Holocene Beaver Damming, Fluvial Geomorphology, and Climate in Yellowstone National Park, Wyoming
Author | : Lyman Persico |
Publisher | : |
Total Pages | : 14 |
Release | : 2009 |
ISBN-10 | : OCLC:1305859480 |
ISBN-13 | : |
Rating | : 4/5 (80 Downloads) |
Download or read book Holocene Beaver Damming, Fluvial Geomorphology, and Climate in Yellowstone National Park, Wyoming written by Lyman Persico and published by . This book was released on 2009 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: We use beaver-pond deposits and geomorphic characteristics of small streams to assess long-term effects of beavers and climate change on Holocene fluvial activity in northern Yellowstone National Park. Although beaver damming has been considered a viable mechanism for major aggradation of mountain stream valleys, this has not been previously tested with stratigraphic and geochronologic data. Thirty-nine radiocarbon ages on beaver-pond deposits fall primarily within the last 4000 yr, but gaps in dated beaver occupation from ~ 2200-1800 and 950-750 cal yr BP correspond with severe droughts that likely caused low to ephemeral discharges in smaller streams, as in modern severe drought. Maximum channel gradient for reaches with Holocene beaver-pond deposits decreases with increasing basin area, implying that stream power limits beaver damming and pond sediment preservation. In northern Yellowstone, the patchy distribution and cumulative thickness of mostly