Fighting Invasive Weeds Through Prescribed Burns

Case Study: Russian Ridge Open Space Preserve

Diverse plant communities, miles of forest edge, and abundant springs make Russian Ridge Open Space Preserve an outstanding habitat for wildlife. To effectively and economically manage the valuable grasslands of this area, the District implements a variety of resource management strategies, including mowing, herbicide treatment, grazing, seeding, cutting and digging, and fire.

Invasive Plant: Harding Grass

Fire benefits the natural environment by clearing out dead vegetation and facilitating:

restoration and regeneration of biological diversity
seasonal wildflower blooming
forage production for wildlife
invasive plant control
wildfire hazard reduction

While settlement and urbanization has necessitated the suppression of natural fires, the District conducts prescribed burns-- intentionally set fires in a wildland setting-- to reintroduce fire as an ecological process. As part of the District's Grassland Management Implementation Plan, prescribed burns, also known as controlled burns, reduce fuel (vegetation) load, provide fire suppression training, and limit the growth and spread of invasive, non-native plant species.

Russian Ridge 2007 Prescribed Burn

Prescribed Burns: 2007

In a joint effort with CAL FIRE, the District conducted a prescribed burn in Russian Ridge Open Space Preserve in July 2007. The burn served to control dense stands of the invasive, perennial Harding grass and yellow star thistle.

Results: 2008

In April 2008, senior District resource management staff surveyed the previously burned areas and reported significant environmental improvements, including:

minimal thatch (dead grass) in the burned area
multiple small areas of exposed soil
greater diversity of green sprouting plants
(consisting of a mix of native, nonnative, annual, perennial grasses and forbs)
approximately 19 species of blooming native wildflowers
signs of active occupation by a burrowing owl

Staff located persistent clumps of stubborn Harding grass, particularly in the north end of the burn area. Staff, contractors, volunteers, and the California Conservation Corps spent approximately 900 hours seeding natives and controlling target invasives with spot-spraying (herbicide), mowing, or brush cutting and digging.

Conclusion

Russian Ridge has many steep and rocky slopes on which mowing and drill seeding are infeasible. Repeat burning, coupled with subsequent spot spraying, selective weed control, and seeding, is an effective and economical way to control persistent invasive plants and to manage the valuable grasslands of Russian Ridge.

5-Year Strategic Plan

Resource Management Policies
(October 1994)

Resource Management Projects