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1
Strukelj, Manuella, Suzanne Brais, Sylvie A. Quideau, et al. "Chemical transformations in downed logs and snags of mixed boreal species during decomposition." Canadian Journal of Forest Research 43, no. 9 (2013): 785–98. http://dx.doi.org/10.1139/cjfr-2013-0086.
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Snags and downed logs are substantial components of the detrital carbon pool in boreal forests. Effects of their decomposition on chemical and physical characteristics of the forest floor remain relatively unknown. The main objective of this study was to characterize chemical transformations of decaying logs and snags of common tree species in the boreal mixedwood forest. Logs and snags from a wide range of decay classes were sampled and analyzed by solid-state 13C nuclear magnetic resonance spectroscopy and by near-infrared spectroscopy. Little or moderate chemical changes appeared in fresh and moderately decayed snags and logs, but in well-decayed logs, substantial degradation of carbohydrates and increases in lignin concentrations occurred. Deciduous species had initially more carbohydrates than coniferous species, but decomposition narrowed their differences, and in well-decayed logs, species differed mainly in terms of their lignin concentrations. Well-decayed deciduous logs reached very low wood densities, and their integration into the forest floor and long-term preservation remains questionable. In contrast, chemical composition of well-decayed coniferous logs resembles that of lignic forest floor (i.e., forest floor originating from deadwood decomposition), with preserved lignins, carbohydrates, and alkyl carbon compounds. Decomposed coniferous wood thus contributes to chemical heterogeneity of the forest floor, possibly promoting diversity of decomposers as well as carbon retention in soils.
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Marra, James L., and Robert L. Edmonds. "Coarse woody debris and forest floor respiration in an old-growth coniferous forest on the Olympic Peninsula, Washington, USA." Canadian Journal of Forest Research 24, no. 9 (1994): 1811–17. http://dx.doi.org/10.1139/x94-234.
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Carbon dioxide evolution rates for downed logs (coarse woody debris) and the forest floor were measured in a temperate, old-growth rain forest in Olympic National Park, Washington, using the soda lime trap method. Measurements were taken every 4 weeks from October 22, 1991, to November 19, 1992. Respiration rates for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.), logs were determined for decay classes 1–2, 3, and 5 in two diameter classes. Overall, western hemlock logs respired at a rate 35% higher (4.37 g CO2•m−2•day−1) than Douglas-fir logs (3.23 g CO2•m−2•day−1). Respiration rates for decay class 1–2 logs of both species were similar to decay class 5 logs (4.46 and 4.07 g CO2•m−2•day−1, respectively), but decay class 3 logs respired at a lower rate (3.23 g CO2•m−2•day−1). Seasonal patterns of respiration rates occurred, particularly for decay class 1 and 2 western hemlock logs where monthly averages ranged from a low of 2.67 g CO2•m−2•day−1 in February 1992 to a high of 8.30 g CO2•m−2•day−1 in September 1992. Rates for decay class 1–2 western hemlock logs were greater than those from the forest floor, which ranged from 3.42 to 7.13 g CO2•m−2•day−1. Respiration rates were depressed in late July and August compared with fall and spring owing to the summer drought characteristic of the Pacific Northwest. Large-diameter western hemlock logs in decay class 1–2 had higher respiration rates than small-diameter logs, whereas large-diameter decay class 3 western hemlock logs had lower respiration rates than small-diameter logs.
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Bingham, Bruce B., and John O. Sawyer Jr. "Volume and mass of decaying logs in an upland old-growth redwood forest." Canadian Journal of Forest Research 18, no. 12 (1988): 1649–51. http://dx.doi.org/10.1139/x88-249.
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A line intersect technique was used to determine the volume and mass of dead, naturally fallen logs at least 25 cm in diameter and 4 m or more in length over an 80-ha mesic, upland old-growth redwood forest in northwestern California. Each log was identified to species and placed in one of three decay classes: sound logs, moderately decayed logs, and logs in an advanced state of decay. Only logs of redwood (Sequoiasempervirens (D. Don) Endl.), Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), and western hemlock (Tsugaheterophylla (Raf.) Sarg.) met the dimension requirements of sampling. Redwood logs in the middle decay class had the greatest volume (528 m3/ha) and mass (116 t/ha). The total volume and mass of all logs were 957 m3/ha and 200 t/ha, respectively. The total volume and mass of decaying logs in this redwood stand exceeded averages typical of other kinds of low-elevation coniferous forests in the Douglas-fir region.
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Simard, Marie-Josée, Yves Bergeron, and Luc Sirois. "Substrate and litterfall effects on conifer seedling survivorship in southern boreal stands of Canada." Canadian Journal of Forest Research 33, no. 4 (2003): 672–81. http://dx.doi.org/10.1139/x02-204.
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Most conifer seeds die as seeds or seedlings within 5 years after dispersal. Understanding what factors keep a few of them alive is essential if natural regeneration is to be maintained in managed forests. For example, decaying logs and the conifer seedlings that often grow on them are rare under certain canopies such as deciduous trembling aspen (Populus tremuloides Michx.). We conducted a seeding experiment to evaluate the role of certain substrates, and litterfall, on early conifer survivorship. Seeds of balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca (Moench) Voss), and eastern white-cedar (Thuja occidentalis L.) were sown during 2 consecutive years on mineral soil, relocated logs, and litter in deciduous aspen and coniferous (Thuja occidentalis dominated) stands. Seedling survivor ship was monitored at the end of the first growing season and 1 year after each sowing. Conifer seedling survivorship was equivalent or greater under aspen than under cedar-dominated canopies. Picea and Thuja survivorship was highest on decaying logs of approximately 9 cm high (compared with logs buried at forest floor level) and lowest on forest floor litter during both the first growing season and the following autumnwinter. Abies survivorship was little affected by substrate type, except for low autumnwinter survival on litter. Thuja autumnwinter survival was significantly reduced by litterfall in both deciduous and coniferous stands.
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Katarzyna, Szewczyk, and Iwanicki Piotr. "Evaluating the suitability of machinery use during skidding of wood in pine stands." Lesne Prace Badawcze / Forest Research Papers 80, no. 3 (2019): 219–26. https://doi.org/10.2478/frp-2019-0020.
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Skidding of large-sized logs requires special machinery such as skidders, clambunks, forwarders or farm tractors with a winch or hydraulic tongs. The precise choice of which skidding machine to use depends largely on the desired efficiency and economic factors. The aim of this research was to evaluate the suitability of three different machines (LKT 81 skidder, John Deere 1110D forwarder and Pronar 1221A agricultural tractor with hydraulic tongs) for wood skidding based on technical and economic indicators. The practical work for this research was carried out in the Mirosławiec Forest Division in areas with fresh mixed coniferous forest habitats where the dominant species in the stands was pine and strip-like clear cutting was the preferred management practice. The best machinery performance values were obtained for skidding using the John Deere forwarder
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Rajala, Tiina, Mikko Peltoniemi, Taina Pennanen, and Raisa Mäkipää. "Relationship between wood-inhabiting fungi determined by molecular analysis (denaturing gradient gel electrophoresis) and quality of decaying logs." Canadian Journal of Forest Research 40, no. 12 (2010): 2384–97. http://dx.doi.org/10.1139/x10-176.
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We investigated the fungal communities inhabiting decaying logs in a seminatural boreal forest stand in relation to host tree species, stage of decay, density, diameter, moisture, C to N ratio, Klason lignin content, and water- and ethanol-soluble extractives. Communities were profiled using denaturing gradient gel electrophoresis fingerprinting of the rDNA ITS1 region coupled with sequencing of fungal DNA extracted directly from the wood. In addition, polypore fruit bodies were inventoried. Logs from different tree species had different fungal communities and different physicochemical properties (e.g., C to N ratio, density, ethanol extractives, and diameter). Ascomycetes comprised a larger portion of communities inhabiting deciduous birch ( Betula spp.) and European aspen ( Populus tremula L.) logs compared with those living on coniferous Norway spruce ( Picea abies (L.) Karst.) and Scots pine ( Pinus sylvestris L.). A relationship between mycelial community structure and density of decaying spruce logs suggested a succession of fungi with mass loss of wood. The fruit body inventory underestimated fungal diversity in comparison with the culture-free denaturing gradient gel electrophoresis analysis that also detected inconspicuous but important species inhabiting decaying wood.
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Prescott, Cindy E., Kirsten Corrao, Anya M. Reid, Jenna M. Zukswert, and Shalom D. Addo-Danso. "Changes in mass, carbon, nitrogen, and phosphorus in logs decomposing for 30 years in three Rocky Mountain coniferous forests." Canadian Journal of Forest Research 47, no. 10 (2017): 1418–23. http://dx.doi.org/10.1139/cjfr-2017-0001.
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Estimates of decomposition rates of coarse woody debris (CWD) and fluxes of nutrients therein are essential components of carbon (C) and nutrient budget models. In a 30-year field experiment, we periodically measured mass remaining and nutrient concentrations in log segments of pine, spruce, and fir in natural, mature coniferous forests in Alberta, Canada. The predicted turnover times (t95; years) were 43–44 years for pine, 42–60 years for spruce, and 38–46 years for fir. Extrapolating from best-fit models, we predict that decomposition of these logs would be complete within 50–60 years. The ratio of carbon to nitrogen (C:N) declined for most of the decomposition period, and ratios of the three species converged at <200 at 90% mass loss. Net release of N occurred only after logs had lost 90% of their original C and C:N had declined to <200. The ratio of carbon to phosphorus (C:P) declined and converged at 500–1000 at 90% mass loss. There was no evidence of net P release from logs even at 90% mass loss. It may be possible to estimate the amounts of N and P that will be incorporated into decaying logs based on the extent to which their initial C:N differs from 200 and their initial C:P differs from 500.
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Prestemon, Jeffrey P., Shushuai Zhu, James A. Turner, Joseph Buongiorno, and Ruhong Li. "Forest Product Trade Impacts of an Invasive Species: Modeling Structure and Intervention Trade-Offs." Agricultural and Resource Economics Review 35, no. 1 (2006): 128–43. http://dx.doi.org/10.1017/s1068280500010108.
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Asian gypsy and nun moth introductions into the United States, possibly arriving on imported Siberian coniferous logs, threaten domestic forests and product markets and could have global market consequences. We simulate, using the Global Forest Products Model (a spatial equilibrium model of the world forest sector), the consequences under current policies of a widespread, successful pest invasion, and of plausible trading partner responses to the successful invasion. We find that trade liberalization would have a negligible effect on U.S. imports of Siberian logs and, consequently, on the risk of a pest invasion. But, if it happened, possibly through trade in other commodities, a successful and widespread pest invasion would have large effects on producers and consumers over the period 2002 to 2030.
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Watchman, A. L., R. A. Lessard, A. J. T. Jull, L. J. Toolin, and Weston Blake. "14C Dating of Laser-Oxidized Organics." Radiocarbon 35, no. 2 (1993): 331–33. http://dx.doi.org/10.1017/s0033822200065024.
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We used a continuous krypton ion laser to rapidly oxidize milligram-sized fragments of coniferous driftwood of known ages, and dated the resulting carbon dioxide by accelerator mass spectrometry (AMS). AMS 14C ages of non-pretreated young wood from different parts of two logs were within 10% of the ages of conventionally determined alkaline insoluble fractions. The age of the oldest whole wood measured after laser oxidation was within the error ranges of conventional values.
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Heppelmann, Joachim B., Eric R. Labelle, Thomas Seifert, Stefan Seifert, and Stefan Wittkopf. "Development and Validation of a Photo-Based Measurement System to Calculate the Debarking Percentages of Processed Logs." Remote Sensing 11, no. 9 (2019): 1133. http://dx.doi.org/10.3390/rs11091133.
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Within a research project investigating the applicability and performance of modified harvesting heads used during the debarking of coniferous tree species, the actual debarking percentage of processed logs needed to be evaluated. Therefore, a computer-based photo-optical measurement system (Stemsurf) designed to assess the debarking percentage recorded in the field was developed, tested under laboratory conditions, and applied in live field operations. In total, 1720 processed logs of coniferous species from modified harvesting heads were recorded and analyzed within Stemsurf. With a single log image as the input, the overall debarking percentage was calculated by further estimating the un-displayed part of the log surface by defining polygons representing the differently debarked areas of the log surface. To assess the precision and bias of the developed measurement system, 480 images were captured under laboratory conditions on an artificial log with defined surface polygons. Within the laboratory test, the standard deviation of average debarking percentages remained within a 4% variation. A positive bias of 6.7% was caused by distortion and perspective effects. This resulted in an average underestimation of 1.1% for the summer debarking percentages gathered from field operations. The software generally performed as anticipated through field and lab testing and offered a suitable alternative of assessing stem debarking percentage, a task that should increase in importance as more operations are targeting debarked products.
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Gejdoš, Miloš, Katarína Michajlová, and Dominik Gretsch. "The use of the acoustic tomograph and digital image analysis in the qualitative assessment of harvested timber – case study." Central European Forestry Journal 69, no. 2 (2023): 106–11. http://dx.doi.org/10.2478/forj-2022-0021.
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Abstract Accurate qualitative evaluation of grown and harvested wood is a key issue from the point of view of its subsequent economic evaluation. With the current trend of global climate change and large volumes of wood damaged by harmful agents, automated methods of wood quality assessment are becoming more and more important. The work aimed to verify the applicability and significance of the results of using the acoustic tomograph for the qualitative assessment of selected tree species logs. Ten samples of log sections of non-coniferous and coniferous trees were evaluated, on which an image analysis of qualitative features was performed on a cross-section from their digital photograph and the image output of an acoustic tomograph software. The results were compared with each other and the accuracy of qualitative feature identification by acoustic tomograph was evaluated. At the same time, the results of the image analysis of the qualitative feature were compared with its assessment through STN EN 1309-3. It was shown that, when evaluated according to the Standard, qualitative features were overestimated by an average of 29.19% compared to the acoustic tomograph and by 28.22% compared to the digital photograph. The use of the acoustic tomograph confirmed a good level of accuracy in the identification of qualitative features even on logs of harvested wood, although it is primarily intended for the qualitative evaluation of standing trees.
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Flora, Donald F. "An equilibrium model of Pacific Rim trade in small softwood logs." Canadian Journal of Forest Research 16, no. 5 (1986): 1000–1006. http://dx.doi.org/10.1139/x86-175.
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Small, lower-graded logs, corresponding roughly to British Columbia's grade 4 sawlogs, make up about 44% of all Pacific Rim softwood log trade, or about 35% of total trade in coniferous sawn wood and roundwood. The 1983 small-log volume of 9 000 m3 is expected to grow to 12 300 m3 in 1990, to 14 000 m3 in 1995, and to be accompanied by a 13% rise in prices at Pacific Coast docks during this decade. Prices of small logs are projected to be level during the early 1990s. This analysis was performed with an equilibrium model of the log economies of each supplying and consuming nation around the Pacific Ocean. Individual export supply and import demand functions were summed to a classical market solution, with reference to free alongside ship prices along the western shores of North and South America. Key assumptions are constant exchange rates and secularly stable economies.
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Shelgaeva, Olga Yurievna. "Research on the impact of Russian log export ban on China's log imports." Current Research, no. 17-2 (199) (April 24, 2024): 52–56. https://doi.org/10.5281/zenodo.11055704.
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<em>Russia’s 2022 log export ban, aimed at retaining 6 million cubic meters of coniferous timber domestically, has significantly impacted China’s log imports due to its heavy reliance on Russian logs. The ban has inhibited China’s import amount and number, increasing the average import price. However, it also led to a trade transfer effect, with imports from 15 other countries significantly increasing. The study suggests countermeasures such as improving domestic timber supply, diversifying import sources, accelerating industry transformation and upgrading, and enhancing enterprise risk control awareness.</em>
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Robonen, E. V., N. P. Chernobrovkina, B. V. Raevsky, A. V. Egorova, M. I. Zaitseva, and G. N. Kolesnikov. "Obtaining Woody Greens Enriched with L-Arginine during Forestry Management of Young Scots Pine Stands (Scientific Review)." Lesnoy Zhurnal (Forestry Journal), no. 5 (November 5, 2020): 9–37. http://dx.doi.org/10.37482/0536-1036-2020-5-9-37.
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Forests produce a huge amount of organic matter, which is a source of renewable raw materials for the production of technical, feed, food and pharmaceutical products. The logging and woodworking industry in Karelia, as in Russia as a whole, is based exclusively on stem wood. Woody greens are formed while felling ripe and over-mature stands, thinning and implementation of measures for the conservation, protection and reproduction of forests including forest stands cutting. The development of technologies for the use of woody greens is necessary for the multi-purpose utilization of the entire phytomass produced by forest plant communities. An additional economic incentive for young stands thinning and limbing, that are used to improve the quality of logs, is the ability to reduce costs or even ensure the profitability of these measures driven by the development of processing plants and the use of wastes generated during transportation: thinners, low-quality and low-value decidous wood, woody greens, that are raw materials for the production of biologically active preparations of various action. The urgent tasks are to increase the use of importsubstituting pharmaceutical substances and to search the alternative methods for producing raw materials for nutrient mixtures and feed stuff. Technologies for modifying the biochemical composition of coniferous greens, resulting in production of plant raw materials enriched with target biologically active substances, are being developed for the exploration of new plant sources. The water-soluble fraction of coniferous greens contains free amino acids, in particular L-arginine, which plays an important role in the life of animals. A promising way is to increase the free amino acids content in coniferous raw materials and change their quantitative ratio by regulation of the mineral nutrition regime of woody plants. An original scheme of additional supply of coniferous plants with nitrogen and boron is proposed in order to obtain coniferous greens enriched with L-arginine. The use of conifers as bioproducers of L-arginine and the study of its metabolism with reference to climatic factors, conditions of mineral nutrition, seasonal and daily dynamics in the natural environment, the search for ways to increase its level in organs and tissues is of current interest both on the theoretical and practical sides. Obtaining coniferous greens enriched with L-arginine will allow organizing the production of coniferous products for nutrient and pharmaceutical use. It is necessary to analyze the potential sources of raw materials taking into account their availability, costs for enriching the needles with L-arginine and product yield per unit area to assess the economic feasibility of organizing such production. A developed sequence of forestry measures will make it possible to obtain needles enriched with L-arginine, both in the process of implementing various types of forest use, and in carrying out activities aimed at increasing the productivity of forests and preserving their useful functions. Herewith, it is possible to turn costly cleaning and fertilizing of young Scots pine stands into profitable ones with additional products. Technologies of intentional changes in the chemical composition and pharmacological properties of plant raw materials obtained from woody plants will allow the development of new raw materials for biologically active substances.
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van der Wal, Annemieke, Paulien klein Gunnewiek, and Wietse de Boer. "Soil-wood interactions: Influence of decaying coniferous and broadleaf logs on composition of soil fungal communities." Fungal Ecology 30 (December 2017): 132–34. http://dx.doi.org/10.1016/j.funeco.2017.08.006.
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Laiho, Raija, and Cindy E. Prescott. "The contribution of coarse woody debris to carbon, nitrogen, and phosphorus cycles in three Rocky Mountain coniferous forests." Canadian Journal of Forest Research 29, no. 10 (1999): 1592–603. http://dx.doi.org/10.1139/x99-132.
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The contribution of coarse woody debris to C, N, and P cycles was assessed in forests of lodgepole pine (Pinus contorta Dougl. ex Loud.), white spruce (Picea glauca (Moench Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) - Engelmann spruce (Picea engelmannii Parry ex Engelm.) in southwestern Alberta. Mass loss and changes in C, N, and P concentrations in decomposing log segments were measured for 14 years. Litter input was measured during 10 years for coarse woody debris, 1 year for ground vegetation, and 5 years for other aboveground litter types. Release of C, N and P from decomposing litter were simulated for a period of 40 years. After 14 years, log segments of pine, spruce, and fir had lost on average 71, 38, and 40%, respectively, of their dry mass. The N content of the pine logs increased, spruce changed little, and fir lost N. Phosphorus accumulated in all logs. The greatest imports of N and P occurred at the pine sites and fir sites, respectively, where these nutrients were the least available, indicating that wood decay organisms may compete with vegetation for limiting nutrients in these forests. Coarse woody debris comprised 3-24% of aboveground litter and contributed less than 5% of the N and P released. Coarse woody debris does not appear to make a significant contribution to N and P cycling in these forests.
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Gee, Carole, Douglas Sprinkel, Mary Beth Bennis, and Dale Gray. "Silicified logs of Agathoxylon hoodii (Tidwell et Medlyn) comb. nov. from Rainbow Draw, near Dinosaur National Monument, Uintah County, Utah, USA, and their implications for araucariaceous conifer forests in the Upper Jurassic Morrison Formation." Geology of the Intermountain West 6 (November 20, 2019): 77–92. http://dx.doi.org/10.31711/giw.v6.pp77-92.
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A new local flora of silicified logs and wood has been discovered in the Upper Jurassic Morrison Formation in the Rainbow Draw area near Dinosaur National Monument, northeastern Utah, USA. Fossil logs and wood were found in the Salt Wash Member at nine sites at Rainbow Draw and at one site near Miners Draw, south of Blue Mountain. The fossil logs are large and relatively intact, the longest measuring 11 m. The wood is well preserved, coniferous, and can be identified to the species level. Diagnostic anatomical features include resin plugs in the ray cells and axial tracheids, araucarioid tracheary pitting and crossfield pitting, and the lack of resin canals and true, regularly occurring growth rings. This taxon of fossil wood, originally described as Araucarioxylon hoodii Tidwell et Medlyn, is recognized here as a new combination, Agathoxylon hoodii (Tidwell et Medlyn) Gee, Sprinkel, Bennis et Gray, which pertains to the conifer family Araucariaceae. Based on the preserved girth of the logs, the minimum height of the trees could be reconstructed. The largest fossil logs measured at least 127 cm in diameter and hence reached a minimum height of 28 m. Judging from the growth habit of all naturally occurring araucariaceous trees today, the fossil plants likely formed forests of moderately tall trees and were well over 100 years old. The lack of true growth rings shows that there was no seasonality in the local paleoclimate, neither variations in summer–winter temperatures, nor wet–dry cycles. Thus, during the Late Jurassic, tall conifer forests with Agathoxylon hoodii grew in at least two areas in what is now Utah: east of the city of Vernal and near Mt. Ellen in the Henry Mountains. Coupled with the fossil evidence of conifer seed cones and pollen found in the Morrison Formation throughout eastern Utah, the newly discovered fossil logs and wood argue for the reconstruction of Upper Jurassic habitats in this region as mesic and wooded, and the climate as equable, not seasonal, nor semi-arid or arid.
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Gejdoš, Miloš, Tomáš Gergeľ, Katarína Michajlová, Tomáš Bucha, and Radovan Gracovský. "The Accuracy of CT Scanning in the Assessment of the Internal and External Qualitative Features of Wood Logs." Sensors 23, no. 20 (2023): 8505. http://dx.doi.org/10.3390/s23208505.
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The qualitative evaluation of harvested raw logs and sawlogs is mainly based on the quantitative and qualitative evaluation of the visible macroscopic features of the wood. Modern methods allow for the analysis of whole logs by means of computed tomography. These devices can analyze the internal qualitative features of wood that are not visible on the external structures of the logs. The aim of this work was to evaluate the detection accuracy of a CT-scanning device intended for scanning logs on the internal qualitative features of wood using model trunks. Two logs of beech and oak with a length of 4 m were selected for the analysis, based on availability. Qualitative features were identified through computed tomography scanning, visually identified on cut sections, and then manually measured in accordance with applicable legislation. Relatively good agreement was demonstrated for the detected features in terms of identifying their location (dimension in millimeters from the end of the log). For this parameter, the average differences were 0.90% on the beech log and only 1.21% on the oak log. Relatively high accuracy was shown via CT detection of qualitative features in the beech section (with average differences in dimensions of only 3.5%). In the case of the oak log, the dimensions of the quality features were significantly overestimated. These results indicate that CT scanning technology may have a problem with some hardwood species. It was primarily developed for coniferous tree species, and software algorithms are, therefore, not yet fully adapted to the precise detection of the dimensions of individual quality features. Despite the detected differences, it was confirmed that the CT technology of scanning harvested wood can have a fundamental impact on optimization procedures in the recovery and processing of wood. Renting a scanning line for a certain capacity of wood volume appears to be a deployment option for forestry operations and smaller wood processing operations. Thus, this technology can become an important factor in improving the economic evaluation of the final production of wood.
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Hagemann, Ulrike, Martin T. Moroni, and Franz Makeschin. "Deadwood abundance in Labrador high-boreal black spruce forests." Canadian Journal of Forest Research 39, no. 1 (2009): 131–42. http://dx.doi.org/10.1139/x08-166.
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Deadwood (woody debris (WD), standing dead trees (snags), stumps, and buried deadwood) abundance was estimated in Labrador humid high-boreal black spruce (Picea mariana (Mill.) BSP) forests regrown following natural and anthropogenic disturbances. Aboveground deadwood (DW) abundance in Labrador was similar to values observed in other boreal forests experiencing drier or warmer climates. Clear-cut harvest generated large amounts of WD, which had almost completely decomposed 34–36 years following harvesting, with a fitted volume reduction rate of –0.058 year–1. Total WD in all harvested stands was composed of predominantly <10 cm pieces, which should be included in DW inventories of disturbed coniferous boreal forests. Postfire WD likely peaked ∼20 years following disturbance, as a result of the collapse of snags, and was dominated by large amounts of medium-sized logs (10.0–19.9 cm). Buried DW stocks considerably exceeded total aboveground DW stocks in old-growth, middle-aged, and older harvested stands. Old-growth stands contained 179.3 m3·ha–1 of buried DW, a vast amount indicative of long-term accumulation requiring significantly depressed rates of WD decomposition following burial. DW stocks could be significantly underestimated if buried DW is excluded from DW inventories in cool and moist coniferous forests with long fire-return intervals.
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Soldatov, Aleksandr V., Eduard F. Gerts, Andrey V. Mekhrentsev, and Alina F. Urazova. "Justification of Raw Material Supply for a Timber Industry Enterprise." Lesnoy Zhurnal (Forestry Journal), no. 2 (April 5, 2025): 128–42. https://doi.org/10.37482/0536-1036-2025-2-128-142.
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The article presents the characteristics of the forest fund of the Republic of Bashkortostan, its area, estimated cutting area and quality indicators. An increase in the share of softwood species in the forest fund and a decrease in the yield of industrial wood as a result of the felling of high-quality pine forests have been noted. The relevance of placing in the region an enterprise for processing unclaimed low-quality wood raw materials, Kronoshpan OSB LLC, the world’s largest manufacturer of wood boards, has been substantiated. The issues of substantiation of wood grading and the adoption of a bucking program during exploitation of leased forest plots have been considered using the example of the enterprise mentioned. The calculations of the bucking program (bucking balance) have been carried out based on the condition of specialization in the production of target grades that are in high demand in the market, and maximum provision of raw materials from our own production. Roundwood grading has been determined using the methodology for calculating assortment resources developed at the Ural State Forestry Engineering University. The methodology is based on bucking large samples of full-length logs of deciduous and coniferous species. The samples of full-length logs have been formed in the lower warehouses of Bashkortostan logging enterprises, and their bucking has been carried out taking into account the existing technical requirements for the production of roundwood. The methodology is based on regression equations characterizing the relationship between the ratios of the maximum yield of assortments depending on the average diameter of full-length logs during their specialized bucking, which have been tested in the conditions of the enterprises of the Bashlesprom plant. When determining the varietal structure of birch plywood logs and pine sawlogs, regression equations have also been used to show the relationship between the varietal structure and the average diameter of the bucked full-length logs. Thus, the required assortment of roundwood and the volumes of target grades (plywood logs and sawlogs) of only grades 1 and 2 have been identified for their possible use by specialized enterprises, and the volumes of wood processing for Kronoshpan OSB LLC have been determined.
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Narukawa, Y., and S. Yamamoto. "Development of conifer seedlings roots on soil and fallen logs in boreal and subalpine coniferous forests of Japan." Forest Ecology and Management 175, no. 1-3 (2003): 131–39. http://dx.doi.org/10.1016/s0378-1127(02)00125-1.
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Baño, Vanesa, Daniel Godoy, Diego Figueredo, and Abel Vega. "Characterization and Structural Performance in Bending of CLT Panels Made from Small-Diameter Logs of Loblolly/Slash Pine." Materials 11, no. 12 (2018): 2436. http://dx.doi.org/10.3390/ma11122436.
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The main objective of this work was to study the structural viability of using small-diameter logs of Uruguayan Loblolly/Slash pine, mainly from thinning operations, to design cross-laminated timber (CLT) panels. A visual grade named “CTH” (coniferous thinning) was proposed, and 45 specimens of sawn timber boards were tested, resulting in 51% lower bending strength than that of the minimum strength class C14. Subsequently, 20 CLT panels were manufactured and experimentally tested, the results showed that the bending strength of the CLT panels was 43% above that of the individual layers. Additionally, the structural performance of the CLT panels for use in floors was calculated, and the thickness-span relationship depending on strength class and imposed load are presented. Results showed than the use of CTH timber to design CLT floors implies a volume (m3/m2) 17% higher than that using C24 timber.
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Szewczyk, Katarzyna, and Piotr Iwanicki. "Evaluating the suitability of machinery use during skidding of wood in pine stands." Forest Research Papers 80, no. 3 (2019): 219–26. http://dx.doi.org/10.2478/frp-2019-0020.
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AbstractSkidding of large-sized logs requires special machinery such as skidders, clambunks, forwarders or farm tractors with a winch or hydraulic tongs. The precise choice of which skidding machine to use depends largely on the desired efficiency and economic factors. The aim of this research was to evaluate the suitability of three different machines (LKT 81 skidder, John Deere 1110D forwarder and Pronar 1221A agricultural tractor with hydraulic tongs) for wood skidding based on technical and economic indicators. The practical work for this research was carried out in the Mirosławiec Forest Division in areas with fresh mixed coniferous forest habitats where the dominant species in the stands was pine and strip-like clear cutting was the preferred management practice.The best machinery performance values were obtained for skidding using the John Deere forwarder.
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Vakula, Jozef, Milan Zúbrik, Juraj Galko, et al. "Is the double-spined bark beetle Ips duplicatus a new threat to Picea omorika in urban habitats?" Plant Protection Science 57, No. 3 (2021): 248–51. http://dx.doi.org/10.17221/7/2021-pps.
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The double-spined bark beetle Ips duplicatus (Coleoptera: Curculionidae, Scolytinae) is an invasive forest pest having a broad range of coniferous hosts within Europe. We found this species to be also developing in the Serbian spruce Picea omorika. Ips duplicatus infested 14 (52%) of 27 P. omorika mature trees in an arboretum garden in northern Slovakia in Central Europe during the summer of 2019. Logs from the upper part of stems of P. omorika trees placed in eclectors in the laboratory, yielded a total of 179 individuals of three scolytine species, with prevalence of I. duplicatus. Our results show that I. duplicatus also colonized less likely host such as the Serbian spruce, causing threat to this ornamental tree and contributing to its mortality in urban habitats during hot and dry summer weather.
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Chećko, Ewa, Bogdan Jaroszewicz, Katarzyna Olejniczak, and Anna J. Kwiatkowska-Falińska. "The importance of coarse woody debris for vascular plants in temperate mixed deciduous forests." Canadian Journal of Forest Research 45, no. 9 (2015): 1154–63. http://dx.doi.org/10.1139/cjfr-2014-0473.
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Deadwood in various stages of decomposition and diverse spatial arrangements provides habitat for numerous organisms. However, knowledge on the colonization of deadwood by vascular plants in mixed deciduous forests is insufficient. We carried out our study in an oak–lime–hornbeam forest in northeastern Poland. Downed logs were colonized by 49 vascular plant species, a number higher than reported from any other type of forest. Species richness and abundance of plants increased with log diameter and decomposition. The former was higher on broadleaf deadwood than on coniferous deadwood (46 vs. 38 species). The frequency and abundance on logs were higher for small-seeded plants (<1 mg) than for bigger, heavier seeded plants. Deadwood surface served as an ecological filter, keeping small seeds in cracks, but allowing bigger seeds to roll down. Tree seedling density increased with wood decomposition. However, for eight of nine species, it was higher on the ground than on deadwood. Only spruce seedlings were recorded almost exclusively on deadwood, constituting a crucial substrate for spruce regeneration in meso-eutrophic forests. Therefore, we stress the importance of constant deadwood supply, on the scale of decades, to ensure the diversity of this substrate and to allow the natural dynamics of deadwood-dependent species populations.
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Baño, Vanesa, Daniel Godoy, Diego Figueredo, and Abel Vega. "Characterization and Structural Performance in Bending of CLT Panels Made from Small-Diameter Logs of Loblolly/Slash Pine." Materials 11, no. 12 (2024): 2436. https://doi.org/10.3390/ma11122436.
Full textAbstract:
The main objective of this work was to study the structural viability of using small-diameterlogs of Uruguayan Loblolly/Slash pine, mainly from thinning operations, to design cross-laminatedtimber (CLT) panels. A visual grade named “CTH” (coniferous thinning) was proposed, and 45specimens of sawn timber boards were tested, resulting in 51% lower bending strength than that of theminimum strength class C14. Subsequently, 20 CLT panels were manufactured and experimentallytested, the results showed that the bending strength of the CLT panels was 43% above that of theindividual layers. Additionally, the structural performance of the CLT panels for use in floors wascalculated, and the thickness-span relationship depending on strength class and imposed load arepresented. Results showed than the use of CTH timber to design CLT floors implies a volume(m3/m2) 17% higher than that using C24 timber. Keywords: cross-laminated timber; CLT; characterization; structural performance; small-diameterlogs; thinning operations; Pinus taeda/Pinus elliotii; bending tests
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Mirski, Radosław, Marek Wieruszewski, Adrian Trociński, Jakub Kawalerczyk, and Karol Łabęda. "Elastic moduli of butt-end logs and the variable knots distribution in Scots pine from Western Poland." BioResources 16, no. 1 (2021): 1842–53. http://dx.doi.org/10.15376/biores.16.1.1842-1853.
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In studies on Polish pine wood, the parameters determining its usefulness for processing are highly variable. In contrast, international studies on the optimum utilization of coniferous sawn wood describes its visual features as those indicating the distribution of defects and their impact on the selected mechanical and physical properties of sawn wood. Knottiness is one of the qualitative properties of sawn wood that is essential for wood grading. The objective of this study was to determine a correlation between variable knots and their soundness on the one hand and their selected strength parameters on the other. One of the basic issues of this work includes structural timber optimization. For Polish sawn wood, these indicators are still relatively new. The study material involved edged butt-end log lumber from a 120-year-old forest stand. The results confirmed a correlation between knots frequency and modulus of elasticity. The correlation was strong, indicating that sound knots play a major role in the process of the strength assessments. The study did not demonstrate a significant share of rotten knots and their effect on strength.
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Ota, Takayuki, Takashi Masaki, Hisashi Sugita, Tatsuo Kanazashi, and Hisashi Abe. "Properties of stumps that promote the growth and survival of Japanese cedar saplings in a natural old-growth forest." Canadian Journal of Forest Research 42, no. 11 (2012): 1976–82. http://dx.doi.org/10.1139/x2012-141.
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In a natural forest that has experienced logging and lacks large fallen logs, cut stumps are expected to become a suitable substrate for regeneration. We investigated the properties of stumps that promoted the natural regeneration of coniferous species in a natural old-growth forest dominated by Cryptomeria japonica (L.f.) D. Don. A comparison of C. japonica saplings growing in three microsites (ground, stumps, and fallen logs) revealed that sapling density was highest on the stumps; 75% of saplings were distributed on stumps, which occupied only 3% of the projected forest area. The mortality of saplings during the 3-year study period did not differ significantly among the three microsites. Six properties of stumps were quantified: height, diameter at ground level, decay class, species taxon, type (i.e., cause of occurrence: logging or natural disturbance), and light conditions. Of these properties, the type of stump was the most influential. The density of saplings was significantly greater on stumps produced by logging than on naturally broken stumps. Taller stumps exhibited a significantly higher density of saplings; indeed, there were no saplings on stumps less than 60 cm in height. Saplings on stumps were concentrated in higher positions on the stump, and survivorship tended to be greater when their root location was higher. We concluded that the height of the microsite was an important factor for regeneration of C. japonica at this research site, where saplings were under competition with dense undergrowth vegetation. Most of the fallen logs were less than 60 cm in height and it appeared unlikely that they would function as regeneration sites for C. japonica.
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Iijima, Hayato, Masato Shibuya, and Hideyuki Saito. "Effects of surface and light conditions of fallen logs on the emergence and survival of coniferous seedlings and saplings." Journal of Forest Research 12, no. 4 (2007): 262–69. http://dx.doi.org/10.1007/s10310-007-0012-1.
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Han, Sang-Kyun, Han-Sup Han, Deborah S. Page-Dumroese, and Leonard R. Johnson. "Soil compaction associated with cut-to-length and whole-tree harvesting of a coniferous forest." Canadian Journal of Forest Research 39, no. 5 (2009): 976–89. http://dx.doi.org/10.1139/x09-027.
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The degree and extent of soil compaction, which may reduce productivity of forest soils, is believed to vary by the type of harvesting system, and a field-based study was conducted to compare soil compaction from cut-to-length (CTL) and whole-tree (WT) harvesting operations. The CTL harvesting system used less area to transport logs to the landings than did the WT harvesting system (19%–20% vs. 24%–25%). At high soil moisture levels (25%–30%), both CTL and WT harvestings caused a significant increase of soil resistance to penetration (SRP) and bulk density (BD) in the track compared with the undisturbed area (p < 0.05). In the center of trails, however, only WT harvesting resulted in a significant increase of SRP and BD compared with the undisturbed area (p < 0.05). Slash covered 69% of the forwarding trail area in the CTL harvesting units; 37% was covered by heavy slash (40 kg·m–2) while 32% was covered by light slash (7.3 kg·m–2). Heavy slash was more effective in reducing soil compaction in the CTL units (p < 0.05). Prediction models were developed that can be used to estimate percent increases in SRP and BD over undisturbed areas for both CTL and WT harvesting systems.
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Rukomojnikov, Konstantin P., Evgeny М. Tsarev, Sergey E. Anisimov, Denis S. Tatarinov, Viktoriia O. Kuptcova, and Tatiana A. Gilyazova. "Upgrading the Feller-Delimber-Crosscutter Mechanism of a Forest Harvester." Lesnoy Zhurnal (Forestry Journal), no. 3 (June 1, 2022): 130–38. http://dx.doi.org/10.37482/0536-1036-2022-3-130-138.
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There is an annual increase in the number of modern forestry machines at logging enterprises both in Russia and in foreign countries. At the same time, the fleet of forestry machines is becoming more diverse and multifunctional, and their manufacturers, competing for market outlets, find themselves interested in constant upgrading of existing and development of new design and technological solutions. The research is aimed at finding a new engineering solution that will allow along with harvesting high-quality logs to perform their partial debarking without a significant reduction in the processing speed. The effective result is achieved by the fact that the proposed new method of processing tree trunks provides the possibility of timber barking in strips, i.e. removing the bark from a fallen tree along its entire length, as well as bast removal (partially or completely). The method involves, as in the traditional model of harvesting (processing) head functioning, crosscutting of the trunk by the sawing mechanism and delimbing by delimbing knives. This leads to accelerated natural drying of wood during its storage in the warehouses and significantly increases the floatability of thin coniferous logs during their further timber floating. The implementation of the proposed option of harvesting debarked timber at the logging site and the working body of harvesters (processors) to carry out such harvesting will increase the share of logging waste at the logging site. The design of the new harvesting (processing) head does not require significant financial expenses for its upgrading. The design of the new harvester head allows the logs to be barked in strips along the entire length. Additional drive of working mechanisms is not required. This will enable the implementation of rough debarking with minimal financial costs already at the stage of logging operations and increase the efficiency of logging and timber processing enterprises.
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Nair M K, Smitha, Rekha Parmar, Anurag Talwar, Sabitha Nair M K, and Subhose V. "Clinical Evaluation of Pleurotus florida (White Oyster Mushroom) – Chatraka in the management of Vitamin D deficiency." International Journal of Ayurvedic Medicine 14, no. 3 (2023): 831–36. http://dx.doi.org/10.47552/ijam.v14i3.3994.
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Oyster mushroom (Pleurotus florida) commonly called in India as 'dhingri' develops spontaneously on dead and rotting wooden logs or sporadically on dying trunks of deciduous or coniferous trees in temperate and tropical woodlands. On exposure to sunlight or UV lamp, oyster mushrooms produce concentrations of Vitamin D that are nutritionally significant. Though long periods of storage and different types of cooking tend to decrease the vitamin D level of UV-exposed oyster mushrooms, the vitamin D level in all probability expected to remain at 10ug/100g fresh weight, which is greater than the amount in the majority of foods containing vitamin D and comparable to the recommended daily intake of vitamin D at the global level. Eligible candidates (n=50) were screened by computerized randomization method to receive Pflorida soup during the 03-month study. The efficacy parameters were evaluated through the blood investigation Vit D 25 (OH).
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CZESZCZEWIK, DOROTA, WIESŁAW WALANKIEWICZ, CEZARY MITRUS, et al. "Importance of dead wood resources for woodpeckers in coniferous stands of the Białowieża Forest." Bird Conservation International 23, no. 4 (2012): 414–25. http://dx.doi.org/10.1017/s0959270912000354.
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SummaryMany woodpecker species are known to be sensitive to the removal of dead wood. In 1999–2001 and 2007–2009 woodpeckers and dead wood abundance were studied in coniferous stands of the Białowieża Forest, Poland. Transects (3.9–6 km long) were established in three zones of different types of management: 1) primeval, unmanaged stands (BNP); 2) partially managed nature reserve (RES); 3) heavily managed stands (MAN). Woodpeckers were counted along transects three times per season, and tree stand measurements (number of standing and fallen trees, diameter at breast height, volume of fallen logs) were made once every three years. Woodpecker indices were highest in BNP and lowest in RES in both three-year study periods. The highest number of species (seven) was recorded in RES. Indices of four woodpeckers including two focal species (Three-toed Woodpecker Picoides tridactylus and White-backed Woodpecker Dendrocopos leucotos) were dependent on the basal area of dead standing trees. The same relation was found for the whole woodpecker assemblage. The highest indices were recorded in BNP, where the highest density of dead standing trees was recorded, and the lowest in the MAN transect with the lowest density of dead trees. However in the RES plot the amount of dead wood was much lower than in the national park. We recommend that the management regulations in Polish nature reserves be changed. In coniferous reserves, it would be best to leave at least 2 m2 ha-1 (basal area) of freshly killed spruce Picea sp. after each bark beetle outbreak.
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Kislov, Dmitry E., and Kirill A. Korznikov. "Automatic Windthrow Detection Using Very-High-Resolution Satellite Imagery and Deep Learning." Remote Sensing 12, no. 7 (2020): 1145. http://dx.doi.org/10.3390/rs12071145.
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Wind disturbances are significant phenomena in forest spatial structure and succession dynamics. They cause changes in biodiversity, impact on forest ecosystems at different spatial scales, and have a strong influence on economics and human beings. The reliable recognition and mapping of windthrow areas are of high importance from the perspective of forest management and nature conservation. Recent research in artificial intelligence and computer vision has demonstrated the incredible potential of neural networks in addressing image classification problems. The most efficient algorithms are based on artificial neural networks of nested and complex architecture (e.g., convolutional neural networks (CNNs)), which are usually referred to by a common term—deep learning. Deep learning provides powerful algorithms for the precise segmentation of remote sensing data. We developed an algorithm based on a U-Net-like CNN, which was trained to recognize windthrow areas in Kunashir Island, Russia. We used satellite imagery of very-high spatial resolution (0.5 m/pixel) as source data. We performed a grid search among 216 parameter combinations defining different U-Net-like architectures. The best parameter combination allowed us to achieve an overall accuracy for recognition of windthrow sites of up to 94% for forested landscapes by coniferous and mixed coniferous forests. We found that the false-positive decisions of our algorithm correspond to either seashore logs, which may look similar to fallen tree trunks, or leafless forest stands. While the former can be rectified by applying a forest mask, the latter requires the usage of additional information, which is not always provided by satellite imagery.
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Spears, J. DH, S. M. Holub, M. E. Harmon, and K. Lajtha. "The influence of decomposing logs on soil biology and nutrient cycling in an old-growth mixed coniferous forest in Oregon, U.S.A." Canadian Journal of Forest Research 33, no. 11 (2003): 2193–201. http://dx.doi.org/10.1139/x03-148.
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This study investigated the effect of coarse woody debris (CWD) on mineral soils at the H.J. Andrews Experimental Forest in the central Cascade Range of Oregon, U.S.A. Nutrients in CWD leachates were compared with (i) forest floor (control) leachates, (ii) over a decay chronosequence, and (iii) among CWD of four species. There were few differences among CWD leachates and forest floor leachates. Soils under CWD were warmer but not wetter than control soils. Water-soluble organic carbon was higher in soils under CWD than in controls at 515 cm depth (p < 0.02), but soil C concentrations did not differ. Gross N mineralization was faster in control soils. We found no differences in N, P, microbial biomass, Biolog plate assays, or enzyme activity in soils. Nutrient leachate differences among CWD species were small. Differences in solutions and in soils among CWD and controls were largest during the middle decay classes. This study suggests that either (i) CWD has no long-term effect and does not contribute large amounts of organic matter to the soil profile or (ii) the effect of CWD is so prolonged that no spatial affect is noticeable because all soils have been affected by CWD at some time.
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Toropov, Aleksandr S., and Viktor E. Byzov. "Morphological Analysis and Optimization of Technological Process for Rip Cutting of Round Timber." Lesnoy Zhurnal (Forestry Journal), no. 2 (April 15, 2023): 132–45. http://dx.doi.org/10.37482/0536-1036-2023-2-132-145.
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Coniferous sawn timber is extensively used in construction. However, the dimensional and qualitative composition of the round timber for lumber production has recently deteriorated significantly. The number of sawn logs with a diameter of 14–20 cm represents barely 50 % of the total supply of raw materials for sawmills. Besides that, large-diameter logs frequently have some signs of decay, which is mostly heartwood rot. Thus, the sawlog must be handled with caution. The problem is to intensify the sawing process, especially when logs have a presence of heartwood rot. This is possible to achieve with the implementation of modern technological sawing processes and specified equipment. A method of morphological research is used to select flowsheet diagrams of sawing and construction solutions for rip cutting equipment. The completeness of the morphological table is determined by the sum of all properties of the concept objects and is evaluated by obtaining effective technological and constructive solutions. According to the morphological method, a procedure of search systematization is developed. The patent search identified the main protective and published application documents concerning programs about ripping machines for round timber. The flowsheet diagrams for rip cutting of round timber and operational schemes for the equipment are adjusted according to the discovered regularities. A new sawing program is proposed in order to improve the efficiency of the equipment. It was licensed under a national patent of the Russian Federation. The evaluation of the possibility of implementing the technological process is made by analyzing the target costs for the production arrangement, the production rate per shift, and the quality of the final products. The proposed method for selecting directions to intensify the rip cutting of round timber gives the possibility to determine the effective technological and technical decisions at a project’s preliminary problem-solving stage. For citation: Toropov A.S., Byzov V.E. Morphological Analysis and Optimization of Technological Process for Rip Cutting of Round Timber. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 2, pp. 132–145. (In Russ.). https://doi.org/10.37482/0536-1036-2023-2-132-145
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Vilkovská, Tatiana, Ivan Klement, Peter Vilkovský, Igor Čunderlík, and Anton Geffert. "Chemical reagent for detecting tension wood in selected tree species." BioResources 19, no. 3 (2024): 4335–51. http://dx.doi.org/10.15376/biores.19.3.4335-4351.
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Reaction wood is a wood defect arising during the growth of the tree in the part of the trunk that is under tension (hardwood tree species) or compression (coniferous tree species). Beech (Fagus sylvatica L.) tension wood has different anatomical and chemical characteristics than normal (opposite) wood. The difference in density is conditioned by the percentage of the gelatinous layer (G-layer). Fibre cells in reaction beech wood have a different cell wall structure and a different chemical composition. Tension wood cannot be detected by the naked eye. It is only possible to assume its occurrence based on the macroscopic characteristics of the logs, such as a woolly surface, taper or eccentric pith, and so forth. However, these are imprecise and unreliable methods that have minimal effectiveness, especially when shortening the length of the log for cut-outs. This study aimed to create a unique chemical reagent for the detection of tension wood in logs and timber and wood products immediately. The present research can contribute to the mitigation of flaws resulting from the reaction of wood in timber production while addressing noticeable constraints in manufacturing, such as energy resources and the availability of wood raw materials. This can be achieved through the efficient identification of reaction wood in materials. The colour change is only temporary and will fade over time. After the chemical reagent has dried on the surface, the surface can be milled. The colour change extends to a depth of approx. of 3 to 5 mm.
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Herrmann, Steffen, and Cindy E. Prescott. "Mass loss and nutrient dynamics of coarse woody debris in three Rocky Mountain coniferous forests: 21 year results." Canadian Journal of Forest Research 38, no. 1 (2008): 125–32. http://dx.doi.org/10.1139/x07-144.
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Mass loss and changes in C, N, and P concentrations were measured in 20 cm long log segments of lodgepole pine ( Pinus contorta Dougl. ex Loud.), white spruce ( Picea glauca (Moench) Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) that had been placed in three Rocky Mountain coniferous forests 21 years earlier. Pine, spruce, and fir lost 76%, 39%, and 64%, respectively, of their initial mass during the 21 years. The corresponding mean decay rates (k) were 0.072, 0.024 and 0.052·year–1. The decay patterns of pine and spruce were similar with the highest k between 6 and 14 years. Fir k increased during the course of decomposition with the highest rate between 14 and 21 years. The correlation between original dry mass and k was negative for pine (r = –0.28), positive for fir (r = 0.35), and not significant for spruce. C/N, C/P, and N/P ratios declined and converged to a similar value in relation to mass loss for all three species. The N/P ratios of logs of all three species stabilized at about 19. These findings indicate that patterns of wood decay are difficult to predict (even with 14 year data), and so models that incorporate wood-decay estimates will be associated with considerable uncertainty.
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Zhao, Lilin, Wei Wei, Xinzhong Liu, Le Kang, and Jianghua Sun. "A novel rapid sampling method for pinewood nematode, Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae)." Canadian Journal of Forest Research 37, no. 10 (2007): 1867–72. http://dx.doi.org/10.1139/x07-049.
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The pinewood nematode, Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, is listed as a quarantine pest in the legislation of more than 40 countries. Rapid and accurate detection of the pinewood nematode in coniferous chips, sawn wood, and logs is critical in preventing the introduction of the nematode and forms the basis for quarantine regulations. The traditional but laborious Baermann-funnel sampling technique delays the detection of pinewood nematode. We applied the chemotactic response of pinewood nematode to its insect vector, Monochamus alternatus Hope, to develop a novel and rapid sampling method. A trap tube, baited with a blend of attractant terpenes (α-pinene, β-pinene, and longifolene, 1:2.7:1.1) is shown to effectively capture third-stage dispersal juveniles of pinewood nematode from infested wood under laboratory and field conditions. Nematodes were first isolated after a 2 h trapping period, and the number of nematodes recovered increased with the duration of trapping. This chemical attraction technique is simple, effective, and rapid and should assist greatly in the detection of pinewood nematode at both ports-of-entry and forest habitats.
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Yano, Keisuke, and Masato Shibuya. "Site preference and occurrence patterns of Picea jezoensis and Abies sachalinensis on decayed logs in natural coniferous forests in Hokkaido, northern Japan." Journal of Forest Research 15, no. 2 (2010): 108–14. http://dx.doi.org/10.1007/s10310-009-0162-4.
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Burton, Philip J., Daniel D. Kneeshaw, and K. David Coates. "Managing forest harvesting to maintain old growth in boreal and sub-boreal forests." Forestry Chronicle 75, no. 4 (1999): 623–31. http://dx.doi.org/10.5558/tfc75623-4.
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Old-growth stands can be rare in northern coniferous forests, and hence are worthy of protection and special management. We describe some quantitative guidelines for recognizing old-growth stands and options for maintaining a long-term supply of old-growth values in landscapes managed for timber production. In the Sub-Boreal Spruce forests of central British Columbia, attributes most indicative of old-growth status include stand age, the density of large (> 1.0 m3) snags and downed logs, stand basal area and volume. It is suggested that partial cutting could occur in some old-growth stands, while still maintaining their structural and functional attributes, if large logs, snags and trees are retained at the threshold densities necessary to recognise old-growth status. At the landscape level, the use of extended timber crop rotations is advocated. Planning for a tapered forest age class distribution (with decreasing areas of forest allowed to persist to successively older ages) is suggested as a means of sustainably generating true old-growth, and as an alternative to the use of partial cutting and patch retention. Arithmetic formulas are developed which provide guidelines for the proportion of the forest land base to be kept in each successive age class. This model for regulating human disturbance in commercial forests holds promise as a mechanism for allowing continued timber harvest and even-aged stand management while retaining a near-natural proportion of old-growth forest in northern landscapes. Key words: disturbance regime, even-aged management, extended rotations, forest age class structure, forest management, old-growth attributes, rotation length, silvicultural systems, sub-boreal spruce zone, timber supply planning.
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Anderson, Nate, René Germain, and Eddie Bevilacqua. "Characteristics of transborder wood flow to sawmills in eastern Canada." Forestry Chronicle 85, no. 1 (2009): 110–19. http://dx.doi.org/10.5558/tfc85110-1.
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This paper characterizes the wood procurement operations of Canadian sawmills within 300 kilometres of the Northern Forest, which is a 12 million hectare area of mixed hardwood and coniferous forest that spans 4 states in the northeastern United States. Based on data collected from a mail survey administered in 2006, wood procurement is quantified in terms of the percentage of supply from transborder sources, the geographic range of procurement operations, the relative importance of alternative sawlog sources, and perceived changes in the availability and quality of the sawlog resource. Over 1/3 of the 5.17 million m3 of procurement reported in the survey originated in the United States. On average, mills that have little or no procurement in Canada routinely range 240 kilometres or more to meet procurement requirements, predominantly from roadside sources in the United States. Mills that procure all of their wood within Canada range 114 kilometres on average, and procure 73% of their wood supply from provincial Crown lands. A majority of mills in the sample reported that the quality of logs and the volume per log within their woodshed declined between 1994 and 2005. Based on a logistic regression model of 4 predictor variables, distance to the U.S. border and access to logs from provincial Crown lands are significant predictors of the use of transborder log sources. In addition to providing valuable baseline data, results suggest that mills without access to provincial Crown lands may be disproportionately impacted by high fuel prices and parcelization of private forest land in the United States. Results are discussed in light of these and other industry trends. Key words: sawmill industry, log imports, international trade, wood procurement
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Redhead, S. A. "Notes on the genus Xeromphalina (Agaricales, Xerulaceae) in Canada: biogeography, nomenclature, taxonomy." Canadian Journal of Botany 66, no. 3 (1988): 479–507. http://dx.doi.org/10.1139/b88-073.
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Eleven of the 13 North American species of Xeromphalina are reported from Canada. A key to 14 North American and northern Eurasian species is given. Type specimens for 9 names were examined. In Canada, subgenus Heimiomyces is represented by two species: X. tenuipes (Schw.) Smith (sect. Heimiomyces) and X. fulvipes (Murr.) Smith (sect. Fulvipes). Subgenus Xeromphalina is represented by sections Xeromphalina and Mutabiles. Xeromphalina brunneola Miller and X. campanella (Batsch: Fr.) Kuhner & Maire are circumboreal species documented from across Canada. Xeromphalina kauffmanii Smith occurs in southern Quebec, Nova Scotia, Costa Rica, the eastern United States, and in Japan. Section Mutabiles stat.nov. is completely revised based on pigmentation of the pileipellis, on the distribution and types of pileocystidia, and on the pigmentation of the stipe, in addition to characters used previously in the genus. The term "circumcystidia" is coined for pileocystidia largely confined to a band around the pileus margin. In North America, the name X. cauticinalis (Fr.) Kühner & Maire frequently has been misapplied to X. cornui (Quél.) Favre, a common, widespread species in Canada. Xeromphalina fraxinophila Smith is reported from across Canada and the United States and in Eurasia. The name Marasmius cauticinalis is neotypified. In North America X. cauticinalis ssp. cauticinalis occurs in western areas. Xeromphalina cauticinalis ssp. pubescentipes (Peck) comb. et stat. nov. occurs in eastern areas in North America, in Japan, and together with ssp. cauticinalis in Europe. Xeromphalina parvibulbosa (Kauff. & Smith) comb.nov. occurs across North America. Xeromphalina cirris sp.nov. from montane or boreal coniferous forests floors in British Columbia, Ontario, Colorado, Idaho, New Mexico, Oregon, Utah, Washington, and Wyoming and X. campanelloides sp.nov. from coastal British Columbia and Washington, and eastern montane New York and Quebec, on coniferous logs, are described. Rhizomorphs are formed by all Canadian species except X. tenuipes.
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Stoilov, Stanimir, Antonio Zumbo, Chavdar Ustabasciev, Georgi Angelov, Salvatore F. Papandrea, and Andrea R. Proto. "Performance Evaluation of Long-Distance Road Transportation of Roundwood in Mountainous Conditions." Forests 16, no. 5 (2025): 781. https://doi.org/10.3390/f16050781.
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In Europe, long-distance transport of wood from landings to consumers is most often carried out by trucks and trucks with trailers. In forests located mainly in mountainous areas with rugged terrain and frequent curves, the construction of forest roads is complicated and often access for trucks with trailers is difficult or there is not enough space on the landing for maneuvers. In these cases, the truck leaves the trailer next to the public road and without it moves to the landing and loads the wood with Palafinger hydraulic crane model Epsilon Kran GmbH mounted on it, which it transfers to the trailer on the way back. Then, the truck moves to the landing to load itself, returns, hooks up the trailer and transports the wood to the customer. This study, conducted in a coniferous stand in Bulgaria, aimed to determine and develop models for the productivity and costs associated with transporting a truck with a trailer and to evaluate the suitability of this method. To study this very common method of long-distance transport, observations were made of 185 turns of a truck with a trailer operating with coniferous wood in Rila-Rhodope Mountain Massif, Southern Bulgaria. It was found that the duration of the working cycle is affected by the total mileage (average 65.41 km), the volume of the load and the number of logs. The productivity with and without delays, 7.80 and 7.30 m3/h, respectively, is affected by the mileage and the volume of the wood, while the corresponding transportation productivity (177.46 and 167.24 m3 km/h) is affected by the transport distance loaded and the volume of the load. To increase efficiency and reduce the cost of transporting wood over long distances, investments are needed to improve forest roads to eliminate the need to uncouple the trailer.
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Dubrovskis, Edgars, Eduards Rācenis, Oskars Krišāns, Jānis Donis, Guntars Šņepsts, and Āris Jansons. "FINANCIAL IMPLICATIONS OF STORM DAMAGE TO CONIFEROUS FORESTS IN LATVIA." SOCIETY. TECHNOLOGY. SOLUTIONS. Proceedings of the International Scientific Conference 1 (April 17, 2019): 2. http://dx.doi.org/10.35363/via.sts.2019.6.
Full textAbstract:
INTRODUCTION
 Storms are the primary factor reducing carbon sequestration in Europe’s forests, thus negatively affecting the ability of countries to fulfil their targets related to greenhouse gas balance (emission vs. sequestration). The impact of storms is rising due to an increase in forest cover, a preference for less wind-firm species (namely the Norway spruce) as well as the aging of forests in Europe (leading to greater vulnerability). Furthermore, climate change will affect the amount of damage. The frequency of windstorms and/or high speed wind gusts is expected to increase. The largest storms in our region occur mostly in autumn/winter – in the future this is likely to increase due to conditions in which it is more likely that tree anchorage is weak, due to the soil not being frozen and being saturated with water. From a sustainable forestry perspective, it is important to note that recreational use of those forests affected by storms as well as secondary damage (e.g. by bark beetle) will also be substantially reduced. Forest owners suffer direct financial losses as a result of storms. The aim of this study is to estimate the losses caused by storms and evaluate measures that could be used to reduce storm damage.
 MATERIALS AND METHODS
 Forest owners suffer direct damage as a result of a loss of timber value from stem cracks (which is estimated to account for 20% of the volume of first (bottom) logs reduced to fire-wood quality), increased logging costs as well as additional regeneration, tending and precommercial thinning. The cost of these processes and the timber prices used in calculations are obtained from the Central Statistical Bureau of Latvia; information on the amount of timber damage during storms in the last decade is provided by the State Forest Service. To obtain information on the possibility of reducing storm damage, growth models (LSFRI Silava) are used in addition to assessments of vulnerability to storm damage (ForestGALES). The financial impact of damage-reduction measures is given as equivalent annual annuity (EAA) - interest rate 4%.
 RESULTS
 During the last decade, windstorms in Latvia alone have caused direct economic losses to forest owners of around €164 million, an average of €9 per m3 of wood from salvage logging. Vulnerability to damage increases as tree height increases (as critical wind speed decreases). Lower planting density slightly increases the critical wind speed (by 3-9%) (for Scots pine: 1500 trees ha-1vs current 3000 tree ha-1) and notably reduces the financial impact of storm damage: EAA for pine stands planted on the best soils is €15 ha-1 with sparser planting, and -€11 ha-1 with denser planting. If final harvest is planned by the stand age (101 years in majority of cases in Latvia), the financial impact of wind damage is higher in the best growing pine stands (site index Ia): in sparse stands the affect of wind damage reduces EAA by 38%, while stands with a lower site index are reduced by 25%. The reason for this is that faster-growing trees reach certain height, at which they are vulnerable to smaller (in terms of m s-1) critical wind speed, at earlier age. For example, the above-mentioned sparse Ia stand has a critical wind speed of ≤20ms-1 for 38% of its total rotation period, compared to 26% for the I stand. Thus, harvesting by constant age reduces the financial gain from the best-quality sites and silvucultural treatments aimed at increasing tree growth (e.g. planting best-growing genotypes). Therefore, harvesting by target diameter is recommended.
 CONCLUSION
 Major damage to forests mean owners are less willing to invest – thus reducing future potential wood flow for the industry. Therefore, changes in legislation concerning criteria for initial stand density and target diameter are recommended to minimize the negative economic impact of climate change (adapt).
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Fukasawa, Yu, Yoko Ando, and Zewei Song. "Comparison of fungal communities associated with spruce seedling roots and bryophyte carpets on logs in an old-growth subalpine coniferous forest in Japan." Fungal Ecology 30 (December 2017): 122–31. http://dx.doi.org/10.1016/j.funeco.2017.10.001.
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PRIEDITIS, NORMUNDS. "Status of wetland forests and their structural richness in Latvia." Environmental Conservation 26, no. 4 (1999): 332–46. http://dx.doi.org/10.1017/s0376892999000442.
Full textAbstract:
Wetland forest communities are seriously reduced and degraded throughout most of Europe, but significant areas still survive in the east and north-east. Data from 91 forest structures that support biodiversity are analysed in 369 relevés of Latvian wetland forests. These structures include variations in topography, stand composition, water movement and dead wood features occurring in semi-natural conditions undisturbed by management. There is clear structural differentiation between coniferous and deciduous wetlands. The study supports the widely held views on European forest quality: low volume of high-diameter (>50 cm) snags and logs, too few overmature trees, and the threat to pattern heterogeneity caused by traditional forestry and silviculture. Twenty areas (totalling c. 3800 ha) are identified as reserves that should be strictly protected in Latvia in order to maintain representative and intact samples of wet forest belonging to Eurosiberian alder swamps (Alnetea glutinosae), broad-leaved forests (Querco-Fagetea) and boreal forest (Vaccinio-Piceetea) communities. Based on habitat features and site ecology, the concept of sustainable forestry must be incorporated widely in utilization of European wetland forests in order to prevent further loss of biodiversity.
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Höwler, Kirsten, Dominik Seidel, Tobias Krenn, et al. "Evaluation of Softwood Timber Quality—A Case Study on Two Silvicultural Systems in Central Germany." Forests 13, no. 11 (2022): 1910. http://dx.doi.org/10.3390/f13111910.
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Norway spruce (Picea abies (L.) H.Karst) trees planted with high stem densities produce finely branched, solid logs but are vulnerable to extreme weather events, e.g., storms. Over the last decades spruce stands have been planted at lower stand densities, resulting in wider crowns, lower crown bases, and higher stand stability, but this might decrease the quality of coniferous timber due to an increased growing rate and wider annual rings. Therefore, in this case study we investigated the influence of different silvicultural treatments and stand densities on tree morphology and wood properties of 100 spruce trees up to sawn timber as the final product. Tree morphology was assessed using mobile laser scanning. Ring width analysis, wood density measurements, and the four-point bending strength test on visually graded boards were conducted to gain information on wood properties and product quality. In stands thinned from below, higher wood densities were observed due to smaller annual rings compared to stands that were thinned from above at equal annual ring widths. In addition, crown asymmetry and the height-to-diameter ratio were identified as proxies for wood density. Lastly, visually assessed quality differences between the forest stands were discerned on the examined boards.
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Hiura, Tsutom, Junji Sano, and Yasuo Konno. "Age structure and response to fine-scale disturbances of Abiessachalinensis, Piceajezoensis, Piceaglehnii, and Betulaermanii growing under the influence of a dwarf bamboo understory in northern Japan." Canadian Journal of Forest Research 26, no. 2 (1996): 289–97. http://dx.doi.org/10.1139/x26-032.
Full textAbstract:
We studied regeneration patterns of the four canopy dominants, Abiessachalinensis (Fr. Schm.) Masters, Piceajezoensis (Sieb. et Zucc.) Cam, Piceaglehnii (Fr. Schm.) Masters, and Betulaermanii Cham., of an old-growth (>400 years) boreal coniferous forest in northern Japan. Age and size structure, height growth, and diameter growth of tree populations in a 40 × 40 m plot were analyzed. Seedling establishment was restricted to nurse logs and mounds (98%), where the influence of dwarf bamboo (Sasasenanensis (Franch. et Sav.) Rehd.) was limited. Abiessachalinensis had a high density (10 263/ha) but a high mortality (8.4%/year for saplings, 1.7%/year for canopy trees) and a short canopy residence time. It also showed a more rapid tree-ring width increase after disturbances. Piceaglehnii had a low density (1450/ha) but a low mortality (6.9%/year for saplings, 0.1%/year for canopy trees) and a longer residence time in the canopy. Piceajezoensis had an intermediate density (8206/ha) and its mortality rate for canopy trees (0.9%/year) was lower than that of A. sachalinensis, although its sapling mortality rate (8.1%/year) was similar to that of A. sachalinensis. Betulaermanii had a higher mortality (14.1%/year for saplings, 2.4%/year for canopy trees) than the conifers. On the other hand, B. ermanii had the highest height growth and P. glehnii had the lowest. The mortality and average height growth of saplings showed a trade-off relationship. The trade-off relation in life history strategy may contribute to the coexistence of these species. The proportion of the gap area created in the forest was 1.2–2.4%/year, and a forest turnover time calculated from aboveground volumes was 87–99 years. These values were similar to a weighted mean of the estimated life times of the constituent species, 71 years for A. sachalinensis, 123 years for P. jezoensis, and 49 years for B. ermanii.
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Roy, Christian, Marc J. Mazerolle, and Louis Imbeau. "Transforming Abandoned Farm Fields to Conifer Plantations Reduces Ruffed Grouse Density." Journal of Fish and Wildlife Management 6, no. 2 (2015): 405–17. http://dx.doi.org/10.3996/022015-jfwm-021.
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Abstract Natural forests likely will be unable to fulfill society’s needs sustainably for wood fiber in the near future. In an attempt to meet increasing demands while protecting intact forests, producers have increasingly considered alternative sources of timber, such as intensively managed plantations. In regions that are economically dependent on forest harvesting, abandoned farm fields are often targeted for conversion to intensive coniferous plantations. These sites are generally in an early successional stage that is dominated by deciduous stands, which provide an important habitat type for several game species, including ruffed grouse (Bonasa umbellus). Therefore, conversion could represent a loss of habitat for this species and several others that are associated with early successional deciduous stages. We conducted grouse drumming surveys in northwestern Quebec, Canada to evaluate the effects of transforming old fields into conifer plantations on ruffed grouse by comparing densities between two habitat types: abandoned farm fields (n = 22) and old fields converted to conifer plantations (n = 19). To correct any audibility bias between habitat types, we located all drumming males that were heard at each site. We then analyzed the number of individuals that were detected in the sites with repeated count models. Our results show that overall drumming males avoided plantations. Overhead cover increased drumming male densities in both habitat types, whereas lateral cover increased drumming grouse densities only in plantations. The density of deciduous stems and fruit-bearing stems also had a tendency to increase drumming male densities, but their effects were marginal. Most ruffed grouse in abandoned farm fields used piles of woody debris on the ground as drumming structures rather than large logs or rock outcrops. Our results suggest that plantations do not have the vegetative cover and quantity of food stems necessary to support high ruffed grouse densities during the drumming season and that conversion of abandoned farm fields to coniferous plantations may exert negative cascading effects for reproduction and population growth.