Can restoration of fire‐dependent ecosystems reduce ticks and tick‐borne disease prevalence in the eastern United States?

Abstract

Over the past century, fire suppression has facilitated broad ecological changes in the composition, structure, and function of fire-dependent landscapes throughout the eastern US, which are in decline. These changes have likely contributed mechanistically to the enhancement of habitat conditions that favor pathogencarrying tick species, key wildlife hosts of ticks, and interactions that have fostered pathogen transmission among them and to humans. While the longrunning paradigm for limiting human exposure to tick-borne diseases focuses responsibility on individual prevention, the continued expansion of medically important tick populations, increased incidence of tick-borne disease in humans, and emergence of novel tick-borne diseases highlights the need for additional approaches to stem this public health challenge. Another approach that has the potential to be a cost-effective and widely applied but that remains largely overlooked is the use of prescribed fire to ecologically restore degraded landscapes that favor ticks and pathogen transmission. We examine the ecological role of fire and its effects on ticks within the eastern United States, especially examining the life cycles of forest-dwelling ticks, shifts in regional-scale fire use over the past century, and the concept that frequent fire may have helped moderate tick populations and pathogen transmission prior to the so-called fire-suppression era that has characterized the past century. We explore mechanisms of how fire and ecological restoration can reduce ticks, the potential for incorporating the mechanisms into the broader strategy for managing ticks, and the challenges, limitations, and research needs of prescribed burning for tick reduction.

Forest-associated habitat variables influence human–tick encounters in the southeastern United States

“…Land management can alter tick populations by making areas more or less attractive to wildlife (Medlock et al 2013, Gallagher et al 2022). Oftentimes, human-modified habitats result in environments that support tick populations by promoting increased host use.…”

“…The geographic ranges of many tick species are expanding (Alkishe et al 2021, Eisen and Paddock 2021, Rochlin et al 2022), and this is likely associated with the continued increase in human tick encounters in the United States (US). In the southeastern US, lone star ticks ( Amblyomma americanum L.), American dog ticks ( Dermacentor variabilis Say), and blacklegged ticks ( Ixodes scapularis L.) are three commonly encountered tick species (Nieto et al 2018, Trout Fryxell and Vogt 2019, Gallagher et al 2022). Combined, these three species cause the majority of vector-borne diseases in the US (Beard et al 2021, Eisen and Paddock 2021).…”

Human risk to tick encounters in the southeastern United States estimated with spatial distribution modeling

“…For example, soil properties such as percent litter coverage and soil moisture are associated with A. americanum abundance [22,23]. Additionally, land management decisions (e.g., burning) were associated with decreased immature I. scapularis [24] and A. americanum populations [25,26]. Specifically prescribed burns reduce tick abundance by factors such as heat exposure or decrease in soil moisture [26].…”

Controlled Burning and its Effects on Shorea robusta (Sal) Regeneration in Dhansar Block Forest, Rautahat

“…In addition to suppressing certain species, forest fires also encourage other species, leading to changes in vegetation structure (Walters et al, 2004). Fire-tolerant plant species generally increased in abundance at the expense of those killed by fire (fire-sensitive plants) due to a considerable reduction in competition and possibly due to alternations in other conditions (Gallagher et al, 2022). Regeneration of post-fire trees depends on a variety of factors, from climate suitability to the characteristics of the microsite (Wooten et al, 2022).…”