Greening cities: biodiversity and ecosystem services associated with street trees, from ecology to planning

该博士项目将研究一种标志性但研究不足的系统（行道树）在增强城市生物多样性和支持生态系统功能（例如授粉）方面的作用，并与市议会和其他利益相关者合作，以加强政策和规划指南。背景：在世界各地，城市规模不断扩大，人们对城市生态系统的兴趣越来越大，无论是在基础研究还是应用实践方面。虽然有大量关于城市绿色栖息地（花园、公园）生态的信息，但对以柏油碎石或混凝土为主的生态系统知之甚少。可以预计，在这种环境中，群落和生态系统功能将被削弱，但削弱的程度将取决于当地条件（例如裸露土壤的面积、覆盖物的类型、污染）、城市景观的配置和物种的类型。例如，虽然地面昆虫的多样性可能反映了与来源（公园和花园）的距离，但飞行传粉者可能主要取决于景观中花卉资源的可用性以及它们在该环境中导航的能力。为了测试这些效果，行道树是一个理想的系统。它们构成了高度复制的“绿色岛屿”，在一个矩阵的密封表面（高一致性的种植模式在个别街道段），但迄今为止研究甚少。虽然它们已被证明对能源使用和城市用户的福祉有巨大的好处，但它们的管理在英国是一个有争议的话题（参见示例链接），很少包括更广泛的生态考虑。世界各地的城市都在实施植树战略，以增加碳固存并实现生物多样性目标，这使得对城市树木的研究变得紧迫而有影响力。研究系统：地面居住的无脊椎动物和飞行授粉者，在贝尔法斯特，阿伯丁和马尔莫（瑞典）的城市地区。该项目将解决一些生态问题，在项目的前三个月内与贝尔法斯特市理事会共同创建。在这一阶段，他们可能包括：我们可以检测种面积关系的基础上的行道树？什么是物种殖民街道树木的功能配置文件，以及如何由树木的特点与周围城市景观的特点决定？种在街道树木上的物种多样性是如何随着城市景观的组成和配置而变化的？如何增加城市传粉者可用的花卉资源的数量和多样性？所有的传粉者都能飞过一座城市吗？我们能确定最大限度地提高生物多样性的植树战略吗？

This PhD project will investigate the role of an iconic but poorly studied system (street trees) for enhancing urban biodiversity and support ecosystem functions (e.g. pollination), and work with City Councils and other stakeholders to enhance policy and planning guidelines.Background:Across the world, cities are ever increasing in size, and there is growing interest in urban ecosystems, both in terms of fundamental research and applied practice. While there is substantial information on the ecology of urban green habitats (gardens, parks), little is known about ecosystems dominated by tarmac or concrete. It can be expected that in such environments, communities and ecosystem functions would be impoverished, but how much will depend on local conditions (e.g. area of exposed soil, type of cover, pollution), configuration of the cityscape, and the type of species. For instance, while ground insect diversity might reflect distance from sources (parks & gardens), flying pollinators might depend mostly on the availability of floral resources in the landscape, and their capacity to navigate that environment. To test these effects, street trees are an ideal system. They constitute highly replicated 'green islands' in a matrix of sealed surfaces (high consistency of planting patterns on individual street segments), but have been so far poorly studied. While they have been shown to have huge benefits for energy use and the wellbeing of urban users, their management is a controversial topic in the UK (see e.g. example link), and rarely includes wider ecological considerations. Across the world, cities are implementing tree planting strategies to increase carbon sequestration as well as address biodiversity objectives, making the study of urban trees urgent and impactful.Study system: ground dwelling invertebrates and flying pollinators, in urban areas of Belfast, Aberdeen, and Malmo (Sweden). This may be expanded to other taxa and locations.The project will address a number of ecological questions, selected within the first three months of the project in co-creation with the Belfast City Council. At this stage, they may include:Can we detect Species-Area relationships at the base of street trees? What is the functional profile of species colonising street trees, and how is that determined by traits of the trees vs characteristics of surrounding cityscape? How does the diversity of species colonising street trees vary with the composition and configuration of the cityscape? How to increase the amount and diversity of floral resources available to urban pollinators? Can all pollinators fly through a city? Can we identify tree planting strategies that maximise biodiversity?