Kay, Charles. 2001. The condition and trend of aspen communities on BLM administered lands in central Nevada - - with recommendations for management. Final report to Battle Mountain Field Office, Bureau of Land Management, Battle Mountain, NV.

RELEVANT TO: LIVESTOCK GRAZING
  FORESTS/RESTORATION
  MONITORING/ADAPTIVE MANAGEMENT

DESCRIPTION

This BLM-funded research report is part of a 2000-2004 aspen study on the Battle Mountain and Elko BLM Districts in Nevada. The research report provides a literature review of aspen ecological significance and trends in the West followed by measurements, photos, and descriptions of 126 representative aspen stands in six mountain ranges of central Nevada. Additionally, measurements were made of all long-term aspen-containing exclosures in the mountain ranges.

For each stand and both inside and outside exclosures, the following was recorded:

  1. location
  2. elevation
  3. grid coordinates
  4. aspect
  5. slope
  6. estimated stand size
  7. estimate of mean percent of each stem that had been damaged by ungulate bark stripping (i.e., elk)
  8. estimate of percent stems greater than 2 m tall but less than 5 cm DBH that showed evidence of ungulate highlining
  9. percent of stems less than 2 m tall that exhibited ungulate browsing
  10. whether or not water was present in or near the stand
  11. number of cattle, domestic sheep, mule deer, and elk pellet groups on each 2/30 m belt transect
  12. number and species of conifers on the aspen belt transect
  13. estimated total percent conifer canopy cover
  14. understory shrub species composition and canopy cover of grass and forbs

The BLM provided grazing history, AUM allocations, and grazing bills.

MAJOR FINDINGS

  1. In these aspen stands, succession to conifers or sagebrush was not occurring in protected aspen stands; elk were not present; and deer browsing was minimal. (p. 130).
  2. Climate was not accounting for aspen declines, as aspen in exclosures were sprouting and growing profusely. (p. 131)
  3. Fire suppression did not account for the reduced aspen. “If only burned aspen stands were capable of producing new stems greater than 6 feet tall, then aspen inside fenced plots or aspen protected by fallen trees, should not be able to successfully regenerate.” (p. 132). They had successfully regenerated in the absence of fire.
  4. Regeneration was found to be occurring wherever cattle were excluded, wherever aspen happened to be protected from livestock by interlocking branches of fallen trees, and when livestock numbers were temporarily reduced or cattle grazing had been changed from season-long to only early-season use. (p. 133)
  5. Aspen was in better condition on steep slopes or farther from water, showing a relation to livestock grazing patterns. (p. 133).
  6. In the 40 aspen exclosures Kay has measured or otherwise evaluated in western U.S. and Canada, “…and in all cases where aspen has been protected, it successfully regenerated and formed multi-aged stands without fire or other disturbance.” (p. 134).
  7. “The single stem-aged stands seen in central Nevada and found throughout the West are not a biological attribute of aspen, but a result of excessive ungulate herbivory.” (p. 134).
  8. While in Yellowstone National Park and some other areas Kay has found too many elk or too many deer to be the problem, domestic livestock are the predominate ungulate herbivore in central Nevada.

QUESTIONS THIS DOCUMENT RAISES FOR SOUTHERN UTAH’S THREE NATIONAL FORESTS

  1. What are the relative roles played by livestock grazing, and wild ungulate browsing in aspen losses on the Fishlake, Dixie, and Manti-La Sal Forests?
  2. 2. How essential is fire to health of Fishlake, Dixie, and Manti-La Sal Forests, given Kay’s note that aspen has formed multi-aged stands without fire in all exclosures he has seen in the U.S. and Canada?
  3. What regeneration of aspen would occur if livestock grazing were modified or excluded from particular aspen sites (i.e., passive restoration)?
  4. What results if any have been observed in livestock/wild ungulate exclosures compared to livestock exclosures and controls on these Forests? [Note: Because of their tiny nature, such exclosures are not able to indicate wild ungulate impacts that would be present in a Dixie, Fishlake, or Manti-La Sal watershed or landscape that is livestock-free.]

RELEVANCE TO FOREST MANAGEMENT

  1. It is important to maintain large areas free of livestock grazing within aspen habitat in order to (a) understand the ecological and biodiversity implications of livestock grazing within aspen habitat and (b) (likely) increase aspen regeneration and native biodiversity, as aspen supports the highest biodiversity of any upland forest type in the West (p. 2).
  2. Aspen is an appropriate, easily-measured management indicator species of both biodiversity and overgrazing (by cattle and/or other wild ungulates) within the three Forests.