Fire-adapted forests; Hazard reduction; Ecosystem restoration; Treatment demonstration; Interdisciplinary research; National replication
Hazard Reduction/Ecosystem Restoration Study: Home

The goal of the soils discipline is to quantify belowground changes following hazard reduction treatments (Control, Thin-only, Thin-and-burn, Burn-only). Numerous soil properties may be altered, potentially influencing soil fertility, forest productivity, and ecosystem function. These changes may be physical or chemical in nature, leading to a number of core variables.

Soils crew sampling in a Burn-only treatment
Core Variables_________________________________

~Soil physical properties

Soil profile descriptions
Soil taxonomy
Soil texture
Bulk density/Soil strength
Exposure of bare mineral soil

~Nitrogen dynamics

Nitrogen mineralization
Inorganic pool sizes
Total nitrogen in soil
Nitrogen concentration in forest floor layers

~Biodiversity and Microbial Activity

Enzyme assays
Phospholipid fatty acid profiles


~Nutrient status

Cations (Ca, Mg, NH4, K, Fe, Na, Al)
Anions (PO4, SO4, NO3)


~Carbon dynamics

Total carbon in mineral soil
Carbon concentration in forest floor layers

Ongoing Studies

~The response of soil physical, chemical, and biological processes to hazard reduction treatments.

~Spatial heterogeneity of plant resources in response to hazard reduction treatments: the response of vegetation diversity.

~Short-term changes in nitrogen mineralization and the soil microbial community following hazard reduction treatments.

Soil hetergeneity sampling
Cooperative Studies

Fuel reduction treatments may differentially alter the spatial distribution of nitrogen. Differing degrees of patchiness and patch sizes may influence vegetation development, composition, and ultimately diversity. Data were collected and interpreted in the first and second year following treatment implementation. These data revealed spatial nitrogen patterns through time following fuel reduction treatments. The role of these resource dynamics in shaping the undergrowth vegetation community has been investigated in conjunction with the vegetation discipline and has been accepted for publication in Ecological Applications (go to Products).

Soils heterogeneity sampling in the Thin-and-burn treatment
Soils Factoids

~There are three soil subgroups on the FFS Lubrecht site: Udic Ustochrepts, Dystic Eutrochrepts, and Typic Eutroboralfs.

~Burn treatments resulted in significant increases in readily available nitrogen in the form of ammonium and nitrate. Most plants require these forms of nitrogen for growth.

~Harvesting resulted in no negative impacts on the soil. This was due in-part to the harvest system used (cut-to-length with a forwarder) and season of harvest (winter).

Useful Links

Soil Science Society of America

Thomas DeLuca - Professor of Forest Soils - University of Montana

Stump consumed in burning
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Lubrecht FFS Home
For information on this study contact Carl Fiedler.

For comments on this website contact Kerry Metlen.