The Impact of Hydromulch on Native and Non-native Species in a Post-Fire Recovery Period within Los Angeles’ Griffith Park
Students: Bailey Blosser and Joelle Jahng
Advisor: Hartmut Walter
Final Report (PDF)
Non-native plant growth after a fire is often a common characteristic associated with a fire-adapted plant community. The relationship between native and non-native plant growth after a fire and the application of erosion-control measures such as hydromulch is not well understood. In this paper, we explore the relationship between diversity, richness, and abundant growth rates in an urban wilderness park setting of native and non-native California chaparral. In the spring of 2008, we studied Los Angeles’ largest urban park, Griffith Park, that experienced an 800-acre fire in May of 2007 and an application of hydromulch to 500 acres of the park. We used the Shannon diversity index and the Student t test to find diversity levels and to measure variation among samples in order to determine if there is a relationship between native and non-native species diversity, richness, and growth rates and the application of hydromulch. We found that plots with no or partial application of hydromulch had slightly higher indices of diversity and richness than plots without hydromulch. No relationship was apparent between hydromulch application and non-native growth dominating over native growth, however there was an overall higher frequency of non-native plant counts, specifically Brassica nigra (Black Mustard) and Daucus carota (Queen Anne’s Lace) over native species plant counts regardless of hydromulch coverage.