Wildfire is the dominant natural disturbance agent in forests of the Greater Yellowstone Ecosystem, and can have long-lasting impacts on local landscapes and limnologic processes. We applied a multi-proxy paleolimnological approach to infer the impact of forest fires on the catchment of Island Lake, Wyoming (USA), over the last ~ 350 years. Specifically, we examined whether fossil diatom assemblages recorded indirect, limnological impacts from fire, including changes in water clarity, nutrient input, and lake mixing. The objective of this study was to determine if post-fire lake changes could be reconstructed effectively using fossil diatom assemblages from Island Lake, Wyoming, by comparing the diatom record to dendrochronological and macroscopic charcoal records. Local and regional fire years AD 1747 and 1900 were determined from tree-ring records, which were corroborated with sediment accumulation rates and magnetic susceptibility in Island Lake sediments. Inferred lacustrine conditions that were associated with fire events, particularly regional, mixed-severity fire year 1900, included increased turbidity, greater water column mixing, and possible augmented influx of total phosphorus to the system. Thus, the fossil diatom assemblage in Island Lake appears to have recorded forest fire activity indirectly, particularly when fire activity was severe or widespread within the catchment. An increase in small colonial Fragilaria (sensu lato) species since 1975, in association with the rise in abundance of Asterionella formosa and Tetracyclus glans , suggests recent changes in thermal stratification patterns, epilimnion temperatures, and available nutrients.

中文翻译：

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怀俄明州 Beartooth 山脉的景观-湖泊相互作用：350 年的火灾历史重建

野火是大黄石生态系统森林中主要的自然干扰因素，会对当地景观和湖泊过程产生长期影响。我们应用了多代理古湖泊学方法来推断森林火灾对怀俄明州（美国）Island Lake 集水区的影响，在过去 ~ 350 年间。具体而言，我们检查了化石硅藻组合是否记录了火灾的间接湖沼学影响，包括水透明度、养分输入和湖泊混合的变化。本研究的目的是通过将硅藻记录与树木年代学和宏观木炭记录进行比较，确定是否可以使用怀俄明州岛湖的化石硅藻组合来有效地重建火灾后湖泊的变化。公元 1747 年和 1900 年的局部和区域火灾年份是根据树轮记录确定的，这些记录与岛湖沉积物中的沉积物积累率和磁化率相一致。推断的与火灾事件相关的湖泊条件，特别是 1900 年的区域性混合严重性火灾，包括浊度增加、水柱混合增加以及总磷流入系统的可能增加。因此，Island Lake 中的化石硅藻组合似乎间接记录了森林火灾活动，特别是在集水区火灾活动严重或广泛时。自 1975 年以来，小型群落 Fragilaria (sensu lato) 物种的增加，与 Asterionella formosa 和 Tetracyclus glans 丰度的增加有关，表明热分层模式最近发生了变化，