EAGER: Linking Crow Roosting Behavior with Nitrogen Biogeochemistry in Urban Ecosystems

地球正在加速城市化，目前有超过一半的人口居住在城市。人类的土地利用和资源消耗对城市、区域和全球尺度上的自然格局和过程产生了深远的影响。但是，虽然人类显然是城市生态系统的主要驱动力，但生活在城市中的动物也可以发挥重要作用。例如，动物将化学物质从人类食物来源转移到与世隔绝的城市森林中，可能会产生独特的化学热点，产生多种潜在后果。即便如此，很少有研究将化学物质的运动与城市野生动物种群的行为和动态联系起来。这个项目将探索美国乌鸦的筑巢行为和氮素移动之间的联系，以在纽约市中心的许多中小城市创造热点。该项目将招募当地代表性不足的少数民族学生参与该项目，该项目还将让公民科学家参与，并提高公众对人与自然联系的意识。该项目还将为当地城市管理人员和县水土保持管理人员提供科学基础。该项目的中心假设是，当城市化的美国乌鸦种群以人类补贴的食物来源为食，并在城市森林斑块高密度栖息时，它们创造了高？有时还会出现间歇性的氮素供应。这改变了森林碎片中氮素循环的模式，影响了反硝化和氮素淋失的关键生态系统过程，并造成了局部的水和空气污染。这项研究提出了两个主要问题。首先，乌鸦栖息地的分布及其与城镇的关联是什么？第二，乌鸦栖息地集中输入氮素的生物地球化学后果是什么？这项研究将调查乌鸦行为(包括觅食、栖息和排泄)与生物地球化学热点形成之间的一种新的联系。它将比较和对比热点地区和没有集中鸟类活动的城市地点之间的氮素转化和转移。它将研究不同的氮素流失途径(淋溶与反硝化)的模式和机制，以及接受脉冲、集中氮素输入的城市热点地区氮气的各种潜在终端形式和溶解损失。最后，它将通过整合人口和生态系统水平的研究来推动城市生态研究，而不是通常关注的人类和树木。该项目将研究动物物种如何在空间异质的城市景观(由人类土地使用决定驱动)和补充能量和材料(由人类食物消费驱动)的新背景下影响生态系统功能的基本方面。

The earth has become urbanized at an accelerating rate, with more than half of its population now living in cities. Human land use and resource consumption have profound impacts on the natural patterns and processes at the city, region, and global scales. But while humans are clearly the dominant drivers of urban ecosystems, animals living in cities can also play important roles. For example, movement of chemicals from human food sources into otherwise isolated urban forests by animals can produce unique chemical hot spots with multiple potential consequences. Even so, very few studies have linked the movement of chemicals with the behavior and dynamics of urban wildlife populations. This project will explore the links between the nesting behavior of American crows and the movement of nitrogen to create hotspots in the many small to medium sized cities in central New York. Under-represented minority students from local areas will be recruited for the project, which will also involve citizen scientists and lead to increased public awareness of human-nature connections. The project will also provide a base of science to local city managers and county soil and water conservation managers. The central hypothesis of this project is that when urbanized American crow populations forage on human-subsidized food sources and roost in high densities in urban forest patches, they create high ? and sometimes episodic - nitrogen availability. That changes the pattern of nitrogen cycling in the forest fragments, affects critical ecosystem processes of denitrification and nitrogen leaching, and causes localized water and air pollution. This study poses two main questions. First, what is the distribution of crow roosts and its association with cities and towns? Second, what are the biogeochemical consequences of concentrated N input from crow roosts? The study will investigate a novel linkage between crow behavior, including foraging, roosting and defecating, and the formation of biogeochemical hot spots. It will compare and contrast nitrogen transformations and transfers between the hot spots and urban sites without concentrated bird activities. It will examine the patterns and mechanisms regulating different pathways of N loss (leaching vs. denitrification) and various potential end forms of nitrogen gas and dissolved losses in urban hot spots receiving pulsed, concentrated N input. Finally, it will advance urban ecological research by integrating population and ecosystem level studies beyond the usual foci of humans and trees. The project will examine fundamental aspects of how animal species affect ecosystem function in the novel context of a spatially heterogeneous urban landscape (driven by human land use decisions) and supplemental energy and material (driven by human food consumption).