Doctoral Dissertation Research: Effects of Forest Fragment Size, Shape, and Structure on Rainfall Redistribution and Solute Flux in Urban Settings

这项博士论文研究项目将研究城市森林碎片的形状和结构特征如何影响大都市区森林生态系统中水和溶质的循环。这位博士生将寻求理清森林碎片化与它们可以提供的生态系统服务之间的复杂关系，方法是更清楚地了解具有不同树冠结构和位置的森林碎片之间在水分和溶质通量方面的差异，这些森林碎片沿着城市到农村的土地利用梯度。该项目将加强有关降水在落到森林碎片中时被分割成几种形式的基本知识，例如从森林树冠中截留的水、从树叶落到地面的水(穿透雨)以及从植物树干和树干流下的水(树干径流)。项目发现应该有助于评估穿透降雨和树干径流与碎片大小和形状、位置和结构特征之间的化学关系。通过这些措施和其他措施，该项目将有助于更准确地量化城市森林碎片提供的生态系统服务，特别是减少雨水径流和修改溶质向地下和地表水水池的运移。除了加强基本认识外，该项目还将为管理森林碎片的方法提供新的见解，以保护城市化地区的绿色/森林空间。这项工作的数据将通过特拉华州环境监测和分析中心的门户网站向公众提供，供那些对改善城市绿地管理感兴趣的人使用。作为博士论文研究改进奖，该奖项也将提供支持，使有前途的学生建立强大的独立研究生涯。这项研究的首要问题是：城市森林碎片的水文功能(即降水到穿透雨和树干径流的分配，以及溶质的淋溶和循环)如何在城市内和城乡梯度上的森林碎片之间变化？这个学生将调查特拉华州威尔明顿的五个森林碎片的截留损失，以及该大都市区城乡坡度上的截留损失，以了解其对水输入的影响以及穿透雨和树干径流的化学特征。她将使用森林水文学和水化学实验室分析中的实地方法来量化降水分配以及穿透雨和树干径流的溶质化学。其他分析将阐明与土地利用有关的降水在空间和时间上分配的动态性质。

This doctoral dissertation research project will investigate the ways in which the shape and structural characteristics of urban forest fragments affect the cycling of water and solutes in wooded ecosystems of metropolitan areas. The doctoral student will seek to disentangle the complex relationship between forest fragmentation and the ecosystem services they can provide by establishing a clearer understanding of the differences in water and solute flux among forest fragments with varying canopy structure and location along an urban-to-rural land-use gradient. This project will enhance basic knowledge of the forms into which precipitation is partitioned when it falls in forest fragments, such as water that is intercepted in forest canopies, water that falls to the ground from leaves (throughfall), and water that flows down the trunks and stems of plants (stemflow). Project findings should help assess the chemistry of throughfall and stemflow in relation to fragment size and shape, location, and structural characteristics. Through these and other measurements, this project will help develop a more accurate quantification of ecosystem services provided by urban forest fragments, particularly the reduction of stormwater runoff and the modification of solute transport to ground- and surface-water pools. In addition to enhancing basic understanding, the project will provide new insights into methods to manage forest fragments for the conservation of green/forested space in urbanizing areas. Data from this work will be made readily available to the public via the Delaware Environmental Monitoring and Analysis Center web portal for those interested in improving the management of urban green spaces. 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.The overarching question of this research is: How does the hydrological function of urban forest fragments (namely the partitioning of precipitation into throughfall and stemflow, and the leaching and cycling of solutes) vary among forest fragments within the city and along an urban-rural gradient? This student will investigate interception losses in five forest fragments in Wilmington, Delaware, and along an urban-to-rural gradient in that metropolitan area in order to understand its effect on water inputs and the chemical signature of throughfall and stemflow. She will employ field methods in forest hydrology and hydrochemical laboratory analyses to quantify both precipitation partitioning and solute chemistry of throughfall and stemflow. Additional analyses will elucidate the dynamic nature of precipitation partitioning over space and through time in relation to land use.