a network radiation pattern.The southwest was not actively distributed with corridors,which was easy to form an ecological island,and the regional connectivity needed to be improved.The ecological network considering the sensitivity of rocky desertification could better reflect the resistance when species migrated,and the ecological corridor could realize the connection between different sources.This paper paid close attention to the characteristics of the environmental conditions in eastern Yunnan's karst ecological fragile area.It constructed a mountain ecological network pattern that considered the sensitivity of rocky desertification.It could provide a new idea for optimizing the ecological network of small and medium-sized cities with similar environmental backgrounds.