CNH2-L: Toward a Theory of Urban Trees as Living Infrastructure

树木现在是美国城市景观中无处不在的组成部分。越来越多的城市树木被要求作为一种生活形式（即绿色）基础设施，用于满足各种市政目标，提供生态系统服务和对抗气候变化的影响，对于美国和国外的许多城市来说，气候变化正在导致城市热岛效应的增加。然而，与通常由城市管理的传统灰色基础设施相比，使用树木作为基础设施带来了新的挑战。本研究解决了我们对城市树木在市政植树、管理和决策以及社区互动结构中提供预期服务的有效性和能力的理解中的主要知识空白。生活基础设施是生物体、环境、社会欲望和治理能力之间反馈的社会-环境-技术系统。以城市树木为例，它们实现市政目标的能力是不确定的，而且可能因城市而异。存在这种不确定性的部分原因是，由于缺乏定量信息和科学研究，无法充分模拟城市树木对当地环境的影响。与此同时，机构管理者成功管理城市树木的能力也不清楚。综上所述，城市可能有树木衍生功能的目标，这些目标与树木所能做的生物物理现实和社区管理实践的现实和局限性都脱节。这项工作的更广泛影响包括对学生和博士后进行融合研究培训，为市政决策提供数据和发现，并通过社交媒体和其他外展机制向公众和其他利益相关者通报城市生活基础设施的作用。这是一个试点项目，其总体目标是了解推动将城市树木作为生活基础设施以产生生态系统服务的运动的智力和制度因素。项目活动将评估市政机构实施和管理城市树木作为城市生活基础设施以实现气候目标的能力。该项目解决了将城市树木视为生活基础设施的社会环境系统中的关键不确定性。它将审查美国各地现有市政林业目标和计划的差异，以及市政当局目前如何制定生活基础设施在减缓和适应气候变化方面的作用。它还检查了当前的科学理解如何与这些目标保持一致，以及需要哪些信息来监视、建模和验证这些过程。该项目包括对美国20个城市现有的城市森林规划进行评估。数据将从不同的学科角度进行评估：即生态系统科学、社区生态学、生态水文学、文化地理学、工程学和景观建筑学。这些数据将辅以额外的数据收集和在三个重点研究城市的利益相关者访谈：加利福尼亚州洛杉矶；亚利桑那州凤凰城;以及马里兰州的巴尔的摩。工作包包括在三个重点城市各举行一次为期1至2天的全团队综合会议，小组将在会上审查和讨论现有数据。随后将举行为期半天的讲习班，吸引当地利益攸关方参加。会议将集中讨论研究问题和进一步阐述生活基础设施的社会环境耦合理论。将成立一个技术咨询委员会，其对利益攸关方决策的投入将纳入工作计划。这项工作将大大有助于建立一个更全面的生活基础设施理论，作为社会、环境和技术系统之间的接口，以及作为在国家范围内可能发生巨大变化的新型城市生态系统的关键组成部分。该项目的社会效益包括将我们的研究成果直接传播给城市土地管理和林业专业人员，并为博士后和本科生提供新的跨学科培训机会。项目成果将直接解决市政当局及其植树计划的需求，这些计划往往寻求以巨大代价扩大城市覆盖范围和多样性，但缺乏可用的科学信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Trees are now ubiquitous components of urban landscapes in the United States. Increasingly urban trees are called upon as a form of living (i.e., green) infrastructure that is used to meet a variety of municipal goals to provide ecosystem services and combat the effects of climate change that, for many cities in the US and abroad, is causing an increase in the urban heat island effect. However, using trees as a form of infrastructure raises new challenges compared to traditional gray infrastructure typically managed by cities. This research addresses major knowledge gaps in our understanding of the effectiveness and capacity of urban trees to provide the services expected within the structure of municipal tree planting, stewardship and decision making and community interaction. Living infrastructure is a socio-environmental-technological system of feedbacks between organisms, the environment, societal desires, and governance capacity. In the case of urban trees, their capacity to meet municipal goals is uncertain and likely varies among cities. Part of this uncertainty exists because the ability to adequately model the effect of urban trees on their local environment suffers from a lack of quantitative information and scientific study. At the same time, the capacity of institutional managers to successfully steward urban trees is also unclear. Taken together, cities may have goals for tree-derived functions that are disconnected from both the biophysical realities of what trees can do and realities and limitations of community management practices. Broader impacts of the work include student and postdoc training in convergent research, providing data and findings to inform municipal decision making, and informing the public and other stakeholders of the role of living infrastructure in cities via social media and other outreach mechanisms. This is a pilot project with an overarching goal to understand the intellectual and institutional factors that have driven the movement to use urban trees as living infrastructure to produce ecosystem services. Project activities will evaluate the capacity of municipal institutions to implement and manage urban trees as living urban infrastructure to achieve climate goals. The project addresses key uncertainties in the socio-environmental system that considers urban trees as living infrastructure. It will examine how existing municipal forestry goals and plans vary throughout the United States, and how municipalities currently frame the role of living infrastructure in climate mitigation and adaptation. It also examines how current scientific understanding aligns with these goals and what information is needed for monitoring, modeling, and validation of these processes. the project includes the evaluation of existing municipal urban forestry plans from 20 cities throughout the United States. Data will be evaluated from the different disciplinary perspectives: i.e., ecosystem science, community ecology, ecohydrology, cultural geography, engineering, and landscape architecture. These data will be complemented with additional data collection and stakeholder interviews at three focal research cities: Los Angeles, California; Phoenix, Arizona; and Baltimore, Maryland. Work packages include a whole-team 1- to 2-day synthesis meeting in each of the three focal cities where existing data will be examined and discussed by the group. This will be followed by a half day workshop that engages local stakeholders. Meetings will focus on addressing research questions and further elaborating the coupled socio-environmental theory of living infrastructure. A Technical Advisory Committee will be constituted and their input on stakeholder decision making will be incorporated into the work plan. This effort will substantially contribute to a more comprehensive theory of living infrastructure as an interface between social, environmental, and technological systems and as a key component of novel urban ecosystems that can vary dramatically at national scales. Societal benefits of the project include the direct dissemination of our research findings to urban land management and forestry professionals, and new interdisciplinary training opportunities for postdoctoral and undergraduate trainees. Project results will directly address the needs of municipalities and their tree planting programs, which often seek to expand urban cover and diversity at great expense, but with a paucity of available scientific information.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.