Douglas-fir and white fir advance regeneration for renewal of mixed-conifer forests

Tesch, Steven D.; Korpela, Ed J.

doi:10.1139/x93-180

Cited by 15 publications

(6 citation statements)

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“…However, absolute as well as relative values increased each year from 1995 to 2000 and thus reached their maximum only 5 years after release. Such delays until reaching maximum height growth after release are common and have been found to last from only a few years to between 10 and 20 years until full potential growth is reached (Tesch and Korpela 1993). The rapid response of root radial increment observed in this study is partly comparable with previous studies that reported an immediate and strong response in root radial increment following release (Urban et al 1994;Vincent et al 2009).…”

Section: Response Of Aboveground and Belowground Radial And Length Insupporting

confidence: 88%

Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal

et al. 2012

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Long regeneration periods, which result in two-layered or multilayered forest stands, are an important element of the close-to-nature forest management paradigm in central Europe. Such extended regeneration periods, however, may lead to undesirable development of advance regeneration, specifically in species such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) where root growth is strongly curtailed under competition. We hypothesized that root systems of naturally regenerated Douglas-fir that had grown under closed canopy for prolonged periods would be inhibited in their capacity to develop adequate structural root systems following release through removal of the canopy. Complete root systems of six approximately 25-year-old Douglas-fir that had grown for at least 12 years underneath a closed canopy before overstory removal were excavated using subterranean explosives. Root elongation, radial increment of primary lateral and vertical roots, and aboveground stem growth were investigated using retrospective analysis of growth rings. Structural roots of the previously suppressed Douglas-fir were capable of strongly responding to release from competition relative to growth prior to removal, but this response, particularly in the form of root elongation, was delayed. However, since the growth response of roots was not stronger than that above ground, an imbalanced root to shoot ratio, likely developed in trees when grown under the canopy, was not reverted. Generalizing interpretation of the derived findings of this study is limited because of the small sample size and the lack of freely grown control trees. Whether or not previously suppressed trees can develop the same physical stability as open-grown individuals therefore deserves further investigation.Résumé : De longues périodes de régénération qui produisent des peuplements forestiers biétagés ou multiétagés sont un élément important du paradigme de l'aménagement forestier proche de la nature en Europe centrale. Cependant, de telles pé-riodes prolongées de régénération peuvent entraîner le développement de régénération préétablie indésirable telle que le douglas vert (Pseudotsuga menziesii (Mirb.) Franco) dans les endroits où la croissance des racines est fortement limitée par la compétition. Nous avons formulé l'hypothèse que le système racinaire de la régénération naturelle de douglas vert qui s'était développée sous couvert fermé pendant de longues périodes inhiberait leur capacité à développer un système racinaire structural adéquat à la suite du dégagement causé par l'élimination de la canopée. Le système racinaire complet de six arbres de douglas vert âgés d'environ 25 ans qui s'étaient développés pendant au moins 12 ans sous un couvert fermé avant l'élimina-tion de l'étage dominant a été excavé à l'aide d'explosifs souterrains. L'élongation des racines, l'accroissement radial des racines primaires latérales et verticales, ainsi que l'accroissement de la tige au-dessus du niveau du sol ont été étudiés par l'analyse rétrospective des cernes annuels. Le...

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Section: Response Of Aboveground and Belowground Radial And Length Insupporting

confidence: 88%

Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal

et al. 2012

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“…This analysis does not indicate the decline of height response around 15-20 years after release that was reported in black spruce (Paquin andDoucet 1992, Pothier et al 1995), Douglas-fir and white fir (Tesch and Korpela 1993), and grand fir (Ferguson and Adams 1980). A similar decline of diameter increment was also reported by Lussier et al (1992) in small and medium size trees of black spruce.…”

Section: Discussionmentioning

confidence: 68%

“…The developed models have a fair predictive power in comparison with similar work on black spruce (Pothier et al 1995) and Douglas-fir and white fir (Tesch and Korpela 1993). An improvement in growth prediction of released trees is possible if detailed descriptions of trees, site, and stand conditions and more observations are included.…”

Section: Discussionmentioning

confidence: 85%

“…A similar decline of diameter increment was also reported by Lussier et al (1992) in small and medium size trees of black spruce. Tesch and Korpela (1993) tried to explain the gradual levelling off of height growth through increasing competition after release. Pothier et al (1995) pointed out that growth characteristics, such as the allocation among foliage, stem, and roots and age-tree size relation may influence response course.…”

Section: Discussionmentioning

confidence: 99%

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Meta-analysis of understory white spruce response to release from overstory aspen

Man¹,

Greenway²

2004

The Forestry Chronicle

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Meta-analysis was used to summarize the research results on the growth response of understory white spruce to release from overstory aspen from different studies available from published and unpublished sources. The data were screened for the suitability for meta-analysis. Treatment effect sizes were calculated using response ratio from mean cumulative increments of released and control trees since release in height, diameter, and volume and modeled using a polynomial mixed effect regression procedure. Predictor variables include linear, quadratic, and cubic components of three independent variables initial tree height, number of years after release, and residual basal area at release and their linear interactions. Models with a reasonable predictive power were developed for height, diameter, and volume response, but no significant model was identified for survival. The models developed in this study can be applied to predict the growth response of understory white spruce to release, based on the growth of unreleased control trees, initial tree height, residual basal area at release, and time since release. The individual tree prediction can be easily scaled up to stand level if residual tree density and distribution is known. Key words: meta-analysis, boreal mixedwood, mixed model, polynomial regression, response ratio, growth, survival

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“…In the boreal forests of North America, seedlings and saplings of shade tolerant conifers often survive and grow slowly for a long time in the shaded understory. This creates advance regeneration that can give shade tolerant species a potential advantage in reestablishing canopy dominance after a windstorm or outbreak of defoliating insects (Groot 1984;Doucet 1988;McCaughey and Ferguson 1988;Ruel 1989Ruel , 1991Béland and Bergeron 1993;Tesch and Korpela 1993). This is in contrast to the advantage of shade intolerant species that prosper after colonising areas opened up by wildfires, which destroy any advance regeneration.…”

Section: Introductionmentioning

confidence: 99%

Functional ecology of advance regeneration in relation to light in boreal forests

Messier¹,

Doucet²,

Ruel³

et al. 1999

Can. J. For. Res.

296

102

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This paper reviews aspects of the functional ecology of naturally established tree seedlings in the boreal forests of North America with an emphasis on the relationship between light availability and the growth and survival of shade tolerant conifers up to pole size. Shade tolerant conifer species such as firs and spruces tend to have a lower specific leaf mass, photosynthetic rate at saturation, live crown ratio, STAR (shoot silhouette area to total needle surface area ratio), and root to shoot ratio than the shade intolerant pines. The inability of intolerant species such as the pines and aspen to survive in shade appears to be mainly the result of characteristics at the shoot, crown, and whole-tree levels and not at the leaf level. Although firs and spruces frequently coexist in shaded understories, they do not have identical growth patterns and crown architectures. We propose a simple framework based on the maximum height that different tree species can sustain in shade, which may help managers determine the timing of partial or complete harvests. Consideration of these functional aspects of regeneration is important to the understanding of boreal forest dynamics and can be useful to forest managers seeking to develop or assess novel silvicultural systems.Résumé : Cet article passe en revue les aspects de l'écologie fonctionnelle des semis établis naturellement dans les forêts boréales de l'Amérique du Nord, avec une emphase sur la relation entre la disponibilité de la lumière et la survie et la croissance de conifères tolérants à l'ombre jusqu'au stade perchis. Les conifères tolérants à l'ombre comme les sapins et les épinettes tendent à avoir une masse foliaire spécifique, un taux de photosynthèse au point de saturation, des rapports de cime vivante, des indices STAR (rapport de la surface de la silhouette de la pousse par rapport à la surface foliaire totale) et des rapports racines/pousse inférieurs en comparaison avec les pins intolérants à l'ombre. L'incapacité à survivre à l'ombre des espèces intolérantes comme les pins et le peuplier faux-tremble semble résulter principalement des caractéristiques au niveau de la pousse, de la cime et de l'arbre entier et non pas au niveau foliaire. Même si les sapins et les épinettes coexistent fréquemment dans des sous-bois ombragés, leurs patrons de croissance et leurs architectures de cime diffèrent. Les auteurs proposent un cadre conceptuel basé sur la hauteur maximale que les différentes espèces peuvent atteindre à l'ombre et qui pourrait aider les aménagistes à décider du moment où procéder à une récolte partielle ou totale. La prise en compte de ces aspects fonctionnels de la régénération est importante pour la compréhension de la dynamique des forêts boréales et peut être utile aux aménagistes forestiers cherchant à développer ou évaluer des systèmes sylvicoles innovateurs.[Traduit par la Rédaction] Review / Synthèse 823

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Douglas-fir and white fir advance regeneration for renewal of mixed-conifer forests

Cited by 15 publications

References 0 publications

Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal

Root system response of naturally regenerated Douglas-fir (Pseudotsuga menziesii) after complete overstory removal

Meta-analysis of understory white spruce response to release from overstory aspen

Functional ecology of advance regeneration in relation to light in boreal forests

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