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，导致过多的雨水径流和城市热岛问题。绿色屋顶由种植在浅生长介质中的植被层组成，可以解决多种城市环境问题。过去的研究表明，增加绿色屋顶上的植物物种多样性可以减少雨水径流，但许多其他功能也可以通过精心选择的物种混合物来优化。 短期目标 1.预测在绿色屋顶的生态系统功能中，哪两种混合物将优于单一物种种植。 2.确定空间环境异质性对绿色屋顶中物种共存和生态系统功能的作用。 3.确定在同一地点共同生长的历史是否允许两个物种的种群更有可能长期共存并增加生态系统功能。 方法 我和我的学生将进行绿色屋顶和温室实验，比较物种混合和单一栽培。对于每一种单一物种种植（单一栽培）和物种混合，我们将量化一系列的好处，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，碳储存和抵御干旱的能力。我们将比较具有不同功能性状的物种与具有相似性状的物种的混合物。 为了测试空间异质性环境是否可以支持更多的物种和更高水平的生态系统功能，我们将比较土壤深度变化的绿色屋顶系统与土壤总量相同的均质系统。我们还将研究种植物种多样性的空间尺度在创造环境变化中的作用，这反过来又可能增加绿色屋顶作为无脊椎动物栖息地的价值。 为了确定共存的历史是否会影响两个物种的种群如何相互作用，我们将选择两个广泛分布的物种，它们共同生活在同一栖息地（岩石贫瘠地），并在不同地区的三个地点收集每个物种对的种子。这些将在一个共同的绿色屋顶环境中生长，我们将在实验中研究共存和生态系统服务配对的人口的每一个组合。 这项研究将导致一个有形的改善绿色屋顶的性能，并确定工程最佳物种混合物的基本原则。这项工作将为两名博士生，四名硕士生和至少六名本科荣誉学生提供一个刺激的培训平台。

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.