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Abstract
Timber management in Sitka spruce / western hemlock temperate rainforests is increasingly focused on secondary even-aged stands that re-established after primary forest removal during the 20th century. After clear-cut harvest, abundant natural regeneration fosters rapid stand initiation forming dense, close canopy forests. Understory vegetation declines rapidly after canopy closure and is nearly absent during the prolonged stem exclusion phase of stand development. Productive understory vegetation is important for wildlife habitat and subsistence food resources across the ecoregion. Precommercial thinning is widely used to enhance crop tree growth and preserve or improve understory plant communities by reopening the canopy and increasing light transmission. Tree pruning can improve wood quality and may also enhance understory production through additional canopy light transmission. An improved understanding of the effects of silvicultural pruning is needed to guide management application of related prescriptions across Sitka spruce / western hemlock forests of North America. In this study, we utilize two long-term stand manipulation experiments on the Tongass National Forest, Alaska, USA to evaluate (1) how pruning lift height and (2) the proportion of trees pruned affects crop tree characteristics and understory plant communities.
Parent Publication
Citation
Nelson, Kellen; Barnard, Jeff; Massingham, Preston; Crotteau, Justin. 2022. Effect of pruning in Sitka spruce-western hemlock forests in the Pacific Temperate Rainforest. In: Jain, Theresa B.; Schuler, Thomas M. [comp.]. Foundational concepts in silviculture with emphasis on reforestation and early stand improvement - 2022 National Silviculture Workshop. Proc. RMRS-P-80. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 4 p.
