Dissertations and Theses @ UNI


Open Access Thesis


Typha--Effect of water pollution on; Typha--Identification; Invasive plants--Identification;


In the Midwestern United States, Typha x glauca is a hybrid of the native Typha latifolia and the non-native Typha angustifolia. Typha x glauca is considered invasive, and it is dominating Typha latifolia when they co-occur. Wetlands in the Midwest face nutrient pollution, due to fertilization used within the agricultural industry. Wetlands are nutrient sinks, which store the increased levels of nitrogen and phosphorus. These nutrients are known to increase Typha growth. Within this thesis, it was hypothesized that an increase of nitrogen in the wetland may increase the width of Typha leaves, making it difficult to distinguish the native Typha latifolia from the invasive Typha angustifolia and Typha x glauca. Other factors that may affect leaf width, such as the length of the leaf and whether or not the ramet was flowering were also analyzed. It was found that leaf length, nitrogen levels, flowering status, and taxa significantly impacted the leaf width of Typha taxa, making leaf width alone an unreliable identifier in the field.

A secondary potential cause of Typha invasion was examined through a simulation using the wetland modeling program MONDRIAN. Through MONDRIAN, the effects of differing nitrogen levels and rhizome branching probability in both monocultures of Typha and in a scenario with five different theoretical Typha taxa in competition with one another were analyzed. Typha taxa with a low rhizome branching probability had a higher growing season stem density and net primary productivity under high nutrient conditions than taxa with a high rhizome branching probability, regardless of whether taxa are grown in monoculture or in competition with one another.

Year of Submission


Degree Name

Master of Science


Department of Biology

First Advisor

Kenneth Elgersma, Chair, Thesis Committee

Date Original


Object Description

1 PDF file (vii, 40 pages)



File Format


Included in

Botany Commons