Salt-Lick-Induced Soil Disturbance in the Teton Wilderness, USA

Abstract

Manmade salt licks on public lands throughout the Rocky Mountain West have been created to attract large game for hunting purposes. This practice is both illegal and controversial, but is of particular importance in otherwise pristine wilderness landscapes. The impact of widespread saltlicks on public lands has never been quantified. This study was undertaken to examine the degree of change in soil physical and chemical properties caused by approximately 10-60 years of salt application in the Teton Wilderness of Wyoming, USA. A total of 27 sites were identified, surveyed, and paired with non-salt-affected control areas. Three replicate sampling points were located within each salt site and in each of the paired control areas. Soil samples from each site were analyzed for soil bulk density, soil salinity as electrical conductance (EC), pH, organic matter content, sodium absorption ratio (SAR), and exchangeable concentrations of sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+). Salt-treated site centers were found to have elevated EC, bulk density, pH, SAR, and Na+ concentration compared to the no-salt controls. Salt-affected sites also contained decreased organic matter contents and decreased concentrations of Ca2+ and Mg2+. Observed differences were due to the addition of Na+ to the soil solum as well as direct effects of ungulates. Soil compaction appears to have a greater impact on plant establishment than the actual presence of NaCl. Salt licks established in wilderness areas habituate animals to localized zones causing extensive soil trampling and consumption of surface soils by grazing ungulates.