Recovery of Douglas-fir seedlings and saplings wounded during overstory removal

Abstract

Damaged and undamaged Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings and saplings, ranging in height from 15 to 450 cm, were monitored for 6 years after overstory removal to evaluate recovery from an assortment of logging wounds. Mortality (26%) was concentrated in seedlings less than 75 cm tall and was not related to damage. Surviving trees recovered from most wounds within the 6-year period. In most cases, lateral branches turned up to replace broken terminal leaders or stems; bole wounds healed over; and trees that had been pushed over returned to an upright position. A combination of a bole wound and being pushed to the ground resulted in the poorest recovery, especially for larger trees. With discriminant analysis, initial crown ratio alone enabled correct reclassification of sample trees as crop trees from 64 to 71% of the time; small trees were the most difficult to classify correctly. The addition of preharvest height growth and percentage of bole girdled variables improved the reclassification slightly. Across all three size classes analyzed, damaged trees with initial crown ratios of at least 0.66 were classified as crop trees a minimum of 75% of the time after 6 years. Significant height growth reductions were found only for damaged trees taller than 150 cm.

Croissance et rendement de la régénération naturelle d'épinettes noires (Picea mariana (Mill.) B.S.P.) après traitements sylvicoles dans les terrains dénudés boréaux /

“…Selon la littérature, le passage de la machinerie cause des dommages à la régénération pré-établie, pouvant ainsi influencer la croissance des tiges ayant survécu à ces traitements sylvicoles (Doucet 1988;Ruel et al 1991;Pominville et Ruel 1995;Pothier 2000;Prévost et Dumais 2003). En plus des dommages, les perturbations modifient le milieu de la régénération pré-établie, notamment par la récolte de Parbre-mère, par l'ouverture du milieu ainsi que par la diminution de la végétation de compétition (Tesch et al 1993;Ruel et al 1995;Paquin et al 1999). Bien que le scarifiage détruise et blesse une partie des pré-établis du site (Arnup et al 1988;Doucet 1988;Pominville et Ruel 1995;Pothier 2000), ceux qui demeurent devraient être avantagés une fois acclimatés à l'impact des traitements Paquin et Doucet 1992;Pothier et al 1995;Prévost 1997;Pothier 2000;Prévost et Dumais 2003;Bloom et Mallik 2004).…”

“…Plusieurs études Paquin et Doucet 1992;Pothier et al 1995;Prévost 1997 blessures physiques causées par la machinerie, le statut de la branche reliant la marcotte à l'arbre-mère avant sa récolte ainsi que le niveau de développement racinaire et du feuillage (Paquin 1990;Lussier et al 1992;Tesch et al 1993;Ruel et al 1995;Paquin et al 1999). Il est donc possible que la régénération pré-établie des sites à l'étude ne se soit pas encore acclimatée à l'impact des perturbations cinq années après ces dernières.…”

Examining the utility of advance regeneration for reforestation and timber production in unsalvaged stands killed by the mountain pine beetle: Controlling factors and management implications

“…It may be possible to identify biologically based indicators to assess the release potentials of advance regeneration at different developmental stages. Ruel et al (2000) suggested that age-height growth relationships may be controlled by tree live crown, which has been shown as a good indicator for release potential (Helms and Standiford 1985;Tesch et al 1993;Ruel et al 1995). Other potential tree release indicators may include pre-release height growth, height-to-diameter ratios, the degree of internodal and nodal branching, and the degree of apical control (McCaughey and Ferguson 1988;Murphy et al 1999;Ruel et al 2000).…”

Comparison of growth and physiology of layers and naturally established seedlings of black spruce in a boreal cutover in Quebec

“…In a study investigating the mortality of black spruce advance growth following clear-cutting, Ruel et al (1995) demonstrated that first-year survival and, to a lesser degree, second-and third-year survival were related to wound severity. Furthermore, Tesch et al (1993) observed that the recovery time of vigorous Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings and saplings from logging damage was 6 years.…”