Arizona hedgehog cactus (Echinocereus arizonicus subsp. arizonicus) ongoing restoration efforts on Tonto National Forest

Echinocereus arizonicus subsp. arizonicus (Arizona hedgehog cactus or AHC) is a US federally listed endangered subspecies under the Endangered Species Act since 1979 and is endemic to an approximately 25km² area in central Arizona, growing largely within the Tonto National Forest. AHC prefers rocky microsites such as cliffs, bluffs, outcrops and boulders within a narrow range of Madrean woodlands and chaparral plant communities from approximately 1000-1740m in elevation. The US Fish and Wildlife Service estimated current population at 6,000-6,700 individuals in January 2021. Between 1979 and 2021, AHC abundance and habitat both continuously declined due to road construction projects, mining operations and recent mega-wildfire. The Telegraph Fire of June 2021 burned 180,000 acres of Forest and other lands, including more than 20% of the subspecies’ known habitat and 56% of its estimated habitat. Approximately 1600 plants mapped by the US Forest Service prior to the fire fell within the fire’s perimeter.
Desert Botanical Garden (DBG) has been involved in conservation of AHC by seed banking, monitoring, propagation, population genetics studies and salvaging. In March 2022, staff transplanted 60 previously salvaged stems in the new Pinto Creek Bridge area, concluding a conservation project begun in 2017 under Section 7 funding from the Endangered Species Act (ESA).
In October 2021, authors started a new project under Section 6 funding (ESA) in which we test effectiveness in restoration practice of a newly developed technique: harvesting stems from wild AHC plants to root under controlled conditions for transplant into native habitat in order to augment subspecies numbers toward delisting. With this technique, we have produced mature, reproductive individuals in a short period of time (1 year) compared to propagation by seed (estimated 8-10 years), at a size that can survive and establish under field conditions. We have begun restoration of the target subspecies by transplanting ~260 of a total 300 asexually propagated individuals at three sites within the subspecies’ range on the Tonto National Forest, with the help of US Forest Service, US Fish and wildlife, and DBG staff from January-March 2023. We will continue restoration by planting the final ~40 individuals at the third site in April 2023, allowing us to compare survivorship between a post-fire site, a post-construction site and a control site with healthy habitat. We will also compare winter-planted survivorship with spring-planted survivorship. Our presentation illustrates the background, scope, methodology and results so far of our AHC restoration project on public lands.