Secondary stand structure and its timber supply implications for mountain pine beetle attacked forests on the Nechako Plateau of British Columbia.

Residual mature trees and secondary stand structure after mountain pine beetle attack in central British Columbia

“…In north central BC, Coates et al (2006) reported that 20-30% of stands have enough secondary stand structure to contribute to a mid-term timber supply if left unsalvaged and an additional 40-45% of stands have sufficient understory to be considered stocked (stands have a minimum number of healthy stem, according to BC legislation 900 stem/ha if height is >4 m or 700 if height is >6 m for MPB-attacked stand) in a certain height group. Retaining such stands would reduce the rotation age by 10-30 years, compared to starting anew (Coates et al, 2006), help to mitigate the projected mid-term timber supply shortfall (Pousette and Hawkins, 2006;Pousette, 2010) and enhance ecological diversity. Coates et al (2006) also suggested that only 20-25% of stands needed some form of intervention due to lack of secondary stand structure.…”

Aftermath of Mountain Pine Beetle Outbreak in British Columbia: Stand Dynamics, Management Response and Ecosystem Resilience

“…In another study, Coates et al [51] indicated that stands with healthy, vigorous, and well-spaced advanced regeneration may develop rapidly following MPB attack and can contribute harvestable volumes of 200-300 m 3¨h a´1 within 25-40 years, which is greater than target timber production (150 m 3¨h a´1) for MPB-infected stands in BC. Similarly, Pousette [78] showed that a significant number of MPB killed stands in central BC can contribute mid-term merchantable timber within 30 years of MPB attack. In an earlier study Coates and Hall [76], suggested that after MPB-induced pine mortality, residual spruce in well-stocked stands with good basal area recovered to pre-attack basal areas within 50 years in two of four experimental stands in BC.…”

“…Different types of models such as SORTIE-ND, PrognosisBC and their hybrids are mainly used to predict the dynamics of MPB-attacked stands in BC. Among them, SORTIE-ND is intensively applied to predict future or mid-term timber supply analysis across BC [51,54,[75][76][77][78]. Based on projections by Hawkins et al [54], stands with a minimum of 900 stems/ha (tree > 4 m height but < 7.5 cm DBH) of residual secondary stand structure can reach minimum merchantable volumes (150 m 3¨h a´1) in most of the age classes within 30 years after MPB attack.…”

Consequences of mountain pine beetle outbreak on forest ecosystem services in western Canada

“…However, the scenario could be different than forecasted if salvage logging activity is carried out only where it is most beneficial (i.e., in forests that are not forecast to achieve minimum merchantable timber volumes (150 m 3 ha -1 ) based on residual understory and surviving trees after the outbreak) (Burton 2006;Coates et al 2006Coates et al , 2009Hawkins et al 2012;. Multiple field investigations have revealed that a large percentage of MPB-impacted, unsalvaged stands have D r a f t enough residual secondary structure (seedlings, saplings, sub-canopy, and canopy trees that will survive a beetle attack) to provide minimum merchantable timber volumes (150 m ha -1 ) within years (Coates et al 2006, Pousette 2010Hawkins et al 2012;Dhar et al 2013;). Other studies have reported that only 17-25% of unsalvaged stands may need some level of management intervention to achieve target merchantable mid-term timber volumes (Coates et al 2006;Dhar et al 2013).…”