Soil Morphology and Carbon Stocks of Deflation Basin Wetlands in Eastern Nebraska, USA

Authors

Aubrey Grace Kemper, University of Nebraska-LincolnFollow

First Advisor

Judith K. Turk

Date of this Version

7-2021

Document Type

Article

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Natural Resource Sciences, Under the Supervision of Professor Judith K. Turk. Lincoln, Nebraska: July 2021

Copyright © 2021 Aubrey Grace Kemper

Abstract

Wetlands contribute important ecosystem services such as water filtration and storage, wildlife habitat, and carbon sequestration. The objective of this study is to compare the soil morphology and the carbon and nitrogen stocks between the upland, basin edge, and basin floor in playa wetlands of eastern Nebraska. This work was conducted in three deflation basin wetlands in the Todd Valley, a loess-mantled, former course of the Platte River, in eastern Nebraska. Soil morphological descriptions were evaluated to two meters’ depth using cores collected along three transects from the upland to the basin floor in three basins, carbon and nitrogen stocks were evaluated for each core, and particle size analysis determined for a subset of the cores. Results show evidence of colluviation, leaching and accumulation of pedogenic clay, and the presence of diffuse carbonates in one basin. Comparisons of carbon and nitrogen stocks between the basins and uplands showed varied trends between the three basins. One basin had the highest carbon and nitrogen stock in the uplands, another had the highest carbon and nitrogen stocks on the basin floor (due to a buried soil in the profile), and another showed no significant difference in carbon and nitrogen stocks in relation to transect position. Profile distributions of carbon suggest that the limited carbon storage in these wetlands is, at least in part, due to leaching losses of dissolved organic carbon. Future efforts toward wetland restoration in eastern Nebraska should consider what the soil morphology and characterization data indicate about the legacy of basin infilling, as well as carbon sequestration of these distinctive wetlands.

Advisor: Judith K. Turk