Alternative Invasive Species Management: Manual Russian Olive Removal Along the San Juan River
Elissa Rothman
Canyon Country Discovery Center, Monticello, Utah USA elissar@ccdiscovery.org
Though logistical challenges created by COVID-19 interrupted chemical treatment of Russian olive (Elaeagnus angustifolia) on the banks of the San Juan river, the pandemic presented an opportunity for innovation. In partnership with the Bureau of Land Management, the Canyon Country Youth Corps has chemically treated E. angustifolia at the Gold Mine Site in San Juan County, Utah since 2017. In 2020, the COVID-19 pandemic stalled scheduled treatment until June, at which time southwestern willow flycatcher (Empidonax traillii extimus) nesting season had begun. Hoping to continue work in some way, stakeholders turned their attention to the E. angustifolia seedlings emerging under the canopy opened by previous stump-cut and frill treatments. Following initial success, in 2021 the crew endeavored to formally test whether hand-pulling of E. angustifolia could successfully remove seedlings and prevent regrowth without chemical treatment. Three test plots were designed to represent distinct treatment histories across the site: an area with chemically-treated mature trees and no E. angustifolia regrowth present, a chemically-treated area with masticated mature E. angustifolia and minimal seedling regrowth, and an area with growing E. angustifolia seedlings under chemically-treated snags. These plots were studied over the course of six months to measure E. angustifolia seedling growth and regrowth. At the end of the growing season, researchers concluded that manual treatment shows promise to end the cycle of regrowth for E. angustifolia.
In light of these results, the study inspires new theories of how manual efforts might enhance chemical treatment of E. angustifolia on the Colorado Plateau. Moreover, the lack of technical skill needed to manually remove E. angustifolia seedlings creates an opportunity to involve local communities in land stewardship. While E. angustifolia’s three-year seed viability demands future seasons of study at the Gold Mine Site, the initial investigation of the effect of hand-pulling E. angustifolia seedlings contributes new information to Integrated Pest Management on the San Juan River.