In late 2009, a local collaborative working group of landowners and agency representatives was formed to begin addressing control of invasive Russian Olive and Tamarisk trees along the lower Green River riparian corridor between Fontenelle Dam and the inflow area of the Flaming Gorge Reservoir. The level of Russian Olive and Tamarisk tree invasion along this reach of river was a major concern, but the densities of these invasive species have not yet reached the level where control efforts would be futile. The working group believes a coordinated effort to strategically inventory, prioritize, plan, implement, rehabilitate and monitor multiple phased control projects will successfully control the Russian Olive and Tamarisk trees while promoting sustainable native riparian tree and shrub communities along this river corridor reach.
The City of Green River Parks and Recreation Department is an active participant in the river corridor working group and the urban riparian greenbelt area adjacent to and through the City. This corridor along the Green River is experiencing the highest observed densities of Russian Olive invasion of any location within the river corridor between Fontenelle Dam and the Flaming Gorge Reservoir. This urban riparian greenbelt area is suspected of being the primary source for Russian Olive seed dispersal (bird ingested seeds as the likely upstream vector) both up and downstream within the focus river corridor area. Seed dispersal from this area now threatens important native riparian habitats currently experiencing little or no Russian Olive establishment such as lands within the Seedskadee National Wildlife Refuge.
The City of Green River Parks and Recreation Department compiled an inventory of the location for Russian Olive and Tamarisk trees growing on city administered property along the greenbelt corridor, including some Union Pacific Railroad Company lands and BLM lands leased to the City of Green River for parkland. BOSS Reclamation, LLC., was contracted in 2011 to treat these areas mechanically using a specialized patented track-hoe attachment that surgically extracts the entire invasive plant and intact root crown, which is key to successful control, as it severs lateral roots from the root crown allowing for practical follow-up chemical treatment the next year to kill re-sprouts and eliminate lateral root growth. A large rotary grinder followed behind the track-hoe and chipped all Russian Olive and Tamarisk biomass that was extracted to be used for reclamation mulch on site. The removal process was completed in July 2012.
An essential component of the Russian Olive and Tamarisk control project will be rehabilitating the treated sites with larger sized native riparian tree and shrub plantings. Speedy re-establishment of large stature native riparian tree and shrubs not only will provide the horizontal and vertical structure needed for wildlife habitat and the appropriate species composition for maintaining sound ecological processes, but will serve an important initial demonstration role for encouraging skeptical private landowners along the entire reach of the Green River corridor to participate in the Russian Olive and Tamarisk control effort.
Grant monies and in-kind services totaling $150,000 were received from:
• The City of Green River
• Wyoming Landscape & Conservation Initiative (WLCI)
• Wyoming Game & Fish
• Fish and Wildlife Service
• Wyoming Wildlife Natural Resources Trust
This cost sharing covered the costs of performing the mechanical Russian Olive and Tamarisk control on 50 acres of the City of Green River administered and leased property within the riparian greenbelt area along the Green River. The cost share also will be used to purchase 95 native tree and shrubs from nursery specializing in native species and hire a qualified contractor to plant the trees and shrubs in the spring of 2013. The City of Green River will conduct follow-up chemical control and native tree planting maintenance (for 3-years) to complete this invasive species control and native tree/shrub rehabilitation project.