Canadian Forest Service Publications
Volcanic ash soils: sustainable soil management practices, with examples of harvest effects and root disease trends. 2007. Curran, M.; Green, P.; Maynard, D.G. Pages 97-119 in D.S. Page-Dumroese, R. Miller, J. Mital, P. McDaniel, and D. Miller, technical editors. Volcanic-ash-derived forest soils of the inland northwest: properties and implications for management and restoration, November 9-10, 2005, Coeur d'Alene, ID. USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO, Proceedings PMRS-P-44. 220 p.
Issued by: Pacific Forestry Centre
Catalog ID: 26836
Availability: PDF (download)
Sustainability protocols recognize forest soil disturbance as an important issue at national and international levels. At regional levels continual monitoring and testing of standards, practices, and effects are necessary for successful implementation of sustainable soil management. Volcanic ash-cap soils are affected by soil disturbance and changes to soil properties influence ecosystem responses such as productivity and hydrologic function. Soil disturbance from timber harvesting, reforestation, or stand tending is mainly a result of moving equipment and trees. Compaction and organic matter removal are of primary concern. The severity and extent of disturbance depend on the harvest system, soil and climatic conditions. Ash-cap soils can be susceptible to disturbance and schemes to predict compaction, displacement and erosion hazards are useful for planning forest management operations. On-site effects range from permanent loss of growing sites because of roads, to more subtle changes in soil properties that ultimately influence site productivity. Off-site effects may include erosion and landslides. Soil disturbance during operations should be regulated and monitored to minimize both on- and off-site effects, which can take years or decades to appear. Forest health issues vary on volcanic ash-cap soils. An analysis of Armillaria root disease incidence across the National Forests of the Inland Northwest indicates some potential relationships among root disease, and soil and site factors. The strong relations between presence of susceptible host and development of fungal biomass may be the strongest causal agent, with the soil and site factors supporting the presence of the pathogen and susceptible host. Thicker ash soils of more northerly areas are related to habitat types that historically supported white pine and a higher diversity of less susceptible species. After root disease mortality occurs, these more mesic environments also fill in with other species rapidly, so higher levels of root disease are more difficult to discern. Recommendations are made for soil management and about information needs for soil disturbance and root disease relations.