Blacklegged tick population synchrony between oak forest and non-oak forest

Abstract:1.
Fluctuations in abundance of blacklegged ticks in space and time are
well-documented, but the extent to which populations fluctuate synchronously
across habitat types is poorly understood. In oak forests, blacklegged tick
density depends on small mammal abundance, which is in turn driven by
fluctuations in acorn production. It is currently unknown whether fluctuations
in tick abundance in oak forest, long understood to depend largely on masting
events, are shared with nearby non-oak forest.

2.
In this study, we analyzed 22 years of tick population data from nine forest
plots in southeastern New York in order to compare fluctuations of nymphal and
larval blacklegged tick populations in oak-dominant forests and non-oak
forests.

3.
We found that population peak densities of nymphal ticks were strongly
synchronous in oak and non-oak forests among years and that larval population
dynamics were weakly synchronous between these two forest types.

4.
Our results suggest that drivers of immature tick density in oak-dominant
forest, including climatic factors and mast-driven host dynamics, may also
influence tick population fluctuations in the surrounding landscape.Methods:Tick
collection was conducted at all grids from 1995 to 2016. Ticks were collected
from each grid by drag sampling using a 1m2 white corduroy drag
cloth (Ostfeld et al., 1996). Ticks were
identified by life stage, counted, and removed from the grid. Due to
differences in grid layout, ticks were removed every 30m on the oak-dominant
grids (450m2 total) and every 20m on the non-oak grids (400m2
total). Collection occurred approximately once every three weeks from April to
November.

摘要：1. 黑腿蜱种群在时空维度上的丰度波动已有详实记录，然而，其种群在各类生境中同步波动的程度仍鲜为人知。在橡树林中，黑腿蜱的密度依赖于小型哺乳动物的丰度，而小型哺乳动物的丰度则受橡实产量波动的影响。目前尚不清楚，在橡树林中，长期以来被认为主要依赖于结实事件的蜱种群丰度波动是否与邻近的非橡树林共享。2. 本研究分析了纽约东南部九个林地的22年蜱种群数据，以比较橡树林和橡树林以外生境中若虫和幼虫黑腿蜱种群的波动情况。3. 我们发现，若虫蜱的种群峰值密度在橡树林和非橡树林中在年度间表现出强烈的同步性，而在这两种森林类型之间，幼虫种群动态的同步性则较弱。4. 我们的研究结果表明，橡树林中未成熟蜱密度驱动因素，包括气候因素和由结实驱动的宿主动态，也可能影响周围景观中蜱种群波动。方法：从1995年到2016年，在所有网格点进行了蜱的采集。通过使用1平方米的白色帆布拖网（Ostfeld等人，1996年）进行拖网采样收集每个网格点的蜱。根据生活阶段对蜱进行鉴定、计数并将其从网格点移除。由于网格布局的不同，橡树林网格点上每30米移除一次（总面积450平方米），非橡树林网格点上每20米移除一次（总面积400平方米）。从4月到11月，大约每三周采集一次。