Biodiversity, species coexistence and ecosystem functiioning

生态系统的功能是地球上生命的基础，在过去的几十年里，人们一直在努力研究物种多样性和生态系统功能之间的关系。人们通过建设污水处理湿地和绿色屋顶等生态系统来提供特定的生态系统服务，但对生态系统中物种数量与所需服务绩效之间的关系研究较少。 拟议的研究将评估增加植物物种和不同植物生命形式（草、多肉植物、灌木等）数量的作用。改善绿色屋顶性能。 将在复制的绿色屋顶微观世界中评估绿色屋顶提供夏季降温、冬季升温、碳捕获、雨水滞留和抵抗不良植物入侵等服务的能力。 将对最佳地发挥这些不同服务的植物物种和生命形式的特征进行评估，以确定一般植物特征与生态系统功能之间的关系。 这将允许在许多不同地区选择植物，以优化绿色屋顶功能。 只有当多种物种或生命形式能够共存而不被竞争淘汰时，屋顶上增加植物生物多样性的好处才能长期持续下去。 我们将确定在绿色屋顶上表现最佳的物种是否可以稳定共存，并确定允许这种共存的机制。 虽然物种差异对于生物多样性加强生态系统功能至关重要，但最近的“中性模型”表明，物种的长期共存并不需要这种差异。 我们将研究物种共存的程度是否取决于依赖于物种差异的机制。 这项研究将导致有形的改善绿色屋顶的性能，这将反过来导致能源和经济节约。

Ecosystem functions are essential for life on earth, and there has been a major research effort in past decades to determine the relationships between species diversity and ecosystem functioning. People construct ecosystems such as sewage treatment wetlands and green roofs to provide specific ecosystem services, but the relationships between the number of species in the ecosystem and performance of desired services has been little investigated. The proposed research will evaluate the role of increasing the number of plant species and different plant life-forms (grasses, succulents, shrubs etc.) in improving green roof performance. The ability for green roofs to provide services such as summer temperature reductions, winter temperature increases, carbon capture, stormwater retention and resistance to invasion by undesirable plants will be evaluated in replicated green roof microcosms. The traits of plant species and life-forms that optimally perform these different services will be assessed to determine the relationships between general plant traits and ecosystem functions. This will allow for selection of plants in many different regions to optimize green roof functioning. The benefits of increased plant biodiversity on roofs will only be sustained in the long-term if multiple species or life-forms can coexist without being outcompeted. We will determine whether the species that perform optimally on green roofs can coexist stably, and determine the mechanisms that allow such coexistence. While species differences are essential for biodiversity to enhance ecosystem functioning, recent "neutral models" suggest that such differences are not required for long-term coexistence of species. We will investigate whether the degree to which species coexistence is governed by mechanisms that rely on species differences. This research will result in tangible improvement to green roof performance that will in turn lead to energy and economic savings.