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

University Of Delaware, Newark DE

Investigators

Abstract

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.