Aerial mulching techniques-trough fire

Abstract

The Trough fire occurred in August 2001 on the Mendocino National Forest of northern California. A burned area emergency rehabilitation team evaluated the fire effects on the watershed. Concerns were soil from the denuded slopes moving into streams affecting fishery values, reservoir sedimentation and storm runoff plugging culverts leading to road wash outs. Past evaluations have shown hand straw mulching to be a superior method in protecting soil from raindrop impact, surface runoff and erosion. However, hand mulching is a long and expensive process with safety factors dictating mulching only on ridges and not steep stream banks. On the Trough fire two aerial mulching techniques were evaluated on stream banks. Both evaluations were done in cooperation with USDA, Forest Service, San Dimas Technological and Development Center. One technique was in conjunction with the California Straw Supply Co-op. Work consisted of straw baling techniques and dispersal of straw by helicopter. Field testing on the Trough fire involved 60 ac being treated at a cost of $450 ac-1. This cost included unit layout, work crews, straw, trucking costs and helicopter flight time. In March 2002, San Dimas and Erickson Air-Crane contacted the Forest to test a new hydromulch formulation in a burned area. The helicopter hydromulch drops wereeffective in creating swaths along two steep burned streams. Cost for the treatment was $3,000 ac-1 plus mobilization. During treatment, some germinated native plants were covered with hydromulch. Over time, most of these perished. The Forest Botanist surveyed treated and untreated land. Untreated areas had more plant diversity than the treated area. In November 2002, the hydromulch area was inspected for product effectiveness. After a 6 inch rain, the mulch was mostly intact with native plants germinating through the mulch. Surface erosion and some rill erosion were halted by the hydromulch.

Parent Publication

• Proceedings of the 2002 fire conference: managing fire and fuels in the remaining wildlands and open spaces of the Southwestern United States

Citation

Faust, Robert. 2008. Aerial mulching techniques—trough fire. In: Narog, Marcia G., tech. coord. 2008. Proceedings of the 2002 Fire Conference: Managing fire and fuels in the remaining wildlands and open spaces of the Southwestern United States. Gen. Tech. Rep. PSW-GTR-189. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. p. 91-98