Effets de l'élagage sur la résistance électrique cambiale de la tige de jeunes Sapins baumiers

1988 ◽  
Vol 18 (12) ◽  
pp. 1655-1658 ◽  
Author(s):  
Robert R. Gagnon ◽  
Michel Chabot ◽  
Marius Pineau
Keyword(s):  
Electrical Resistance ◽  
Physiological Significance ◽  
Balsam Fir ◽  
Clear Cut ◽  
Breast Height ◽  
Advanced Regeneration ◽  
Factors Influencing ◽  
Tree Stem

In the spring of 1985, 125 young balsam fir trees (Abiesbalsamea (L.) Mill.) originating from advanced regeneration following a clear-cut in 1970 were pruned to live crown ratios of 0.6, 0.4, 0.2 and 0.0 as compared with control trees which had naturally developped a live crown ratio of 0.8. Subsequently, the cambial electrical resistance of these trees was measured at breast height 17 times between June and October. Ten days after pruning, there was a decrease in cambial electrical resistance. Relating these results to factors influencing the movement of water through the tree leads to a better understanding of the physiological significance of tree stem cambial electrical resistance.

Factors Influencing the Weight of Black Spruce and Balsam Fir Stems

1972 ◽  
Vol 2 (4) ◽  
pp. 427-433 ◽  
Author(s):  
S. M. Pnevmaticos ◽  
T. A. Jaeger ◽  
E. Perem
Keyword(s):  
Moisture Content ◽  
Black Spruce ◽  
Stem Bark ◽  
Balsam Fir ◽  
Regression Equations ◽  
Green Density ◽  
Stem Wood ◽  
Independent Variables ◽  
Breast Height ◽  
Factors Influencing

The factors influencing green weight of black spruce and balsam fir stems were investigated. It was found that for black spruce stems, moisture content and sapwood content could be predicted by the age and height of the tree. For balsam fir, however, it was difficult to establish meaningful correlations. Stem bark volume was well correlated for both species with diameter at breast height. Regression equations for stem green density with different combinations of independent variables estimated at breast height were developed; it was found that breast height specific gravity and moisture content were the most important variables in predicting stem green density. Stem wood volume was very well correlated with stem weight immediately after felling.

Electrical resistance measurements on young balsam fir trees in relation to specific volume increment, foliar biomass, and ion content of bark and wood

1984 ◽  
Vol 14 (2) ◽  
pp. 177-180 ◽  
Author(s):  
H. Plene ◽  
R. G. Thompson ◽  
J. E. McIsaac ◽  
D. S. Fensom
Keyword(s):  
Electrical Resistance ◽  
Specific Volume ◽  
Balsam Fir ◽  
Ion Content ◽  
Volume Increment ◽  
Electrical Resistance Measurements ◽  
Foliar Biomass

Electrical resistance in young balsam fir (Abiesbalsamea (L.) Mill.) trees was inversely (nonlinear) correlated with specific volume increment, total foliar biomass, and the combined weight of the current and 1-year-old foliage. These relationships were stronger before budbreak than after. No relationship existed between concentrations of N, P, K, Ca, and Mg in the bark and wood collected around time of budbreak, and electrical resistance.

Attributes of forest strips used by snowshoe hare in winter within clear-cut boreal landscapes

2005 ◽  
Vol 35 (10) ◽  
pp. 2521-2527 ◽  
Author(s):  
François Potvin ◽  
Normand Bertrand ◽  
Jean Ferron
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Snowshoe Hare ◽  
Forest Patches ◽  
Clear Cut ◽  
Important Prey ◽  
South Central ◽  
Snowshoe Hares ◽  
Riparian Strips

The snowshoe hare (Lepus americanus Erxleben) is an important prey for many predators in the boreal forest. In this biome, clear-cut landscapes are generally large and consist of aggregated cutting blocks separated by narrow forest strips (typically 60–100 m wide). To identify attributes of forest strips that are important for snowshoe hares, we measured the use of strips using track counts over two winters in six clear-cut landscapes (23–256 km2) in south-central Quebec. Surveys were conducted in 20 riparian strips (RS), 20 upland strips (US), and 15 control sites (CO) at the periphery of clear-cut landscapes. Overall, 392 signs of hare presence were recorded along 50 km of transects. Snowshoe hares were present in one-third of the strips surveyed and were five times less abundant in US and RS than in CO. The species avoided strip edges. Hares were more common in the wider strips (>100 m), in the strips adjacent to residual forest patches (≥25 ha), or in those having a denser shrub canopy, which is often associated with a greater basal area in balsam fir (Abies balsamea (L.) Mill.). To maintain snowshoe hare at moderate densities in large clear-cut landscapes, we suggest leaving uncut forest strips >100 m wide in areas having a good shrub cover with presence of balsam fir.

Cambial electrical resistance related to the number of vascular cambial cells in balsam fir

1984 ◽  
Vol 14 (6) ◽  
pp. 950-952 ◽  
Author(s):  
K. T. Smith ◽  
R. O. Blanchard ◽  
W. C. Shortle
Keyword(s):  
Electrical Resistance ◽  
Growing Season ◽  
Balsam Fir ◽  
Periodic Growth ◽  
Cambial Zone ◽  
Dormant Season ◽  
Cambial Cells ◽  
The Relationship ◽  
Number Of Cells ◽  
Scanning Electron

Cambial electrical resistance (CER) was related to the number of cells per radial file of vascular cambium in dominant and codominant balsam fir (Abiesbalsamea (L.) Mill.) trees sampled during the growing season. Scanning electron microscopy (SEM) was used to examine the vascular cambial zone (VCZ) of balsam fir during the growing and dormant seasons. Trees selected for SEM were categorized as having growing season CER < 10 kΩ or CER > 12 kΩ. The two growing trees with CER < 10 kΩ had a mean of seven cells per radial file of VCZ in contrast with four cells per radial file in the two trees of CER > 12 kΩ. Trees of either growing season category had dormant season CER > 12 kΩ and four cells per radial file of VCZ. The relationship between CER and the number of cells per radial file of VCZ supports the hypothesis relating CER to periodic growth rate in balsam fir.

Formation of organic sulfur in forest soils: a biologically mediated process

1983 ◽  
Vol 13 (6) ◽  
pp. 1077-1082 ◽  
Author(s):  
John W. Fitzgerald ◽  
Jaru T. Ash ◽  
Timothy C. Strickland ◽  
Wayne T. Swank
Keyword(s):  
Organic Matter ◽  
Pine Forests ◽  
Covalent Linkage ◽  
Carbon Availability ◽  
Clear Cut ◽  
Factors Influencing ◽  
Acid And Base ◽  
Extractable Fraction ◽  
Bacteria And Fungi ◽  
Inorganic Sulfate

The ability of soils from hardwood, clear-cut, and pine forests to incorporate sulfur from added inorganic sulfate into salt-extractable (adsorbed) and nonsalt-extractable forms was investigated. At least 65% of the added sulfate was adsorbed while 8–27% of the sulfate added was recovered only after treatment of salt-extracted samples with acid and base (nonsalt-extractable sulfur). The incorporation of sulfur into this latter fraction was dependent upon incubation time, temperature, and depth and exhibited both spatial as well as seasonal variation in samples taken along a transect of one of the watersheds. Sulfur incorporation into the nonsalt-extractable fraction was inhibited 75–87% by sodium azide, 62–84% by erythromycin, and 41–68% by candicidin suggesting that the process is mediated by bacteria and fungi. Data on factors influencing sulfur incorporation suggest that sulfate was incorporated into organic matter as a covalent linkage and released after rupture of this linkage during acid and base treatment. The observations that 35S incorporation was inhibited 93–99% by unlabelled sulfate and stimulated 21–65% by increased carbon availability are consistent with this suggestion.

scholarly journals Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec

2011 ◽  
Vol 87 (05) ◽  
pp. 669-683 ◽  
Author(s):  
Martin Riopel ◽  
Jean Bégin ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Annual Rainfall ◽  
Deciduous Species ◽  
Partial Cutting ◽  
Coniferous Species ◽  
Breast Height ◽  
Silvicultural Treatments ◽  
Heavy Equipment

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.

Bulldozing stumps and nitrogen fertilization affect growth of Douglas-fir seedlings

1988 ◽  
Vol 18 (6) ◽  
pp. 803-806 ◽  
Author(s):  
W. G. Thies ◽  
E. E. Nelson
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Fertilization ◽  
Growing Season ◽  
Douglas Fir ◽  
Olympic Peninsula ◽  
Diameter At Breast Height ◽  
Clear Cut ◽  
Breast Height ◽  
Growing Seasons ◽  
Growth Of Seedlings

Eight treatments involving stump removal by bulldozing in combination with nitrogen fertilization were applied to 0.04-ha circular plots in a clear-cut on the Olympic Peninsula, Washington. Treatments included stump removal (either all stumps removed or the plot left undisturbed) and broadcast fertilization with ammonium nitrate (0, 336, 672, or 1345 kg N ha−1). Diameter at breast height and height of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings, planted several months after treatment, were recorded five and eight seasons after outplanting. The results showed that either bulldozing stumps from the site or fertilizing with ammonium nitrate increased growth of seedlings through their eighth growing season. After eight growing seasons, bulldozing had increased seedling height by 23% and diameter at breast height by 43%; fertilizing produced increases of 13% in height and 17% in diameter at breast height.

Relation between air water potential and cambial electrical resistance of balsam fir and white spruce after budbreak

1987 ◽  
Vol 17 (2) ◽  
pp. 105-108 ◽  
Author(s):  
Robert R. Gagnon ◽  
Eric Bauce ◽  
Marius Pineau
Keyword(s):  
Relative Humidity ◽  
Water Potential ◽  
Correlation Coefficient ◽  
Electrical Resistance ◽  
White Spruce ◽  
The Other ◽  
Balsam Fir ◽  
Simultaneous Measurements ◽  
Electrical Resistance Measurements ◽  
Made In

Cambial electrical resistance in 10 balsam fir (Abiesbalsamea (L.) Mill.) and 10 white spruce (Piceaglauca (Moench) Voss) trees in Québec was measured 42 times during July and August 1985. Simultaneous measurements of relative humidity and temperature were also taken so that water potential in air (ψa) could be determined. In both species, cambial electrical resistance, corrected to a constant temperature of 15 °C (CERCOR), was negatively correlated with ψa. On the other hand, 10 measurements on 14 balsam fir trees that had been severely defoliated by the spruce budworm (Choristoneurafumiferana (Clem.)) in 1983 and 1984, and 12 measurements on 14 protected trees showed that the correlation was stronger for sprayed trees than for those that had been defoliated. We propose that the correlation coefficient between cercor and ψa may be a useful index of tree vigor. However, in situations where plots can be visited only once during the season, cambial electrical resistance measurements should be made in the morning when the relative humidity is high.

scholarly journals Changes in biometric, density, and microscopic features of Parrotia persica trees in longitudinal and radial directions of the stem

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3563-3574
Author(s):  
Ali Hassanpoor Tichi ◽  
Hadi Gholamiyan ◽  
Mojtaba Rezanezhad Divkolae
Keyword(s):  
Transverse Direction ◽  
Growth Ring ◽  
Basic Density ◽  
Tree Height ◽  
Anatomical Study ◽  
Dry Density ◽  
Breast Height ◽  
Microscopic Features ◽  
Tree Stem ◽  
Diffuse Porous

The biometric, density, and microscopic features of Parrotia persica species were investigated in this work. Three completely healthy P. persica trees were randomly felled. Three discs of 5 cm thickness were cut at three height levels (at breast height, 3 m, and 4.5 m) of each stem. The test specimens were sequentially taken from pith to bark. The biometric characteristics of the fiber and their density were analyzed. The microscopic features were studied according to the IAWA List of Hardwoods. It was found that all biometric factors of P. persica were decreased with increasing tree height from base to top. In contrast, these factors were also increased with the increase of distance from the pith toward the bark. Oven-dry density and basic density were decreased with an increase in the height along the tree stem. However, in the transverse direction, oven-dry density and basic density were increased from pith to bark. The anatomical study indicated that P. persica is a diffuse-porous hardwood that has distinct growth ring boundaries, heterogeneous rays, scalariform perforation, and alternative intervessel pits.

scholarly journals EFFECTS OF DEFOLIATION BY SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA CLEM.) ON RADIAL GROWTH AT BREAST HEIGHT OF BALSAM FIR (ABIES BALSAMEA (L.) MILL.) AND WHITE SPRUCE (PICEA GLAUCA (MOENCH) VOSS.)

1958 ◽  
Vol 34 (1) ◽  
pp. 39-47 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Picea Glauca ◽  
Radial Growth ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
First Year ◽  
Growth Ratio ◽  
Breast Height

The relationship between spruce budworm defoliation and radial growth at breast height for balsam fir and white spruce trees of merchantable size was studied in various stands in northwestern Ontario. Defoliation was recorded yearly for these stands from the beginning of the infestation, and radial growth measurements were obtained from increment cores. The first year of radial growth suppression was calculated by comparing the growth of the affected species with that of jack pine and red pine trees by means of a growth-ratio technique. Apparent suppression in balsam fir and white spruce varied between stands, and, generally, occurred at the earliest in the second year and at the latest in the fourth year of severe defoliation. A wide ring at the base of the tree coinciding with the first year of suppression as reported by Craighead was non-existent.

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