The effects of initial spacing on wood density, fibre and pulp properties in jack pine (Pinus banksiana Lamb.)

Relationships between basic tree and wood properties, and species, seed source, geographic location, site conditions and management decisions are very complex. The objective of this study was to quantify the effects of forest management practices on wood density, fibre and pulp properties in jack pine, one of the most important commercial species in Northern America. A better understanding of the relationship between initial spacing and wood and end-product quality should help define improved forest management strategies required to produce quality wood and products in the future. On the basis of the oldest jack pine initial spacing trial established in 1941 by the USDA Forest Service, this study examined the impact of four different initial spacing trials on tree growth, wood density, fibre and pulp properties of jack pine. The results clearly show that initial stand spacing has a significant effect on all of these properties, and thus it is possible to improve yield and wood and pulp fibre properties of jack pine through stand density regulation. Additionally, a positive effect of pre-commercial thinning on fibre properties was also demonstrated. As a consequence of these results, basic prescription information for decision-making in the establishment of jack pine plantations with desirable pulp properties can be elucidated.