Practicum Project | 2008

Effects of Hydromulch on Post-Fire Seed Germination

Students: Caroline Evans, Angel Kwok, and Sarah Maquindang

Final Report

One of Southern California’s latest fires occurred on May 8, 2007 at Griffith Park, the largest municipal park in the United States located in Los Angeles. In order to increase slope stability and protect homes, the city aerially applied hydromulch to over half of the burned area. However, the effectiveness of hydromulch as a slope stabilizer and its potential effects on post-fire vegetation are not well known. We used two experiments, one in the field and one in plant containers, to determine whether or not hydromulch had any significant negative effects on post-fire chaparral vegetation recovery. In the field experiment, there were no significant differences in plant density between our study areas with hydromulch compared to areas without hydromulch. The second seeding experiment showed growth underneath the hydromulch, from which can be concluded that enough sunlight is available underneath hydromulch to support plant growth. Thus, the insignificant differences between vegetation growth and density in hydomulched and non-hydromulched for both experiments indicated that the application of hydromulch might not be as detrimental towards vegetation germination as previously hypothesized.