Invasive Annual Grass in the Basin
Monitoring of medusahead rye invaded area. Part of the SOWR project, monitoring team from the High Desert Partnership.
The Malheur Watershed Council has long held invasive annual grass treatment as a priority. The Council sees the threat these grasses pose to not only habitat and forage availability, but their role in increasing fire frequency, increased erosion potential and degradation of the watershed. The Council has funded projects in the past to treat localized areas, but recently there has been momentum gaining to tackle this issue at a larger scale.
Recently emerging treatment options, including the herbicide Rejuvra, offer more effective control of these invasive annual grasses than has been available in the past. Rejuvra has the ability, when applied and incorporated into the soil properly, to stop the growth of shallow-rooted annuals for 3-5 years. This is unique in that it allows the slower growing perennials the chance to strengthen and spread, setting them up to outcompete invasive annuals when the herbicide’s effectiveness fades. Coupled with increasing movement to enhance fire resiliency, the effort to control these grasses seems to be reaching a critical level. “Until a few years ago treatment options where so limited that it seemed as if it was inevitable that the annual invasive grasses would eventually take over all our rangeland drastically affecting all animals trying to survive on the range”, states Amanda Zander, the Malheur County Weed Inspector.
In February 2022, the Oregon Department of Forestry allocated $5 million as part of Senate Bill 762 to the Harney County Wildfire Collaborative (HCWC), a High Desert Partnership collaborative, to address fire suppression, prevention, and restoration of sagebrush sea landscape in Harney and Malheur Counties. Named the Southeast Oregon Wildfire Resiliency Project (SOWR Project), HCWC partners have worked together with Malheur County partners to implement actions on the ground to build a more wildfire resilient landscape. The project boundary fell partially within the Malheur River Basin, impacting both Harney and Malheur County.
What the partners accomplished in 2022 within the parameters of the SOWR Project:
Aerial applications of pre-emergent herbicide applied to 70,908 acres of private, tribal, state and federal land to inhibit germination of invasive annual grasses for up to four years.
Contracted juniper cutting and pile burning on 837 acres.
Seeding 300 acres with grasse seeds following an invasive grass herbicide application.
Collecting and cleaning native plant seeds from strategic sites in both Harney and Malheur Counties.
Arial application of herbicide Rejuvra. Photo taken by Erika Fitzptarick.
The most significant actions taken to impact the Malheur River Basin was led by Tom Segal, a Wildlife Biologist with the OregonDepartment of Fish and Wildlife, who was collaborating on the SOWR Project. He is working with landowners to treat thousands of private acres of invasive annual grasses in prime sage grouse habitat within the Malheur River Basin. They are targeting cheatgrass and medusahead rye with the Rejuvra herbicide to prevent germination for several years, allowing perennial grasses, forbs, and shrubs to grow without competition. Through these treatments the landscape will be more resistant to wildfire, habitat will improve for wildlife, and livestock benefit from increased forage. “In southeast Oregon, wildfire is the greatest threat to wildlife populations. In many cases, when wildfire comes through, we lose our sagebrush and bitterbrush, which provide valuable food and cover for a suite of wildlife species, and then low statured annual grass takes over,” Tom states. “These new herbicide chemistries provide a tool like we haven’t seen before to get ahead of the annual grass problem in places where we still have good habitat. With the SOWR project work, I really think we’ve set things up so that if a wildfire does start during hot and windy conditions in or near the project area, the size and impact of the fire will be minimized.”
The SOWR project is a prime example of how efforts to engage multiple stakeholders under a common goal, while using the best available tools, can work to accomplish something greater than any one entity. Its actions benefit both the Malheur and Harney Basins and can be a model to work from going forward.
Amanda Zander hopes to build on this momentum to continue combating invasive annual grasses in Malheur County. She helped consult with on management areas in the County with Tom Segal during the SOWR project and is actively participating in another collaborative effort, successfully securing funding for invasive annual grass treatments. She is working to piece together different treatment efforts to form a barrier between the degraded lands and the intact ecosystems, creating a starting point to contain invasive annual grasses and hopefully begin restoration work down the road. This concept stems from the “Defend the Core” framework being promoted by Working Lands for Wildlife, an emerging, proactive strategy being used by a variety of efforts across the West. “I am trying to work myself out of a job, but I doubt I will run out of weeds to combat in my lifetime!” says Amanda.
Zander’s position is supported by the Malheur Watershed Council, which serves as the grant sponsor for the Oregon Department of Agriculture grants used to fight invasive species in Malheur County.
This article was written with supporting information from the High Desert Partnership and the Harney County Wildfire Collaborative.