Aspen recruitment study at Wolf Creek Ranch
In 2009, Wild Utah Project was contacted by landowners from the 14,000 acre Wolf Creek Ranch near Kamas, UT. They were worried about eventually losing their aspen stands, one of the most popular features of the ranch. Homeowners suspected increased elk herbivory to be a factor influencing their aspen stands. A collaborative effort among Wild Utah Project, Utah State University, Utah Open Lands (who holds the Conservation Easement for the property), Utah Forestry, Fire and State Lands, and the Wolf Creek Ranch Homeowners Association was formed to investigate the condition of the aspen stands in question.
Using GIS mapping, we generated 50 random study plots throughout Ranch. The team trained about a dozen of the Wolf Creek Ranch landowners in the use of the aspen stand health assessment method that our team used for the study, which includes measures of both aspen regeneration, and recruitment into the overstory. When analyzed this data clearly pointed to both an aspen regeneration, but mostly a recruitment problem, with the culprit being a combination of the 400+ elk on the property, and a band of domestic sheep that travel through the ranch to and from the adjacent Wasatch Cache national Forest every spring and fall.
The results of the analysis are summarized in the paper Quaking Aspen in the Residential-Wildland Interface: Elk Herbivory Hinders Forest Conservation in the Natural Areas Journal. Additionally, the team recommended a suite of experimental treatments at the ranch, which included some aspen-regeneration stimulation treatments (i.e. thinning), some fencing treatments, and some sites that included both treatments. Wild Utah Project and the landowners have continued monitoring both the aspen regeneration and recruitment at these sites, and understory vegetation and plans to publishing the results.