Vertical distribution of foliar biomass in western larch (Larix occidentalis)

2018 ◽  
Vol 48 (1) ◽  
pp. 42-57 ◽  
Author(s):  
Geoffrey M. Williams ◽  
Andrew S. Nelson ◽  
David L.R. Affleck
Keyword(s):  
Larix Occidentalis ◽  
Western Larch ◽  
Morphological Response ◽  
Breast Height ◽  
Resistant Species ◽  
Fill Volume ◽  
Northwestern North America ◽  
Stand Conditions ◽  
Diffuse Distribution ◽  
Foliar Biomass

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.

Epicormic sprouting of pruned western larch

2000 ◽  
Vol 30 (2) ◽  
pp. 324-328 ◽  
Author(s):  
Kevin L O'Hara ◽  
Narayanan I Valappil
Keyword(s):  
Wood Quality ◽  
Western Montana ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Defect Core ◽  
Epicormic Sprouts ◽  
Epicormic Sprouting ◽  
Over Time

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).

Duff mound consumption and cambium injury for centuries-old western larch from prescribed burning in western Montana

2013 ◽  
Vol 22 (3) ◽  
pp. 359 ◽  
Author(s):  
Michael G. Harrington
Keyword(s):  
Prescribed Burning ◽  
Western Montana ◽  
Western North America ◽  
Western Larch ◽  
Tree Vitality ◽  
Breast Height ◽  
Fire Disturbances ◽  
Stand Conditions ◽  
Similar Site ◽  
Smouldering Combustion

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.

Diameter Growth Losses in Western Larch Caused by Larch Casebearer Defoliation

1991 ◽  
Vol 6 (4) ◽  
pp. 105-108 ◽  
Author(s):  
Rene I. Alfaro ◽  
Liang Qiwei ◽  
John Vallentgoed
Keyword(s):  
Environmental Factors ◽  
Correlation Coefficient ◽  
Pseudotsuga Menziesii ◽  
Growth Pattern ◽  
Douglas Fir ◽  
Diameter Growth ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Breast Height ◽  
Coleophora Laricella

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.

scholarly journals Root Growth Potential and Microsite Effects on Conifer Seedling Establishment in Northern Idaho

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 597
Author(s):  
Jacob A. Reely ◽  
Andrew S. Nelson
Keyword(s):  
Root Growth ◽  
Douglas Fir ◽  
Seedling Quality ◽  
Growth Potential ◽  
Larix Occidentalis ◽  
Root Growth Potential ◽  
Western Larch ◽  
Neighborhood Conditions ◽  
Seedling Performance ◽  
Survival And Growth

Environmental conditions and seedling quality interact to produce complex patterns of seedling survival and growth. Root growth potential (RGP) is one metric of seedling quality that can be rapidly measured prior to planting, but the correlation of RGP and seedling performance is not consistent across studies. Site factors including microsite objects that cast shade and competing vegetation can also influence seedling performance. We examined the effects of RGP, presence/absence of a microsite object, and competition cover on the survival and growth of three native conifers to the Inland Northwest, USA, over 5 years. We found that RGP had no effect on the survival or growth of western larch (Larix occidentalis), Douglas fir (Pseudotsuga menziesii var. glauca), and grand fir (Abies grandis) at a mesic north aspect site and a xeric south aspect site. Comparatively, the presence of a microsite increased the odds of survival by 37% for western larch and 158% for grand fir, while the absence of forb cover increased the odds of survival of western larch by 72% and of grand fir by 26%. Douglas fir was less sensitive to microsites and competition. The strong effects of neighborhood conditions around seedlings help inform silvicultural practices to enhance the establishment of western larch and grand fir, including planting seedlings near shading objects and competition control, while these practices may not be as important for Douglas fir.

scholarly journals Predicting Diameter at Breast Height from Stump Measurements of Removed Trees to Estimate Cuttings, Illegal Loggings and Natural Disturbances

2020 ◽  
Vol 11 (1) ◽  
pp. 41-49
Author(s):  
Lucio Di Cosmo ◽  
Patrizia Gasparini
Keyword(s):  
Forest Products ◽  
National Forest Inventory ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Original Dataset ◽  
New Models ◽  
Multiple Species ◽  
Leave One Out ◽  
Stand Conditions ◽  
Better Than

Predicting diameter at breast height (DBH) of trees from stump information may be necessary to reconstruct silvicultural practices, to assess harvested timber and wood, or to estimate forest products’ losses caused by illegal cuttings or natural disasters (disturbances). A model to predict DBH of felled trees was developed by the first Italian National Forest Inventory in 1985 (IFNI85). The model distinguished between the two broad groups of conifers and broadleaves and used stump diameter as the sole quantitative variable. Using an original dataset containing data from about 1200 trees of sixteen species recorded throughout Italy, we assessed the performance of that model. To improve the prediction of the DBH of removed trees over large areas and for multiple species, we developed new models using the same dataset. Performance of the new models was tested through indices computed on cross-validated data obtained through the leave-one-out method. A new model that performs better than the old one was finally selected. Compared to the old NFI model, the selected model improved DBH prediction for fourteen species up to 31.28%. This study proved that species specification and stump height are variables needed to improve the models’ performance and suggested that data collection should be continued to get enhanced models, accurate for different ecological and stand conditions.

Black Bear Damage to Thinned Timber Stands in Northwest Montana

1989 ◽  
Vol 4 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Andrew C. Mason ◽  
David L. Adams
Keyword(s):  
Pinus Contorta ◽  
Black Bear ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Abies Lasiocarpa ◽  
Pinus Monticola ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Engelmann Spruce ◽  
Northwest Montana

Abstract Bear damage was at least five times higher in thinned blocks than in adjacent unthinned blocks of western larch (Larix occidentalis), lodgepole pine (Pinus contorta), and Engelmann spruce (Picea engelmannii) on the Kootenai National Forest in northwest Montana. Western larch suffered the greatest damage (63% of all trees damaged and 92% of the trees killed). Damaged larch ranged from 4 to 13 in. dbh; the 4 to 8-in. dbh class accounted for 85% of the damage. Douglas-fir (Pseudotsuga menziesii), western redcedar (Thuja plicata), subalpine fir (Abies lasiocarpa), western white pine (Pinus monticola), and western hemlock (Tsuga heterophylla) were not damaged. Stand projections showed up to a 17% reduction in board-foot yield from bear damage, after 50 years, compared with hypothetical undamaged stands. West. J. Appl. For. 4(1):10-13, January 1989.

scholarly journals Larch Seed Trees Sustain Arboreal Lichens and Encourage Recolonization of Regenerating Stands

2007 ◽  
Vol 22 (2) ◽  
pp. 94-98 ◽  
Author(s):  
Fred L. Bunnell ◽  
Trevor Goward ◽  
Isabelle Houde ◽  
Curtis Björk
Keyword(s):  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Road Dust ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Source Tree ◽  
Winter Food ◽  
The Difference

Abstract In many areas Bryoria lichen is a major winter food for deer and caribou. We examined the role of western larch (Larix occidentalis) seed trees in retaining arboreal lichens and encouraging recolonization of regenerating stands by Bryoria. Although exposed to desiccation, Bryoria was sustained in significant amounts in larch seed trees. Other than a reduction near roads, apparently by alkaline road dust, arboreal forage lichens were relatively uniformly distributed throughout the regenerating stands. There was little difference in abundance up to 135 m from the source tree. The sorediate form of the lichens did better on lodgepole pine (Pinus contorta), and larger, nonsorediate fragments were more abundant on western larch. We attribute the difference to bark pH. Scattered western larch seed trees were effective at retaining lichens and facilitating recolonization of the regenerating stand.

scholarly journals Wood Changes in Four Size Classes of Fire-Killed Western Larch

2010 ◽  
Vol 25 (2) ◽  
pp. 62-67
Author(s):  
Marcus B. Jackson ◽  
Beverly M. Bulaon ◽  
Michael A. Marsden
Keyword(s):  
Size Class ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Wood Volume ◽  
Size Classes ◽  
Decay Wood ◽  
Large Trees

Abstract Four size classes (8–12, 12.1–16, 16.1–20, and 20.1+ in. dbh) of fire-killed western larch (Larix occidentalis) were monitored and dissected over a 5-year period to assess causes and rates ofpostfire wood changes. Defect and merchantable volume were assessed by a certified scaler during the first 3 years. A greater proportion of wood volume in small trees was affected by decay, wood borers, and checks than in the large trees. Half of the 8‐12 in. dbh size class wood volumewas lost to postfire defects, whereas less than 15% of the 20.1+ in. dbh size class wood volume was lost to postfire defects after 3 years.

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