Critical Landscape Interfaces: The Coupled Role of Hydrologic Flowpaths and Biogeochemical Processes in Controlling Solute Fluxes From Forested Watersheds
EPA Grant Number: U916154Title: Critical Landscape Interfaces: The Coupled Role of Hydrologic Flowpaths and Biogeochemical Processes in Controlling Solute Fluxes From Forested Watersheds
Investigators: Sebestyen, Stephen D.
Institution: SUNY Health Science Center at Syracuse
EPA Project Officer: Cobbs, Gladys M.
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $86,603
RFA: STAR Graduate Fellowships (2003)
Research Category: Academic Fellowships , Fellowship - Aquatic Ecology and Ecosystems , Aquatic Ecosystems
Description:
Objective:The objective of this research project is to focus on N (nitrogen) and its associations with dissolved organic carbon (DOC) and water cycles at the Sleepers River Research Watershed, Vermont, to determine: (1) how variations in soil C (carbon) and N pools, N transformations, and flowpath connections can explain N and DOC fluxes in stream water; and (2) how contributions from various N sources (different subbasins of the Sleepers River Research Watershed) contribute to lowland streams and how dominant transformations in subbasins control N loading. Biogeochemical processes control the movement and retention of solutes in watersheds. Notably, water chemistry can be reset by biogeochemical transformations that occur where electron donors and acceptors converge along flowpaths—the "hot spots" in space (e.g., riparian and hyporheic zones) and "hot moments" in time (e.g., during flushing events).
Approach:Through synoptic stream surveys and detailed event
sampling (rainfall and snowmelt), I will characterize N loads, sources, and
transformations that
influence N movement from landscapes to streams using new tracing techniques
(the isotopes of nitrate, 15N,
17O, and
18O). To characterize the spatial
distribution of nutrients across the watershed, I will measure soil C to N
ratios and the chemistry of stream, soil, and groundwaters (nutrients, DOC,
and cations). Hydrological connectivity of the landscape to the stream will
be determined through hydrometrics (water levels in wells, discharge and recharge
locations with piezometers, streamflow, and soil moisture) and hydrological
modeling (TOPMODEL). With these approaches, I will determine how nutrient sources
and biogeochemical transformations link N in the landscape to streams to understand
factors that influence the fate and transport of solutes from watersheds.
fellowship, biogeochemical processes, hydrologic flow paths, solute fluxes, forested watersheds, nitrogen, N, carbon, C, dissolved organic carbon, DOC, Sleepers River Research Watershed, Vermont, VT, nitrogen load, streamflow, groundwater, nutrients, nutrient sources, water cycles, soil
Relevant Websites:
2004 STAR Graduate Fellowship Conference Poster (PDF, 1p., 312KB, about PDF)