Portable photosynthesis unit to quantify plant performance in constructed ecosystems

绿色屋顶代表了一个工程生态系统，为人类社会提供了许多好处。绿色屋顶在夏季降低屋顶温度，并减少雨水流入下水道系统。尽管最近在加拿大各地对建造绿色屋顶感兴趣，但人们对不同植物物种如何为屋顶生态系统带来好处的了解甚少。我和我的学生建立了一个绿色屋顶研究设施，使我们能够量化绿色屋顶与传统屋顶相比的好处，并评估不同类型植物的相对性能。我们正在申请一个便携式光合作用装置，以测量植物叶片释放的水蒸气和碳吸收率。这些措施将使我们能够了解植物在一年中不同时间对屋顶生长条件的反应。植物吸收和释放的水驱动屋顶冷却和屋顶在暴风雨后保持水分的能力。耗水量少的植物在绿色屋顶的浅层土壤中可能生存得更好，但它们的冷却和水分捕获功能不如其他物种。便携式光合作用装置将使我们能够评估耐旱性和绿色屋顶生态系统服务性能之间的权衡。便携式光合作用装置收集的数据将使我和我的学生能够对绿色屋顶应用的植物做出明智的选择，创造在一年中不同时间表现良好的物种混合物，以最大限度地提高全年效益，并发现植物生理学和绿色屋顶生态系统的有用功能之间的联系。虽然每种植物都是独特的，但它们可以被分成具有相似功能的组。虽然我们已经在我们的实验屋顶上测试了30多种原产于加拿大大西洋的物种，但使用光合作用装置量化这些物种的基本生理性能将使我们能够按功能对物种进行分组。了解一般植物性状与绿色屋顶功能的关系将使我们能够预测我们尚未在加拿大各地测试应用的其他植物的性能。

Green roofs represent an engineered ecosystem that provides many benefits to human society. Green roofs reduce roof temperatures in summer, and reduce storm runoff into sewer systems. Despite recent interest in constructing green roofs across Canada, there is little understanding of how different plant species contribute to the benefits of rooftop ecosystems. My students and I have established a green roof research facility that allows us to quantify the benefits of green roofs compared to conventional roofs, and to evaluate the relative performance of different types of plants. We are requesting a portable photosynthesis unit to measure water vapor released by plant leaves and the rate of carbon uptake. These measures will allow us to understand how plants are responding to the growing conditions on the roof at different times of the year. Water uptake and release by plants drive roof cooling and the roof's ability to retain water after storms. Plants that use little water may survive better in the shallow soils on green roofs, but do not perform cooling and water capture functions as well as other species. The portable photosynthesis unit will allow us to evaluate this trade-off between drought tolerance and performance of green roof ecosystem services. The data collected with the portable photosynthesis unit will allow me and my students to make informed choices about plants for green roof applications, to create mixtures of species that perform well at different times of the year to maximize year-round benefits, and to discover the links between plant physiology and the useful functions of green roof ecosystems. While each plant species is unique, they can be put into groups with similar functions. While we have already tested over 30 species native to Atlantic Canada on our experimental roofs, quantifying basic physiological performance of these species using the photosynthesis unit will allow us to group species by function. Understanding how general plant traits relate to green roof functioning will allow us to predict the performance of other plants we have not yet tested for application across Canada.