Bark thickness analysis of four dominant tree species of Central Himalayan forests varying in exposure to surface fires

Trees ◽  
2021 ◽  
Author(s):  
Surabhi Gumber ◽  
Ripu Daman Singh ◽  
Jeet Ram ◽  
Ashish Tewari ◽  
Surendra P. Singh
2020 ◽  
Vol 3 (1) ◽  
pp. 66
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer

The wood of Scots pine (Pinus sylvestris L.) shows good properties as building and construction timber but also as furniture or pulp and paper, and thus, is one of the most commercially important European tree species. Scots pine are mostly harvested and processed with a high degree of mechanization. In Northeast Germany (federal states of Brandenburg and Berlin), 36% of harvested Scots pine have a diameter at breast height (DBH) between 7 and 19.9 cm. As a typical industrial wood assortment, a large proportion of the resulting small-sized logs are used in the wood industry to produce boards. Although bark is considered a by-product or waste product of the industry, no actual study has quantified the bark thickness, bark volume, bark mass and bark damage of such Scots pine logs. Therefore, the bark characteristics from 50 logs from 10 different piles were analyzed. Bark volume was quantified using the water displacement method, bark mass by weighing, bark thickness with a precision caliper and bark damage by tape measurements. The diameters of the analyzed 150 log discs were normally distributed and the mean value was 12.9 cm. The results showed average bark damages from 12.0%, which were mostly caused during the felling and processing of logs with the harvester. No significant correlation was found between double bark thickness (mean: 3.0 mm) and the diameter; whereas fresh bark volume (mean: 5.6%) and dry bark mass (mean: 3.3%) were significantly affected by the diameter. As shown for spruce by other authors, bark characteristics may change over time and therefore, should be measured regularly. Moreover, it was shown that bark parameters are site dependent. Thus, quantifying bark characteristics for economically important tree species at both the local and national scale is of great relevance. More detailed analyzes are described by Berendt et al. (2021) [1].


2020 ◽  
Vol 71 (9) ◽  
pp. 2641-2649
Author(s):  
Romain Lehnebach ◽  
Tancrède Alméras ◽  
Bruno Clair

Abstract Recent works revealed that bark is able to produce mechanical stress to control the orientation of young tilted stems. Here we report how the potential performance of this function changes with stem size in six Amazonian species with contrasted bark anatomy. The potential performance of the mechanism depends both on the magnitude of bark stress and the relative thickness of the bark. We measured bark longitudinal residual strain and density, and the allometric relationship between bark thickness and stem radius over a gradient of tree sizes. Constant tensile stress was found in species that rely on bark for the control of stem orientation in young stages. Other species had increasing compressive stress, associated with increasing density attributed to the development of sclereids. Compressive stress was also associated with low relative bark thickness. The relative thickness of bark decreased with size in all species, suggesting that a reorientation mechanism based on bark progressively performs less well as the tree grows. However, greater relative thickness was observed in species with more tensile stress, thereby evidencing that this reduction in performance is mitigated in species that rely on bark for reorientation.


1981 ◽  
Vol 57 (4) ◽  
pp. 156-161 ◽  
Author(s):  
J. Harry G. Smith ◽  
A. Kozak

Diameters inside and outside bark from 13 sections were used to define variation in bark percentages for 33 844 trees representing 28 major groups of the commercial tree species of British Columbia. The range of age, height, dbh, and dbh/height associated with each group was determined. Statistical significance of effects of these factors and of up to 12 inventory zones was determined for double bark thickness as a percentage of dbh. Bole bark volumes were compared with wood volumes for trees exceeding two standard deviations of bark percentage at breast height. Thick barked trees were more common and a few have equal portions of wood and bark. Our description of the characteristics of the trees with least or most bark should help guide tree improvement programs. Identification of the extent to which stand factors can influence average bark characteristics may help timber managers grow trees of desired bark proportions.


Plant Ecology ◽  
2011 ◽  
Vol 212 (12) ◽  
pp. 2057-2069 ◽  
Author(s):  
Michael J. Lawes ◽  
Anna Richards ◽  
Josefine Dathe ◽  
Jeremy J. Midgley

Fire Ecology ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 74-87 ◽  
Author(s):  
Jennifer L. Schafer ◽  
Bradley P. Breslow ◽  
Matthew G. Hohmann ◽  
William A. Hoffmann

2005 ◽  
Vol 35 (2) ◽  
pp. 452-460 ◽  
Author(s):  
B W Butler ◽  
B W Webb ◽  
D Jimenez ◽  
J A Reardon ◽  
J L Jones

Bark protects both the living phloem and the vascular cambium of trees. For some tree species the bark has been observed to swell in the radial direction when heated by nearby flames, possibly providing additional protection from thermal injury. In this study, detailed measurements of bark swelling (tumescence) are reported for four species: Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), ponderosa pine (Pinus ponderosa Dougl. ex Laws.), chestnut oak (Quercus prinus L.), and red maple (Acer rubrum L.). Tests were conducted on over 574 samples extracted from 44 separate trees. The results clearly show that bark swelling occurs in the mature bark of Douglas-fir and to a lesser degree in chestnut oak. Ponderosa pine and red maple did not exhibit statistically significant swelling, but rather a modest decrease in overall bark thickness with heating. Significant swelling in Douglas-fir bark began at approximately 125 °C and resulted in a 15%–80% increase in overall bark thickness. Swelling of chestnut oak was observed to begin at an average temperature of 225 °C and resulted in a 5%–10% increase in total bark thickness. The increase in bark thickness occurred primarily in the radial direction in mature bark.


Author(s):  
Chander Shekhar

The genus Quercus comprises very important tree species of the Himalayan forests. Oaks are crucial for a multitude of ecosystem services and livelihood support services reaped by the locals in the Himalayan region. Quercus semecarpifolia is the oldest and dominating species of the Himalayan region. It is considered a lifeline for people of this region due to the wider range of ecosystem and livelihood services provided by it. But this species forest is depleting very rapidly in his region due to over dependency. Major cause of overexploitation is lopping for fodder and fuelwood. The present study attempted to Quantify, recognize, and group the ecosystem services provided by Q. semecarpifolia. Further, certain factors responsible for regular shrinkage of Q. semecarpifolia forests were also addressed.


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