@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 {2790,
	title = {Ecological history of a long-lived conifer in a disjunct population},
	journal = {Journal of Ecology},
	volume = {106},
	year = {2018},
	month = {Jan-01-2018},
	pages = {319 - 332},
	abstract = {    In northern Idaho (USA), more than 100 vascular plant species are disjunct >160 km from their main distribution along the Pacific Northwest coast. It remains unclear whether most species within this interior forest disjunction, including Tsuga mertensiana, survived the last glacial period in a north-Idaho refugium or whether these species colonized the region via long-distance dispersal during the Holocene.
    Sediment cores were extracted from three mid- to high-elevation lakes within T. mertensiana-dominated forests in the Northern Rocky Mountains of Idaho. Pollen and macrofossils were used to reconstruct forest composition, determine the timing of T. mertensiana establishment, examine the hypothesis that the region was a glacial refugium, and contrast how climate, competition and/or dispersal limitation have influenced its modern distribution.
    The modern distribution of T. mertensiana was analysed by constructing a range map and modelling the potential species distribution. The presence of outlier populations surrounding the Idaho disjunction along with broad areas of unoccupied suitable habitat indicates that the range of T. mertensiana is currently expanding. To assess the accuracy of T. mertensiana pollen at detecting its range limit, a network of pollen surface samples was used to analyse the probability of detecting T. mertensiana pollen as a function of distance from its geographical range limit. Consistent T. mertensiana pollen occurrence at >=1\% abundance is likely only within 42 km of its range limit.
    Tsuga mertensiana first appears in the pollen and macrofossil record at the highest-elevation site at c. 4,100 cal year bp, then at the next highest-elevation site at c. 1,600 cal year bp, and last at the mid-elevation site at 800 cal year bp. Tsuga mertensiana pollen occurs continuously at >=1\% at all three sites by c. 300 cal year bp suggesting regional presence. The timing of arrival suggests that T. mertensiana is a recent component of the forests of Idaho, having arrived during the Holocene via long-distance dispersal from coastal populations over 160 km away.
    Synthesis. Comparison with palaeoclimate reconstructions from the broader region suggests that climate was a greater limiting factor than dispersal in the Holocene establishment in the interior, indicating little difficulty overcoming a large dispersal barrier. However, T. mertensiana remained at low abundances for millennia until Little Ice Age climates promoted its recent increase in abundance. Unoccupied areas of suitable habitat suggest that competition, rather than climate or dispersal, is a limiting range infilling in the interior mesic forests today.
},
	keywords = {climate, disjunction, dispersal, Holocene, Idaho, mertensiana, Palaeoecology, pollen, refugia, Tsuga},
	doi = {10.1111/1365-2745.12826},
	url = {https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2745.12826},
	author = {Herring, Erin M. and Gavin, Daniel G. and Dobrowski, Solomon Z. and Fernandez, Matias and Hu, Feng Sheng},
	editor = {Gill, Jacquelyn}
}
@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 {2844,
	title = {A 7000-year history of coastal environmental changes from Mexico{\textquoteright}s Pacific coast: A multi-proxy record from Laguna Mitla, Guerrero},
	journal = {The Holocene},
	volume = {27},
	year = {2017},
	month = {Sep-08-2017},
	pages = {1214 - 1226},
	abstract = {The lack of multi-millennial multi-proxy paleoenvironmental reconstructions from Mexico{\textquoteright}s Pacific coast has limited our understanding of the regional response to climate change and sea-level rise. A 479-cm core covering the last 6900 years was extracted from Laguna Mitla in the state of Guerrero on Mexico{\textquoteright}s Pacific coast. Beginning as a Rhizophora-dominated salt pan ~6900 yr BP, at ~6500 yr BP, the site transitioned to a mangrove swamp dominated by Laguncularia, which lasted about 300 years. The beach barrier formed from ~6200 to 5200 yr BP, during which time, the site existed as an intermittently sheltered bay, the result of large, rapid changes in wave energy associated with the shifting barrier location and changes in stability. After the beach barrier was stabilized at ~5200 yr BP, water level at the coring site became a function of precipitation rather than sea level. Since that time, deposition has alternated between peat, laid down in a mangrove swamp, and clay intervals characterized by high concentrations of titanium and a predominantly regional pollen signal, representing open-water lagoon phases. Seven periods of increased water level, varying in duration, occurred during the backbarrier period, with El Ni{\~n}o-Southern Oscillation (ENSO) likely the main climatic mechanism causing these periodic shifts in the paleo-precipitation levels. We suggest that the deepest water levels detected over the last ~3200 years correlate with periods of increased ENSO activity. The spatial distribution of tropical cyclone rainfall, which represents a significant percentage of total annual precipitation along Mexico{\textquoteright}s Pacific coast, may explain the inconsistencies between our record and paleoclimatic records from Mexico{\textquoteright}s interior, but more work is needed to test this hypothesis.},
	keywords = {El Nino-Southern Oscillation, Laguna Mitla, mangroves, Pacific coast of Mexico, Paleoclimate, paleoenvironmental reconstruction, pollen, Sediment, tropical cyclones, x-ray fluorescence},
	issn = {0959-6836},
	doi = {10.1177/0959683616687379},
	url = {http://journals.sagepub.com/doi/10.1177/0959683616687379},
	author = {Bianchette, Thomas A and McCloskey, Terrence A and Liu, Kam-biu}
}
@article {2447,
	title = {Holocene variability in hydrology, vegetation, fire, and eolian activity in the Nebraska Sand Hills, USA},
	journal = {The Holocene},
	volume = {23},
	year = {2013},
	month = {Jan-04-2013},
	pages = {515 - 527},
	abstract = {This study combined multiple aquatic and terrestrial proxies, including diatoms, pollen, grain size, and bulk-sediment chemistry to reconstruct the history
of three lake sites located in the central Sand Hills of Nebraska, USA. Long-term changes in effective moisture are evident at all sites, with significant
changes occurring at ~6000, ~4000, and ~ 2000 cal. yr BP. Both aquatic and terrestrial indicators suggest that effective moisture was low between
10,000 and ~6000 cal. yr BP, and that this time interval was the driest period of the Holocene. The dominance of benthic and tychoplanktic diatom taxa
indicates relatively shallow lake-level, high sand influx indicates moderately high eolian activity, and the pollen assemblage suggests xeric grasslands with
abundant mud flats. About 6000 cal. yr BP, all three sites experienced an increase in effective moisture. Lake-level rise is indicated by increases in planktic
and tychoplanktic diatoms relative to benthic taxa, while greater abundance of grass pollen and charcoal, and decreased eolian flux indicate stabilized
dunes with dense vegetation sufficient to fuel local fires. A significant hydrologic shift recorded at all sites occurred at ~4000 cal. yr BP. This event was
characterized by substantial lake-level rise, yet decreased grass cover and fire frequency, and increased eolian activity. Water-table rise may have been
caused by a combination of factors including: (1) formation of dune-dams that blocked old drainage channels, (2) reduced grass cover and hence reduced
evapotranspiration, and (3) changes in the frequency and duration of drought. The most likely cause(s) of the differential response of the terrestrial and
aquatic systems at this time is not clear, none-the-less the late Holocene was not nearly as dry as the interval prior to 6000 cal. yr BP. The last ~2000
yr were characterized by several short-term fluctuations in lake level, including an interval of drought between 950 and 750 cal. yr BP, coincident with
increased eolian activity during the latter part of the Medieval Climatic Anomaly.},
	keywords = {diatoms, drought, Holocene climate change, lakes, Nebraska Sand Hills, pollen},
	issn = {0959-6836},
	doi = {10.1177/0959683612463100},
	url = {http://journals.sagepub.com/doi/10.1177/0959683612463100},
	author = {Schmieder, Jens and Fritz, Sherilyn C and Grimm, Eric C and Jacobs, Kimberly C and Brown, Kendrick J and Swinehart, James B and Porter, Stephen C}
}
@article { ISI:000262186900001,
	title = {Stratigraphy, pollen history and geochronology of tidal marshes in a Gulf of Maine estuarine system: Climatic and relative sea level impacts},
	journal = {MARINE GEOLOGY},
	volume = {256},
	number = {{1-4}},
	year = {2008},
	month = {DEC 20},
	pages = {1-17},
	type = {Review},
	abstract = {Sedimentologic and stratigraphic characteristics of five tidal marshes in Great Bay Estuary, New Hampshire, which is located on the western boundary of the Gulf of Maine, were assessed from 20 vibracores. detailed descriptions of surficial environments, pollen analyses, and radiocarbon dating. Modern marsh sequences in Great Bay Estuary initiated with a time-transgressive basal peat that formed at the upland-brackish marsh boundary. The oldest basal peat deposit sampled during this study was dated at similar to 4560 cal yr B.P (based on an age of 4060 +/- 40 C-14 yr B.P.). The original tidal marshes that formed in Great Bay Estuary apparently were unable to accrete at a high enough rate to allow seaward expansion, resulting in a transgressive sequence of low marsh or mudflat sediments overlying the basal peat. The transgressive tidal marsh sequence is capped by high marsh sediments that corresponded to a slowing of relative sea-level (RSL) rise in the region and regressive seaward expansion of the tidal marshes. However, significant variations from these transgressive-regressive sequences occur in the Great Bay tidal marshes as a result of more recent marsh expansion and tidal channel migrations. Detailed pollen analyses of a vibracore taken in a tidal marsh along Squamscott River with a sedimentary record spanning the last similar to 3900 cal yr B.P exhibit five well-documented marker horizons including: 1) an increase of Tsuga (hemlock); 2) the appearance of Picea (spruce); 3) Tsuga and Fagus (beech) declines; 4) an increase in Ambrosia (ragweed) coupled with a sudden decrease in Quercus (oak); and 5) the Castanea (chestnut) decline. Using published ages for these pollen horizons and a calibrated 14C age obtained during this study for a basal peat, accretion rates for this marsh system over five time intervals were calculated: 1) 0.4 to 0.5 mm yr(-1) from similar to 3900 to 2850 cal yr B.P.; 2) 0.6 mm yr(-1) from similar to 2850 to similar to 1960 cal yr B.P.; 3) 0.8 mm yr(-1) from similar to 1960 to similar to 580 cal yr B.P.; 4) 0.7 to 0.8 mm yr(-1) from similar to 580 to similar to 210 cal yr B.P.: and 5) 0.8 to 0.9 mm yr(-1) over the last 210 years. The long-term accretion rate for the entire sequence based on the calibrated C-14 age of the basal peat was 0.6 to 0.7 mm yr(-1). This result agrees with accretion rates determined from calibrated C-14 ages from two other tidal marsh systems in Great Bay Estuary with accretion rates between similar to 0.6 to similar to 0.8 mm yr(-1). Higher accretion rates were obtained at a nearby tidal marsh with 1.2 mm yr(-1) for just the marsh and 1.3 mm yr(-1) for the marsh and underlying subtidal sediment. The results of this study indicate that the sedimentology and stratigraphy of moderate-size tidal marshes in rocky, glaciated coasts are highly variable and are strongly influenced by complex interactions among RSL, climatic variations, and anthropogenic influences. For instance, the early development of many of the marshes in the Great Bay Estuary area were likely driven by changes in rates of RSL resulting in transgressive onlap boundaries, subsequently overlain by regressive intertidal marsh sequences. However, more recent changes in tidal marsh sediment composition deposited during a relatively slow, steady RSL rise likely result from other forcings. such as changes in minerogenic and orogenic sediment inputs due to anthropogenic effects, tidal channel migrations, major storms causing erosion of the marsh, or climatic changes causing shifts in sediment delivery or vegetation. (C) 2008 Elsevier B.V. All rights reserved.},
	keywords = {accretion, climate effects, pollen, relative sea level, salt marshes, sedimentology, stratigraphy},
	issn = {0025-3227},
	doi = {10.1016/j.margeo.2008.08.004},
	author = {Ward, Larry G. and Zaprowski, Brent J. and Trainer, Kevin D. and Davis, P. Thompson}
}
@article {2131,
	title = {Pollen record of the last 500 years from the Doninos coastal lagoon (NW Iberian Peninsula): Changes in the pollinic catchment size versus paleoecological interpretation},
	journal = {Journal of Coastal Research},
	volume = {17},
	year = {2001},
	note = {479bdTimes Cited:6
Cited References Count:46
},
	month = {Sum},
	pages = {705-713},
	abstract = {Pollen, diatom, charcoal and sedimentological analyses of a 4.20-m long core collected in the margin of the Doninos coastal lagoon, northwest Iberian Peninsula, provide information about the environmental evolution of this lagoon during the last 530 yr BP. During this time period, local environmental changes, such as changes in the sand-barrier permeability, alluvial sedimentation and/or anthropogenic activity, played a major role in the evolution of this coastal system. This scenario allows us to test the degree the pollinic signal recorded in the sediments of coastal lagoons is reshaped by the influence of local processes.Diatom and sedimentological data as well as historical archives indicate the development of a lacustrine system at the bottom of the sequence. Therefore, the coring site might be included in the lagoon itself. Pollen data seems to reflect the regional vegetation as a consequence of the large pollinic catchment area. Local Castanea cultivation and anthropogenic deforestation are also recorded.
At the top of the sequence, diatom facies suggest increased marine influence at this time as a consequence of the more common events of breaching of a retrograding barrier. This, plus natural silting up by alluvial sedimentation and man-induced drying up of the lagoonal margins, lead to a progressive decrease in the water body extension. The coring point is now outside of the lagoon, implying a reduction in the pollinic catchment area that gave rise to a gradual increase in the local pollinic rainfall of periphytic vegetation.
From the pollen diagram of this coastal deposit signatures of regional vegetation are swamped by local pollen input. The fluctuations in the percentages of the different pollen taxa are related to the complex interaction between basin size, human activities and breaching of the barrier. Caution must therefore be taken with direct paleoclimatic inferences from pollinic studies in coastal lagoons as an alternative where other continental deposits are lacking.
},
	keywords = {charcoal, coastal lagoon, diatoms, human impact, Late Holocene, late-holocene, nw iberian peninsula, pollen, representation, source area, vegetation, vegetation history},
	isbn = {0749-0208},
	author = {Santos, L. and Bao, R. and Goni, M. F. S.}
}
