Earth and Atmospheric Sciences, Department of


First Advisor

Dr. Jessica Corman

Date of this Version

Spring 5-12-2020


Precious Nyabami, 2020


This was an undergraduate senior Thesis


The importance of reservoirs in widely acknowledged by urban population, yet little is understood scientifically about their ability to process nutrients deposited into them in winter. Nutrients in waste water, lawns and construction runoff are deposited into reservoirs and several ecosystem services are lost which leads to what several researchers call “the urban syndrome”. Some studies have been done on the winter limnology of lakes, yet little is understood about the same process in reservoirs. To fill this missing knowledge gap, a study on one of Nebraska’s lakes (Holmes’ lake) was done. In this study, we simulated how phosphorus, nitrogen and trace nutrients addition would influence this lake’s phytoplankton growth in winter. We found that adding nutrients in a combination significantly increased gross primary production (p<0.1 in the Phosphorous+ Trace element treatment) and net primary production. In single nutrient additions we visually observed higher GPP, NPP in phosphorous and trace elements though this was not statistically significant. In this study we observed that addition of nutrients had no significant influence on extracellular respiration. These results provide ample evidence to suggest that phytoplankton activity continues in winter and Holmes’ lake is nutrient co-limited.

Advisor: Dr. Jessica Corman