Author ORCID Identifier
Document Type
Thesis
Date of Award
2025
Degree Name
Master of Science (MS)
Department
Biology
First Advisor
Jeff Wesner
Abstract
The individual size distribution (ISD) is an individual based model that estimates the relative abundance of individual body sizes in a community. ISD’s slope or lambda (λ) gives insight into the communities’ food web and energy transfer. Climate change is expected to shift mean body sizes and λ as it increases individuals’ energy demands. Alterations in food webs and spatial distribution throughout the middle Missouri River basin may also have an impact on these communities λ. In a mesocosm experiment and field study, planktonic communities were sampled and had body sizes measured. Generalized linear mixed models were fit to calculate communities’ λ and mean body sizes. I found that planktonic communities have a stable λ despite increased temperatures, addition of fish, and spatial variation in the Middle Missouri River Basin. While λ was stable, these same communities had a wide range of mean body sizes in these studies. The mean body size changes might support the hypothesis with change in environment and energy demand, but the stability of λ does not. Stability of ISD suggests that the overall food webs are functioning at expected trophic efficiency and predator-prey ratio.
Subject Categories
Biology
Keywords
mesocosm predator-prey ratio ISD’s slope or lambda (λ)
Number of Pages
63
Publisher
University of South Dakota
Recommended Citation
Reynolds, Staci Ann, "Body size distributions of riverine freshwater plankton communities" (2025). Dissertations and Theses. 364.
https://red.library.usd.edu/diss-thesis/364