Effects of Cattle Traffic on Sclerocactus wrightiae

Cattle grazing has been a historic use of rangelands in Utah since pioneer settlement in the mid-1800’s. Wright fishhook cactus is a small globose cactus endemic to an area of 280,000 ha in south–central Utah and was listed as endangered in October of 1979, by the U.S. Fish and Wildlife Service (USFWS). By 2010, concerns were expressed that soil compaction in proximity to the cactus posed a threat to this species, though there were no empirical data to support such concerns. In order to assess the impact of cattle traffic on Wright fishhook cactus, we used an imprint device to simulate a cow track’s impact. We applied a treatment of either zero, one, or four hoof imprints within 15 cm evenly of 146 cacti within the same population cluster on the same day. We monitored subsequent plant survival as well as reproductive success. Each cactus in the study was visited multiple times and all developed seed was collected. We found that cattle traffic of any amount had no effect on plant survival or seed production and, therefore, concluded that cattle traffic poses no threat to Wright fishhook cactus. The status of this cactus yields no justification for changing the historic land management use of cattle grazing on these rangelands.