Epicormic sprouting of pruned western larch

2000 ◽  
Vol 30 (2) ◽  
pp. 324-328 ◽  
Author(s):  
Kevin L O'Hara ◽  
Narayanan I Valappil

Western larch (Larix occidentalis Nutt.) trees in western Montana, U.S.A., were monitored for 6 years following pruning to assess incidence of epicormic sprouting. Trees were pruned to either 2.4 or 5.5 m. Epicormic sprouts were more prevalent in smaller diameter trees and in trees pruned to shorter live crown lengths than larger or longer crowned trees. Number of sprouts declined since pruning, but over 30% of trees still had epicormic sprouts 6 years after pruning. Sprouts that did not extend from the bole were prone to becoming dormant or dying over time. Extended sprouts were more persistent and will probably form wood-quality defects that remain outside the defect core. Pruning of western larch may still be successful for enhancing clearwood production if trees are pruned to retain at least a 50% live crown ratio and if pruning is delayed until trees reach about 16 cm diameter at breast height for a short pruning lift (2.4 m) or 22 cm for a higher pruning lift (5.5 m).

2005 ◽  
Vol 20 (4) ◽  
pp. 228-232 ◽  
Author(s):  
Kristen M. Waring ◽  
Kevin L. O'Hara

Abstract Western larch (Larix occidentalis Nutt.) is a fast-growing, deciduous conifer that is often managed for timber production in the inland Northwest. No previous study has documented the response of this species to artificial pruning. Trees pruned as part of a pruning cost study in 1992 were followed for 10 years to assess growth and epicormic sprout response. Trees were pruned to two heights: 2.4 and 5.5 m in three stands in western Montana. Epicormic sprouting occurred in a majority of trees in the first 2 years after pruning, but subsequently many sprouts died so that by year 10, only approximately 30% of trees had sprouts. Volume increment was adversely affected by more severe pruning among smaller trees pruned to the shorter lift. The volume increment of the trees that received the 5.5 m lift was generally unaffected, but trees receiving the 2.4 m lift were more sensitive to pruning. Initial tree diameter and residual crown length were important variables in predicting the 10-year volume increment in pruned trees. West. J. Appl. For. 20(4):228–232.


FLORESTA ◽  
2013 ◽  
Vol 43 (2) ◽  
pp. 327 ◽  
Author(s):  
Elder Eloy ◽  
Braulio Otomar Caron ◽  
Rômulo Trevisan ◽  
Denise Schmidt ◽  
Magda Lea Bolzan Zanon ◽  
...  

 Este trabalho teve como objetivo avaliar a variação longitudinal e o efeito do espaçamento de plantio na massa específica básica das árvores de Mimosa scabrella Benth e Ateleia glazioveana Baill, aos 36 meses de idade. Analisou-se um experimento instalado em delineamento de blocos completos casualizados, com três repetições. Os tratamentos foram definidos em função dos espaçamentos (2,0x1,0 m, 2,0x1,5 m, 3,0x1,0 m e 3,0x1,5 m). Foram avaliadas 72 árvores, sendo essas medidas e cubadas pelo método de Smalian. Em seguida, foram retirados discos nas posições do tronco: 0,10 m (base), 1,30 m do solo (DAP – Diâmetro a Altura do Peito), 25%, 50% e 75% da altura total da árvore, para determinação da massa específica básica. A massa específica básica em árvores de Mimosa scabrella apresentou um decréscimo até a região do DAP, seguido de acréscimo, sem tendência de estabilização com a altura. A Ateleia glazioveana apresentou uma tendência de decréscimo no sentido base-topo das árvores. Os espaçamentos influenciaram a variação da massa específica básica em árvores de Mimosa scabrella e Ateleia glazioveana, não sendo verificada uma variação sistemática positiva ou negativa em relação ao espaço vital proporcionado.Palavras-chave:  Variação axial; característica tecnológica da madeira; qualidade da madeira; espaçamento de plantio. AbstractLongitudinal variation and effect of spacing on basic density wood of Mimosa scabrella and Ateleia glazioveana. This study aimed to evaluate the variation in length and effect of spacing of the basic density of Mimosa scabrella Benth e Ateleia glazioveana Baill, trees with 36 months of age. We analyzed an experiment set up in randomized complete block design with three replications. The treatments were defined by the spacing (2.0x1.0 m, 2.0x1.5 m, 3.0x1.0 m, 3.0x1.5 m). 72 trees were evaluated, and these measures and scaled by the method of Smalian. Then, the disks were removed from the trunk positions: 0.10 m (base), 1.30 m (DAP - diameter at breast height), 25%, 50% and 75% of the total height of the tree, determining the basic density. The basic density in trees of Mimosa scabrella showed a decrease to the region of the DAP, followed by addition, without a tendency to stabilize with time. The Ateleia glazioveana showed a decreasing trend towards bottom-up tree. The spacing influenced the variation of basic density in trees of Mimosa scabrella e Ateleia glazioveana not been verified a systematic positive or negative trend in relation to the living space provided. Keywords: Axial variation; technological characteristic of wood; wood quality; planting space.


2013 ◽  
Vol 22 (3) ◽  
pp. 359 ◽  
Author(s):  
Michael G. Harrington

Western larch is one of the most fire-adapted conifers in western North America. Its historical perpetuation depended upon regular fire disturbances, which creates open stand conditions and mineral seedbeds. A stand of 200- to 500-year-old larch in western Montana with deep duff mounds resulting from an unusually long 150-year fire-free period was mechanically thinned and prescribed burned to reduce the probability of high intensity wildfire near a community and increase opportunities for larch regeneration. Little documentation is available regarding basal damage to larch from lengthy duff mound burning; therefore this study was established to assess: duff consumption from prescribed burning and resulting cambial damage and tree vitality. Ninety trees averaging 91-cm diameter at breast height were selected, half with duff mounds measured and burned in autumn and half with mounds removed. Duff depths nearest the bole averaged 20 cm and mound consumption approached 100% including large amounts of the basal bark with smouldering combustion lasting 18–24 h. Cambial mortality ranged from 0 to 36% of the basal circumference but no trees had died after 7 years. The cambium mortality was likely due to the spatially infrequent coincident of deep duff and thinner bark. Under similar site and environmental conditions removal of the potential duff consumption injury hazard appears unwarranted.


1991 ◽  
Vol 6 (4) ◽  
pp. 105-108 ◽  
Author(s):  
Rene I. Alfaro ◽  
Liang Qiwei ◽  
John Vallentgoed

Abstract The diameter growth of western larch, Larix occidentalis, was studied in two stands defoliated by the larch casebearer, Coleophora laricella. Before defoliation, the growth pattern of larch was highly synchronized (correlation coefficient ≥0.82) with that of Douglas-fir, Pseudotsuga menziesii, a nonhost for the casebearer on the same site, indicating that both species were under the influence of the same environmental factors. During the defoliation years, the growth of larch was only loosely related to the growth of Douglas-fir. A model which predicted growth of larch based on growth of Douglas-fir indicated that defoliation caused a loss of approximately 29% in the breast height diameter growth of larch. West. J. Appl. For. 6(4):105-108.


1998 ◽  
Vol 13 (2) ◽  
pp. 41-46
Author(s):  
Robert L. Mathiasen

Abstract Six-hundred dwarf mistletoe-infected western larch (Larix occidentalis) ranging in age from 10-20 yr were sampled to determine the approximate age and height at which they were initially infected by larch dwarf mistletoe (Arceuthobium laricis). The age of each observable mistletoe infection was determined for each sapling, and the age and height of the trees when they were initially infected were estimated based on the age of the oldest mistletoe infection. Few of the young larch sampled were infected before they reached 7 yr old or 1.5 m in height. Most of the young larch, however, were infected before they were 14 yr old or 4 m in height. Initial age and height of infection were significantly influenced by the infection intensity of the overstory larch growing within 12 m of the infected saplings. Because parasitism by larch dwarf mistletoe can be extremely damaging to western larch, infected overstory larch should be removed or killed before nearby larch regeneration reaches 7 yr old or 1 m in height when minimizing infection of the regeneration is a management objective. West. J. Appl. For. 13(2):41-46.


2018 ◽  
Vol 48 (1) ◽  
pp. 42-57 ◽  
Author(s):  
Geoffrey M. Williams ◽  
Andrew S. Nelson ◽  
David L.R. Affleck

Western larch (Larix occidentalis Nutt.) is an endemic pioneer species in northwestern North America and unique as a deciduous conifer and the most shade-intolerant, fastest growing, and most fire-resistant species in the northwestern United States. To better understand its production ecology, we used a multilevel modeling approach to analyze the intrinsic dynamics of western larch vertical foliage distribution and compared it with other species. We found that western larch allocates foliage into a more diffuse distribution as the crown lengthens, whereas shade-tolerant evergreens concentrate foliage into a more monolayered distribution higher within the crown as it lengthens. Crown foliar biomass scaled linearly with diameter at breast height, indicating that western larch does not fill volume in the crown with foliage at an increasing rate like other conifers. Our model supports the hypothesis that foliar shade intolerance and water stress jointly influence foliage allocation in this deciduous conifer. These results also highlight intrinsic foliage distribution as a factor potentially contributing to the inability of western larch to survive light-limiting conditions and its preference for mesic sites. The models developed here provide a basic framework that may be built upon to study the morphological response of western larch to modified stand conditions such as disturbance and silvicultural treatment.


2012 ◽  
Vol 163 (3) ◽  
pp. 96-104 ◽  
Author(s):  
Joachim Klädtke ◽  
Ulrich Kohnle ◽  
Edgar Kublin ◽  
Andreas Ehring ◽  
Hans Pretzsch ◽  
...  

Growth and value production of Douglas-fir under varying stand densities The investigation is focused on the effects of initial tree number and thinning on growth and value performance of Douglas-fir stands. Data base is a coordinated Douglas-fir spacing experiment in South Germany, started 40 years ago and comprising variants of tree numbers with 500, 1,000, 2,000 and 4,000 Douglas-firs per hectare. The treatment was performed according to a standardized experiment program. The results show that at low initial tree numbers, the diameter on breast height (DBH) of (pre)dominant trees at the beginning of the observations (with 12 m top height) is bigger than at higher initial plant numbers. Accordingly, the quotient of height (H) to DBH (as an indicator for tree's static stability) is lower. The further development of DBH and H/DBH quotient is decisively determined by stand treatment, which superimposes the effect of the initial tree number. The total volume growth shows a clear differentiation, too, the variants with initially high tree numbers appearing on top. In the monetary analysis, this ranking is reversed: despite a supposed inferior wood quality, the variants with lower initial tree numbers clearly outperform the ones with higher numbers in terms of value. From these results, the following silvicultural recommendations for Douglas-fir can be derived: the initial tree numbers should be in the range from 1,000 to 2,000 plants per hectare. On technically not accessible sites, even lower tree numbers may come into question. The strong influence of stand treatment on DBH and H/DBH development highlights the problem of postponed thinnings, for this causes growth and stability losses even under favorable starting conditions in terms of competition.


2021 ◽  
Vol 13 (8) ◽  
pp. 4167
Author(s):  
David Kombi Kaviriri ◽  
Huan-Zhen Liu ◽  
Xi-Yang Zhao

In order to determine suitable traits for selecting high-wood-yield Korean pine materials, eleven morphological characteristics (tree height, basal diameter, diameter at breast height, diameter at 3 meter height, stem straightness degree, crown breadth, crown height, branch angle, branch number per node, bark thickness, and stem volume) were investigated in a 38-year-old Korean pine clonal trial at Naozhi orchard. A statistical approach combining variance and regression analysis was used to extract appropriate traits for selecting elite clones. Results of variance analysis showed significant difference in variance sources in most of the traits, except for the stem straightness degree, which had a p-value of 0.94. Moderate to high coefficients of variation and clonal repeatability ranged from 10.73% to 35.45% and from 0.06% to 0.78%, respectively. Strong significant correlations on the phenotypic and genotypic levels were observed between the straightness traits and tree volume, but crown breadth was weakly correlated to the volume. Four principal components retaining up to 80% of the total variation were extracted, and stem volume, basal diameter, diameter at breast height, diameter at 3 meter height, tree height, and crown height displayed high correlation to these components (r ranged from 0.76 to 0.98). Based on the Type III sum of squares, tree height, diameter at breast height, and branch number showed significant information to explain the clonal variability based on stem volume. Using the extracted characteristics as the selection index, six clones (PK105, PK59, PK104, PK36, PK28, and K101) displayed the highest Qi values, with a selection rate of 5% corresponding to the genetic gain of 42.96% in stem volume. This study provides beneficial information for the selection of multiple traits for genetically improved genotypes of Korean pine.


Sign in / Sign up

Export Citation Format

Share Document