Autor: |
Zalatan, R., Gunn, A., Henry, G. H. R. |
Zdroj: |
Arctic, Antarctic, and Alpine Research; November 2006, Vol. 38 Issue: 4 p624-630, 7p |
Abstrakt: |
ABSTRACTThe aim of this study was to reconstruct population dynamics of barren-ground caribou (Rangifer tarandus groenlandicus)herds from the frequency of trampling scars on tree roots of black spruce (Picea mariana[Mill.] BSP) in the forest-tundra of central Northwest Territories, Canada. Two groups of sites were sampled that roughly corresponded with the migration routes of the Bathurst and Beverly caribou herds. The caribou migrate annually for long distances from the forest to the open tundra in late spring, and return to the forest in the autumn. The scar frequency distribution was determined by careful crossdating and the influence of root age was assessed to account for the increasing underestimation of caribou abundance with the increasing age of the roots. The scar frequency distributions (dated from A.D. 1760 to 2000) from both groups of sites showed similar abundance patterns through time. Caribou numbers were high during the mid-1940s, and 1990s, and were very low during the 1920s, 1950s–1970s, and at the turn of the 21st century. These abundance patterns determined from scar frequencies correlate strongly with data obtained from traditional knowledge of Dogrib elders in the region and animal counts based on aerial photography. The scar frequency distribution developed in this study is the longest proxy record of caribou abundance to date. |
Databáze: |
Supplemental Index |
Externí odkaz: |
|