@article {5255, title = {A 1400-Year B{\o}lling-Aller{\o}d Tree-Ring Record from the U.S. Great Lakes Region}, journal = {Tree-Ring ResearchTree-Ring Research}, volume = {73}, year = {2017}, month = {2017/07/01}, pages = {102 - 112}, isbn = {1536-1098}, url = {https://doi.org/10.3959/1536-1098-73.2.102}, author = {Panyushkina, Irina P. and Leavitt, Steven W. and Mode, William N.} } @article {5236, title = {Deglacial hydroclimate for Midcontinental North America.}, journal = {Quaternary Research }, volume = {83}, year = {2015}, chapter = {336}, doi = {10.1016/j.yqres.2015.01.001 }, author = {Voelker, S.L and Stambaugh, M.C. and Guyette, R.P. and Feng, X. and Grimley, D.A. and Leavitt, S.W. and Panyushkina, I.P. and Grimm, E.C. and Marsicek, J.P. and Shuman, B. and Curry, B.B.} } @article {5239, title = {A dynamic leaf gas-exchange strategy is conserved in woody plants under changing ambient CO2: evidence from carbon isotope discrimination in paleo and CO2 enrichment studies}, journal = {Global Change Biology}, year = {2015}, doi = {10.1111/gcb.13102 }, author = {Voelker, S.L. and etal.} } @article {5238, title = {Tree-ring investigation of Holocene flood-deposited wood from the Oneida Lake watershed, New York State.}, journal = {Tree-Ring Research}, volume = {71}, year = {2015}, chapter = {83}, author = {Panyushkina, I.P. and Leavitt, S.W. and Domack, E.W. and Wiedenhoeft, A.C.} } @article {5237, title = {. Ancient boreal forests under the environmental instability of the glacial to post-glacial transition in the Great Lakes region (14,000-11,000 years BP)}, journal = {Canadian Journal of Forest Research }, volume = {43}, year = {2013}, chapter = {1032}, doi = {10.1139/cjfr-2012-0339}, author = {Panyushkina, I.P. and Leavitt, S.W.} } @article {5248, title = {Paleobotanical and environmental implications of a buried forest bed in northern Lower Michigan, USA}, journal = {Canadian Journal of Earth Sciences}, volume = {50}, year = {2013}, chapter = {483}, doi = {10.1139/cjes-2012-0115}, author = {Schaetzl, R.J. and Yansa, C.H. and Luehmann, M.D.} } @article {5228, title = {A high-resolution record of climate variability and landscape response from Kettle Lake, northern Great Plains, North America}, journal = {Quaternary Science Reviews}, volume = {30}, year = {2011}, month = {6/2011}, pages = {2626{\textendash}2650}, chapter = {2626}, abstract = {

A decadal-scale multiproxy record of minerals, pollen, and charcoal from Kettle Lake, North Dakota provides a high-resolution record of climate and vegetation change spanning the entire Holocene from the northern Great Plains (NGP) in North America. The chronology is established by over 50 AMS radiocarbon dates. This record exhibits millennial-scale trends evident in other lower-resolution studies, but with much more detail on short-term climate variability and on the rapidity and timing of major climatic shifts. As a proxy for precipitation, we utilize the rate of endogenic carbonate sedimentation, which depends on groundwater inflow, which in turn depends on precipitation. Independent cluster analyses of mineral and pollen data reveal major Holocene mode shifts at 10.73\ ka (ka\ =\ cal\ yr\ BP), 9.25\ ka, and 4.44\ ka.

The early Holocene, 11.7{\textendash}9.25\ ka, was generally wet, with perhaps a trend to higher evaporation associated with warming temperatures. A switch from calcite to aragonite deposition associated with a severe, but brief drought occurred at 10.73\ ka. From 10.73\ ka to 9.25\ ka, climate was generally humid but punctuated at 100{\textendash}300\ yr intervals by brief droughts, including the most severe drought of the entire Holocene at 9.25\ ka. This event was coeval with the 9.3{\textendash}9.2\ ka event in the Greenland ice cores and observed at a number of sites worldwide. In contrast, the prominent 8.2\ ka event in Greenland is not remarkable at Kettle Lake. The prominence of the 9.25 event locally in the NGP may be due to a major drawdown and northward retreat of Lake Agassiz at this time, reducing its mesoclimatic effect on the NGP and thrusting the region into an insolation controlled regime.

The mid-Holocene, 9.25{\textendash}4.44\ ka, was characterized by great variability in moisture on a multi-decadal scale, with severe droughts alternating with more humid periods. The high abundance of the weedy but drought intolerant Ambrosia generally during the mid-Holocene and specifically during the multi-decadal drought periods is seemingly paradoxical, but can be explained by high interannual variability of moisture overlaid on the multi-decadal variability.

The late Holocene, 4.44 ka{\textendash}present, was also characterized by multi-decadal variability in moisture, but was generally wetter than the mid-Holocene and the magnitude of variability was less. The trends in wet-dry mineral, pollen, and charcoal proxies were similar to the mid-Holocene, but late Holocene mineral-pollen assemblages are distinct from mid-Holocene. The shift to wetter climate in the late Holocene was more gradual than the abrupt shift to arid conditions 9.25\ ka, which may explain the asymmetric retreat and readvance of forest along the eastern margin of the NGP.

Precipitation variations in the NGP have been linked with Pacific and Atlantic sea-surface temperatures, and mid-Holocene drought in the NGP has been linked with sustained La Ni{\~n}a-like conditions in the Pacific. These linkages may explain the decadal- and millennial-scale variations seen in the NGP, but cause of the prominent century-scale variations remains elusive.

}, doi = {10.1016/j.yqres.2008.08.006}, author = {Grimm, Eric C. and Donovan, Joseph J. and Brown, Kendrick J.} } @article {5235, title = {Tapping Ancient Tree-Ring Archives in the U.S. Great Lakes Region.}, volume = {91 (50)}, number = {489}, year = {2010}, author = {Panyushkina, I.P. and Leavitt, S.W.} } @article {5250, title = {Stratigraphy, age, and flora of the Southport forest bed, Southeastern Wisconsin. }, journal = {Journal of Great Lakes}, volume = {35}, year = {2009}, chapter = {538}, author = {Schneider, A.F. and Leavitt, S.W. and Lange, T.} } @article {5225, title = {Environment and paleoecology of a 12 ka mid-North American Younger Dryas forest chronicled in tree rings}, journal = {Quaternary Research}, volume = {70}, year = {2008}, month = {11/2008}, pages = {433{\textendash}441}, chapter = {433}, abstract = {

Until now, availability of wood from the Younger Dryas abrupt cooling event (YDE) in N. America ca. 12.9 to 11.6 ka has been insufficient to develop high-resolution chronologies for refining our understanding of YDE conditions. Here we present a multi-proxy tree-ring chronology (ring widths, {\textquotedblleft}events{\textquotedblright} evidenced by microanatomy and macro features, stable isotopes) from a buried black spruce forest in the Great Lakes area (Liverpool East site), spanning 116\ yr at ca. 12,000\ cal yr BP. During this largely cold and wet period, the proxies convey a coherent and precise forest history including frost events, tilting, drowning and burial in estuarine sands as the Laurentide Ice Sheet deteriorated. In the middle of the period, a short mild interval appears to have launched the final and largest episode of tree recruitment. Ultimately the tops of the trees were sheared off after death, perhaps by wind-driven ice floes, culminating an interval of rising water and sediment deposition around the base of the trees. Although relative influences of the continental ice sheet and local effects from ancestral Lake Michigan are indeterminate, the tree-ring proxies provide important insight into environment and ecology of a N. American YDE boreal forest stand.

}, issn = {00335894}, doi = {10.1016/j.yqres.2008.08.006}, author = {Irina P. Panyushkina and Steven W. Leavitt and Todd A. Thompson and Allan F. Schneider and Todd Lange} } @article {5226, title = {Tree rings, δ13C and climate in Picea glauca growing near Churchill, subarctic Manitoba, Canada. }, journal = {Chemical Geology}, volume = {252}, year = {2008}, month = {05/2007}, pages = {1212{\textendash}1222}, chapter = {88}, abstract = {

How fast and how much climate can change has significant implications for concerns about future climate changes and their potential impacts on society. An abrupt climate change 8200 years ago (8.2\ ka event) provides a test case to understand possible future climatic variability. Here, methane concentration (taken as an indicator for terrestrial hydrology) and nitrogen isotopes (Greenland temperature) in trapped air in a Greenland ice core (GISP2) are employed to scrutinize the evolution of the 8.2\ ka event. The synchronous change in methane and nitrogen implies that the 8.2\ ka event was a synchronous event (within {\textpm}4 years) at a hemispheric scale, as indicated by recent climate model results [Legrande, A. N., Schmidt, G. A., Shindell, D. T., Field, C. V., Miller, R. L., Koch, D. M., Faluvegi, G., Hoffmann, G., 2006. Consistent simulations of multiple proxy responses to an abrupt climate change event. Proceedings of the National Academy of Sciences 103, 837{\textendash}842]. The event began with a large-scale general cooling and drying around \~{}8175{\textpm}30 years BP (Before Present, where Present is 1950 AD). Greenland temperature cooled by 3.3{\textpm}1.1\ {\textdegree}C (decadal average) in less than \~{}20 years, and atmospheric methane concentration decreased by \~{}80{\textpm}25\ ppb over \~{}40 years, corresponding to a 15{\textpm}5\% emission reduction. Hemispheric scale cooling and drying, inferred from many paleoclimate proxies, likely contributed to this emission reduction. In central Greenland, the coldest period lasted for \~{}60 years, interrupted by a milder interval of a few decades, and temperature subsequently warmed in several steps over \~{}70 years. The total duration of the 8.2\ ka event was roughly 150 years.

}, doi = {10.1016/j.chemgeo.2008.01.015}, author = {Tardif, J.C. and Conciatori, F. and Leavitt, S.W.} } @inbook {5240, title = {Insights into Late Pleistocene{\textendash}Early Holocene Paleoecology from fossil wood around the Great Lakes region. In: Late-Glacial History of East-central Wisconsin}, booktitle = {Late-Glacial History of East-central Wisconsin. }, year = {2007}, edition = { T.S. Hooyer}, author = {Panyushkina, I.P. and Leavitt, S.W.} } @inbook {5241, title = {Late-glacial and early Holocene paleoecology: Schneider farm, Calumet County. In: Late-Glacial History of East-central Wisconsin}, booktitle = {Late-Glacial History of East-central Wisconsin}, year = {2007}, edition = {T.S. Hooyer}, author = {Mode, W.N. and Panyushkina, I.P. and Leavitt, S.W. and Williams, J.W. and Santiago, A. and Gill, J. and Edwards, C. and Gertz, H.} } @article {5234, title = {Radiocarbon {\textquotedblleft}wiggles{\textquotedblright} in Great Lakes wood ca. 10,000 to 12,000 BP}, journal = {Radiocarbon}, volume = {49}, year = {2007}, chapter = {855}, author = {Leavitt, S.W. and Panyushkina, I.P. and Lange, T. and Cheng, L. and Schneider, A.F. and Hughes, J.} } @article {5227, title = {Response to Comment on {\textquotedblleft}Redefining the Age of Clovis: Implications for the Peopling of the Americas{\textquotedblright}}, journal = {Science}, volume = {317}, year = {2007}, month = {07/2007}, pages = {320c - 320c}, issn = {0036-8075}, doi = {10.1126/science.1142812}, author = {Waters, M. R. and Stafford, T. W.} } @article {5232, title = {Climate in the Great Lakes region between 14,000 and 4,000 years ago from isotopic composition of conifer wood}, journal = {Radiocarbon}, volume = {48}, year = {2006}, chapter = {205}, author = {Leavitt, S.W. and Panyushkina, I.P and Lange, T. and Wiedenhoeft, A. and Cheng, L. and Hunter, R.D.} } @article {5229, title = {A multiproxy environmental investigation of Holocene wood from a submerged conifer forest in Lake Huron, USA}, journal = {Quaternary Research}, volume = {66}, year = {2006}, month = {07/2006}, pages = {67{\textendash}77}, chapter = {67}, abstract = {

Remains of a Holocene drowned forest in southern Lake Huron discovered in 12.5\ m of water (164\ m above sea level), 4.5\ km east of Lexington, Michigan USA (Sanilac site), provided wood to investigate environment and lake history using several proxies. Macrofossil evidence indicates a forest comprised primarily of conifers equivalent to the modern {\textquotedblleft}rich conifer swamp{\textquotedblright} community, despite generally low regional abundance of these species in pollen records. Ages range from 7095 {\textpm} 50 to 6420 {\textpm} 70 14C yr BP, but the clustering of stump dates and the development of 2 floating tree-ring chronologies suggest a briefer forest interval of no more than c. 400 years. Dendrochronological analysis indicates an environment with high inter-annual climate variability. Stable-carbon isotope composition falls within the range of modern trees from this region, but the stable-oxygen composition is consistent with warmer conditions than today. Both our tree-ring and isotope data provide support for a warmer environment in this region, consistent with a mid-Holocene thermal maximum. This drowned forest also provides a dated elevation in the Nipissing transgression at about 6420 14C yr BP (7350 cal yr BP) in the southern Lake Huron basin, a few hundred years before reopening of the St. Clair River drainage.

}, doi = {10.1016/j.yqres.2006.03.008}, author = {Hunter, R. Douglas and Panyushkina, Irina P. and Leavitt, Steven W. and Wiedenhoeft, Alex C. and Zawiskie, John} } @article {5230, title = {Tree-ring records of near-Younger Dryas time in Central North America- preliminary results from the Lincoln quarry site, central Illinois, USA}, journal = {Radiocarbon}, volume = {46}, year = {2004}, chapter = {933}, author = {Panyushkina, I.P. and Leavitt, S.W. and Wiedenhoeft, A. and Noggle, S. and Curry, B. and Grimm, E.} } @article {5249, title = {A buried spruce forest provides evidence at the stand and landscape scale for the effects of environment on vegetation at the Pleistocene/Holocene boundary}, journal = {Journal of Ecology}, volume = {88}, year = {2000}, chapter = {45}, doi = {10.1046/j.1365-2745.2000.00432.x. }, author = {Pregitzer, K.S. and Reed, D.D. and Bornhorst, T.J. and Foster, D.R. and Mroz, G.D. and McLachlin, J.S. and Laks, P.E., and Stokke, D.D., and Martin, P.E., and Brown, S.E.} } @article {5247, title = {Age verification of the Lake Gribben forest bed and the Younger Dryas Advance of the Laurentide Ice Sheet.}, journal = {Canadian Journal of Earth Sciences}, volume = {36}, year = {1999}, chapter = {383}, doi = {10.1139/e98-095}, author = {Lowell, T.V. and Larson, G.J. and Hughes, J.D. and Denton, G.H.} }