Abstract
The purposes of this study are to 1) quantify the shifts in the macrophyte community structure of five lakes in Sibley County, and 2) to assess the relationships between the macrophyte communities and abiotic factors in these five lakes. In both the early and late growing season of 2019, point-intercept surveys were conducted on High Island Lake, Titlow Lake, Schilling Lake, Silver Lake, and Clear Lake. At each point, water depth was recorded, and all macrophytes sampled were identified and recorded as “present.” There was not a late season survey conducted for High Island Lake in 2019 due to a dewatering event in the middle of the growing season. The macrophyte community shifts in individual lakes during the growing season were quantified by comparing the species presence/absence and mean species richness in the early season to the late season. Additionally, in the early season, a sediment core was retrieved at each point for analysis. All sediment cores were analyzed for particle size and sediment organic matter using the hydrometer method and loss on ignition respectively. In order to assess the relationships between the macrophyte community and abiotic factors at individual lakes, generalized linear regressions were ran with the mean species richness as the dependent variable and water depth, distance from shore, percent sand, percent silt, percent clay, and percent sediment organic matter as explanatory variables. In models where the residuals were spatially autocorrelated, a geographically weighted regression was ran using the variables of the highest performance model. The analyses of the macrophyte community shifts suggest that macrophyte phenology is a primary factor that affects the shifts in community structure over the growing season. The generalized linear regressions identify water depth, distance from shore, and percent silt as significant predictors of mean species richness in multiple models. Water depth and distance from shore are both negatively related to mean species richness in multiple models. Whether silt is positively or negatively related to mean species richness is dependent on the species composition of that lake.
Advisor
Ryan M. Wersal
Committee Member
Matthew A. Kaproth
Committee Member
Mark W. Bowen
Date of Degree
2021
Language
english
Document Type
Thesis
Degree
Master of Science (MS)
Department
Biological Sciences
College
Science, Engineering and Technology
Recommended Citation
Schmid, S. A. (2021). Aquatic macrophyte communities in five Sibley County (Minnesota) lakes and the factors that affect their distribution [Master’s thesis, Minnesota State University, Mankato]. Cornerstone: A Collection of Scholarly and Creative Works for Minnesota State University, Mankato. https://cornerstone.lib.mnsu.edu/etds/1112/
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
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