Ravennagrass eradication

The District undertakes a wide variety of on-the-ground conservation projects as grant funding becomes available. For example, an American Recovery and Reinvestment (ARRA) grant supplemented by funding from the Rose Foundation allowed the RCD to undertake an innovative partnership project to eradicate a potentially devastating infestation of Ravennagrass (Saccharum ravennae) from some 70 miles of Cache Creek in Lake and Yolo Counties. This invasive weed, which was deliberately introduced to California as an ornamental and has been described as “pampas grass on steroids,” could profoundly degrade riparian areas throughout the region if not controlled, and control is particularly difficult because so many of the plants are found in steep, inaccessible terrain deep in the Cache Creek Wilderness.

Primary management responsibility for the project was shared by the East Lake and Yolo County Resource Conservation Districts and Bureau of Land Management. The first step was to delineate the problem, so volunteers from the Woodland-based environmental advocacy group Tuleyome (which had conducted a successful tamarisk eradication project in this area a few years previously) paddled down the creek in kayaks with GPS equipment to pinpoint hundreds of clumps of Ravennagrass, many perched too high on the canyon walls to be accessible from creek level.

The severity of the infestation was far worse than anyone had imagined. Under the supervision of Yolo RCD Vegetation Management Specialist Gillies Robertson, work on the section downstream from Cache Canyon proceeded uneventfully, but the upstream portion remained daunting: not only was the terrain remote and rugged, its designation as federal Wilderness precluded the use of any form of motorized transportation. This meant that work crews faced the prospect of long off-trail hikes in bear country, carrying massive quantities of gear, merely to reach the work site. In the words of East Lake RCD District Manager Greg Dills, “This was one of the most tactically difficult projects we have been involved with to date. There were multiple project partners, some of the most rugged terrain in Northern California, restrictions due to Wilderness designation, multiple landowners (both private and public), and bears.”

The conundrum was solved by Cache Canyon River Trips from Yolo County, which provided two large rubber rafts—rafts that usually carry white water recreationists—to transport equipment, supplies, and work crews down the creek from the Clear Lake dam and through 25 miles of project area. Lake County’s Back Country Horsemen also offered to pack in gear, though it turned out that their assistance wasn’t needed. Although the job remained difficult, it was no longer impossible; an estimated 90 percent of the Ravennagrass on Cache Creek was destroyed, providing a model for protecting the biodiversity of a wilderness area while simultaneously guarding the special values that make wilderness unique.

The problem now is to mop up the scattered plants left behind and to exterminate seedlings before another widespread stand can become established. A little grant money remains for an early treatment in the spring, and both RCDs are looking for additional funding sources to continue the project in the future. Monitoring will be necessary for several years to insure control, and rafters, kayakers, equestrians and hikers are invited to help this effort by surveying for regrowth as they recreate in the area.

Powered by Create your own unique website with customizable templates.