MSA: Dust as an ecosystem driver: determining the ecosystem consequences of cross-system subsidies of nutrients and microorganisms in dusts

土壤(尘埃)的大气输送将遥远的生态系统连接在一起，将营养物质和有机体跨越大陆，并在重力的作用下从低地地区转移到山区荒野。粉尘沉积会影响气候，加速积雪融化，影响空气和水的质量，并对人类健康造成影响。尽管尘埃在环境中很重要，但我们对大气通过时间和空间输送的尘埃的数量和组成知之甚少。该项目将确定美国西部哪个地方的粉尘载量最大，检查收集到的粉尘的组成，并记录尘埃中输送的营养物质和微生物如何影响它们所在的水生生态系统。研究结果将使自然资源管理者和政策制定者了解气候和土地利用活动如何影响顺风向生态系统服务，如水质和社区多样性。该项目将通过让高中生直接参与粉尘样本的收集和检测，为他们提供研究经验。学生将能够比较他们所在地区收集的粉尘的特性，因为它与地理、土地利用和气候有关。这项研究将研究灰尘在向山区生态系统输送具有生态意义的营养物质和微生物方面的作用。由于尘埃可能含有相当浓度的陆地限制性营养物质，因此人们推测，尘埃沉积的增加导致了美国偏远水体的广泛富营养化。此外，尘埃沉积可能是微生物在生态系统中扩散的主要机制，有可能塑造常驻微生物群落的组成和功能。该项目将通过捕获和分析美国西部和中西部地区的大气粉尘来验证这些假设，并通过实验室和现场实验直接检查营养物质的生物有效性和微生物群落组成。这项研究有四个主要目标，1)通过与国家大气沉积计划(NADP)的协调工作，确定美国西部粉尘的重力沉积速率，2)使用受控实验室实验来量化粉尘中的微生物组成和可淋洗和可水解的营养成分，3)现场确定粉尘添加对水生微生物和藻类群落组成的影响，以及4)提供关于测量和跟踪粉尘移动的最佳实践的关键数据。该教育计划将吸引高中地理、地球科学和生态专业的学生参与，并培养对气候和人类土地利用在影响重要生物地球化学循环、空气质量和环境条件方面的作用的兴趣和理解。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。

Atmospheric transport of soil (dust) connects distant ecosystems, moving nutrients and organisms across continents and against gravity from lowland areas to mountain wilderness. Dust deposition can influence climate, accelerate snowmelt, affect air and water quality, and have human health consequences. Despite the importance of dusts within the environment, we know very little about the quantity and composition of dusts transported by the atmosphere through time and space. This project will determine where within the western USA dust loading is greatest, examine the composition of collected dusts, and document how nutrients and microorganisms transported in dusts affect aquatic ecosystems in which they are deposited. The results will inform natural resource managers and policymakers on how climate and land-use activities can influence ecosystem services downwind, such as water quality and community diversity. The project will provide research experiences for high school students by directly involving them in the collection and examination of dust samples. Students will be able to compare the properties of collected dusts in their region as it relates to geography, land-use, and climate. This research will examine the role of dust in transporting nutrients and microorganisms in ecologically meaningful quantities to mountain ecosystems. Because dust can contain appreciable concentrations of terrestrial limiting nutrients, it has been hypothesized that increased dust deposition has led to widespread eutrophication of remote waterbodies in the US. Moreover, dust deposition may represent a major mechanism of microbial dispersal across ecosystems, potentially shaping the composition and function of resident microbial communities. The project will test these hypotheses through the capture and analyses of atmospheric dusts across the western and mid-western USA, with direct examination of nutrient bioavailability and microbial community composition through laboratory and field experiments. The research has four main objectives, 1) determine the gravitational deposition rate of dusts in the western US through a coordinated effort with the National Atmospheric Deposition Program (NADP), 2) use controlled laboratory experiments to quantify the microbial composition and the leachable and hydrolysable nutrient fraction from dusts, 3) determine in situ effects of dust additions on aquatic microbial and algal community composition, and 4) provide critical data on best practices for measuring and tracking dust movement. The education plan will engage high school geography, earth science, and ecology students, and cultivate an interest and understanding of the role of climate and human land-use in affecting important biogeochemical cycles, air quality, and environmental conditions.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.