基于生态网络实证模拟的三峡沿库城镇生态空间优化研究——以重庆开县为例

Landscape connectivity and ecological networks have become the focus of applied landscape ecology and been widely used to optimise conservation of meta-populations in wild environments. There are some problems with the practice of relevant theories in urban environments, including study subjectivity in modelling, and the lack of integration of ecological dynamics empirical study into land design process. With rapid urbanisation in the Three Gorges Reservoir Region, natural area fragmentation and habitat loss is inevitable. Under these circumstances, this research will study the mechanism of configuring well-connected urban ecological networks that can mitigate the biodiversity losses, facilitate multiple ecological processes and enhance urban eco-security. ..Taking Kaixian (Chongqing Municipality), a typical Three Gorges Reservoir Margin Town, as an example, this study will be carried out at urban basin and built-up area scales with 30m and 2m resolution respectively. The research approaches and methods include landscape pattern analysis, habitat/plant community multiple characteristics survey, field observation and experiments, spatial simulation and validation, network structure analysis. Empirical study of indigenous trees (as individual surrogates) and their seed dispersal patterns will be carried out to improve the conventional simulation modelling and network analysis in order to reduce subjectivity and to better suit the specific conditions of urban environments. Through in favor of facilitating indigenous tree genetic exchange, this study will explore Eco-space optimisation approach - a way of following natural processes - to ultimately contribute to the maintenance of ecosystem stability and integrity. According to multi-scales, multidisciplinary and complex characters of urban natural environments, this study will greatly enhance the newly emergent research paradigm of “landscape pattern – ecological process – spatial design” and will be helpful in exploring the theoretical and technical innovations in urban and/or regional ecological planning.

生态网络理论近年来成为景观生态学及应用领域研究的热点之一，较多应用于自然栖息地保护；当运用于城市环境时，普遍存在模型构建主观性较强，生态过程的研究并未实质性融入到设计中等问题。本研究在当前三峡库区快速城市化，栖息地破碎与部分生境消失不可避免的背景下，以沿库新城镇典型代表重庆开县为案例，研究促进生态功能与过程的网络格局，以保障城市生态安全。该研究在城市流域和建成区两个空间尺度上进行，采用景观格局分析、生境/植物群落多种特征调查、样地观测森林植被更新、空间模拟/验证和网络分析等宏观与微观结合的手段，从有利于乡土树种扩散定居过程为切入点，研究遵循自然演进规律，促进本土生态系统种群交流的城市生态空间设计方法，以形成整体生态系统组分与过程连续性的保护网络。立足于城市自然生态系统的特点，本研究旨在促进“景观格局—生态过程—空间设计”研究新范式，对探索城市/镇及区域生态规划理论与技术创新具有重要意义。

生境破碎化是城市生物多样性保护和生态系统完整性面临的主要威胁。构建生态网络，提高生境斑块间的连接水平，可以有效缓解城市生态环境问题。在当前三峡库区快速城镇化、栖息地破碎与部分生境消失不可避免的背景下，本文以库区开州新城为例，从有利于乡土树种扩散定居过程为切入点，以GIS技术为支撑，应用最小费用模型模拟潜在路径，构建城市生态网络；并结合图论功能连接度指数验证网络连接的最优阈值，评价并划分斑块/连接的重要等级，从而确定新城栖息地/廊道保护、恢复的优先顺序。本研究筛选得到75个生境源斑块；乡土树枫杨种子传播的最远距离300 m是网络模拟、评价的适宜阈值。在该距离条件下，识别出98条路径连接，其中重要性高的路径主要分布在澎溪河⁃汉丰湖沿岸，包括规划院附属绿地与湖滨公园连接，跨江高速大桥两侧的湖滨绿地连接；若这两条连接被移除，网络整体连接度将下降19.1%。此外，研究发现，网络路径连接的重要性与其两端的斑块重要性不存在显著相关，但与斑块所处的空间位置及其自身形状特征有关。针对网络现状与模拟空白区存在的问题，本文提出了相应的网络优化对策。研究结果可为三峡库区城市／镇开展生态网络规划提供参考依据。.本研究立足于城市自然生态系统的特点，促进“景观格局—生态过程—空间设计”研究新范式，对探索城市/镇及区域生态规划理论与技术创新具有重要意义。项目资助以第一作者且第一标注共发表高质量SCI期刊论文4篇，在二审的SCI文章2篇，均是城乡规划学、景观学、地理学等领域国际知名SCI期刊。以第一/通讯作者且第一标注共发表中文核心期刊论文7篇，其中5篇发表在中文核心重要期刊。参编由Springer出版社即将出版的英文书籍一部（项目主持人贡献一个章节）。以乡土植物群落保护的生态网络模拟方法拟出版中文专著一部（已与科学出版社签订合同）。培养硕士研究生3名，其中2名已经取得硕士学位，1名在读。