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Moisture content of fresh Scots pine wood in areas near damage caused by harvester head feed rollers
By damaging bark, mechanized harvesting deprives wood of its natural mechanical barrier. This study concerns the effect of this damage on the changes in moisture content that occur near the damaged areas of Scots pine (Pinus sylvestris L.). This study was carried out using 45 randomly selected 11 m long logged pine stems. Additionally, the effect of bark thickness on the depth of damage was measured. To determine the influence of the location of the damage and bark thickness on the wood moisture near the damaged region, wood samples were collected from two sections. The first was located one meter above the log’s base, while the second was located one meter from the end of the log. Two increment cores were taken by a Pressler borer in each section: one from the damaged wood zone and the second from the undamaged wood zone. The average bark thickness one meter from the base of the log was 11.2 mm, which decreased to 1.8 mm in the samples taken one meter from the top of the log. The average depths of the damage caused by feed roller spikes in the two sections were 3.9 and 3.8 mm, respectively, indicating that there was no significant effect of bark thickness on the depth of the damage. The wood samples collected near the damaged wood zone (DW) had about 13 percent lower moisture content than those taken from the undamaged zone (UDW). This difference was statistically significant. We observed greater mean moisture content closer to the top of the log for both the samples taken near the damaged zone and the samples taken from the undamaged zone. One meter from the base of the log, the moisture content difference between the DW and UDW was 9.8 percentage points, which was statistically insignificant. By contrast, significantly lower moisture content (−16%) was observed in the DW one meter from the top of the log.
How the scots pine and beech aging process affects wood
This study investigates the effects of aging trees on wood properties, which are caused by climate change, the withdrawal of coniferous species from Central Europe, and the increased crown sweep in old beech stands. The research was carried out in old tree stands with a high proportion of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.) species. The collected material was from five tree pine stands aged between 151 and 182 and three beech stands between the ages of 165 and 184. The samples were subjected to an analysis of wood properties such as density and modulus of elasticity. The results and findings of this study indicate that the Scots pine currently reaches the optimal wood tissue quality at around 80 years of age, which is approximately 20 years earlier than the species’ anticipated cutting age. However, the beech, which reaches maturity at about 120–140 years, reaches the maximal quality of wood tissue already at the age of 80–90 years. Above the age of 110, the quality of beech wood (density and modulus of elasticity) decreases. Moreover, it is necessary to emphasize that the radial trend of wood density does not coincide with the trend of the modulus of elasticity. Additionally, it is found that wood density is not a perfect representation of its mechanical qualities; it can, however, be regarded as a measure of the technical quality of wood tissue. The results indicate that the pine and the beech that grow on the European Plain mature faster and reach technical quality earlier than just a couple of decades before.
Determination of chemical markers affecting the occurrence of Panolis flammea Den. & Shiff.
AbstractThe research conducted so far on the chemical mechanisms of trees' defence against foliophages has not uncovered the chemical compounds biosynthesized by plants that are essential for these mechanisms. The objective of this study was to identify a chemical indicator for the presence of the pine beauty moth in Pinus sylvestris stands. Fresh needled shoots were collected from the crowns of pine trees in stands where the pine beauty moth tends to occur in large numbers, as well as from control stands. Total phenolic contents, total flavonoids contents, total chlorophyll content, terpene compounds, phenolic compound concentration, LMWOAs, sugar content, and colour analysis were conducted. Chlorophyll content, the presence of Panolis flammea in forest stands, and the colour of pine needles were discovered to be related. Variable L* correlated positively with the concentrations of chlorophyll a and b. In pine needles that were not attacked by the pine beauty moth, significantly higher concentrations of 4‐hydroxybenzoic acid, salicylic acid, chlorogenic acid, syringic acid, quercitin, and rutin were found, with the first compound having the most significant effect (4‐hydroxybenzoic acid). Based on the study results, the connected compounds in pine needles make them susceptible to insect attack. In addition, insect repellent programmes were mentioned.