Honors Program Theses
Award/Availability
Open Access Honors Program Thesis
First Advisor
Kenneth Elgersma
Abstract
Wetlands are essential ecosystems, playing major roles in nutrient cycling, water filtering, and erosion control, and providing important habitats for countless organisms. However, invasive species threaten their functions. One key invasive species in the Midwestern United States is Typha x glauca, a cattail species hybridized from the native T. latifolia and the invasive T. angustifolia. T. x glauca is visually intermediate between its parent species, making it difficult to identify and effectively manage. Ohsowski et al. (2024) presented a model to identify species, but due to its limited sample size (n = 33) and a high number of traits (14), the original model may be capturing random patterns in the dataset rather than robust morphological signals. I constructed two null models to evaluate the effectiveness of the model presented by Ohsowski et al. (2024). The first null model generated completely random data, while the second model generated data using spatially correlated transects. Using R, I ran 1000 iterations of each null model and compared the results to Ohsowski et al. (2024). The first model performed worse than Ohsowski et al. (2024), while the second model greatly outperformed it. This suggests that the success of the Ohsowski et al. (2024) model could have come from the transect structure of the data, rather than species differences. The results of the structured versus unstructured null models emphasize the importance of sample independence for studies on clonal species. In addition, I tracked the phenology of 20 pairs of hybrid cattails, with each pair containing a flowering and a nonflowering ramet. This allowed me to assess the effects of timing on measured variables. Further research will be needed to determine a better way to identify these species. This would benefit from a collaborative effort that emphasizes collecting samples from many independent locations.
Year of Submission
2026
Department
Department of Biology
University Honors Designation
A thesis submitted in partial fulfillment of the requirements for the designation University Honors
Date Original
2026
Object Description
1 PDF file (26 pages)
Copyright
©2026 Sydney Aird
Language
en
File Format
application/pdf
Recommended Citation
Aird, Sydney, "The Importance of Sample Timing and Independence for Typha Species Identification" (2026). Honors Program Theses. 1046.
https://scholarworks.uni.edu/hpt/1046
