The UCUT’s Timber, Fish and Wildlife Programs partnered with Syringa Ecological Consulting, LLC. on a Vegetation Composition, Tree Growth and Ungulate Use Response to Three Forestry Site Preparations Report.
This report summarizes a multi-year study on the effects of post timber harvest vegetation suppression treatments, known as site preparations, on vegetation composition and ungulate (large mammals with hooves) use. Study sites were located on tribal lands of the Kalispel Tribe of Indians, the Coeur d’Alene Tribe of Indians, and the Colville Confederated Tribes.
Prior to the 1990s, most site preparations in eastern Washington forests consisted of broadcast burning and mechanical clearing which involves using heavy machinery to masticate logging debris and scarify the land. Both of these site preparations techniques expose mineral soils and reduce competing vegetation prior to planting crop trees. The use of herbicide as a site preparation treatment can target specific vegetation species and has the potential to effect vegetation composition for up to ten years post application. Since the early 1990s, the use of herbicide has steadily increased in eastern Washington to roughly 10,000 acres per year on both private and state lands. This increase in use of herbicide has led the UCUT to investigate the impacts to native vegetation and ungulate use.
This study compares these three different site preparations (broadcast burning, mechanical, and herbicide) along with no vegetation suppression on five tribal harvest units. We investigated the multi-year effect on vegetation structure including forms important to ungulate browse, tree height and survival, and ungulate use in these treatments.
Additional Resources
Following is the full report, accompanying appendices and a presentation on the report.
