scholarly journals Biomass functions applicable to oak trees grown in Central-European forestry

2008 ◽  
Vol 54 (No. 3) ◽  
pp. 109-120 ◽  
Author(s):  
E. Cienciala ◽  
J. Apltauer ◽  
Z. Exnerová ◽  
F. Tatarinov
Keyword(s):  
Aboveground Biomass ◽  
Strong Predictor ◽  
Tree Height ◽  
Stem Bark ◽  
Quercus Petraea ◽  
Tree Age ◽  
Central European ◽  
Crown Length ◽  
Oak Trees ◽  
Biomass Functions

This study describes the parameterization of biomass functions applicable to oak (<I>Quercus robur, Quercus petraea</I>) trees grown in the conditions of Central-European forestry. It is based on destructive measurements of 51 grown trees sampled from 6 sites in different regions of the Czech Republic important for oak forest management. The samples covered trees of breast height diameter (<I>D</I>) ranging from 6 to 59 cm, tree height (<I>H</I>) from 6 to 32 m and age between 12 and 152 years. The parameterization was performed for total aboveground biomass and its individual components. The two basic levels of biomass functions utilized <I>D</I> either as a single independent variable or in combination with <I>H</I>. The functions of the third level represented the best function for each biomass component with the optimal combination of available independent variables, which included <I>D, H</I>, crown length (<I>CL</I>), crown width (<I>CW</I>), crown ratio (<I>CR = CL/H</I>), tree age and site altitude. <I>D</I> was found to be a particularly strong predictor for total tree aboveground biomass. <I>H</I> was found to always improve the fit, particularly for the individual components of aboveground biomass. The contribution of <I>CW</I> was minor, but significant for all biomass components, whereas <I>CL</I> and <I>CR</I> were found useful for the components of stem and living branches, respectively. Finally, the remaining variables tree age and altitude were each justified only for one component function, namely living branch biomass and stem bark, respectively. The study also compares the fitted functions with other available references applicable to oak trees.

Predicting sugar maple (Acer saccharum) discoloured wood characteristics

2013 ◽  
Vol 43 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Sharad Kumar Baral ◽  
Robert Schneider ◽  
David Pothier ◽  
Frank Berninger
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Tree Height ◽  
Tree Age ◽  
Wood Volume ◽  
Nonlinear Mixed Effects Model ◽  
Crown Length ◽  
Crown Characteristics ◽  
The Relationship ◽  
Wood Columns

The presence of wound (strain) initiated discoloured wood columns in the core of sugar maple (Acer saccharum Marshall) stems reduces the proportion of white-coloured wood and, thus, lowers its commercial value. This study aimed to assess the relationship between tree characteristics and the extent and proportion of discoloured wood in sugar maple tree stems. Using 109 trees from three different sites in southern Quebec, we found that the proportion of discoloured wood increased with decreasing sapwood volume and increasing tree age. Younger trees showed a significantly lower proportion of discoloured wood volume. Discoloured wood volume increases disproportionately with tree diameter, while varying among sites. The third important factor affecting the amount of discolored wood was tree vigour as measured by crown characteristics and growth rate changes. A nonlinear mixed-effects model was used to predict discoloured wood taper. Height along the stem was used as a predictor, along with diameter at 1.3 m (DBH), the ratio of live crown length to tree height, and tree height. Although observed injury surface area was positively correlated to discoloured wood volume, injury information did not explain a large share of discoloured wood proportion variation. Overall, older and larger trees with many injuries on less productive sites are likely to have more discoloured wood.

Factors affecting the relationship between sapwood area and leaf area of balsam fir

1992 ◽  
Vol 22 (11) ◽  
pp. 1684-1693 ◽  
Author(s):  
Marie R. Coyea ◽  
Hank A. Margolis
Keyword(s):  
Leaf Area ◽  
Basal Area ◽  
Tree Height ◽  
Balsam Fir ◽  
Tree Age ◽  
Cross Sectional ◽  
Sapwood Area ◽  
Crown Length ◽  
Basal Area Growth ◽  
Area Growth

The ratio between projected leaf area (LA) and cross-sectional sapwood area (SA) of dominant and codominant balsam fir trees (Abiesbalsamea (L.) Mill.) was determined in 24 forest stands across the province of Quebec. Various physical factors proposed in the Whitehead hydraulic model, and some of the easily measured surrogates of these factors, were tested for their influence on LA:SA ratios. Average growing season vapor pressure deficit, temperature, precipitation, and stand drainage class did not significantly influence LA:SA ratios. On the other hand, LA:SA ratios were positively influenced by sapwood permeability (k), tree height, and crown length. As suggested by the model, there was a positive correlation between sapwood permeability and LA:SA ratio and a negative correlation between tree height or crown length and LA/(SA k). Increases in sapwood permeability with tree age were associated with longer tracheids having larger lumen diameters. Of the various empirical factors tested, only site quality, 5-year basal area growth, and age had a significant influence on LA:SA ratios. Sapwood cross-sectional area at breast height by itself was a reasonable linear predictor of LA for all stands (LA = −0.158 + 0.709 SABH, R2 = 0.75). Using the variables that were previously determined to influence LA:SA ratios, stepwise regressions revealed that only crown length and 5-year basal area growth significantly improved linear predictions of LA based on sapwood area. However, the increase in R2 was relatively modest, i.e., 0.83 for all three independent variables versus 0.75 for SA alone. The results from this study will be useful in integrating physiologically based measurements, such as growth efficiency, into standard forest inventory practices for balsam fir and thus could be beneficial in developing new silvicultural strategies for protecting Quebec's forest resource.

scholarly journals Biomass and Stand Characteristics of a Highly Productive Mixed Douglas-Fir and Western Hemlock Plantation in Coastal Washington

2009 ◽  
Vol 24 (4) ◽  
pp. 180-186 ◽  
Author(s):  
Robert B. Harrison ◽  
Thomas A. Terry ◽  
Christopher W. Licata ◽  
Barry L. Flaming ◽  
Rod Meade ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Tree Height ◽  
Stem Bark ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Biomass Estimation ◽  
High Productivity ◽  
Stem Wood ◽  
Stand Attributes ◽  
Live Tree

Abstract Aboveground biomass predictive equations were developed for a highly productive 47-year-old mixed Douglas-fir and western hemlock stand in southwest Washington State to characterize the preharvest stand attributes for the Fall River Long-Term Site Productivity Study. The equations were developed using detailed biomass data taken from 31 Douglas-fir and 11 western hemlock trees within the original stand. The stand had an average of 615 live trees per hectare, with an average dbh of 35.6 cm (39.1 cm for Douglas-fir and 33.3 cm for western hemlock) and an average total tree height of 31.6 m (32.8 m for Douglas-fir and 30.2 m for western hemlock). Equations developed were of the form ln Y = b1 + b2 ln dbh, where Y = biomass in kg, dbh = diameter in cm at 1.3 m height, b1 = intercept, and b2 = slope of equation. Each tree part was estimated separately and also combined into total aboveground biomass. The total aboveground biomass estimation equations were ln Y = −0.9950 + 2.0765 ln dbh for Douglas-fir, and ln Y = −1.6612 + 2.2321 ln dbh for western hemlock. The estimate of the aboveground live-tree biomass was of 395 Mg ha−1 (235 Mg ha−1 for Douglas-fir and 160 Mg ha−1 for western hemlock), with 9.5, 29.3, 12.9, 308, and 32.7 Mg ha−1 in the foliage, live branches, dead branches, stem wood, and stem bark, respectively. When compared with biomass estimates from six other studies, ranging in age from 22 to 110 years and from 96.3 to 636 Mg ha−1, the biomass of the Fall River site was relatively high for its age, indicating very high productivity.

Seed production of Pinus sylvestris after release cutting

2000 ◽  
Vol 30 (6) ◽  
pp. 982-989 ◽  
Author(s):  
Christer Karlsson
Keyword(s):  
Pinus Sylvestris ◽  
Seed Production ◽  
Seed Quality ◽  
Seed Viability ◽  
Tree Height ◽  
Tree Age ◽  
Cone Production ◽  
Crown Length ◽  
Viable Seeds ◽  
Individual Trees

The effects of release cutting on cone, seed production, and seed quality were investigated in 1995-1996 among Scots pine (Pinus sylvestris L.) seed trees in central Sweden. The effects of diameter, height, crown length, and age of trees on cone production were also examined. Cone and seed production were about five times higher in seed trees that had been released for 4 or 5 years, compared with control trees in the unreleased forest. Seed trees released for less than 3 years had about the same level of cone production as the controls. After release, the number of cones increased more in the lower part of the tree crowns than in the uppermost 2 m. The mean 1000-seed weight, seed viability, and number of viable seeds per cone were not significantly different between released and unreleased trees. In 1996, there were about eight times more cones than in 1995, probably because summer temperatures were higher in 1994 than in 1993, the years when the respective flower buds were initiated. Within the investigated range of diameters, 250-430 mm at breast height, a 10-mm increase in diameter was correlated with a 10% increase in mean cone production. However, the variation in cone production between individual trees was considerable. Tree height, length of green crown, and tree age showed no significant correlations with cone production.

scholarly journals Spring Freeze Damage of Pecan Bloom: A Review

Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 82
Author(s):  
Amandeep Kaur ◽  
Louise Ferguson ◽  
Niels Maness ◽  
Becky Carroll ◽  
William Reid ◽  
...  
Keyword(s):  
Tree Height ◽  
The United States ◽  
Reproductive Organs ◽  
Tree Age ◽  
The Us ◽  
Nut Production ◽  
Freeze Damage ◽  
Terminal Buds ◽  
And Function ◽  
The Impact

Pecan is native to the United States. The US is the world’s largest pecan producer with an average yearly production of 250 to 300 million pounds; 80 percent of the world’s supply. Georgia, New Mexico, Texas, Arizona, Oklahoma, California, Louisiana, and Florida are the major US pecan producing states. Pecan trees frequently suffer from spring freeze at bud break and bloom as the buds are quite sensitive to freeze damage. This leads to poor flower and nut production. This review focuses on the impact of spring freeze during bud differentiation and flower development. Spring freeze kills the primary terminal buds, the pecan tree has a second chance for growth and flowering through secondary buds. Unfortunately, secondary buds have less bloom potential than primary buds and nut yield is reduced. Spring freeze damage depends on severity of the freeze, bud growth stage, cultivar type and tree age, tree height and tree vigor. This review discusses the impact of temperature on structure and function of male and female reproductive organs. It also summarizes carbohydrate relations as another factor that may play an important role in spring growth and transition of primary and secondary buds to flowers.

scholarly journals Differentiating mature and old-growth forests in the Upper Foothills and Subalpine Subregions of west-central Alberta

2003 ◽  
Vol 79 (3) ◽  
pp. 602-612 ◽  
Author(s):  
Luigi E Morgantini ◽  
John L Kansas
Keyword(s):  
Forest Management ◽  
Growth Index ◽  
Tree Height ◽  
Tree Age ◽  
Old Growth ◽  
West Central ◽  
Decay Class ◽  
Management Area ◽  
Growth Attributes ◽  
Live Tree

Weyerhaeuser Company Ltd. is developing harvest strategies that will maintain appropriate levels of late to very late seral stages ("old growth") in its Drayton Valley Forest Management Area. This management area encompasses 490 570 ha in the Foothills and Rocky Mountain Natural Regions of west-central Alberta. In planning for future forest landscapes, Weyerhaeuser intends to maintain a range of age structures consistent with the ecological processes characteristic of each natural region and subregion. The absence of a discrete point separating mature forest from old growth means that the age at which a stand is currently identified as "old growth" and subject to special management practices is arbitrary. In a research study initiated in the summer of 2000, we seek to understand the differences in structure and composition between forests of various ages and topographic site conditions (elevation, aspect, and slope angle). Using 95 sampling plots in a 123-km2 study area in the Upper Foothills and Subalpine Natural Subregions, we quantified vegetation structure and composition for stands ranging in age from 70 to 300 years. Variables measured and analysed included live-tree height and diameter, snag density, diameter and decay class, downed woody material volume, diameter and decay class, vascular plant species richness, sapling and regeneration density, and duff depth. An old-growth index was developed for each sampled stand that took into account multiple attributes. Preliminary results indicate that specific attributes (snag basal area and density, decay stage and density of downed woody material, variation in live-tree age, and variation in live-tree height and age) separate a younger forest from a more mature one and hence may describe "old-growth" conditions. The age of onset of these old-growth attributes is variable but appears to occur between 160 and 180 years. Key factors other than stand age that contribute to or modify the development of old-growth attributes (as measured by the old-growth index) are elevation and moisture regime (as modified by site position). Further investigation is required to more accurately assess the effect of site factors on old-growth attributes. These results are now used by Weyerhaeuser to address retention of late seral stages in long-term forest planning. Key words: old growth, mature forests, old growth protection, forest management, Alberta, Weyerhaeuser, Rocky Mountains foothills

Incidence of main stem infections of lodgepole pine by western gall rust decreases with tree age

2005 ◽  
Vol 35 (6) ◽  
pp. 1314-1318 ◽  
Author(s):  
Peter V Blenis ◽  
Wuhan Li
Keyword(s):  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Stem Elongation ◽  
Tree Height ◽  
Shoot Elongation ◽  
Main Stem ◽  
Tree Age ◽  
Precommercial Thinning ◽  
Two Factors ◽  
Artificial Inoculations

Infection of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) by western gall rust has been shown to decrease with tree height and age, but the effects of those two factors have not been separated. Five replicate artificial inoculations were done on a total of 327 trees of different ages in two height classes. Temperature and percentage of spore germination at the height of inoculation, shoot development (stem elongation at the time of inoculation as a proportion of final shoot elongation), main stem leader length at the time of inoculation, tree height, and tree age were measured. Modeled percentages of infected trees and the number of galls per 10 cm of shoot length decreased by 85% and 88%, respectively, as tree age increased between 2 and 10 years, indicating the undesirability of early, aggressive precommercial thinning of lodgepole pine stands in areas where western gall rust is common. By controlling and (or) statistically accounting for inoculum, microclimate, and phenological factors, it was possible to demonstrate that changes in susceptibility with tree age are sufficient to account for the reduction in infection with tree height.

Influence de la densité du couvert forestier sur le développement architectural de jeunes chênes sessiles, Quercus petraea (Matt.) Liebl. (Fagaceae), en régénération forestière

2000 ◽  
Vol 78 (12) ◽  
pp. 1531-1544 ◽  
Author(s):  
Eric Nicolini ◽  
Daniel Barthélémy ◽  
Patrick Heuret
Keyword(s):  
Quercus Petraea ◽  
Growth Unit ◽  
Growth Morphology ◽  
Basal Diameter ◽  
Canopy Density ◽  
Sessile Oak ◽  
The North ◽  
Oak Trees ◽  
Branching Patterns ◽  
Number Of Branches

The growth and branching patterns of the main axis of 6-year-old sessile oak, growing in a natural regeneration in the north of France, were analysed each year retrospectively according to three increasing canopy density conditions: large gap, small gap, and dense canopy. Increasing gap size is associated with an increase in the total height, basal diameter, branching probability, and global polycyclism rate of the trees. At the growth unit or annual shoot level, from dense canopy to large gaps these botanical entities also show an increase in their total length, number of nodes, polycyclism, and branching rate as well as mean number of branches and mean internode length. A discussion of our results revealed some endogenous features of growth and branching patterns in young sessile oak trees. It is also shown that increasing canopy density generally tends to reduce the expression of the endogenous architectural sequence of differentiation of young sessile oak trees. Young trees growing below dense canopy thus seem to be "delayed" in their sequence of differentiation and appear to be in a "waiting" status, whereas young trees growing in large gaps exhibit an architecture very similar to trees growing in nurseries under nonlimiting growth conditions.Key words: architecture, Quercus petraea, growth, morphology, canopy density.

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