Ecology of Eastern prickly pear cactus (Opuntia humifusa) in Oak Openings Preserve, northwestern Ohio

Opuntia humifusa (eastern prickly pear cactus) is listed as potentially threatened in Ohio, and we examined the characteristics of O. humifusa sites in Oak Openings Preserve in northwestern Ohio’s Oak Openings region in an attempt to provide data that may help protect this species. Opuntia humifusa occurrences were associated with loose sands of the xeric Udipsamment Ottokee and Oakville soil series on sites that had been cleared before the 1940s during failed agricultural attempts. Shading by encroaching canopy trees is a threat to several O. humifusa populations in Oak Openings Preserve, and treatments that reduce canopy cover at these sites may help sustain this species and increase the proportion of flowering individuals. Because the patchy distribution of O. humifusa makes the species susceptible to local extinctions, the acquisition of sites by conservation organizations containing O. humifusa or providing suitable habitat is consistent with the perpetuation of this rare species in the Oak Openings region. Sandy sites previously disturbed by agricultural clearing, sand mining, or other soil disturbances should not be overlooked for their potential to provide O. humifusa habitat in this region