@article {2817,
	title = {Deglacial temperature controls on no-analog community establishment in the Great Lakes Region},
	journal = {Quaternary Science Reviews},
	volume = {234},
	year = {2020},
	month = {Jan-04-2020},
	pages = {106245},
	abstract = {Understanding the drivers of vegetation dynamics and no-analog communities in eastern North America is hampered by a scarcity of independent temperature indicators. We present a new branched glycerol dialkyl glycerol tetraether (brGDGT) temperature record from Bonnet Lake, Ohio (18{\textendash}8 ka) and report uncertainty estimates based on Bayesian linear regression and bootstrapping. We also reanalyze a previously published brGDGT record from Silver Lake, Ohio, using improved chromatographic methods. All pollen- and brGDGT-based temperature reconstructions showed qualitatively similar deglacial trends but varying magnitudes. Separating 5- and 6- methyl brGDGTs resulted in substantially lower estimates of deglacial temperature variations (6.4 {\textdegree}C) than inferred from earlier brGDGT methods and pollen (11.8 {\textdegree}C, 12.0 {\textdegree}C respectively). Similar trends among proxies suggest good fidelity of brGDGTs to temperature, despite calibration uncertainties. At both sites, the rise and decline of no-analog communities closely track brGDGT-inferred temperatures, with a lag of 0{\textendash}150 years. The timing of temperature and ecological events varies between Bonnet and Silver Lakes, likely due to age model uncertainties. Climate sensitivity analyses indicate a linear sensitivity of vegetation composition to temperature variations, albeit noisy and significant only with a 500-year bin. The formation of no-analog plant communities in the upper Midwest is closely linked to late-glacial warming, but other factors, such as temperature seasonality or end-Pleistocene megafaunal extinctions, remain viable.},
	keywords = {biomarkers, brGDGT, Climate sensitivity, Lagoons \& swamps, lakes, No-analog, North America, paleoclimatology, Pleistocene, pollen, sedimentology, Temperature, vegetation},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2020.106245},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379119303713},
	author = {Fastovich, David and Russell, James M. and Jackson, Stephen T. and Williams, John W.}
}
@article {2846,
	title = {Temperature variations in the southern Great Lakes during the last deglaciation: Comparison between pollen and GDGT proxies},
	journal = {Quaternary Science Reviews},
	volume = {182},
	year = {2018},
	month = {Jan-02-2018},
	pages = {78 - 92},
	abstract = {Our understanding of deglacial climate history in the southern Great Lakes region of the United States is primarily based upon fossil pollen data, with few independent and multi-proxy climate reconstructions. Here we introduce a new, well-dated fossil pollen record from Stotzel-Leis, OH, and a new deglacial temperature record based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) at Silver Lake, OH. We compare these new data to previously published records and to a regional stack of pollen-based temperature reconstructions from Stotzel-Leis, Silver Lake, and three other well-dated sites. The new and previously published pollen records at Stotzel-Leis are similar, but our new age model brings vegetation events into closer alignment with known climatic events such as the Younger Dryas (YD). brGDGT-inferred temperatures correlate strongly with pollen-based regional temperature reconstructions, with the strongest correlation obtained for a global soil-based brGDGT calibration (r2 = 0.88), lending confidence to the deglacial reconstructions and the use of brGDGT and regional pollen stacks as paleotemperature proxies in eastern North America. However, individual pollen records show large differences in timing, rates, and amplitudes of inferred temperature change, indicating caution with paleoclimatic inferences based on single-site pollen records. From 16.0 to 10.0ka, both proxies indicate that regional temperatures rose by \~{}10 {\textdegree}C, roughly double the \~{}5 {\textdegree}C estimates for the Northern Hemisphere reported in prior syntheses. Change-point analysis of the pollen stack shows accelerated warming at 14.0 {\textpm} 1.2ka, cooling at 12.6 {\textpm} 0.4ka, and warming from 11.6 {\textpm} 0.5ka into the Holocene. The timing of B{\o}lling-Aller{\o}d (B-A) warming and YD onset in our records lag by \~{}300{\textendash}500 years those reported in syntheses of temperature records from the northern mid-latitudes. This discrepancy is too large to be attributed to uncertainties in radiocarbon dating, and correlation between pollen and brGDGT temperature reconstructions rules out vegetation lags as a cause. However, the YD termination appears synchronous among the brGDGT record, regional pollen stack, and Northern Hemisphere stack. The cause of the larger and lagged temperature changes in the southern Great Lakes relative to Northern Hemisphere averages remains unclear, but may be due to the effects of continentality and ice sheet extent on regional climate evolution.},
	keywords = {Continental biomarkers, GDGT, Lagoons and Swamps, lakes, North America, paleoclimatology, Pleistocene, pollen, sedimentology},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2017.12.011},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379117306467},
	author = {Watson, Benjamin I. and Williams, John W. and Russell, James M. and Jackson, Stephen T. and Shane, Linda and Lowell, Thomas V.}
}
@article {57,
	title = {Inferring local to regional changes in forest composition from Holocene macrofossils and pollen of a small lake in central Upper Michigan},
	journal = {Quaternary Science Reviews},
	volume = {98},
	year = {2014},
	pages = {60-73},
	abstract = {Vegetational response to climatic change involves processes of population and community dynamics within local stands, which scale up to landscape-level changes in vegetation composition and broad-scale changes in species distributions. Understanding these dynamics poses a critical challenge to paleoecological explanation, because of the broad range of scales at which these dynamics take place and interact. We present an 8600-year paleoecological record of local and regional changes in forest composition from a small (2.6 ha) lake in central Upper Michigan. Plant macrofossils provide a spatially precise record of local forest composition, while pollen data provide a spatially integrated record of regional vegetational changes. Temporal patterns among different macrofossil types within species show overall coherence, indicating that changes in macrofossil abundance generally record changes in local tree abundance. Temporal patterns in macrofossil sequences correspond to patterns in pollen sequences, indicating that local changes contributed to the large-scale changes in the surrounding region. The pollen and macrofossil records show nearly continuous turnover in vegetation composition throughout the past 8600 years; the longest period without major compositional change was ca 1600 years, and dynamics at multidecadal to multicentennial scales are observed during many periods. Coordinated application of temporally precise sequences of pollen and macrofossil data at multiple sites can support inferences concerning vegetation dynamics at multiple spatial and temporal scales, and test mechanistic hypotheses.},
	issn = {0277-3791},
	doi = {10.1016/j.quascirev.2014.05.030},
	url = {http://www.sciencedirect.com/science/article/pii/S027737911400211X},
	author = {Jackson, Stephen T. and Booth, Robert K. and Reeves, Kelly and Andersen, Jennifer Jewell and Minckley, Thomas A. and Jones, Rachel A.}
}
@article {156,
	title = {Climatic and megaherbivory controls on late-glacial vegetation dynamics: a new, high-resolution, multi-proxy record from Silver Lake, Ohio},
	journal = {Quaternary Science Reviews},
	volume = {34},
	year = {2012},
	note = {id: 2141},
	pages = {66-80},
	abstract = {Novel plant assemblages are a long-recognized feature of late-glacial North America, but identifying their causes has been hampered by inaccurate radiocarbon chronologies and the multiplicity of ecological and climatic events during the late Pleistocene. Recently we reported that the formation of no-analog vegetation may have been linked to declines in Pleistocene megafaunal communities, based on pollen and spores from the coprophilous fungus Sporormiella at sites in Indiana and New York. We present a new, multi-proxy analysis from Silver Lake, OH, which 1) updates the radiocarbon chronology of a classic pollen record with a well-established zone of no-analog vegetation, 2) combines a new sub-centennial pollen record with charcoal, Sporormiella, and x-ray fluorescence (XRF) spectroscopy analyses for an integrated record of landscape change before, during, and after the period of no-analog vegetation, and 3) replicates both the absolute and relative temporal patterns of landscape change at Appleman Lake, IN. At Silver Lake, the decline in Sporormiella at 13.9 ka BP was immediately followed by the formation of novel plant assemblages, as well as the highest-magnitude charcoal peak in the record. Increased Ca and Sr concentrations during the no-analog interval indicate either increased moisture, increased input of nutrients from deciduous litter, or both. The duration of the no-analog assemblages (13.9{\textendash}11.8 ka BP) roughly corresponds to the period of peak insolation dissimilarity, but is more temporally constrained than previously reported in subcontinental-scale syntheses (17{\textendash}11 ka BP). We propose a hierarchy of controls on late-glacial plant communities, where biotic interactions such as megaherbivory mediate climate-driven vegetation change.},
	issn = {0277-3791},
	doi = {10.1016/j.quascirev.2011.12.008},
	url = {http://www.sciencedirect.com/science/article/pii/S027737911100401X},
	author = {Gill, Jacquelyn L. and Williams, John W. and Jackson, Stephen T. and Donnelly, Jeffrey P. and Schellinger, Grace C.}
}
