Conserving soil characteristics such as integrity, function, and productivity are always important in logging operations, but soil management is particularly challenging during harvest activities on steeper slopes (>35%). Soil conservation is important for future forest productivity, conservation of hydrologic function, and prevention of erosion, especially on steep slopes and above fish-bearing streams.
Specific examples of equipment operations damaging soil include side-tracking and turning, which can lead to displacement, mixing, and berms. Such disturbance of the natural layering and density of soils reduces productivity and moisture retention, among other effects. Ruts created by machinery are especially prone to allowing runoff, sediment movement, and overland flow of water, especially when combined with soil compaction. There are however, management practices available to mitigate soil-resource impacts, such as aerial logging, but when that is not feasible, placement of slash-mats from cut-to-length and forwarder operations have proven to be beneficial.
The Forest Service has a pilot project underway on the Fremont-Winema National Forest to look at the utilization and effectiveness of slash mats and overall impacts of logging on steep slopes. This presentation covered some of the basics of soil preservation in forest management with a focus on steep slopes, and report preliminary findings on the latter pilot project studying slash-mats. Since current federal regional and forest standards require that no more than 20 percent of an active area can be adversely affected, it takes continuous conscious efforts to try new approaches, improve old practices, as well as knowing when to refrain from adverse activities to ensure that soils will retain their long-term productivity.