Wood chemical components and decay resistance of four common mongolian softwoods

To utilize wood resources in Mongolia, amounts of wood chemical components (hot-water extracts, 1% NaOH extracts, ethanol-toluene extracts, holocellulose, -, -, and -cellulose, Klason lignin, and ash) were determined in four common Mongolian softwoods, Pinus sylvestris, Pinus sibirica, Picea obovata, and Larix sibirica. In addition, decay resistance of heartwood was evaluated against a white-rot fungus Trametes versicolor, and a brown-rot fungus Formitopsis palustris. Among the four species, heartwood of Larix sibirica was chemically characterized by higher amounts of hot-water and 1% NaOH extracts, and lower amounts of holocellulose and Klason lignin. These characteristics may be related to the presence of arabinogalactan which is easily extracted with cold water. Mean mass loss in each softwood ranged from 6.9% to 28.1% in white-rot fungus, and from 24.8% to 48.3% in brown-rot fungus. Among four species, Pinus sibirica showed the highest decay resistance against both fungi. By the linear mixed-effects model analysis, negative relationships were found between mass loss and amounts of extracts in heartwood, suggesting that heartwood having larger amounts of extracts showed higher natural decay durability.

Comparison of selected properties of natural aged wood and contemporary timber of Pinus sylvestris L. investigated using standard methods and measuring of transition speed of ultrasounds along the fibre

Scots pine wood (Pinus sylvestris L.) is the most common wood material used in historical buildings in many parts of Central and Eastern Europe. Experiments were conducted natural aged wood (263 – 459 years old), extracted from construction elements of four historical buildings (from seven construction elements), and contemporary wood extracted from 5 construction elements. A strong relationship was observed between density and static bending strength (MOR) of natural aged wood (R2 = 0.5599), and also of contemporary timber (R2 = 0.7863). Antique wood compared to contemporary wood with the same average moisture content and density is characterized by significantly lower modules (static and dynamic), the speed of ultrasonic waves transitions, and bending strength. Differences in these properties increase with increasing wood density.

Gene pool of Scots pine (Pinus sylvestris L.) under reforestation in extreme environmen

The article is devoted to the study of the gene pool formation mechanisms of arboreal plant populations at the sites of mining and processing of mineral resources and may be useful in managing the processes of natural forest remediation of disturbed lands. The aim of the research is to study the genetic diversity and spatial differentiation of the Scots pine (Pinus sylvestris L.) undergrowth thriving on the industrial waste discharge of the Uchaly Mining and Processing Plant (the Southern Urals).
Isoenzymes of 7 enzymes were used as markers (encoded by 10 polymorphic loci Aat-1, Aat-2 and Aat-3, Gdh-1, Fdh-1, Lap-1, Lap-1, Skdh-1, 6-Pgdh-1 and Dia-1), separated by polyacrylamide disc electrophoresis. Genetic variability of the undergrowth under the forest canopy (7 samples, average number of avenues per locus A = 2.3-2.8, the observed heterozygosity was HO = 0.207 – 0.260, the expected heterozygosity HE = 0.201 – 0.273) and in industrial waste discharges (4 samples, A = 1.9 – 3.1, HO = 0.225 – 0.277; HE = 0.240 -0.298) varies over a wide range. In the parent stand, the observed heterozygosity (HO = 0.203) was lower than in any of the undergrowth samples. A comparatively high genetic differentiation of the undergrowth was found (the between-sample subdivision FST index was 3.8%, the average Nei genetic distance DNei = 0.015 with changes in individual pairs from 0.003 to 0.032), comparable with genetic differences in geographically separated populations.