Author ORCID Identifier

https://orcid.org/0000-0002-5749-0544

Defense Date

2019

Document Type

Thesis

Degree Name

Master of Science

Department

Biology

First Advisor

Dr. Paul A. Bukaveckas

Abstract

To assess how urbanization impacts stream nutrient uptake, a series of instantaneous (i.e. slug) nutrient additions were conducted in 3 urban and 3 non-urban streams during open and closed canopy conditions. Single additions of N, P, and combined additions of N and P were performed at each site. These data were used to test the hypothesis that high N:P concentrations in urban streams would result in P-limited conditions, and to assess differences in nutrient uptake kinetics (i.e., the relationship between uptake and concentration) between urban and non-urban streams. The results show that there were no consistent differences in N vs. P limitation among urban and non-urban streams suggesting that ambient N:P ratios are not useful predictors of nutrient limitation at the ecosystem scale. Areal uptake rates of N in urban streams were greater than non-urban streams coinciding with elevated N concentrations. Conversely, areal uptake rates of P were similar between urban and non-urban streams because these systems have similar ambient concentrations of P. Urban and non-urban streams demonstrated similar uptake velocity and areal uptake rate responses to increasing nutrient concentrations. However, unique to this study, urban streams had greater uptake velocities at ambient nutrient concentrations. These findings suggest that urban streams could have a greater capacity for nutrient uptake over a broad range of nutrient concentrations, but prior work indicates that this capacity may be constrained by the duration of the nutrient addition.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

7-26-2019

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