Impacts of erosion control treatments on native vegetation recovery after severe wildfire in the Eastern Cascades, USA

Abstract

Slope stabilization treatments like mulching and seeding are used to increase soil cover and reduce runoff and erosion following severe wildfires, but may also retard native vegetation recovery. We evaluated the effects of seeding and fertilization on the cover and richness of native and exotic plants and on individual plant species following the 2004 Pot Peak wildfire in Washington State, USA. We applied four seeding and three fertilization treatments to experimental plots at eight burned sites in spring 2005 and surveyed vegetation during the first two growing seasons after fire. Seeding significantly reduced native non-seeded species richness and cover by the second year. Fertilization increased native plant cover in both years, but did not affect plant species richness. Seeding and fertilization significantly increased exotic cover, especially when applied in combination. However, exotic cover and richness were low and treatment effects were greatest in the first year. Seeding suppressed several native plant species, especially disturbance-adapted forbs. Fertilization, in contrast, favored several native understorey plant species but reduced tree regeneration. Seeding, even with native species, appears to interfere with the natural recovery of native vegetation whereas fertilization increases total plant cover, primarily by facilitating native vegetation recovery.

Citation

Dodson, Erich K.; Peterson, David W.; Harrod, Richy J. 2010. Impacts of erosion control treatments on native vegetation recovery after severe wildfire in the Eastern Cascades, USA. International Journal of Wildland Fire. 19: 490-499.