An ecological approach to green roof ecosystem functioning

我的研究计划的长期目标是确定生态群落的结构如何影响生态系统服务的提供。 城市的特点是地表坚硬，导致雨水径流过多和城市热岛问题。绿色屋顶由种植在浅层生长介质中的植被层组成，可以解决多种城市环境问题。过去的工作表明，增加绿化屋顶上的植物物种多样性可以减少雨水径流，但通过精心挑选物种混合物，许多其他功能也可能得到优化。 短期目标 1.预测在绿化屋顶的各种生态系统功能方面，哪些两种混交林的表现将优于单一树种种植。 2.确定空间环境异质性对屋顶绿化中物种共存和生态系统功能的影响。 3.确定在同一地方共同生长的历史是否允许两个物种的种群长期共存的可能性更高，生态系统功能更强。 方法 我和我的学生将进行屋顶绿化和温室试验，比较混合栽培和单一栽培。对于每个单一物种种植(单一栽培)和物种混合，我们将量化一系列好处，包括减少建筑能耗的热功能、减少雨水径流的水文功能、为无脊椎动物提供栖息地、碳储存和抗旱能力。我们将比较具有不同功能特征的物种混合和那些表现出相似特征的物种。 为了测试空间异质环境是否能够支持更多物种和更高水平的生态系统功能，我们将比较土壤深度不同的绿色屋顶系统与土壤总量相同的同质系统。我们还将研究种植物种多样性的空间尺度在创造环境多样性方面的作用，这反过来可能会增加绿色屋顶作为无脊椎动物栖息地的价值。 为了确定共存历史是否会影响两个物种的种群相互作用，我们将选择两个分布广泛的物种，它们共同生活在同一栖息地(岩石荒地)，并在不同地区的三个地点收集每个物种对的种子。这些植物将在共同的绿色屋顶环境中种植，在那里我们将在实验中检查共存和生态系统服务，将每种种群组合配对。 这项研究将导致绿化屋顶性能的切实改善，并确定工程优化树种混合的基本原则。这项工作将为两名博士生、四名硕士学生和至少六名本科生提供一个激励性的培训平台。

The long-term goal of my research program is to determine how the structure of ecological communities affects the provisioning of ecosystem services. Cities are characterized by hard surfaces, leading to problems with excessive stormwater runoff and urban heat islands. Green roofs consist of a vegetation layer planted in a shallow growing medium and can address multiple urban environmental problems. Past work shows that increasing plant species diversity on green roofs can reduce stormwater runoff, but many other functions might also be optimized by carefully selected species mixtures. Short-term objectives 1. Predict which two-species mixtures will outperform single species plantings for a variety of ecosystem functions in green roofs. 2. Determine the role of spatial environmental heterogeneity on species coexistence and ecosystem functioning in green roofs. 3. Determine whether a history of growing together in the same place allows populations of two species a higher likelihood of long-term coexistence and increased ecosystem functioning. Approach My students and I will conduct green roof and greenhouse experiments comparing species mixtures with monocultures. For each single species planting (monoculture) and species mixture we will quantify a suite of benefits, including thermal functions that reduce building energy consumption, hydrological functions that mitigate stormwater runoff, habitat provisioning for invertebrates, carbon storage, and resilience against drought. We will compare mixtures of species with contrasting functional traits to those exhibiting similar traits. To test whether a spatially heterogeneous environment can support more species and higher levels of ecosystem functioning, we will compare green roof systems with variation in soil depth to homogeneous systems with the same total amount of soil. We will also examine the role of the spatial scale of planted species diversity in creating environmental variability, which in turn may increase the value of green roofs as habitat for invertebrates. To determine whether a history of coexistence influences how populations of two species interact, we will select two widespread species that live together in the same habitat (rock barrens) and collect seed from each species pair at three sites in different regions. These will be grown in a common green roof environment where we will examine coexistence and ecosystem services in experiments pairing each combination of populations. This research will lead to a tangible improvement of green roof performance and identify fundamental principles for engineering optimal species mixtures. This work will provide a stimulating training platform for two PhD students, four MSc students, and at least six undergraduate honours students.