Article Clearcutting and Site Preparation, but Not Planting, Promoted Early Tree Regeneration in Boreal Alaska Miho Morimoto 1,*, Glenn Juday 1 and Brian Young 2 1 School of Natural Resources and Extension, University of Alaska Fairbanks, Fairbanks, AK 99775, USA;
[email protected] 2 Natural Science, Landmark College, Putney, VT 05346, USA;
[email protected] * Correspondence:
[email protected]; Tel.: +1‐907‐371‐6562 Academic Editors: Brian J. Palik and Timothy A. Martin Received: 11 November 2016; Accepted: 16 December 2016; Published: 25 December 2016 Abstract: The stand initiation stage decisively influences future forest structure and composition, particularly in the boreal forest which is a stand replacement disturbance driven system. In boreal Alaska, the conventional forest management paradigm has focused on the production of large‐ dimension timber, particularly white spruce (Picea glauca). However, energy generation and heating from wood is increasing, and is likely to significantly expand total forest harvest, further shifting management focus to fuelwood production. We evaluated the effects of forest harvest management practices on post‐harvest regeneration by examining whether harvest type, site preparation method, and reforestation technique resulted in differences in forest regeneration in terms of species presence, dominance, basal area, and total stem biomass using a stochastic gradient boosting (TreeNet algorithm). We recorded diameter at breast height and height of white spruce, birch (Betula neoalaskana), and aspen (Populus tremuloides) in 726 plots from 30 harvest units, distributed across the various harvest and treatment types, harvest years, harvest sizes, and geographical locations. Our results indicate that management practices suitable/acceptable for woody biomass production differ from the more traditional dimensional timber production from white spruce‐focused management.