Pollen-Derived Paleovegetation Reconstruction and Long-Term Carbon Accumulation at a Fen Site in the Attawapiskat River Watershed, Hudson Bay Lowlands, Canada

AbstractMultiple proxies from a 319-cm peat core collected from the Hudson Bay Lowlands, northern Ontario, Canada were analyzed to determine how carbon accumulation has varied as a function of paleohydrology and paleoclimate. Testate amoeba assemblages, analysis of peat composition and humification, and a pollen record from a nearby lake suggest that isostatic rebound and climate may have influenced peatland growth and carbon dynamics over the past 6700 cal yr BP. Long-term apparent rates of carbon accumulation ranged between 8.1 and 36.7 g C m− 2 yr− 1 (average = 18.9 g C m− 2 yr− 1). The highest carbon accumulation estimates were recorded prior to 5400 cal yr BP when a fen existed at this site, however following the fen-to-bog transition carbon accumulation stabilized. Carbon accumulation remained relatively constant through the Neoglacial period after 2400 cal yr BP when pollen-based paleoclimate reconstructions from a nearby lake (McAndrews et al., 1982) and reconstructions of the depth to the water table derived from testate amoeba data suggest a wetter climate. More carbon accumulated per unit time between 1000 and 600 cal yr BP, coinciding in part with the Medieval Climate Anomaly.

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Bird trends from long-term observation data at sites in the Hudson Bay Lowlands

Avian Conservation and Ecology ◽

10.5751/ace-01821-160110 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Rodney W. Brook ◽

Lisa A. Pollock ◽

Kenneth F. Abraham ◽

Glen S. Brown

Keyword(s):

Hudson Bay ◽

Observation Data ◽

Hudson Bay Lowlands ◽

Long Term Observation

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Lichens on the Hudson Bay Lowlands: a long-term survey in Wapusk National Park, Manitoba

The Lichenologist ◽

10.1017/s002428291600027x ◽

2016 ◽

Vol 48 (5) ◽

pp. 581-592 ◽

Cited By ~ 2

Author(s):

Michele D. PIERCEY-NORMORE ◽

Irwin M. BRODO ◽

Chris DEDUKE

Keyword(s):

Species Diversity ◽

National Park ◽

Hudson Bay ◽

Beach Ridge ◽

Habitat Types ◽

Hudson Bay Lowlands ◽

Coastal Beach ◽

Physiographic Regions ◽

Unique Species

AbstractWapusk National Park is part of the Hudson Bay Lowlands in Manitoba and covers 11 475 km2. Lichen surveys were initiated in 2002 but none have reported all species incorporating broad habitat types or a baseline on which to make management decisions. The objectives of this study were: 1) to determine species diversity, including species richness and evenness of the lichens present; 2) to explore species distributions; and 3) to compare lichen growth form and substratum relationships among physiographic regions. Fifty-six locations in four habitat types (physiographic regions: open coastal beach ridge, forested coastal beach ridge, boreal transition forest, and peat plateau bog) and three burned locations were visited over nine years and specimens were collected at each location. A total of 276 species and subspecies were collected. One species is new to Canada (Buellia uberior Anzi) and ten species are new to Manitoba. Species diversity, evenness, and richness were highest in the coastal beach ridge. The open coastal beach ridge, boreal transition forest, and peat plateau bogs formed separate clusters in the non-metric multidimensional scaling (NMS) but the forested coastal beach ridge overlapped with the open coastal beach ridge. Unique species in each region may serve as indicators to monitor long-term changes. While the coastal beach ridge facilitates travel along the coast, it also represents the region with the highest need for intervention to conserve species diversity.

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Global warming triggers the loss of a key Arctic refugium

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.1887 ◽

2013 ◽

Vol 280 (1772) ◽

pp. 20131887 ◽

Cited By ~ 52

Author(s):

K. M. Rühland ◽

A. M. Paterson ◽

W. Keller ◽

N. Michelutti ◽

J. P. Smol

Keyword(s):

Global Warming ◽

Sea Ice ◽

Sediment Cores ◽

Freshwater Ecosystems ◽

The Arctic ◽

Hudson Bay ◽

Native Communities ◽

Hudson Bay Lowlands ◽

Short Period

We document the rapid transformation of one of the Earth's last remaining Arctic refugia, a change that is being driven by global warming. In stark contrast to the amplified warming observed throughout much of the Arctic, the Hudson Bay Lowlands (HBL) of subarctic Canada has maintained cool temperatures, largely due to the counteracting effects of persistent sea ice. However, since the mid-1990s, climate of the HBL has passed a tipping point, the pace and magnitude of which is exceptional even by Arctic standards, exceeding the range of regional long-term variability. Using high-resolution, palaeolimnological records of algal remains in dated lake sediment cores, we report that, within this short period of intense warming, striking biological changes have occurred in the region's freshwater ecosystems. The delayed and intense warming in this remote region provides a natural observatory for testing ecosystem resilience under a rapidly changing climate, in the absence of direct anthropogenic influences. The environmental repercussions of this climate change are of global significance, influencing the huge store of carbon in the region's extensive peatlands, the world's southern-most polar bear population that depends upon Hudson Bay sea ice and permafrost for survival, and native communities who rely on this landscape for sustenance.

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Long-term successional changes in peatlands of the Hudson Bay Lowlands, Canada inferred from the ecological dynamics of multiple proxies

The Holocene ◽

10.1177/0959683614556384 ◽

2014 ◽

Vol 25 (1) ◽

pp. 92-107 ◽

Cited By ~ 8

Author(s):

Kathryn E Hargan ◽

Kathleen M Rühland ◽

Andrew M Paterson ◽

James Holmquist ◽

Glen M MacDonald ◽

...

Keyword(s):

Hudson Bay ◽

Ecological Dynamics ◽

Hudson Bay Lowlands

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Ecohydrological controls on apparent rates of peat carbon accumulation in a boreal bog record from the Hudson Bay Lowlands, northern Ontario, Canada

Quaternary Research ◽

10.1017/qua.2021.22 ◽

2021 ◽

pp. 1-14

Author(s):

Marissa A. Davies ◽

Jerome Blewett ◽

B. David A. Naafs ◽

Sarah A. Finkelstein

Keyword(s):

Accumulation Rate ◽

Membrane Lipid ◽

Carbon Accumulation ◽

Testate Amoeba ◽

Hudson Bay ◽

Bacterial Membrane ◽

Northern Ontario ◽

Hudson Bay Lowlands ◽

Poor Fen ◽

Lipid Biomarker

Abstract A multiproxy Holocene record from a bog in the Hudson Bay Lowlands, northern Ontario, Canada, was used to evaluate how ecohydrology relates to carbon accumulation. The study site is located at a somewhat higher elevation and on coarser grained deposits than the surrounding peatlands. This promotes better drainage and thus a slower rate of carbon accumulation relative to sites with similar initiation age. The rate of peat vertical accretion was initially low as the site transitioned from a marsh to a rich fen. These lower rates took place during the warmer temperatures of the Holocene thermal maximum, confirming the importance of hydrological controls limiting peat accretion at the local scale. Testate amoebae, pollen, and plant macrofossils indicate a transition to a poor fen and then a bog during the late Holocene, as the carbon accumulation rate and reconstructed water table depth increased. The bacterial membrane lipid biomarker indices used to infer paleotemperature show a summer temperature bias and appear sensitive to changes in peat type. The bacterial membrane lipid biomarker pH proxy indicates a rich to a poor fen and a subsequent fen to bog transition, which are supported by pollen, macrofossil, and testate amoeba records.

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Linking testate amoeba assemblages to paleohydrology and ecosystem function in Holocene peat records from the Hudson Bay Lowlands, Ontario, Canada

The Holocene ◽

10.1177/0959683620972792 ◽

2020 ◽

pp. 095968362097279

Author(s):

David Bysouth ◽

Sarah A Finkelstein

Keyword(s):

Water Table ◽

Trophic Position ◽

Carbon Accumulation ◽

Ecosystem Functions ◽

Testate Amoeba ◽

Hudson Bay ◽

Accumulation Rates ◽

Hudson Bay Lowlands ◽

Water Tables ◽

Carbon Accumulation Rates

Peat cores from boreal bog and fen sites in the Hudson Bay Lowlands of Northern Ontario, Canada, were analysed to calculate Holocene carbon accumulation rates, and to show how testate amoeba taxonomic assemblages, inferred depths to water table, and four morpho-traits that may be linked to function (mixotrophy, aperture size, aperture position, and biovolume) changed since peatland initiation. Carbon accumulation rates were on average higher for the Holocene in the fen record (19.4 g C m−2 yr−1) in comparison with the bog record (15.7 g C m−2 yr−1), which underwent a fen-to-bog transition around 6900 cal yr BP. Changes in rates of carbon accumulation were most strongly driven by changes in rates of peat vertical accretion, with more rapid rates in the fen record. Carbon accumulation rates were highest following peatland initiation when reconstructed water tables were highest, and in the late Holocene, when water table positions were variable. Taxa with larger biovolumes and apertures were generally more abundant when reconstructed water tables were higher, most notably following peatland initiation. Mixotrophic taxa were more prevalent in drier conditions and in the bog record. Changing frequencies of morpho-traits suggest that testate amoebae may occupy a higher trophic position in the microbial food web during wetter periods, signaling the possibility of internal feedbacks between peatland ecohydrology and critical ecosystem functions including long-term carbon accumulation.

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Spatio-temporal features of permafrost thaw projected from long-term high-resolution modeling for a region in the Hudson Bay Lowlands in Canada

Journal of Geophysical Research Earth Surface ◽

10.1002/jgrf.20045 ◽

2013 ◽

Vol 118 (2) ◽

pp. 542-552 ◽

Cited By ~ 16

Author(s):

Yu Zhang

Keyword(s):

High Resolution ◽

Hudson Bay ◽

Hudson Bay Lowlands ◽

Permafrost Thaw ◽

Temporal Features ◽

Spatio Temporal

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Multiple Deglaciations of the Hudson Bay Lowlands, Canada, Since Deposition of the Missinaibi (Last-Integlacial?) Formation

Quaternary Research ◽

10.1016/0033-5894(83)90025-x ◽

1983 ◽

Vol 19 (1) ◽

pp. 18-37 ◽

Cited By ~ 83

Author(s):

J. T. Andrews ◽

W. W. Shilts ◽

G. H. Miller

Keyword(s):

Alternative Hypothesis ◽

Ice Sheet ◽

Laurentide Ice Sheet ◽

Hudson Bay ◽

Fluvial Sediments ◽

Last Interglacial ◽

Sea Levels ◽

Hudson Bay Lowlands ◽

Global Ice Volume

AbstractThe stratigraphic record in the James and Hudson Bay Lowlands indicates that the sequence of glacial events at the geographical center of the 12.6 × 106 km2 Laurentide Ice Sheet may have been more complex than hitherto imagined. Isoleucine epimerization ratios of in situ and transported shells recovered from till and associated marine and fluvial sediments cluster into at least 4 discrete groups. Two alternative explanations of the data are offered, of which we strongly favor the first. Hypothesis 1: Setting the age of the “last interglacial” marine incursion, the Bell Sea, at 130,000 yr B.P. results in a long-term average diagenetic temperature for the lowlands of +0.6°C. Using this temperature enables us to predict the age of shells intermediate in age between the “last interglaciation” and the incursion of the Tyrrell Sea 8000 yr ago. Between these two interglacial marine inundations, Hudson Bay is predicted to have been free of ice along its southern shore about 35,000, 75,000, and 105,000 yr ago based on amino acid ratios from shells occurring as erratics in several superimposed tills and fluvial sediments. These results suggest (1) that traditional concepts of ice-sheet build-up and decay must be reexamined; (2) that “high” sea levels may have occurred during the Wisconsin Glaciation; and (3) that a critical reappraisal is required of the open ocean δ18O record as a simple indicator of global ice volume. An alternative, Hypothesis 2, is also examined. It is based on the assumption that the 35,000-yr-old deposits calculated on the basis of Hypothesis 1 date from the “last interglaciation”; this, in effect, indicates that the Missinaibi Formation, commonly accepted as sediments of the “last interglaciation,” are about 500,000 yr old and that the effective diagenetic temperature in the lowlands during approximately the last 130,000 yr has been close to −6°C. We argue for rejection of this alternative hypothesis.

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