Prescribed Fire and Ticks in the New Jersey Pine Barrens
- Research Area:
- Science Theme:
- Forest Disturbance Processes
- Science Topic
- Science to support the National Fire and Fuels Strategy
Tick populations and reported incidence of tick-borne disease in humans have increased notably over the past half century in the eastern US. This is presumably due to changes in environmental conditions associated with forest fragmentation, climate change, broad shifts in forest composition and structure, as well as increased prevalence of white-tailed deer. In pine forests of the southeastern US, research has shown a strong link between reductions in tick encounters, and the prevalence of some tickborne diseases, and recurrent prescribed fire - a factor that was historically far more frequent and widespread throughout the eastern US than today.
Research across more ecosystems is needed to better understand the relationships between fire and ticks as well as the mechanisms that drive tick abundance. Researchers from the Northern Research Station, Penn State, Tall Timbers Research Station, and the Rutgers Center for Vector Biology are studying ticks and their habitat conditions in burned and unburned forests of the New Jersey Pinelands to better understand how prescribed fire may be useful for reducing local ticks that carry diseases.
Our research focuses on comparing tick populations and fire effects at the Northern Research Station’s Silas Little Experimental Forest and in the surrounding area of the New Jersey Pineland National Reserve. Contrary to many eastern landscapes, the New Jersey Pinelands has maintained a rich history of fire management and landscape-scale prescribed burning for public safety and ecological purposes throughout the past century and continues to today, providing a unique opportunity for replicated research on fire and ticks across many forests.
Researchers have been collecting ticks, measuring vegetation and detritus that ticks live in, and analyzing microclimates at 27 stands across the landscape that reflect a range of recent prescribed fire conditions as well as unburned forest conditions. The researchers’ intent is to compare tick population and disease prevalence estimates with tick habitat characteristics that are directly impacted by prescribed fire, including temperature and moisture conditions and the supply of physical structure required by ticks for hiding and for optimizing their chances of encountering a host.
With their experimental design, researchers are also able to examine how frequency and severity of fire may play into the effects they observe. The team expected to find mostly blacklegged ticks, the critical vector for Lyme disease, and hypothesized that tick populations and disease burdens would decrease with an increase in prescribed fire frequency and severity.
The team has completed its first year of work in 2019, with about 5,000 ticks sampled. Preliminary research results show a large initial decrease in ticks that is proportional to treatment severity. However, this pattern may be somewhat complicated due to a sporadic large hatch of larva in late 2019. Researchers are looking forward to continuing sampling the sites in 2020 to see how these patterns play out as time since fire increases. Researchers also found that treatments (e.g. No Fire, Low, Moderate, or High Severity) impacted forest structure and microclimates and are working to understand specifically how these changes in landscape condition vary and influence tick habitat. Interestingly, over 95 percent of all the ticks in all study areas found were lone star ticks (Amblyomma americanum), rather than blacklegged ticks (Ixodes scapularis), which were thought to be more common in the study area.
These preliminary results have been presented at local universities, regional land manager meetings, and to land management agencies, with two papers on the study currently under way. The study is expected to continue at least through the end of 2020 to account for potential recovery of tick populations.
- Michael Gallagher, USDA Forest Service, Northern Research Station, Research Ecologist
- Jesse Kreye, Penn State, College of Agricultural Sciences, Department of Ecosystem Science and Management
- Nicholas Skowronski, USDA Forest Service, Northern Research Station, Research Forester
- Andrea Egizi, Rutgers University Center for Vector Biology and Monmouth County Division of Mosquito Control
- Jeremy Webber, New Jersey Forest Fire Service
- Last modified: May 5, 2020