Short-Term Responses of Aspen to Fire and Mechanical Treatments in Interior Alaska
2007
Paragi, T.F. | Haggstrom, D.A.
Fire suppression and limited timber markets presently hinder maintenance of the early successional broad-leaved forest for wildlife habitat near settlements in interior Alaska. During 1999-2003, we evaluated the efficacy of prescribed burning, felling, and shearblading (with and without debris removal) to regenerate quaking aspen (Populus tremuloides). Treatments were conducted largely during the dormant period for aspen: prescribed burns in mid-May and mechanical treatments in late August through early April. Prescribed burns on loess hills produced 40,900-233,000 stems/ha by the second growing season. Low relative humidity, slope of more than 10°, southerly aspect, and juxtaposition to open areas produced fire behavior adequate to ensure top killing and vigorous sprouting response. Felling by chainsaw on loess hills produced 34,800-89,800 stems/ha, whereas dozer shearblading on glacial outwash (loam over gravel) produced 74,200-209,200 stems/ha (cleared portions and windrows combined) and a sandy loam floodplain produced 31,400-64,800 stems/ha. Pushing debris into windrows or scraping thick moss allowed warmer soils and produced greater sprouting on cleared sites relative to sections where debris or moss remained. Mechanical treatments were 25-75% of current prescribed fire costs, but debris accumulation may hinder access by browsing species and attract terrestrial predators of gallinaceous birds.
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