@article {2637,
	title = {Evidence of Ice Age humans in eastern Beringia suggests early migration to North America},
	journal = {Quaternary Science Reviews},
	volume = {205},
	year = {2019},
	month = {Jan-02-2019},
	pages = {35 - 44},
	abstract = {Our understanding of the timing and pathway of human arrival to the Americas remains an important and polarizing topic of debate in archaeology and anthropology. Traditional consensus, supported by archaeological and paleoenvironmental data, favors a {\textquoteright}swift peopling{\textquoteright} of the Americas from Asia via the Bering Land Bridge during the last Glacial termination. More recent genetic data and archaeological finds have challenged this view, proposing the {\textquoteright}Beringian standstill hypothesis{\textquoteright} (BSH), wherein a population of proto-Americans migrated from Asia during, or even prior to the Last Glacial Maximum (LGM) and lived in Beringia for thousands of years before their eventual spread across the American continents. Using a sediment archive from Lake E5 (68.641667 degrees N, 149.457706 degrees W), located on Alaska{\textquoteright}s North Slope, we present new data supporting the BSH and shedding new light on the environmental impact of these early American populations. Fecal biomarkers support human presence in the environs of the lake, and our data demonstrate elevated biomass burning in this region during the last Glacial. Elevated burning defies the expectation that natural fires would be less frequent in the Arctic during the last Glacial, thereby suggesting human ignition as the likely culprit. Our data shed new light on the pathway and timing of human migration to the Americas and demonstrate the possibility of the sustainable coexistence of humans and the Ice Age megafauna in Beringia prior to their extinction. (C) 2018 Elsevier Ltd. All rights reserved.},
	keywords = {Beringia, charcoal, Fecal sterols, Last Glacial, Paleofire, Polycyclic aromatic hydrocarbons (PAHs)},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2018.12.003},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379118307716https://api.elsevier.com/content/article/PII:S0277379118307716?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0277379118307716?httpAccept=text/plain},
	author = {Vachula, Richard S. and Huang, Yongsong and Longo, William M. and Dee, Sylvia G. and Daniels, William C. and Russell, James M.}
}
@article {2857,
	title = {Temperature-controlled tundra fire severity and frequency during the last millennium in the Yukon-Kuskokwim Delta, Alaska},
	journal = {The Holocene},
	volume = {29},
	year = {2019},
	month = {Jan-07-2019},
	pages = {1223 - 1233},
	abstract = {Wildfire is an important disturbance to Arctic tundra ecosystems. In the coming decades, tundra fire frequency, intensity, and extent are projected to increase because of anthropogenic climate change. To more accurately predict the effects of climate change on tundra fire regimes, it is critical to have detailed knowledge of the natural frequency and extent of past wildfires and how they responded to past climate variability. We present analyses of fire frequency and temperature from a lake sediment core from the Yukon-Kuskokwim (YK) Delta. Our ca. 1000 macroscopic charcoal record shows more frequent but possibly less severe tundra fires during the first half of the last millennium, whereas less frequent, possibly more severe fires characterize the latter half. Our temperature reconstruction, based on distributional changes of branched glycerol dialkyl glycerol tetraethers (brGDGTs), shows slightly warmer conditions from ca. AD 1000 to 1500, and cooler conditions thereafter (ca. AD 1500 to 2000), suggesting that fire frequency increases when climate is relatively warmer in this region. When wildfires occur more frequently, fire severity may decrease because of limited biomass (fuel source) accumulating between fires. The data suggest that tundra ecosystems are highly sensitive to climate change, and that a warmer climate, which is predicted to develop in the near future, will result in more frequent tundra wildfires.},
	keywords = {alaska, Arctic, charcoal, glycerol dialkyl glycerol tetraethers (GDGTs), late-holocene, Paleoclimate, Paleofire},
	issn = {0959-6836},
	doi = {10.1177/0959683619838036},
	url = {http://journals.sagepub.com/doi/10.1177/0959683619838036},
	author = {Sae-Lim, Jarunetr and Russell, James M and Vachula, Richard S and Holmes, Robert M and Mann, Paul J and Schade, John D and Natali, Susan M}
}
