@article {2863,
	title = {Holocene Vegetation, Climate, and Carbon History on Western Kodiak Island, Alaska},
	journal = {Frontiers in Earth Science},
	volume = {7},
	year = {2019},
	month = {Sep-04-2019},
	abstract = {At Phalarope Pond, western Kodiak Island, a multidisciplinary study using pollen and spores, macrofossils, stable isotopes, and carbon accumulation provides the Holocene vegetation and climate history following the deglaciation that began over 16,000 cal years ago (yr BP). Following a cold and dry Younger Dryas, a warm and wet early Holocene was characterized by abundant ferns in a sedge tundra environment with maximum carbon accumulation, similar to high latitude peatlands globally. About 8,700 cal yr BP sedge and ferns declined and climate remained warm as drier conditions prevailed, limiting carbon sequestration. The abrupt shift in D/H isotopes of about 60\% indicates a shift to cooler conditions or a more distal moisture source. Neoglaciation beginning about 3,700 cal yr BP is evident from increases in Artemisia, Empetrum and Betula, signifying cooler conditions, while Alnus declines, paralleling regional trends.},
	doi = {10.3389/feart.2019.00061},
	url = {https://www.frontiersin.org/article/10.3389/feart.2019.00061/full},
	author = {Peteet, Dorothy M. and Nichols, Jonathan E. and Mann, Daniel H.}
}
@article {2786,
	title = {Younger-Dryas cooling and sea-ice feedbacks were prominent features of the Pleistocene-Holocene transition in Arctic Alaska},
	journal = {Quaternary Science Reviews},
	volume = {169},
	year = {2017},
	month = {Jan-08-2017},
	pages = {330 - 343},
	abstract = {Declining sea-ice extent is currently amplifying climate warming in the Arctic. Instrumental records at high latitudes are too short-term to provide sufficient historical context for these trends, so paleoclimate archives are needed to better understand the functioning of the sea ice-albedo feedback. Here we use the oxygen isotope values of wood cellulose in living and sub-fossil willow shrubs (δ18Owc) (Salix spp.) that have been radiocarbon-dated (14C) to produce a multi-millennial record of climatic change on Alaska{\textquoteright}s North Slope during the Pleistocene-Holocene transition (13,500{\textendash}7500 calibrated 14C years before present; 13.5{\textendash}7.5 ka). We first analyzed the spatial and temporal patterns of δ18Owc in living willows growing at upland sites and found that over the last 30 years δ18Owc values in individual growth rings correlate with local summer temperature and inter-annual variations in summer sea-ice extent. Deglacial δ18Owc values from 145 samples of subfossil willows clearly record the Aller{\o}d warm period (\~{}13.2 ka), the Younger Dryas cold period (12.9{\textendash}11.7 ka), and the Holocene Thermal Maximum (11.7{\textendash}9.0 ka). The magnitudes of isotopic changes over these rapid climate oscillations were \~{}4.5{\textperthousand}, which is about 60\% of the differences in δ18Owc between those willows growing during the last glacial period and today. Modeling of isotope-precipitation relationships based on Rayleigh distillation processes suggests that during the Younger Dryas these large shifts in δ18Owc values were caused by interactions between local temperature and changes in evaporative moisture sources, the latter controlled by sea ice extent in the Arctic Ocean and Bering Sea. Based on these results and on the effects that sea-ice have on climate today, we infer that ocean-derived feedbacks amplified temperature changes and enhanced precipitation in coastal regions of Arctic Alaska during warm times in the past. Today, isotope values in willows on the North Slope of Alaska are similar to those growing during the warmest times of the Pleistocene-Holocene transition, which were times of widespread permafrost thaw and striking ecological changes.},
	keywords = {alaska, Arctic, Bering Strait, Climate change, dendrochronology, north pacific, oxygen isotopes, Paleoclimate, Sea ice, Younger Dryas},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2017.05.012},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379117301713},
	author = {Gaglioti, Benjamin V. and Mann, Daniel H. and Wooller, Matthew J. and Jones, Benjamin M. and Wiles, Gregory C. and Groves, Pamela and Kunz, Michael L. and Baughman, Carson A. and Reanier, Richard E.}
}
@article { ISI:000342993200010,
	title = {Radiocarbon age-offsets in an arctic lake reveal the long-term response of permafrost carbon to climate change},
	journal = {JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES},
	volume = {119},
	number = {{8}},
	year = {2014},
	month = {AUG},
	pages = {1630-1651},
	type = {Article},
	abstract = {Continued warming of the Arctic may cause permafrost to thaw and speed the decomposition of large stores of soil organic carbon (OC), thereby accentuating global warming. However, it is unclear if recent warming has raised the current rates of permafrost OC release to anomalous levels or to what extent soil carbon release is sensitive to climate forcing. Here we use a time series of radiocarbon age-offsets (C-14) between the bulk lake sediment and plant macrofossils deposited in an arctic lake as an archive for soil and permafrost OC release over the last 14,500 years. The lake traps and archives OC imported from the watershed and allows us to test whether prior warming events stimulated old carbon release and heightened age-offsets. Today, the age-offset (2ka; thousand of calibrated years before A.D. 1950) and the depositional rate of ancient OC from the watershed into the lake are relatively low and similar to those during the Younger Dryas cold interval (occurring 12.9-11.7ka). In contrast, age-offsets were higher (3.0-5.0ka) when summer air temperatures were warmer than present during the Holocene Thermal Maximum (11.7-9.0ka) and BOlling-AllerOd periods (14.5-12.9ka). During these warm times, permafrost thaw contributed to ancient OC depositional rates that were similar to 10 times greater than today. Although permafrost OC was vulnerable to climate warming in the past, we suggest surface soil organic horizons and peat are presently limiting summer thaw and carbon release. As a result, the temperature threshold to trigger widespread permafrost OC release is higher than during previous warming events.},
	keywords = {carbon cycling, lake sediment, paleoclimatology, permafrost, radiocarbon, Younger Dryas},
	issn = {2169-8953},
	doi = {10.1002/2014JG002688},
	author = {Gaglioti, Benjamin V. and Mann, Daniel H. and Jones, Benjamin M. and Pohlman, John W. and Kunz, Michael L. and Wooller, Matthew J.}
}
