Canadian Forest Service Publications
Exploring the potential of two-aged white spruce plantations for the production of sawlog volume with simulations using Sortie-ND. 2020. St-Gelais, V.; Béland, M.; Thiffault, N.; Reforesta. 10: 11-24
Issued by: Laurentian Forestry Centre
Catalog ID: 40304
CFS Availability: PDF (request by e-mail)
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The main objective for even-aged plantation (EAP) management of producing sawlog material has driven practices towards low initial planting densities and lower post thinning densities. For semi-shade tolerant species, the resulting stand density potentially leaves enough growing space for the introduction of a second cohort of trees in the understory, making it a two-aged plantation (TAP). TAPs could have many silvicultural benefits, especially in sensitive areas where intensive treatments associated with EAPs are incompatible with local management objectives. White spruce (Picea glauca) is a good candidate species for modeling TAPs because it is the most widely planted tree species in Canada and has proven tolerance to understory planting. SORTIE-ND, a single-tree spatially explicit growth model was used to explore the yield of variable density and rotation length scenarios when each white spruce cohort is introduced mid rotation, compared to traditional even-aged management. All TAP scenarios tested produced more sawlog volume and more merchantable volume than equivalent densities of EAPs. The lowest density tested, 400 stems ha-1 planted every 35 years, had the highest sawlog yields (3.23 m3 ha-1 yr-1). Considering smaller size products changes the optimum TAP scenario but maintains the advantage over EAPs.