EAGER: The role of native and nonnative plants in structuring food webs in urban ecosystems

城市里既有原生植物，也有非原生植物，与附近的自然区域相比，这些植物往往具有异乎寻常的多样性。城市中植物的高度多样性表明，城市地区可能会支持不同种类的取食昆虫，以及以这些昆虫为食的鸟类。然而，鉴于城市中的许多植物不是该地区原产的，目前还不清楚它们是否为当地的昆虫和野生动物提供了同样的条件和好处。在这项研究中，来自加州州立大学洛杉矶分校的一组研究人员将评估原生和非原生树木在支持昆虫和鸟类组成的食物网方面的作用。这项研究将集中在橡树(栎属)上，因为橡树以拥有高度的昆虫多样性和支持鸟类种群而闻名。目前尚不清楚鸟类能否控制这些橡树上的昆虫。鸟类通常盛产橡树。洛杉矶研究区种植了本地和非本地橡树，从而提供了一个机会来比较昆虫在树上的积累和鸟类对树的利用。该项目涉及在一系列城市环境中种植200棵橡树，其中包括本地和非本地物种，旨在提供线索，了解本地和非本地树木是否支持最多样化和最丰富的昆虫物种，进而提供鸟类是否被这些昆虫吸引，或者是否以不同的方式使用本地和非本地橡树。该项目的实地地点将设在整个洛杉矶的显眼区域，因此公共宣传和教育将在整个项目中有机地进行。此外，这项研究将吸引和雇用来自代表性不足群体的学生，重点是来自加州州立大学洛杉矶分校所在的东洛杉矶的学生。总体而言，这项研究将为识别如何更好地景观和设计城市以促进原生生物多样性提供新的和独特的结果。本研究的目标是批判性地评估原生和非原生树木在构建由植物、昆虫和鸟类组成的城市食物网中的作用。虽然这些问题已经在非城市环境中得到了解决，但几乎没有工作在实验上评估树种对城市环境中鸟类和昆虫的潜在影响。这项研究将解决这个问题，在构建城市食物网方面，非本地橡树在功能上与本地树木相似。鸟类的影响将通过调查鸟类的使用情况和在不同树木上停留的时间来推断。该项目将建立一个大规模的田间试验，涉及种植200棵本地和非本地橡树(Quercus spp.)这项研究将包括本科生和一名研究生，以及项目合作者，以收集试验点本地和非本地树木上的植物生长、草食、昆虫和鸟类群落以及鸟类取食行为的现场数据。此外，这项研究将使用复杂的统计分析和实验室方法，包括叶片性状分析和植物上昆虫群落的DNA代谢编码，以阐明营养水平之间的食物网络/联系。这项工作将通过外展展示和在实验地点(学生和公众访问率较高的十个机构)安排的活动，吸引更广泛的洛杉矶社区。外展活动将侧重于本土植物、当地生物多样性和城市食物网的重要性。此外，该项目将影响城市的生态，因为研究团队将努力将研究成果与城市化地区的生物多样性管理相结合。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Cities contain a mixture of native and nonnative plants that are often unusually diverse when compared with nearby natural areas. The high diversity of plants in cities suggests urban areas can potentially support a diverse mixture of feeding insects as well as birds that eat those insects. However, given that many plants in cities are not native to the region, it is unclear whether they provide the same conditions and benefits to local insects and wildlife. In this study, a team of researchers from California State University Los Angeles will assess the role of native and nonnative trees in supporting food webs composed of insects and birds. The research will focus on oak trees (genus, Quercus) as oaks are renowned for harboring high levels of insect diversity and supporting bird populations. It is not known if birds, which generally are abundant in oaks, can control the insects on those oak trees. Both native and nonnative oaks are planted throughout the Los Angeles study area thus offering an opportunity to compare the accumulation of insects on trees and the use of trees by birds. This project, which involves planting 200 oak trees in sets that include native and non-native species across a range of urban settings, is designed to provide clues about whether native versus nonnative trees support the most diverse and abundant collection of insects, and in turn, whether birds are attracted to feeding on those insects or to using native versus non-native oak trees differentially. The field locations for this project will be set in highly visible areas throughout Los Angeles, and thus public outreach and education will happen organically throughout the project. Further, the study will engage and employ students from underrepresented groups, with a focus on students from East Los Angeles, where California State University Los Angeles is located. Overall, this research will provide novel and unique outcomes for discerning how to better landscape and design cities to promote native biodiversity.The goal of this study is to critically evaluate the role of native and nonnative trees, in structuring urban food webs, composed of plants, insects, and birds, in Los Angeles, CA (L.A), USA. While these questions have been addressed in non-urban settings, almost no work has experimentally evaluated the potential influence of tree species on birds and insects in an urban setting. This research will address the question, are nonnative oak trees functionally similar to native trees in structuring urban food webs. The influence of birds will be inferred by surveys of bird usage and time spent in the different trees. The project will erect a large-scale field experiment, involving the planting of 200 native and nonnative oak trees (Quercus spp.) and a reference species, the Southern Magnolia, Magnolia grandiflora, at 10 locations throughout L.A. The study will include undergraduate students and a graduate student, plus project collaborators, to collect field data on plant growth, herbivory, insect and avian communities, and bird feeding behavior, on the native and nonnative trees at experimental sites. Further, the study will use sophisticated statistical analyses and laboratory methodologies, including leaf-trait analyses and DNA metabarcoding of insect communities on plants to elucidate food web networks/connections among trophic levels. The work will engage the broader community of Los Angeles through outreach displays and scheduled activities at experimental sites (ten institutions with high visitation rates of students and the public). Outreach events will focus on the importance of native plants, local biodiversity, and urban food webs. Further, the project will influence the ecology of the city as the research team will work to integrate research findings with the management of biodiversity in the urbanized region.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.