Prescribed burn at the Bouverie Preserve

by Sherry Adams, Sonoma HPR Project Leader
and Daniel Gluesenkamp, Ph.D., Habitat Protection and Restoration Specialist

On June 14, 2007, Audubon Canyon Ranch staff had the pleasure of overseeing a small prescription burn of about four acres at the Bouverie Preserve's front grassland. The primary goal of the burn was to combat the spread of the invasive medusahead grass (Taeniatherum caput-medusae). Medusahead contains high levels of silica, which makes it unpalatable to wildlife and livestock. It can spread rapidly and leaves a thick layer of thatch, which suppresses the plant species diversity. Research has shown that a fire, if timed to coincide with when medusahead seeds are immature, is very effective at halting the spread of the noxious weed.

Photo: Medusahead grass
Copyright © 2007 Charles Kanard
Courtesy of Marin Sonoma Weed Management Area

While the fire was completed in just two short hours, it was the culmination of years of work. In 2001, the Audubon Canyon Ranch Board of Directors passed a fire management plan that recognized that fire can be an essential tool for restoring natural areas, and staff began planning grassland restoration work that employed this powerful tool. Last year we conducted a detailed inventory of medusahead at Bouverie Preserve using Geographic Information System (GIS) technology. This allowed us to develop detailed maps of medusahead infestations and plan a small prescription burn to address its spread. In a stroke of luck, the local Glen Ellen Cal Fire personnel agreed to conduct a training burn to start off the 2007 fire season, at precisely the time that medusahead seeds are most susceptible to fire.

Photo: Glen Ellen Cal Fire manages the fire
by Dan Gluesenkamp

Fire is just one of many tools used in our ongoing efforts to preserve and protect our sanctuaries, and like all tools, it is imperfect. While fire is known to effectively control medusahead grass, Audubon Canyon Ranch staff are concerned that fire alone may favor the growth of other invasive plant species, such as hairy catsear (Hypochaeris radicata) and sheep sorrel (Rumex acetosella). For this reason we will be monitoring the populations of these species and will perform follow-up work to prevent other invasive species from taking over the medusahead removal site. We also intend to conduct controlled scientific experiments to fine tune the prescription for removing medusahead, and we will share the results of our field research with restoration partners throughout the region.

Photo: Prescribed burn at the Bouverie Preserve
June 14, 2007
by Len Nelson