The Effects of Straw Mulching on Post-Wildfire Vegetation Recovery in South Eastern British Columbia

Abstract

Following the severe wildfire season of 2007 in southeastern British Columbia, straw mulching was used to stabilize soil on burned hillslopes and to reduce the risk of debris flows and flooding after the fires. The effects of the straw mulch on vegetation recovery and the introduction of invasive species were studied in two elevation classes over 2 years following the fires. The study measured percent of live vegetation cover including native, non-native, and invasive species in mulched and untreated control plots in highseverity burns. Total percent vegetation cover was not significantly different between treatments in either elevation class. A slightly slower rate of vegetation growth in mulched sites may suggest that mulch inhibits growth. Invasive species were present prior to mulching in both elevation classes. In the lowelevation class, the invasive species cover increased in both treated and control plots and in both years of the study. High-elevation plots showed a decrease in invasive species in the second year. Non-native species introduced with the mulch did not increase after the first year in either elevation class. This study shows that the use of straw mulch as an erosion control treatment has minimal effects on vegetation growth, but considerable effort should be taken to access mulch that does not contain seed to prevent the introduction of invasive species.