Distribution of Paradine plains cactus in pinyon-juniper woodland on the North Kaibab Ranger District, Kaibab National Forest

Abstract

Surveys for Paradine plains cactus (Pediocactus paradinei B. W. Benson) conducted for the Kaibab National Forest, North Kaibab Ranger District in 1992-94 qualitatively showed a fairly substantial population of scattered individuals in the pinyon-juniper woodland, and indicated that there might be a correlation between plant distribution and dripline of trees. This project was initiated in 1999 to test that possibility. Field surveys in July of 2000 showed an apparent sharp decrease in numbers of cacti since 1994, probably due to conditions caused by a drought from 1998 to the summer of 2000. The plants that were located showed no statistical correlation between dripline and distribution when both tree species were considered together; however, there was a positive correlation between juniper and Pediocactus distribution on the dripline, and a negative correlation between pinyon and Pediocactus on the dripline. Mycorrhizal association may be responsible for the positive correlation of juniper and Pediocactus. The small sample size due to low numbers of plants makes these conclusions preliminary.

Parent Publication

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

Citation

Phillips, Arthur M., III; Kennedy, Debra J.; Phillips, Barbara G.; Weage, Diedre. 2001. Distribution of Paradine plains cactus in pinyon-juniper woodland on the North Kaibab Ranger District, Kaibab National Forest. 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. 221-227.