Wildfires release terrestrial elements to the atmosphere as aerosols, and these events are becoming more frequent and intense in the Arctic boreal forest as the climate is warming. We quantified the impact of atmospheric deposition of aerosols from local wildfires on metal(loid) fluxes using macroscopic charcoal accumulation rates, historical fire mapping, and element concentrations in ²¹⁰Pb‐dated lake sediment from five subarctic lakes with small catchments. Lake sediments showed small but significant increases in fluxes (median = 5–10%) for 22 trace metals, metalloids, or major ions following fire events. The impact of wildfire aerosols on element fluxes was mostly due to short‐term (≤2 years) increasing sedimentation rate (6 ± 41% increase), whereas sediment element concentrations were not strongly impacted. Wildfire‐associated deposition to lake sediments was mainly composed of Ca, Al, Fe, Mg, K, Mn, and Na, which are major constituents of ash from burned biomass, but changes in sediment flux were greatest for Sb, As, Ni, Ba, Mn, Mo, and Sr compared to pre‐disturbance conditions. Compared to anthropogenic sources of pollution, wildfire‐associated atmospheric fluxes of metal contaminants to the lakes (e.g., Hg, Pb, As, Sb, and Cd) were low. This study provides quantitative estimates of wildfire impacts on atmospheric geochemical fluxes to subarctic lakes, which can be used for modeling larger‐scale impacts under changing fire regimes.

中文翻译：

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野火衍生的大气沉积到亚北极湖中的痕量金属（主离子）和主要离子的古植物学评估（加拿大西北地区）

野火以气溶胶的形式向大气释放地面元素，随着气候变暖，这些事件在北极北方森林中变得更加频繁和强烈。我们使用宏观的木炭积累速率，历史火图和^210中的元素浓度来量化局部野火在大气中沉积的气溶胶对金属（胶体）通量的影响来自五个弧形小流域的亚弧湖泊的含铅日期的湖泊沉积物。火灾发生后，湖中的沉积物显示22种痕量金属，准金属或主要离子的通量小而显着增加（中位数= 5-10％）。野火气溶胶对元素通量的影响主要是由于短期（≤2年）沉积速率增加（增加6±41％），而沉积物元素浓度并未受到强烈影响。野火引起的湖泊沉积物沉积主要由Ca，Al，Fe，Mg，K，Mn和Na组成，它们是燃烧后的生物质中灰分的主要成分，但Sb，As，Ni，Sb的沉积物通量变化最大。 Ba，Mn，Mo和Sr与干扰前的条件相比。与人为污染源相比，与野火相关的大气污染物通向湖泊的金属通量（例如，汞，铅，砷，锑，和Cd）较低。这项研究提供了野火对流向北极湖的大气地球化学通量的影响的定量估计，可用于模拟不断变化的火情下的更大范围的影响。