Spruce trees from a melting ice patch: evidence for Holocene climatic change in the Colorado Rocky Mountains, USA

被引:24
作者
Benedict, James B. [1 ]
Benedict, Robert J.
Lee, Craig M. [2 ]
Staley, Dennis M. [3 ]
机构
[1] Ctr Mt Archeol, Ward, CO 80481 USA
[2] Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA
[3] US Geol Survey, Golden, CO 80401 USA
关键词
Ice patches; climatic change; Colorado Front Range; Picea engelmannii; sclerotia; snowbed loess; timberline fluctuations; windblown snow; Holocene;
D O I
10.1177/0959683608095578
中图分类号
P9 [自然地理学];
学科分类号
0705 ; 070501 ;
摘要
In September, 2006, we found the remains of timber-sized spruce trees (Picea engelmannii) on the floors of melting ice patches at altitudes of 3465-3480 m in the Mummy Range of north-central Colorado. The ice patches occupy northeast-facing recesses in which windblown snow, scoured from a tundra upland to the southwest, accumulates deeply. We hypothesize that the upland was timbered during the early to middle Holocene. Dense forest vegetation intercepted snow, preventing it from blowing to the recesses, and allowing trees to become established there. Neoglacial cooling led to gradual deforestation of the upland, renewed transport and deposition of snow by wind, and death of the ice-patch trees. Radiocarbon dates show that the trees died between 3860 +/- 15 and 3780 +/- 20 C-14 yr BP (c. 4200 cal yr BP). The trunks show decay similar to that of historic log structures built above timberline during the late nineteenth and early twentieth centuries, suggesting that they have been protected by ice for all but a small portion of the past 4200 years. A series of warm summers and dry winters led to their recent emergence. The study illustrates the importance of monitoring glaciers and ice patches for floral, faunal and archaeological remains whenever severe melting occurs.
引用
收藏
页码:1067 / 1076
页数:10
相关论文
共 63 条
[21]   Twentieth century climate change: Evidence from small glaciers [J].
Dyurgerov, MB ;
Meier, MF .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2000, 97 (04) :1406-1411
[23]   Late Pleistocene and Holocene seasonal temperatures reconstructed from fossil beetle assemblages in the Rocky Mountains [J].
Elias, SA .
QUATERNARY RESEARCH, 1996, 46 (03) :311-318
[24]  
Embleton C., 1975, Periglacial Geomorphology
[25]  
Fall PL, 1997, GEOL SOC AM BULL, V109, P1306, DOI 10.1130/0016-7606(1997)109<1306:TFALQP>2.3.CO
[26]  
2
[27]  
Farnell R, 2004, ARCTIC, V57, P247
[28]   Late quaternary paleoenvironments of the White River Plateau, Colorado, USA [J].
Feiler, EJ ;
Anderson, RS ;
Koehler, PA .
ARCTIC AND ALPINE RESEARCH, 1997, 29 (01) :53-62
[29]  
GLIDDEN DE, 1982, WINTER WIND STUDIES
[30]  
HARDEN D, 1977, ARCTIC, V30, P28