Spatiotemporal dynamics of ticks and tick-borne disease at NEON sites across a sub-continental scale
Date of Award
Spring 6-10-2023
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Biological Science
First Advisor
Jalene LaMontagne, PhD
Second Advisor
Benjamin Zuckerberg, PhD
Third Advisor
Windsor Aguirre, PhD
Abstract
Tick-borne diseases in humans such as Lyme disease cases in the United States have doubled between 2004 and 2016. Understanding the dynamics of infectious diseases has long been of interest for ecologists. Tick and tick-borne diseases are influenced by temperature and precipitation at local scales, indirectly through mast seeding in forest trees which increases the abundance of tick hosts (e.g., small mammals), as well as direct effects on survival. Most tick studies occur at local scales that comprise only a small part of their range. The aim of my thesis is to characterize spatiotemporal dynamics of ticks and tick-borne diseases in the eastern United States. I used datasets from National Ecological Observatory Network (NEON) from 2014 to 2021 to quantify the level of synchrony in tick dynamics in seven NEON Domains, representing different ecoregions, and spanning distances up to 2,000 km. I used multiple regression matrices (MRM) to examine patterns of synchrony across sites in regional to sub-continental patterns of host-seeking ticks, and climatic variation. I found that spatial synchrony in temporal patterns of nymph abundance for both Amblyomma americanum and Ixodes scapularis declined with increasing distance between NEON sites. Weather variables associated with the spatiotemporal dynamics and key predictors of ticks and tick-borne diseases vary between the two species. A. americanum was driven by lags in July temperature differences, ∆T3 (difference in mean July temperatures in year t-3 and t-4) and ∆T4 (difference in mean July temperatures in year t-4 and t-5); and January conditions impacted tick survival for I. scapularis. The proportion of nymph-infected ticks was explained by environmental factors for the genus A. americanum. Whereas, for I. scapularis proportion of infected nymphs we were unable to explain. Nymph abundance and tick-borne diseases could be understood by identifying environmental variables influencing tick spatiotemporal patterns, allowing for potential prediction of a future tick outbreak.
Recommended Citation
Rivera, Ana Sofia, "Spatiotemporal dynamics of ticks and tick-borne disease at NEON sites across a sub-continental scale" (2023). College of Science and Health Theses and Dissertations. 467.
https://via.library.depaul.edu/csh_etd/467
SLP Collection
no