基于生态单元制图的城乡生物多样性保护体系构建

Biotope mapping is a process of identification and specification of different types of land use or land cover based on a classification of biotope. Taking the city of Baoji as a pilot study area, a modified biotope classification integrated with 4 vegetation structural parameters, i.e. continuity of vegetation cover, age of dominant canopy trees, horizontal structure and vertical structure, will be created, and a series of biotope maps will be drawn accordingly in terms of the classification as well as field survey and computer mapping. In order to test the validity of the modified biotope mapping scheme for urban biodiversity information collection, an evaluation was conducted from two aspects in particular: 1) comparison of species richness between long-continuity and short-continuity forests using vascular plant species, and 2) spatial distribution of animals in the green space in relation to vegetation structure. Given the above test results, the biodiversity values of the individual biotopes will be assessed and their existing problems within and between these biotopes will be identified and analyzed as well. Finally, the relevant strategies and suggestions will be proposed for urban biodiversity planning and conservation. The results of this project aim to provide theoretical basis and practical methods for the biodiversity-oriented urban landscape planning in future.

生态单元制图是基于生态单元分类系统划分和记录不同土地使用类型或土地覆盖类型的过程。本研究以宝鸡地区为研究对象，通过实地调研和室内制图相结合的方法，创建一套融入4个植被结构因子（植被覆盖的连续性因子、乔木层优势种的年龄因子、植被横向结构因子、植被竖向结构因子）的生态单元分类系统。通过长、短连续性林地中维管束植物物种丰富度的对比以及观测到的动物种在不同植被结构生境中的分布，检验此分类系统的生态单元制图模型在城乡生物多样性信息采集中的有效性。基于制图信息和检验结果，实现城乡生物多样性的综合评价，并运用景观生态学方法分析研究区域内绿色空间结构的问题，提出相关生物多样性规划和保护的解决方案。本研究旨在通过融入植被结构因子的生态单元制图模型在城乡生物多样性保护中的研究，以期为我国以生物多样性为导向的城市绿地规划提供理论依据和实践方法。

生态单元制图可以将城市生态环境现状及未来的规划前景落实在图谱之上。为探寻适合我国城乡生物多样性保护的有效措施和方法，本项目以宝鸡地区为研究对象，通过实地调研和对宝鸡市建成区遥感数据（高分二号卫星数据）分析相结合的方法，构建了一套融入植被横向结构因子、乔木优势种的年龄因子、植被竖向结构因子和林木类型4个因子的生态单元分类系统，将研究区域内的城市绿地生境现状以图谱形式展现。通过对不同植被结构绿地的维管束植物物种丰富度的对比以及观测到的鸟类在不同植被结构生境中的分布，检验了此分类系统在城乡生物多样性信息采集中的有效性。基于制图信息和检验结果，选用维管束植物总数、乡土植物种占植物总数百分比、鸟类总数、鸟类单种出现频度、生态单元稀有度、管理强度6个指标对各类生境进行生物多样性价值评价。最后基于评价结果，提出宝鸡市城乡生物多样性保护方案：①基于生态单元制图图谱，划定宝鸡市城市绿线；②建立大尺度生态廊道，构建绿蓝网络；③降低生态单元同质性，提高绿地生态单元丰富度；④控制外来种比例，丰富维管束植物种类。研究结果表明融入植被结构因子的生态单元制图可作为今后我国城乡生物多样性保护的有效规划工具。