Collaborative Research: Forest Water Use and the Influence of Acid Deposition

合作研究：森林用水和酸沉积的影响

• 批准号: 1562055
• 负责人: Lixin Wang
• 金额: $ 9.92万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1562055&HistoricalAwards=false
• 关键词: Collaborative; Research; Forest; Water; Use

Forest Water Use Efficiency (WUE) is defined as the ratio of carbon uptake per unit water vapor loss via transpiration. Micrometeorological measurements suggest that forest WUE has dramatically increased over the last two decades, in excess of what would be expected from increases in atmospheric carbon dioxide concentrations. Coinciding with observed trends in forest WUE have been marked decreases in acid deposition throughout much of North America and Europe. There is evidence that acid deposition may impact forest WUE, either by altering the availability of nutrients in forest soils or by directly affecting foliar physiology. Changes in WUE could also lead to changes in stream discharge from forested catchments. The hypothesized response of forests to changing levels of acid deposition is not currently considered in the land surface components of global climate models (GCMs). Since carbon dioxide and water vapor are the two most important greenhouse gases, it is vital to accurately model their land-atmosphere exchange. The proposed research uses a catchment-based approach to investigate the effects of changing acid deposition on forest WUE. Tree ring carbon isotopes will be used to reconstruct historical WUE time series within six catchments that have been differentially impacted by acid deposition due to distinctions between their underlying bedrock mineralogy and geological histories. The research will also capitalize on experimental treatments that have altered soil biogeochemistry in paired catchment designs (Bear Brook, ME; Hubbard Brook, NH; and Fernow Experimental Forest, WV). Stream discharge analysis and model-based approaches will be applied to detect the impact of acid deposition on forest WUE. The project will support a Ph.D. student, who will receive training in a wide range of field, laboratory, and modeling techniques, and at least eight undergraduate students. High school students will also be involved through established programs, and will include their participation in both field and lab activities. All senior members of the project team have track records of recruiting students from underrepresented groups. Results will be communicated to the broader scientific community through journal publications and conference presentations, and a special conference session will be organized with an objective of sharing research findings with the modeling community.

森林用水效率（WUE）定义为每单位水蒸气通过蒸腾损失的碳吸收比。微量学学的测量表明，在过去的二十年中，森林杂志已经大幅增加，超过了大气二氧化碳浓度增加所期望的。在整个北美和欧洲大部分地区的酸性沉积中，与观察到的森林Wue的趋势相吻合。有证据表明，酸沉积可能会通过改变森林土壤中养分的可用性或直接影响叶面生理学来影响森林。 WUE的变化也可能导致林集水区流出的流河流变化。 目前，在全球气候模型（GCM）的地表成分中尚未考虑森林对变化酸沉积水平的假设反应。由于二氧化碳和水蒸气是两种最重要的温室气体，因此必须准确地对其陆地喷气交换进行建模至关重要。拟议的研究采用基于集水的方法来研究改变酸沉积对森林WUE的影响。树环碳同位素将用于重建六个流域内的历史WUE时间序列，这些流域由于其基础基岩矿物学和地质历史的区别而受到酸沉积的差异影响。这项研究还将利用在配对的集水区设计中改变土壤生物地球化学的实验处理（Bear Brook，ME； Hubbard Brook，NH； NH； WV）Fernow实验性森林。流排放分析和基于模型的方法将用于检测酸沉积对森林WUE的影响。该项目将支持博士学位。学生将接受各种领域，实验室和建模技术的培训，以及至少八名本科生。高中生还将通过既定的计划参与其中，并将包括他们参与现场和实验室活动。项目团队的所有高级成员都有从代表性不足的小组招募学生的记录。结果将通过期刊出版物和会议演讲将结果传达给更广泛的科学界，并将组织特别会议，目的是与建模社区共享研究结果。