The temperate rainforest of the Pacific Northwest extends from northern California to south-central Alaska and delivers a wide range of ecosystem goods and services, including quality fiber, biological diversity, subsistence lifestyle support, clean air and water, prolific fisheries, and stunning scenery. Much of the temperate rainforest lies within the Tongass National Forest, which manages 16.9 million acres in southeast Alaska. The Tongass has assigned strategic land use designations to optimize the delivery of ecosystem goods and services across the forest, in line with the Tongass Land and Resource Management Plan. The subset of forestland specifically designated for timber development provides globally valuable products and jobs to rural economies and includes both old-growth and young-growth stands. In recent years and per the Tongass Advisory Council’s recommendation, the Tongass has been transitioning away from a predominantly old-growth management approach to primarily young-growth management.
While managing young-growth forests has become a priority, questions remain about intermediate silvicultural treatments (treatments that occur in between regeneration and harvesting, like thinning). Silviculturists on the Tongass aim to manage within the bounds of existing land use designations (e.g., manage for timber in area designated for timber), but managers are also keenly interested in improving wildlife habitat, especially forage for the Sitka black-tailed deer. These small deer are endemic to the Alexander Archipelago and are valuable prey to local bear and wolves. The deer are also a staple of the subsistence lifestyle for local people, including Alaska Natives. Managers need to know what management techniques are appropriate to balance immediate and long-term needs (i.e., deer forage and timber, respectively) in young-growth stands.
A series of projects were co-developed by the Pacific Northwest Research Station and the Tongass National Forest between 2001 and 2010 to address this question. Research frameworks were set up to provide a scientifically rigorous basis for adaptive management of these young-growth forests. These include the geographically extensive Tongass-Wide Young-Growth Studies (TWYGS), and Prince of Wales Commercial Thinning Study (POW-CT), and a study of subcanopy snow and slash patterns by treatment age. Together, these valuable long-term studies are demonstrating the effects and tradeoffs of silvicultural techniques such as alder enrichment planting, precommercial thinning with wide spacing, pruning, slash treatment, and commercial thinning methods on understory response, timber growth, and wildlife habitat.
These studies have been implemented in operational stand settings to provide relevance for future management and meaningful forage areas for Sitka black-tailed deer. TWYGS and POW-CT studies use repeat measurements of vegetation structure and composition to demonstrate ecosystem response over time. Vegetation data are input into the Food and Resource Evaluation System for Habitat (FRESH) – Deer calculator to model combined forage nutrition and availability across treatments. These measurements of vegetation structure, composition, and forage provide a valuable means of comparing the long-term effects of treatment options. These research studies have been hallmarks of research-management collaboration thanks to active engagement by the Rocky Mountain Research Station, Pacific Northwest Research Station, and Tongass National Forest.
Findings are still being developed. Current findings include:
Crotteau, Justin S.; McClellan, Michael H.; De Santo, Toni L.; Spores, Sheila R.; Barnard, Jeffrey C., 2020. Sharing the load to develop young-growth silviculture for forage and biodiversity in southeast Alaska. In: Pile, Lauren S.; Deal, Robert L.; Dey, Daniel C.; Gwaze, David; Kabrick, John M.; Palik, Brian J.; Schuler, Thomas M., comps. The 2019 National Silviculture Workshop: a focus on forest management-research partnerships. Gen. Tech. Rep. NRS-P-193. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern Research Station: 170-192.
Crotteau, Justin S.; Rue-Johns, Annelise Z.; Barnard, Jeffrey C., 2019. Effects on understory biomass and forage 8-10 years after precommercial thinning of Sitka spruce - western hemlock stands in southeast Alaska.Canadian Journal of Forest Research. 32(4): 215-225.
Eckrich, C.A.; Flaherty, E.A.; and Ben-David, M. 2013. Estimating leaf area index in southeast Alaska: A comparison of two techniques. PLoS ONE 8(11): e77642.
Eckrich C.A.; Flaherty, E.A.; and Ben-David, M. 2018. Functional and numerical responses of shrews to competition vary with mouse density. PLoS ONE 13(1): e0189471.
Hanley, Thomas A.; McClellan, Michael H.; Barnard, Jeffrey C.; Friberg, Mary A. 2013. Precommercial thinning: implications of early results from the Tongass-Wide Young-Growth Studies experiments for deer habitat in southeast Alaska. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Res. Pap. PNW-RP-593. Portland, OR. 64 p.
McClellan, M.H., 2008. Adaptive management of young stands on the Tongass National Forest. In: Integrated restoration of forested ecosystems to achieve multi-resource benefits: Proceedings of the 2007 National Silviculture Workshop. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Gen. Tech. Rep. PNW-GTR-733. Portland, OR: 225-232.
Minkova, T.V.; and Arnold, J.S. 2019. A structured framework for adaptive management: Bridging theory and practice in the Olympic Experimental State Forest. Forest Science fxz011:1-12.
Schultz, M.; McClellan, M.; Scott, C.; and Danley, C. 2010. Insect and Armillaria sp. survey of Tongass Wide Young Growth Studies (TWYGS) Experiment 4 (35 yrs.+ old trees) Plots. USDA Forest Service Region 10, State and Private Forestry, Forest Health and Protection, Report R10-S&PF-FHP-2010-1.
Sikes D.S.; and Stockbridge, J. 2013. Description of Caurinus tlagu, new species, from Prince of Wales Island, Alaska (Mecoptera, Boreidae, Caurininae). ZooKeys 316: 35–53.
Stockbridge, J.M. 2014. Beetles and Spiders as Indicators of Recovery on Prince of Wales Island, Alaska. M.S. Thesis. University of Alaska Fairbanks. 131 p.
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