Collaborative Research: MRA: Particulates in canopy flowpaths: A missing mass flux at the macrosystem scale?

合作研究：MRA：冠层流动路径中的颗粒物：宏观系统尺度上缺失的质量通量？

• 批准号: 2213623
• 负责人: John Van Stan
• 金额: $ 224.28万
• 依托单位: Cleveland State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2213623&HistoricalAwards=false
• 关键词: Collaborative; Research; MRA; Particulates; canopy; Collaborative; Research; MRA; Particulates; canopy

Forests cover one-third of the land on Earth. For rainfall to pass through the forest canopy, it must drain along two “hydrologic highways”: throughfall (water that drips through gaps and from leaves or bark); and stemflow (water that runs down stems). As throughfall and stemflow drain, they wash particles from leaves and bark. Although tiny, particles washed from the canopy by these hydrologic highways can constitute a significant chemical input to the soil, and represent a wide range of materials, from nutrients to pollutants. Despite this, no large-scale effort has sought to measure, scale, and predict the amount and quality of particles descending down these hydrologic highways. These particles are generally “missing” from current ecological theory of how forests cycle elements. This study seeks to fill this gap by monitoring storm conditions, throughfall, stemflow, and the particles in these hydrologic highways across sites representing major forest types in North America. Results will link throughfall and stemflow to common models used to inform freshwater and forest management. Outcomes will inform outreach efforts, including science comics and illustration exhibits, open-access articles written for (and reviewed by) primary and secondary school children with Frontiers for Young Minds, and YouTube videos with MinuteEarth, a channel with an international viewership of millions. The project will also provide research experiences to members of underrepresented groups to broaden participation in science.For 40% of the North American continent and one-third of global land surface, rainfall must pass through forests to reach the soil surface. This rainfall is partitioned by the forest canopy into two net rainfall fluxes: a drip flux called throughfall (TF), and a flow of water down stems, called stemflow (SF). How much rain travels along these hydrologic highways can alter water supply by 20-50%, and what they carry from the canopy can supply 100 kg per hectare of various materials to the soil surface each year. These canopy ecohydrological processes are on the front line of climate and land use change, being that the forest-rainfall interactions that initiate terrestrial hydrological pathways and supply nutrients/pollutants to the surface are the first ecosystem elements impacted by hydrologic intensification. Ignoring these fluxes, and their particulate traffic, introduces error in water and nutrient flux models at the first point where terrestrial biogeochemistry and hydrological cycles entwine, and which may cascade those errors through downgradient processes. This project aims to extend current macrosystem biological understanding to include throughfall and stemflow particulate concentrations, fluxes and composition, specifically addressing 3 major objectives: (1) estimate the net rainfall (TF+SF) water and particulate mass flux across forest types; (2) characterize the particulate composition (C:N:P, including C components like total C, organic C, black C, and microplastic C) of TF and SF; and (3) identify major drivers of macrosystem variability in net rainfall particulate flux and composition. Field monitoring of the above variables across 11 sites of the National Ecological Observatory Network representing the major US forest domains allows links to be tested between existing functional characteristics and the practical integration of throughfall and stemflow dynamics into continental-to-global scale biogeophysical models. The project will also support research training of a postdoctoral researcher, masters and doctoral students, and a technician.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.

森林覆盖了地球上土地的三分之一。为了使降雨通过森林冠层，它必须沿着两个“水文高速公路”沥干：贯穿（水从间隙，叶子或树皮中滴落的水）；和茎流（从台阶下延伸的水）。随着贯穿和干流的排水，它们会从叶子和树皮上洗涤颗粒。尽管这些水文高速公路从树冠上洗涤的微小，但颗粒可以构成对土壤的重要化学输入，并代表从养分到污染物的广泛材料。尽管如此，尚无大规模的努力来测量，扩展和预测降低这些水文高速公路的颗粒的数量和质量。这些粒子通常是从当前关于森林循环元素的生态学理论“缺失”的。这项研究旨在通过监测代表北美主要森林类型的地点的风暴条件，贯穿，干流量和颗粒来填补这一空白。结果将链接到遍布和茎流与用于告知淡水和森林管理的常见模型。结果将为外展工作提供信息，包括科学漫画和插图展览，为年轻思想的前沿和YouTube视频撰写（并由）撰写（并由）撰写的开放式文章，并带有Minnerearth，这是一个具有数百万美元的国际收视率。该项目还将为代表性不足的群体的成员提供研究经验，以扩大参与科学的参与。对于40％的北美大陆和全球土地表面的三分之一，降雨必须穿过森林才能到达土壤表面。这次降雨被森林冠层分为两个净降雨通量：一种称为贯穿（TF）的滴水通量，以及称为茎流（SF）的水流。沿着这些水文高速公路的雨水在多少雨水中可以将​​供水供应量增加20-50％，而它们从冠层携带的东西每年每年都可以每公顷各种材料供应100 kg的土壤表面。这些冠层生态过程位于气候和土地利用变化的前线，是因为启动陆地水文途径的森林荒地相互作用是向表面供应陆生的水文途径，并且向表面供应养分/污染物是受水平强化影响的第一个生态系统元素。忽略这些通量及其特殊交通，在第一点陆地生物地球化学和氢周期缠绕的水和养分通量模型中引入了错误，并且可以通过降级过程级联这些错误。该项目旨在扩展当前的宏观系统生物学理解，包括遍布和干流的特定浓度，通量和组成，特别解决了3个主要目标：（1）估计跨森林类型的净降雨量（TF+SF）水和特定的质量流量； （2）表征特定的组成（C：N：P，包括TF和SF的总C，有机C，黑C和微塑料C）等C组分； （3）确定净降雨特定的通量和组成中宏观系统变异性的主要驱动因素。对代表美国主要森林领域的国家生态天文台网络的11个地点的上述变量进行现场监测，可以在现有功能特征与贯穿量和茎流动力学的实际整合到连续的全球量表生物地球物理模型之间进行测试。该项目还将支持博士后研究员，硕士和博士生的研究培训，以及技术奖。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估标准来通过评估来支持的。