Multidisciplinary Investigations of Alpine Ice Patches in Southwest Yukon, Canada: Paleoenvironmental and Paleobiological Investigations

摘要: Since the discovery of dung-rich alpine ice patches in southwest Yukon 1997, continuing multidisciplinary studies have provided a unique window on biology, climate, and hunting activity this region over much Holocene. Aerial surveys identified 72 variable size, 65 been ground-surveyed for organic remains. Of these, 35 yielded an abundance biological specimens, including caribou other rare large mammal remains, mummified small mammals birds, artifacts spanning 8000 years. The dung provides pollen plant macrofossils analysis paleoenvironmental reconstruction, as well dietary, genetic, parasitic information. Stratigraphically controlled sampling within layers has geochronology placing their formation early 8300 to years BP. Ice patch was nearly continuous except interval between 6700 4700 BP another 1440 1030, when warm or dry conditions (or both) resulted no net accumulation. Resumption accumulation following 500 likely culminated Little Age. size during period is made evident by lichen-free zone that haloes each patch. More recently, interpretation air photos from 1946 2001 found significant reduction dimensions. Daily temperature records Whitehorse (1942-2001) were used calculate melting degree-day values account part variation indicating while considerable occurred since end Age, are highly sensitive decadal changes temperature.