Carbon Supply in a Subsurface Ecosystem: Sources, Patterns, and Response to Nitrogen LoadingEPA Grant Number: U915845
Title: Carbon Supply in a Subsurface Ecosystem: Sources, Patterns, and Response to Nitrogen Loading
Investigators: Gurwick, Noel P.
Institution: Cornell University
EPA Project Officer: Hahn, Intaek
Project Period: August 1, 2000 through August 1, 2003
Project Amount: $102,000
RFA: STAR Graduate Fellowships (2000) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology and Ecosystems
The goal of this research project is to compare carbon (C)-availability among morphologically distinct organic matter patches in C-poor subsurface soils below the water table and to use paired site comparisons to assess feedback between groundwater nitrogen (N) loading and root-derived (C)-supply in subsurface ecosystems.
To understand sources of microbially available C in subsurface riparian ecosystems, the investigator is conducting laboratory studies using aerobic incubations. Within-site spatial variation in C-availability is being assessed using 1-meter long soil cores taken from: (1) a transect through poorly-drained glacial outwash; and (2) a transect along a steep hydrology-vegetation gradient. These cores are also being used in combination with soil pits to characterize soil profiles, and to measure root biomass, total C, and soil particle size distribution. To assess variation in C-avalability among subsurface patches, characteristic patch material (e.g., lenses, buried horizons, root channels) is being incubated.
To assess feedback between N-loading and C-supply, root production, C-availability in soil, C:N ratios in belowground biomass, and in-situ decomposition rates will be compared between paired sites differing primarily in the magnitude of subsurface N-loads. This comparison will be interpreted as a long-term fertilization experiment. Root production will be measured using ingrowth cores, and root biomass will be measured using static cores to 1 meter.
This study is expected to result in a better understanding of microbially availalble C in subsurface riparian ecosystems.