How Forests Impact New Jersey’s Tick Population
Ticks are widespread in the New Jersey Pinelands. An understanding of their population dynamics in different habitats can guide management decisions and reduce the risk of tick-borne pathogen transmission for humans, pets, and livestock. The New Jersey Pinelands rely on a variety of forest management techniques for forest health and growth. Of these, forest thinning is especially important in areas where prescribed burning is not feasible or is impractical for desired management goals. Thinning drastically changes the microclimate of the forest, a parameter which plays a significant role in tick abundance and survival.
Through a collaboration with the Rutgers Pinelands Field Station, the Center for Vector Biology, the George H. Cook Scholars program, the United States Forest Service, and the Rutgers Center for Remote Sensing and Spatial Analysis, Julia Brennan (SEBS ‘22, ecology, evolution, and natural resources major) is studying the impacts of forest thinning on tick population abundance and pathogen prevalence in the New Jersey Pinelands. Under the guidance of George H. Cook advisers—Dina Fonseca, professor in the Department of Entomology, and Henry John-Alder, professor in the Department of Ecology, Evolution, and Natural Resources—Brennan will draw upon a variety of field and laboratory techniques to answer the question of how thinning impacts tick populations in the Pinelands.
For this George H. Cook thesis project, Brennan is conducting weekly surveys of tick population abundance during an eight-month period (March through October 2021) in thinned and unthinned forest stands in the New Jersey Pinelands. Tick surveys include both tick dragging and sweeping, during which ticks are collected using large swatches of white fabric, dragged or swept across the ground. Forest composition will be characterized within each thinned and unthinned site to investigate relationships of tick abundance and pathogen prevalence. Microclimate will be monitored through continuous collection of temperature and relative humidity data through the entire field study.
According to Brennan, forest characterization will include standard forest and understory inventory, seasonal leaf litter measurements, and species compositions. The land surface temperature of each stand will also be characterized through a collaboration with the Rutgers Center for Remote Sensing and Spatial Analysis.
During the study, pathogen prevalence will be measured by testing ticks for common tick-borne pathogens in order to understand how environmental parameters may influence not only population levels, but also disease transmission. Determination of drivers in tick population abundance and pathogen prevalence in accordance with forest thinning can inform forest management decisions as well as personal protection from tick-borne pathogens.