Soil Quality is Fundamental to Ensuring Healthy Forests and Reducing Risks Associated with Forest Pest or Operations

Deborah Page-Dumroese, Martin Jurgensen, Carl Trettin, Mike Curran , and Dan Neary

USDA Forest Service Rocky Mountain Research Station (1,5) and Southern Research Station (3), Michigan Technological University (2), and British Columbia Ministry of Forests (4)

Maintenance of soil quality is an outcome government agencies and landowners strive to achieve after site management to maintain site productivity, hydrologic function, and ecosystem health. Soil disturbance resulting from timber harvesting, prescribed fire, or site preparation activities can cause declines, improvements, or have no effect on site productivity and hydrologic function.  Soil resource information can be used to determine the stress level and ecosystem functions of stands and may be one method used to determine disease or insect outbreak risk.  Soil physical properties, water regimes, and biogeochemical properties are key characteristics that can be affected by soil disturbance and in turn affect site quality and the susceptibility of stands to insects and disease outbreaks.  In addition, overstocked stands, increased climatic variation, drought, type conversion, and susceptibility to wildfire can contribute to changes in soil quality that leads to outbreaks of insects and diseases in many ecosystems.  For example, changes in ecosystem properties associated with changes in overstory properties alter the resilience of these stands.  Similarly, loss of western white pine in the northwestern USA from blister rust infection has caused a type conversion to forest species that are not tolerant of root diseases, are not fire resistant and sequester nutrients in the surface mineral soil and tree crown that can later be lost through logging or fire.  In the southwestern USA, overstocked ponderosa pine stands become water and nutrient stressed leading to insect outbreaks and catastrophic wildfires.  These relationships and others can be used in conjunction with soil resource data bases to assess susceptibility to threats and to help develop management strategies to mitigate disturbances. 

Land Session - Wednesday Afternoon

corrresponding author:

Deborah Page-Dumroese
USDA Forest Service
Rocky Mountain Research Station
1221 S. Main
Moscow, ID 83843
208-883-2339
ddumroese@fs.fed.us