Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA.
WRA Inc., San Rafael, CA.
J Med Entomol. 2021 May 15;58(3):1171-1187. doi: 10.1093/jme/tjaa297.
Timber harvest may impact tick-borne disease by affecting small mammal and tick community structures. We assessed tick and small mammal populations in older second-growth redwood (Sequoia sempervirens (D. Don) Endl) habitat at two harvested sites in Santa Cruz County, California, where local risk of tick-borne disease is high and determined the prevalence of tick-borne pathogens in ticks. After single-tree removal harvest in 2014, there was a modest reduction in canopy, primarily toward the end of the study. Harvested sites showed strong reductions in California mouse (Peromyscus californicus, (Gambel)) captures 2-yr after harvest, resolving such that treatments and controls were comparable by the end of the study. Following harvest, treated sites experienced a transient decreased tick infestation while control plots experienced an increase. Ixodes angustus (Neumann) infestation probability on harvested plots decreased immediately after harvest, increasing with time but remaining lower than control plots, whereas I. pacificus (Cooley and Kohls) prevalence was higher shortly after the harvest on harvested plots, and continued to increase. Mean abundance of ticks on vegetation increased on control plots. We detected Borrelia burgdorferi ((Johnson et al.) Baranton) and Anaplasma phagocytophilum ((Foggie 1949) Dumler) in 3.8 and 3.1% of ticks on rodents, but no differences were associated with harvest. Impacts of forest harvest on tick-borne disease depend on removal practice and intensity, whether or not hosts are habitat specialists, and whether or not ticks are host specialists.
采伐可能通过影响小型哺乳动物和蜱虫群落结构来影响蜱传疾病。我们评估了加利福尼亚州圣克鲁斯县两个已采伐地点的较老第二代红杉（Sequoiasempervirens(D.Don)Endl）栖息地中的蜱虫和小型哺乳动物种群，该地区蜱传疾病的当地风险较高，并确定了蜱虫中的蜱传病原体的流行率。在 2014 年进行单株采伐后，树冠适度减少，主要是在研究结束时。在收获后 2 年内，收获点的加利福尼亚鼠（Peromyscuscalifornicus，（Gambel））捕获量大幅减少，到研究结束时，处理组和对照组之间的差异不再明显。收获后，处理组的蜱虫感染率暂时下降，而对照组的蜱虫感染率则上升。收获后，收获区的窄扇头蜱（Ixodesangustus（Neumann））侵染概率立即下降，随着时间的推移而增加，但仍低于对照组，而太平洋硬蜱（Ixodes pacificus（Cooley andKohls））的流行率在收获后不久在收获区更高，并持续增加。在对照组中，植被上的蜱虫平均丰度增加。我们在啮齿动物上的 3.8%和 3.1%的蜱虫中检测到了伯氏疏螺旋体（Borrelia burgdorferi（（Johnsonetal.）Baranton））和无形体（Anaplasmaphagocytophilum（（Foggie1949）Dumler）），但与收获无关。森林采伐对蜱传疾病的影响取决于采伐方式和强度、宿主是否为栖息地专家以及蜱虫是否为宿主专家。
