Monitoring of Peebles Navajo Cactus (Pediocactus peeblesianus subsp. peeblesianus), a small, solitary, globose cactus endemic to Navajo County, Arizona. It’s known from only two core populations and was listed as endangered in 1979.
Since 1986 three plots have been monitored. The total number of live plants in the monitoring plots fluctuates from 185 plants in 1986 up to a maximum count of 415 plants in 1995, and down to a minimum count of 42 plants in 2018. Threats to the species include: loss of habitat including gravel pit operations used for road construction, overutilization by cacti collectors, trampling from grazing cattle, lack of regulatory protection, limited distribution restricted to a specific soil type, rodent and lagomorph predation, and damage by off-highway vehicles and dust debris..
(Credit: Museum of Northern Arizona/Nancy Wiechec)