Five-Year Monitoring Study of Siler's Pincushion Cactus (Pediocactus sileri) in Kane County, Utah

Abstract

Siler's pincushion cactus (Pediocuctus sileri) occurs primarily on Bureau of Land Management (BLM) lands in Washington and Kane Counties in southwestern Utah and across the border in northwestern Arizona. This 5 year (1993-1997) monitoring study was set up as a challenge cost-share project between Red Butte Garden and the Utah State BLM Office in Salt Lake City. A permanent study plot was established about 10 miles east of Kanab, in Kane County, to annually monitor growth, reproduction, recruitment, mortality, and threats to the species. The cactus grew an average of 0.42 cm in height and 0.33 cm in width per year. Plants were about 10 years old before they produced fruit. Four demographic patterns were observed: (1) the total number of individuals nearly doubled, (2) the average annual recruitment rate was approximately four times greater than the average annual mortality rate, (3) the population appeared young, vigorous and viable, and (4) the cactus population may have responded to above-normal precipitation at the study site. Livestock and off-road vehicle tracks were observed in the study area but apparently are not major threats to the species. The Kane County population may be the most viable of all the populations currently under study in Utah and Arizona.

Parent Publication

• Southwestern rare and endangered plants: Proceedings of the Third Conference

Citation

Hreha, Alyce M.; Meyer, Therese B. 2001. Five-Year Monitoring Study of Siler's Pincushion Cactus (Pediocactus sileri) in Kane County, Utah. In: Maschinski, Joyce; Holter, Louella, tech. eds. Southwestern rare and endangered plants: Proceedings of the Third Conference; 2000 September 25-28; Flagstaff, AZ. Proceedings RMRS-P-23. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 83-94.