University of Saskatchewan Radiocarbon Dates X

Rutherford, A A; Wittenberg, J.; Gordon, Bryan C.

doi:10.1017/s0033822200006652

Cited by 26 publications

(5 citation statements)

References 24 publications

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“…There is a mismatch between the modern observed vegetation (grassland) and the modern estimated vegetation (deciduous), though this could be because of the increasing mosaic landscape ( 70 – 72 ). At Sjovold, there is a mismatch between the paleovegetation interpretation of grassland to parkland transition ( 73 – 77 ) and the ecometric estimate of moderately high likelihoods of both deciduous and evergreen ( Fig. 3 B ), possibly because of the large age range of the site (0 to 4,500 y).…”

Section: Resultsmentioning

confidence: 94%

Trophically integrated ecometric models as tools for demonstrating spatial and temporal functional changes in mammal communities

Short

McGuire

Polly

et al. 2023

Proc. Natl. Acad. Sci. U.S.A.

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We are in a modern biodiversity crisis that will restructure community compositions and ecological functions globally. Large mammals, important contributors to ecosystem function, have been affected directly by purposeful extermination and indirectly by climate and land-use changes, yet functional turnover is rarely assessed on a global scale using metrics based on functional traits. Using ecometrics, the study of functional trait distributions and functional turnover, we examine the relationship between vegetation cover and locomotor traits for artiodactyl and carnivoran communities. We show that the ability to detect a functional relationship is strengthened when locomotor traits of both primary consumers (artiodactyls, n = 157 species) and secondary consumers (carnivorans, n = 138 species) are combined into one trophically integrated ecometric model. Overall, locomotor traits of 81% of communities accurately estimate vegetation cover, establishing the advantage of trophically integrated ecometric models over single-group models (58 to 65% correct). We develop an innovative approach within the ecometrics framework, using ecometric anomalies to evaluate mismatches in model estimates and observed values and provide more nuance for understanding relationships between functional traits and vegetation cover. We apply our integrated model to five paleontological sites to illustrate mismatches in the past and today and to demonstrate the utility of the model for paleovegetation interpretations. Observed changes in community traits and their associated vegetations across space and over time demonstrate the strong, rapid effect of environmental filtering on community traits. Ultimately, our trophically integrated ecometric model captures the cascading interactions between taxa, traits, and changing environments.

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Section: Resultsmentioning

confidence: 94%

Trophically integrated ecometric models as tools for demonstrating spatial and temporal functional changes in mammal communities

Short

McGuire

Polly

et al. 2023

Proc. Natl. Acad. Sci. U.S.A.

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“…ka BP basal peat age sampled 100 km west of northern Reindeer Lake (8335±160 14 C a BP, S‐1332; Rutherford et al . 1984; Dalton et al . 2020).…”

Section: Deglacial Historymentioning

confidence: 99%

“…This is based on a tentative correlation to the Whitecap Moraine, and a 9.2AE0.29 cal. ka BP basal peat age sampled 100 km west of northern Reindeer Lake (8335AE160 14 C a BP, S-1332; Rutherford et al 1984;Dalton et al 2020).…”

Section: Quinn Lake Ice Streammentioning

confidence: 99%

Patterns of ice recession and ice stream activity for the MIS 2 Laurentide Ice Sheet in Manitoba, Canada

Gauthier

Breckenridge²,

Hodder

2021

Boreas

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Reconstruction of deglacial ice margins provides insights into the demise of past ice sheets and ice‐marginal lakes and helps to understand how former ice sheets responded to climate change. Here, we reconstruct deglacial Laurentide Ice Sheet margins across Manitoba (Canada), a dynamic region that in MIS 2 spanned from an inner core region of the Keewatin dome to the periphery of the ice sheet (~900 km north of the Last Glacial Maximum limit). The area was also overrun by ice flowing from both the Quebec‐Labrador dome and the Hudson Bay Ice Saddle. The surficial landscape of Manitoba contains inherited relict and palimpsest glacial landscapes, which need to be separated from deglacial features. Ice‐impounded glacial Lake Hind was present in southwest Manitoba at 13.0 cal. ka BP, meaning most of Manitoba was covered by ice at the start of the Younger Dryas. Northwest drainage of glacial Lake Agassiz in front of the Highrock Lake–Cree Lake moraine could have occurred near the end of the Younger Dryas, prior to 11.5 cal. ka BP, though the volume of the lake varies greatly depending on ice‐margin reconstructions. Our interpretation is incompatible with the hypothesis that Lake Agassiz drainage to the Arctic Ocean triggered the Younger Dryas climatic cooling. Numerous ice streams developed across central and southern Manitoba during deglaciation, including the Souris, Red River, The Pas, Hayes and Quinn Lake. The dominant ice source was from the north early in deglaciation, switching to the northeast with growth of the Hudson Bay Ice Saddle and then back to the north again with demise of the saddle. The ice‐margin ages are largely unconstrained, and thus we are unable to accurately assign climatic drivers to various ice stream events. Nonetheless, we record the development and demise of terrestrial ice streams over both hard‐bed and soft‐bed substrates.

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“…Over the next two decades, a succession of expeditions followed the same route, leaving behind a rich descriptive and photographic record providing insight into Glacier study area. Numbers indicate sampling sites from this study and letters indicate sample sites from Rutherford et al (1984), Ryder and Thomson (1986) and . the response of Franklin Glacier to climate changes in the first half of the 20th century (Munday, 1926(Munday, -1927(Munday, , 1930(Munday, , 1931a(Munday, , 1931b(Munday, , 1933(Munday, , 1934(Munday, -1935(Munday, , 1939.…”

Section: Research Backgroundmentioning

confidence: 99%

“…Waddington area highlighting location of previously studied glaciers in the region and geographic features and (b) Franklin Glacier study area. Numbers indicate sampling sites from this study and letters indicate sample sites from Rutherford et al (1984), Ryder and Thomson (1986) and Coulthard et al (2013).…”

Section: Introductionmentioning

confidence: 99%

Latest Pleistocene and Holocene behaviour of Franklin Glacier, Mt. Waddington area, British Columbia Coast Mountains, Canada

Mood

Smith

2015

The Holocene

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Franklin Glacier is an 18-km-long valley glacier that originates in a broad icefield below the west face of Mt. Waddington in the central British Columbia Coast Mountains, Canada. Radiocarbon-dated wood samples from the proximal faces of lateral moraines flanking Franklin Glacier show that the glacier expanded at least nine times since 13,000 cal. yr BP. A probable Younger Dryas advance of Franklin Glacier at 12,910-12,690 cal. yr BP followed the late glacial retreat and down wasting of the Cordilleran Ice Sheet from ca. 16,000 to 12,900 cal. yr BP. During the succeeding early Holocene warm period, Franklin Glacier appears to have retreated significantly, leaving no record of glacial expansion until the mid-Holocene when it repeatedly advanced at 6360-6280, 5470-5280 and 4770-4580 cal. yr BP. Down wasting of the glacier surface after ca. 4770-4580 cal. yr BP was followed by intervals of expansion at 4260-4080, 3210-3020 and 2620-2380 cal. yr BP. Following ice expansion at ca. 2620-2380 cal. yr BP into trees over 224 years in age, there is no record of the glacier activity until 1570-1480 cal. yr BP when Franklin Glacier thickened and advanced into young subalpine fir trees. During the 'Little Ice Age', advances at 800-680, 610-560 and 570-510 cal. yr BP preceded a mid-19th to early 20th century advance that saw Franklin Glacier attain its maximum Holocene extent. The dendroglaciological record at Franklin Glacier is among the most comprehensive recovered from the British Columbia Coast Mountains and showcases the complexity of mid-to late Holocene glacier expansion in the region.

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University of Saskatchewan Radiocarbon Dates X

Cited by 26 publications

References 24 publications

Trophically integrated ecometric models as tools for demonstrating spatial and temporal functional changes in mammal communities

Trophically integrated ecometric models as tools for demonstrating spatial and temporal functional changes in mammal communities

Patterns of ice recession and ice stream activity for the MIS 2 Laurentide Ice Sheet in Manitoba, Canada

Latest Pleistocene and Holocene behaviour of Franklin Glacier, Mt. Waddington area, British Columbia Coast Mountains, Canada

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