Doctoral Dissertation Research: Synoptic Climatological Approaches to Assessing Subcanopy Hydrologic and Nutrient Fluxes in a Temperate Deciduous Forest

博士论文研究：评估温带落叶林亚冠水文和养分通量的天气气候学方法

• 批准号: 1233592
• 负责人: Delphis Levia
• 金额: $ 1.38万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1233592&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Synoptic; Climatological

This doctoral dissertation research project will focus on the flow of water and chemicals through forest canopies under different precipitation regimes. Deciduous temperate forests comprise over 280 million hectares in North and Central America and provide vital ecosystem services through the cycling of water and nutrients. During storm events, water moves through the forest canopy and exchanges nutrients and pollutants with vegetation and deposits the chemically altered precipitation to the forest floor. Both storm characteristics, such as intensity, duration, and magnitude, and the structural parameters of forest canopies have a significant control on the quantity and quality of such water, but how these may be influenced by altered precipitation regimes as a result of changing climates is largely uncertain. This project will yield a better understanding of the cycling of nutrients and pollutants within a forest canopy through hydrologic pathways that are ultimately controlled by atmospheric circulation and precipitation patterns at a field site in the Mid-Atlantic region. The doctoral student will link synoptic climatology with water and solute flux in temperate forests. Meteorological characteristics will be monitored at 5-minute intervals. These real-time ground observations will complement a long-term synoptic calendar, which will be developed to categorize common weather patterns experienced in the region. The partitioning of precipitation into throughfall (water intercepted by the canopy that continues to fall to the forest floor) and stemflow (water that is intercepted by the canopy and funneled down the tree trunk and deposited directly to the base of the tree) will be measured by automated tipping buckets at 5-minute intervals during storm events for two tree species of varying bark thickness and canopy geometry in order to understand the varying responses of precipitation in a heterogeneous forest canopy. Precipitation, throughfall, and stemflow samples will be collected after storm events and analyzed for important nutrients, such as dissolved organic carbon, calcium, magnesium, potassium, and sodium, and for anions, such as nitrates and sulfates, which can form acid rain. This project will provide new methodologies for estimating hydrologic and nutrient fluxes in forest canopies by integrating techniques of synoptic climatology and weather pattern analysis. This study will demonstrate how synoptic analysis of large-scale atmospheric circulation patterns may be used to estimate surface environmental conditions, thus reducing the demand for costly, fine-scale field observations. The dataset compiled in this study will be used to reconstruct a historical nutrient budget of Mid-Atlantic forests of similar composition and potentially forecast changes in forest hydrologic and nutrient budgets as a result of climate-induced changes to precipitation regimes. A more thorough understanding of the movement of water, nutrients, and pollutants in forest ecosystems will improve management capabilities and climate change mitigation efforts. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

该博士学位论文研究项目将集中于在不同降水状态下通过森林檐篷的水和化学物质的流动。 落叶森林在北美和中美洲占地2.8亿公顷，并通过循环水和养分提供重要的生态系统服务。 在暴风雨事件中，水通过森林冠层移动，并将营养物质和污染物与植被交换，并将化学变化的降水沉积到森林地板上。 风暴特征，例如强度，持续时间和幅度，以及森林檐篷的结构参数都对这种水的数量和质量都有很大的控制，但是由于气候变化而导致的降水状况改变可能会影响这些水的数量和质量。 该项目将更好地了解森林冠层中营养物质和污染物的循环，这些途径通过水文途径最终受到中大西洋地区田间现场的大气循环和降水模式控制的水文途径。 博士生将在温带森林中将天气气候与水和溶质通量联系起来。 气象特征将以5分钟的间隔进行监测。 这些实时的地面观察将补充长期的概要日历，该日历将开发以对该地区经历的共同天气模式进行分类。 The partitioning of precipitation into throughfall (water intercepted by the canopy that continues to fall to the forest floor) and stemflow (water that is intercepted by the canopy and funneled down the tree trunk and deposited directly to the base of the tree) will be measured by automated tipping buckets at 5-minute intervals during storm events for two tree species of varying bark thickness and canopy geometry in order to understand the varying responses of precipitation in a异质森林冠层。 在暴风雨事件发生后，将收集降水，渗透和干流样品，并分析重要的营养素，例如溶解的有机碳，钙，镁，钾和钠，以及用于硝酸盐和硫酸盐等阴离子，可以形成酸雨。该项目将通过整合天气气候和天气模式分析技术来提供新的方法来估算森林檐篷中的水文和营养通量。 这项研究将证明大气循环模式的概要分析如何用于估计表面环境条件，从而减少对昂贵，精细的现场观测的需求。 本研究中编译的数据集将用于重建具有类似组成的中大西洋森林的历史营养预算，并可能由于气候引起的降水状态的变化而可能预测森林水文和养分预算的变化。 对森林生态系统中水，养分和污染物的运动的更透彻了解将提高管理能力和缓解气候变化的工作。 作为博士学位论文研究改进奖，该奖项还将提供支持，使有前途的学生能够建立强大的独立研究职业。