scholarly journals Wood properties of exotic larch grown in eastern Canada and north-eastern United States

1995 ◽  
Vol 71 (5) ◽  
pp. 639-646 ◽  
Author(s):  
Y. H. Chui ◽  
Glenda MacKinnon-Peters

The rapid growth performance of exotic larch such as Japanese larch (Larix leptolepis (Sieb. et Zucc) Gord.) and European larch (Larix decidua Mill.) has attracted the attention of the forestry sector in eastern Canada and north-eastern United States for lumber and pulp production. While growth performance of these species in North America has been well documented, little is known with regards to their wood properties. The objective of this study was to evaluate the primary lumber grade yields, mechanical properties, fiber length, specific gravity and cold-water soluble extractives of larch from plantations in Maine, Nova Scotia, New Brunswick and Prince Edward Island. Samples were obtained from a Japanese (age 31), three European (age 17, 34 and 63) and one Japanese × European hybrid (age 22-27) larch stands. It was found that the structural grade yields of these species were relatively low because of the influence of knots. The mechanical properties (modulus of rupture and modulus of elasticity) of the mature European larch appeared to be comparable with published data for some native softwood species. Fiber length, specific gravity and cold-water soluble extractive content of all samples were similar to those found for other softwood species which are used for pulp production. Fiber length of the juvenile wood of European larch was significantly shorter than that of mature wood. Extractive content was highest in newly formed heartwood. Contrary to common belief, extractive content in young trees may not be low. Key words: Japanese larch (Larix leptolepis Gord.), European larch (Larix decidua Mill.), European × Japanese hybrid (Larix eurolepis), Wood properties, Lumber yields

1988 ◽  
Vol 18 (10) ◽  
pp. 1325-1331 ◽  
Author(s):  
C. T. Keith ◽  
G. Chauret

A number of basic wood quality characteristics were evaluated in 10 European larch (Larixdecidua Mill.) trees, 5 from each of two rapidly growing plantations in eastern Ontario (approximately 30 years old) and western Quebec (approximately 25 years old). Characteristics evaluated included growth rate, relative density, fibre dimensions, longitudinal shrinkage, alcohol–benzene and water-soluble extractives, and Klason lignin. Radial and longitudinal patterns of variation in wood characteristics were examined and particular attention was given to the distribution of juvenile wood within the stems. Extractive contents were more closely related to the extent of heartwood and sapwood in the stems than to differences between juvenile and mature wood. Relative density was generally lower at the centre of the stem than in the mature outer wood, but the change was usually gradual, with no distinct boundary between juvenile and mature wood zones. The most useful characteristic for delimiting the juvenile wood zone appeared to be longitudinal shrinkage. On this basis, the transition from juvenile to mature wood occurs at about 15 rings out from the pith at breast height. Ranking of individual trees for wood density was judged to be reliable at about 7 years of age at this height level.


1988 ◽  
Vol 64 (6) ◽  
pp. 475-479 ◽  
Author(s):  
D. P. Fowler ◽  
J. D. Simpson ◽  
Y. S. Park ◽  
M. H. Schneider

Yield data from a 25-year-old trial of Japanese larch (20 provenances), European larch (3 provenances) and tamarack (2 provenances) are presented. Japanese larch is genetically variable in volume of wood produced at age 25 years. The pattern of variation is not closely related to any commonly measured geographic or environmental variables.Japanese larch, managed over short rotations, is capable of producing two to three times more wood than other conifer species commonly planted in the Maritimes Region of Canada. The mean annual increment of merchantable wood for trees of the three best provenances at age 25 years is about 12 m3/ha per year, while that of the poorest provenance is about the same as for European larch and tamarack, 4 m3/ha per year. Japanese larch wood sawed, dried and machined well. It appears suited for general construction use and may be eligible for a stress grade.


1959 ◽  
Vol 91 (6) ◽  
pp. 379-381 ◽  
Author(s):  
W. A. Smirnoff ◽  
R. Béique

The poplar sawfly, Trichiocampus viminalis Fall., is indigenous to Europe, where it is common and widespread, but is also prevalent in the north-eastern United States, Eastern Canada and British Columbia. For the past five or six years it has caused serious defoliation to Populus nigra and P. deltoides in the vicinity of Quebec City.


2021 ◽  
pp. 2100011
Author(s):  
Alexander T. Fritz ◽  
Jaime C. Cazotti ◽  
Omar Garcia‐Valdez ◽  
Niels M. B. Smeets ◽  
Marc A. Dubé ◽  
...  

Author(s):  
Aida Mekhoukhe ◽  
Nacer Mohellebi ◽  
Tayeb Mohellebi ◽  
Leila Deflaoui-Abdelfettah ◽  
Sonia Medouni-Adrar ◽  
...  

OBJECTIVE: the present work proposed to extract Locust Bean Gum (LBG) from Algerian carob fruits, evaluate physicochemical and rheological properties (solubility). It aimed also to develop different formulations of strawberry jams with a mixture of LBG and pectin in order to obtain a product with a high sensory acceptance. METHODS: the physicochemical characteristics of LBG were assessed. The impact of temperature on solubility was also studied. The physical and the sensory profile and acceptance of five Jams were evaluated. RESULTS: composition results revealed that LBG presented a high level of carbohydrate but low concentrations of fat and ash. The LBG was partially cold-water-soluble (∼62% at 25°C) and needed heating to reach a higher solubility value (∼89% at 80 °C). Overall, the sensorial acceptances decreased in jams J3 which was formulated with 100% pectin and commercial one (J5). The external preference map explained that most consumers were located to the right side of the map providing evidence that most samples appreciated were J4 and J2 (rate of 80–100%). CONCLUSION: In this investigation, the LBG was used successfully in the strawberry jam’s formulation.


2014 ◽  
Vol 91 (5) ◽  
pp. 473-481 ◽  
Author(s):  
Guiai Jiao ◽  
Xiangjin Wei ◽  
Gaoneng Shao ◽  
Lihong Xie ◽  
Zhonghua Sheng ◽  
...  

1984 ◽  
Vol 47 (10) ◽  
pp. 753-755 ◽  
Author(s):  
R. E. GINN ◽  
V. S. PACKARD ◽  
T. L. FOX

The 3M Company has developed a sample-ready system (Petrifilm ™ SM) for enumerating bacteria in milk and other food products. The testing unit consists of Standard Methods culture medium coated onto a base film and overlaid with a second film coated with a cold-water-soluble gelling agent and tetrazolium indicator dye. As such, the system is ready to accept samples of product. A pipette or 0.001-ml plate loop continuous pipetting syringe can be used for applying samples. In this study, both methods of sample addition were used and results compared with those of the Standard Plate Count (SPC) and standard Plate Loop (PL) methods for determining bacteria numbers in raw milk. In total, 108 samples were analyzed in duplicate by each of the four methods. The correlation coefficients (r) between the 3M-SPC and SPC, 3M-PL and PL, 3M-PL and SPC and PL and SPC were 0.946, 0.935, 0.941, and 0.974, respectively. Repeatability, as measured by mean log10 variance for duplicate determinations, was essentially the same for the four methods, and in all instances less than 0.005. The mean log10 differences between the SPC and 3M-SPC, and SPC and 3M-PL were, respectively, −0.177 and −0.168. The preceding statistical criteria suggest the Petrifilm™ SM method to be a suitable alternative to the SPC or the PL procedure.


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