Changes in vegetative cover on Western Arctic Herd winter range from 1981 to 2005: potential effects of grazing and climate change

  • Kyle Joly Bureau of Land Management, Fairbanks District Office, 1150 University Avenue, Fairbanks, AK, 99709, USA
  • Randi R. Jandt Bureau of Land Management, Alaska Fire Service, P. O. Box 35005, Fort Wainwright, AK 99703, USA
  • Cynthia R. Meyers Bureau of Land Management, Kotzebue Field Station, P. O. Box 1049, Kotzebue, AK 99752, USA
  • Martha J. Cole Bureau of Land Management, Fairbanks District Office, 1150 University Avenue, Fairbanks, AK, 99709, USA
Keywords: Alaska, assessment, grazing, habitat, lichens, monitoring, Rangifer tarandus granti, vegetation change, Western Arctic Herd, winter range

Abstract

The population of the Western Arctic Herd, estimated at 490 000 caribou (Rangifer tarandus granti) in 2003, is at its highest level in 30 years. Twenty permanent range transects were established in the winter range of the Western Arctic Herd in 1981 to assess the impacts of grazing. These transects were revisited in 1995 and 1996 (1995/96). Only 18 of the transects were re-located, so an additional 7 transects were established in 1996. In 2005, all 25 remaining transects were revisited. Lichen coverage dropped by a relative 45.1% between 1981 and 1995/96 and by an additional relative 25.6% between 1995/96 and 2005. There was a significant decline in primary forage lichens between 1995/96 and 2005. Caribou use was greater in areas with high lichen abundance. Graminoid cover increased by a relative 118.4% from 1981 to 1995/96 and again by a relative 26.1% from 1995/96 to 2005. Shrub cover increased during the study whereas forb cover declined. The decline in lichen abundance on the winter range of the Western Arctic Herd over 24 years is an index of caribou habitat condition. The observed changes in vegetation cover can be attributed to caribou grazing, fire, and possibly global climate change. Continued declines in lichen cover could lead to population declines within the herd, range shifts, or both.
Published
2007-04-01
How to Cite
JolyK., JandtR. R., MeyersC. R., & ColeM. J. (2007). Changes in vegetative cover on Western Arctic Herd winter range from 1981 to 2005: potential effects of grazing and climate change. Rangifer, 27(4), 199-207. https://doi.org/10.7557/2.27.4.345