Paleoecology of the Boutellier Nonglacial Interval, ST. Elias Mountains, Yukon Territory, Canada^*

* Yukon Refugium Project Contribution No. 45.

Abstract

Alluvial, organic-rich sediments associated with the mid-Wisconsin Boutellier nonglacial interval (38,000 to 30,000 BP), St. Elias Mountains, Yukon Territory, yielded fossil pollen and bryophytes. Twenty-five pollen taxa were identified; Cyperaceae, Gramineae, and Artemisia dominated the pollen assemblages. Arboreal pollen was rare, while Salix was the only common shrub. Of the fossil bryophytes Drepanocladus brevifolius was the most common; Calhergon giganteum and Scorpidium scorpioides were less frequent and less well preserved.

The pollen record suggests a tundra meadow-tundra steppe mosaic with local willow groves. The bryophytes indicate an un-weathered minerotrophic substrate. Comparisons with other dated mid-Wisconsin pollen localities of Alaska and Yukon suggest that the Boutellier pollen samples represent the upper zone of an altitudinal vegetational sequence similar to that of the present, but displaced downslope.