Document Type
Article
Publication Date
12-31-2025
Keywords
Stable isotopes, hydrologic variation, food web, dynamic stability, trophic position
Abstract
Food chain length (FCL) is a primary determinant of food web structure and is hypothesized to be influenced by habitat size, productivity, and disturbance. Understanding the environmental characteristics that determine food chain length can assist in understanding how food webs may be impacted due to changes in habitats and environmental characteristics. This study examines the impact of hydrologic disturbance on stream food webs when the top predator is constant. We analyzed FCL in less disturbed groundwater flashy streams and more disturbed runoff flashy streams using stable isotopes. Despite no difference in species richness or fish density, food chains in more disturbed streams had a lower FCL compared to food chains in more stable streams. Assemblage analysis showed that flow regime and drainage area significantly impacted individual species abundances. The more disturbed runoff flashy streams had higher proportions of primary consumer fish, such as the algivorous Campostoma sp. (Stonerollers), which likely drives the reduced FCL. Drainage area and land cover had non-significant relationships with FCL. Shifting community structure due to hydrologic variability likely leads to differences in diet of Micropterus dolomieu (Smallmouth Bass), and thus a difference in FCL.
Citation
Sorensen, S. F., & Magoulick, D. D. (2025). Disturbance is the primary determinant of food chain length when the top predator is constant. Journal of Freshwater Ecology, 40 (1) https://doi.org/10.1080/02705060.2025.2552789
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Comments
Web of Science
Taylor & Francis