Hostname: page-component-5c6d5d7d68-vt8vv Total loading time: 0.001 Render date: 2024-08-14T17:56:06.491Z Has data issue: false hasContentIssue false

Postglacial Vegetation and Climate in the Northwestern Great Plains of Montana

Published online by Cambridge University Press:  20 January 2017

Cathy W. Barnosky*
Affiliation:
Department of Geology and Planetary Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15260; and Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, Pennsylvania 12213

Abstract

Two pollen records from the northern Great Plains of Montana portray vegetational and climatic changes during the last 12,200 yr in a region where few other data are available. A 6.4-m core from Guardipee Lake, east of the Rocky Mountains in the area formerly covered by the Two Medicine glacial lobe, contains the Glacier Peak G and Mt. St. Helens Jy volcanic ashes. Pollen percentage data are dominated by Pinus, Poaceae, Artemisia, and Chenopodiaceae/Amaranthaceae. High nonarboreal percentages and small amounts of Juniperus, Alnus, Salix, and Populus pollen in sediments deposited between ca. 12,200 and ca. 9300 yr B.P. suggest a temperate grassland with shrubs growing locally in mesic settings. After ca. 9300 yr B.P. an increase in Chenopodiaceae/Amaranthaceae pollen and a concomitant decline in Artemisia indicate the development of more xerophytic grassland and the beginning of the altithermal period. The lake probably was intermittently dry thoughout the Holocene. A high sedimentation rate and the presence of cereal taxa characterize the last ca. 100 yr of Euroamerican settlement. Lost Lake at the northern margin of the Highwood Mountains yielded a 16.94-m core with no volcanic ashes that spans the last 9400 yr. High amounts of Chenopodiaceae/Amaranthaceae, Artemisia, and Poaceae pollen, from ca. 9400 to ca. 6000 yr B.P., suggest the presence of xeric grassland and a climate drier than at present. After ca. 6000 yr B.P. Chenopodiaceae/Amaranthaceae values declined and Artemisia, Poaceae, Pinus, Picea, Salix, Alnus, and Betula increased. The inferred spread of shrubs in wet habitats at this time and the expansion of forest in nearby mountain ranges indicate the end of the altithermal period and the onset of cooler/moister conditions.

Type
Research Article
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Albrandt, T.S. Swinehart, J.B. Maroney, D.G. The dynamic Holocene dune fields of the Great Plains and the Rocky Mountain Basins, U.S.A. Brookfield, M.E. Albrandt, T.S. Eolian Sediments and Processes 1983 Elsevier Amsterdam 379 409 Google Scholar
Baker, R.G. Holocene vegetation history of the western United States Wright, H.E. Jr. Late Quaternary Environments of the United States Vol. 2 1983 Univ. of Minnesota Press Minneapolis 109 127 Google Scholar
Barkley, T.M. Flora of the Great Plains 1986 Great Plains Flora Association, University of Kansas Lawrence Google Scholar
Barnosky, C.W. Late Quaternary vegetation in the southwestern Columbia Basin, Washington Quaternary Research 23 1985 109 122 Google Scholar
Barnosky, C.W. Grimm, E.C. Wright, H.E. Jr. Towards a postglacial history of the northern Great Plains: A review of the paleoecologic problems Annals of the Carnegie Museum 56 1987 259 273 Google Scholar
Barnosky, C.W. Anderson, P.M. Bartlein, P.J. The northwestern U.S. during deglaciation: Vegetation and paleoclimatic implications Ruddiman, W.F. Wright, H.E. Jr. North America and Adjacent Oceans during the Last Deglaciation The Geology of North America Vol. K-3 1987 Geological Society of America Boulder 289 321 Google Scholar
Beiswenger, J.M. Late Quaternary Vegetation of Grays Lake, Idaho and the Ice Slough, Wyoming Unpublished Ph.D. dissertation 1987 University of Wyoming Google Scholar
Brant, L.A. A Palynological Investigation of Postglacial Sediments at Two Locations along the Continental Divide near Helena, Montana Unpublished Ed.D. dissertation 1980 Pennsylvania State University Google Scholar
Carrara, P.E. Wilcox, R.E. Short, S.K. Deglaciation of the mountainous region of northwestern Montana east of the Continental Divide Arctic and Alpine Research 18 1986 317 325 CrossRefGoogle Scholar
Cvancara, A.M. Clayton, L. Bickley, W.B. Jr. Jacob, A.F. Ashworth, A.C. Brophy, J.A. Shay, C.T. Delorme, L.D. Lammers, G.E. Paleolimnology of late Quaternary deposits: Seibold Site, North Dakota Science 171 1971 172 174 Google Scholar
Cwynar, L.C. Burden, E. McAndrews, J.H. An inexpensive sieving method for concentrating pollen and spores from fine-grained sediments Canadian Journal of Earth Sciences 16 1979 1115 1120 Google Scholar
Davis, O.K. Sheppard, J.C. Robertson, S. Contrasting climatic histories for the Snake River Plain, Idaho, resulting from multiple thermal maxima Quaternary Research 26 1986 321 339 CrossRefGoogle Scholar
Faegri, K. Iversen, J. Textbook of Pollen Analysis 1975 Munksgaard Copenhagen Google Scholar
Fullerton, D.S. Colton, R.B. Stratigraphy and correlation of the glacial deposits on the Montana Plains Sibrava, V. Bowen, D.Q. Richmond, G.M. Quaternary Glaciations in the Northern Hemisphere Quaternary Science Reviews 5 1986 69 82 Google Scholar
Küchler, A.W. Potential Natural Vegetation of the Conterminous United States (map) American Geographical Society Special Publication Vol. 36 1964 map scale, 1:3,168,000 Google Scholar
Kutzbach, J.E. Model simulation of the climatic patterns during the deglaciation of North America Ruddiman, W.F. Wright, H.E. Jr. North America and Adjacent Oceans during the Last Deglaciation The Geology of North America Vol. K-3 1987 Geological Society of America Boulder 425 446 Google Scholar
Kutzbach, J.E. Guetter, P.J. The influence of changing orbital parameters and surface boundary conditions on climatic simulations for the past 18,000 years Journal of the Atmospheric Sciences 43 1986 1726 1759 Google Scholar
Lichti-Federovich, J. The pollen stratigraphy of a dated section of late Pleistocene lake sediment from Central Alberta Canadian Journal of Earth Sciences 7 1970 938 945 CrossRefGoogle Scholar
Little, E.L. Jr. Atlas of United States Trees Vol. 1 1971 “Conifers and Important Hardwoods.” U.S. Department of Agriculture Miscellaneous Publication 1146 Google Scholar
MacDonald, G.M. Late Quaternary paleoenvironments of the Morley Flats and Kananaskis Valley of southwestern Alberta Canadian Journal of Earth Sciences 19 1982 23 25 Google Scholar
MacDonald, G.M. Postglacial development of the subalpine-boreal transition forest of western Canada Journal of Ecology 75 1987 303 320 CrossRefGoogle Scholar
MacDonald, G.M. Cwynar, L. A fossil pollen based reconstruction of the late Quaternary history of lodgepole pine (Pinus contorta ssp. latifolia) in the Western interior of Canada Canadian Journal of Forestry Research 15 1985 1039 1044 Google Scholar
Mack, R.N. Rutter, N.W. Valastro, S. Holocene vegetation history of the Kootenai River Valley, Montana Quaternary Research 20 1983 177 193 Google Scholar
Markgraf, V. Lennon, T. Paleoenvironmental history of the last 13,000 years of the eastern Powder River Basin, Wyoming, and its implications for prehistoric cultural patterns Plains Anthropologist 31 1986 1 12 Google Scholar
McAndrews, J.H. Berti, A.A. Norris, G. Key to the Quaternary Pollen and Spores of the Great Lakes Region 1973 Royal Ontario Museum Toronto, Canada Life Sciences Miscellaneous Publication Google Scholar
McAndrews, J.H. Stewart, R.E. Bright, R.C. Paleoecology of a Prairie pothole: A preliminary report North Dakota Geological Survey Miscellaneous Series 30 1967 101 113 Google Scholar
Mehringer, P.J. Jr. Late-Quaternary pollen records from the Pacific Northwest and Northern Great Basin of the United States Bryant, V.M. Jr. Holloway, R.G. Pollen Records of Late Quaternary North American Sediments 1985 American Association of Stratigraphic Palynologists Foundation Dallas 167 189 Google Scholar
Mehringer, P.J. Jr. Arno, S.F. Peterson, K.L. Postglacial history of Lost Trail Pass Bog, Bitterroot Mountains, Montana Arctic and Alpine Research 9 1977 345 368 Google Scholar
Mehringer, P.J. Jr. Sheppard, J.C. Foit, F.F. Jr. The age of Glacier Peak tephra in westcentral Montana Quaternary Research 21 1984 36 41 Google Scholar
Moore, P.D. Webb, J.A. An Illustrated Guide to Pollen Analysis 1978 Wiley New York Google Scholar
Radle, N.J. Vegetation History and Lake-Level Changes at a Saline Lake in Northeastern South Dakota Unpublished M.S. thesis 1981 University of Minnesota Google Scholar
Richmond, G.M. Glaciation of the Rocky Mountains Wright, H.E. Jr. Frey, D.G. The Quaternary of the United States 1965 Princeton Univ. Press Princeton, NJ 217 230 Google Scholar
Richmond, G.M. Tentative correlation of deposits of the Cordilleran ice-sheet in the northern Rocky Mountains Sibrava, V. Bowen, D.Q. Richmond, G.M. Quaternary Glaciations in the Northern Hemisphere Quaternary Science Reviews 5 1986 129 134 Google Scholar
Ritchie, J.C. The Past and Present Vegetation of the Far Northwest of Canada 1984 Univ. of Toronto Press Toronto Google Scholar
Soil Conservation Service General Soils Map: Blackfeet Indian Reservation, Cut Bank Area 1969 Montana State University Agricultural Experiment Station Miscellaneous Publication 8 Google Scholar
Thompson, L.S. Kuijt, J. Montane and subalpine plants of the Sweetgrass Hills, Montana, and their relation to early postglacial environments of the northern Great Plains Canadian Field-Naturalist 90 1976 432 448 Google Scholar
Watts, W.A. Bright, R.C. Pollen, seed, and mollusk analysis of a sediment core from Pickerel Lake, northeastern South Dakota Geological Society of America Bulletin 79 1968 855 876 CrossRefGoogle Scholar
Wright, H.E. Jr. Mann, D.H. Glaser, P.H. Piston corers for peat and lake sediments Ecology 65 1983 657 659 Google Scholar