Spatial Synchrony of Predator-Prey Dynamics in Response to Cyclic Temperature Fluctuations

Date
2021-09-21
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Abstract
Spatial synchrony in populations occurs for many species, but is most apparent for species with populations that experience cyclic fluctuations. Population cycles can enhance the strength of synchrony-producing mechanisms by phase-locking cycles through dispersal events, or by entraining cycles to local cyclic environmental perturbations. Comparative evidence shows that density-dependent population regulation can differ spatially based on local environmental fluctuations that drive synchrony, but there is a lack of empirical evidence to further support this mechanism. This study looked to determine whether population cycles and cyclic environmental fluctuations impact the occurrence and persistence of spatial synchrony. A literature review was conducted that supported the relation between spatial synchrony and population cycles. A Rosenzweig-MacArthur model with oscillating density dependence was produced to establish expected results for empirical tests. Patches of microcosm jars were then cycled between different temperatures to create environmental perturbations on model protist species Tetrahymena pyriformis and Euplotes patella which generate predator-prey cycles. The population cycles were manipulated by varying media enrichment and temperature cycle period length to establish a threshold synchrony range. Model results show that spatial synchrony occurs at high amplitude cyclic environmental fluctuations with cycle periods that closely match to the cycle period of the populations that are being synchronized. Due to COVID-19 restrictions, the experiment could not be carried out as initially intended, and results reflect the limitations imposed. Results suggested by the model could not be replicated experimentally. Future directions are suggested for studies with no pandemic-related restrictions.
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Keywords
Population Cycles, Spatial Synchrony
Citation
Osterlund, K. B. (2021). Spatial Synchrony of Predator-Prey Dynamics in Response to Cyclic Temperature Fluctuations (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.