Search Results (66)

Birch stands, dominated by Betula pendula Roth, are a common feature of boreal forests. Within the Krasnoyarsk (central) group of regions, they are concentrated in the taiga, subtaiga and forest steppe zones of actively managed forests, represented by stands of seed and shoot origin. The health and productivity of birch forests is often determined by the activity of wood-decay fungi, which leads to rot and decay in trees. The objective of the research is to evaluate the impact of stem rot on birch forests in the study area, with a focus on key ecological and silvicultural factors. The research methods employed included a reconnaissance survey of birch forests, a detailed forest pathology survey of forest stands on research plots (31 pcs.), comprehensive macroscopic diagnostics of stem rot, identification of xylotrophic fungi by basidiomes, integrated assessment of forest health, graph analytics and statistical data analysis. Stem rot has been identified in all birch forests in the study area. In shoot origin stands, the incidence rate has reached the stage of the disease center (i.e., more than 10% of trees are infected). The following wood-decay fungi have been detected on the trunks of living trees affected by rot: Fomes fomentarius, Fomitopsis pinicola, Inonotus obliquus, Phellinus igniarius, and Trametes versicolor. The infection typically infects trees via spores, finding entry through dying branches or mechanical and thermal wounds on trunks. In trees of shoot origin, stem rot is frequently transmitted via mycelium from stumps left after felling. This, in conjunction with diminished immunity, contributes to a substantially elevated incidence of stem rot in comparison to stands of seed origin. The research has not established a reliable correlation between the incidence of stem rot and forest stand characteristics due to the impact of human activity on birch forests (e.g., cutting, fires, tree injury). At the same time, no reliable connection has been established between the spread of stem rot and the stage of recreational disturbance. Trees of various sizes are affected by stem rot, usually proportional to their representation in the structure of the forest stand. The disease has a detrimental effect on the trees, which is clearly evident in the decline of forest health. Full article

This paper discusses the possibilities of using stump wood as a raw material for energy generation. The research was based on an analysis of the state of knowledge, forest field studies, and participatory observations. A formula was sought to optimise the procurement cost of stump wood appropriate to Polish conditions. Conceptualisation was carried out in a selected area of the Notecka Forest in the Wielkopolska region, located in western Poland. A pilot study was designed to test a computational formula to assess the profitability of harvesting wood from stump wood resources for energy generation. The potential of stump wood is estimated to be around half a million cubic metres per year from the Notecka Forest area alone. This resource provides an opportunity for business development in both forestry and the renewable energy sources (RESs) sector, despite the barriers and risks shown in this study. Full article

Windthrow determines major changes in tree stand evolution due to the felling or breaking of either isolated trees or entire stands. It has a major ecological, social and economic impact. Wood loss resulting from tree felling and cross-cutting operations is a less-studied aspect related to windthrow. Wood loss is represented by high stumps, broken or split stems, wood lost in the felling of trees that remain standing, wood lost in felling cuts that attempt to remove the stem from the root plate of partially or totally uprooted trees and wood lost as a result of stem cross-cutting. The study focused on estimating losses and their indices in a spruce tree stand located in the Curvature Carpathians. Windthrow took place in this tree stand in February 2020. The results showed that the total wood loss index is 7.747%. The main losses are represented by wood losses in high stumps (5.319%). The amount of wood loss depends on the proportion of uprooted or standing trees, ground inclination and the uprooting direction of trees as opposed to ground inclination, as well as on tree dimension. Tree volume significantly influences wood loss in high stumps (p < 0.001). The closer the uprooting direction is to the highest slope, the higher the tree stump becomes. Wood loss caused by stem breaking and splitting represents 2.280%, tree felling cuttings and stem removal from the root plate in uprooted trees account for 0.138% while loss resulting from stem cross-cutting represents 0.10%. Full article

A previously buried paleosol was found on the continental shelf during a study of sea floor scour, nucleated by large artificial reef structures such as vessel hulks, barges, train cars, military vehicles, etc., called “scour nuclei”. It is a relic paleo-land surface of sapling-sized tree stumps, root systems, and fossil animal bone exhumed by scour processes active adjacent to the artificial reef structure. Over the span of five research cruises to the site in 2022–2024, soil samples were taken using hand excavation, PONAR grab samplers, split spoon, hollow tube auger, and a modified Shelby-style push box. High-definition (HD) video was taken using a Remotely Operated Vehicle (ROV) and diver-held cameras. Radiocarbon dating of wood samples returned ages of 42,015–43,417 calibrated years before present (cal yrBP). Pollen studies, together with the recovered macrobotanical remains, support our interpretation of the site as a freshwater forested wetland whose keystone tree species was Taxodium distichum—bald cypress. The paleosol was identified as an Aquult, a sub-order of Ultisols where water tables are at or near the surface year-round. A deep (0.25 m+) argillic horizon comprised the bulk of the preserved soil. Comparable Ultisols found in Georgia wetlands include Typic Paleaquult (Grady and Bayboro series) soils. Full article

The European beech (Fagus sylvatica L.) is a tree species common throughout Europe, with the eastern boundary of its range extending across Poland. Samples were collected in several microhabitats of beech stands (e.g., leaf litter, rotting wood, moss growing on tree stumps) in the Wronie Forest Reserve. The aim of this study was to determine the effect of microhabitat conditions found in beech forests on the diversity of mite assemblages and their species richness. The collected samples comprised a total of 144 identified species (78 species of Oribatida, 66 species of Mesostigmata), represented by 74,433 mite individuals (71,124 Oribatida and 3309 Mesostigmata). All the analyzed microhabitats varied in terms of their mite assemblages. The highest number of species was identified in moss on beech stumps (72 species—53 Oribatida and 19 Mesostigmata) and in samples collected from beech litter (68 species—48 Oribatida and 20 Mesostigmata). The most numerously represented species in the analyzed material was Parachipteria willmanni, which was classified to superdominants in moss on beech stumps and moss on beech trunks (0.5 and 2.0 m), which were the most similar microhabitats. In contrast, mite assemblages in rotting wood and marsh litter differed greatly. Full article

The European hazelnut is a temperate nut crop, often managed as a multi-stemmed shrub due to its natural aptitude to produce several suckers at the base of the stump, depending on variety. Traditional hazelnut-growing regions such as Italy, Turkey, and Spain typically adopt this architecture, while other hazelnut-producing countries such as the USA, France, and Chile increasingly use single-trunk systems to facilitate orchard management. Multi-stemmed plants allow gradual renewal through sucker selection but may lead to excessively dense canopies, reducing the effectiveness of pest and disease control, increasing biennial bearing, and lowering nut yields in vigorous cultivars. In order to drive the ongoing enlargement of hazelnut cultivation, attempts in designing high-density (HD), and more occasionally super-high-density (SHD), hazelnut orchards are on-going, although these are poorly explored in terms of suitable plant training systems, such that, sometimes, multi-stemmed plant shapes are used; otherwise, single-trunk solutions are adopted. In order to explore new hazelnut planting and training solutions focused on sustainable intensification, a trial was established in 2019 in central Italy to evaluate the eligibility of three training systems (treatment A: regular four-stemmed shrub; treatment B: single-trunk sapling; treatment C: traditional multi-stemmed shrub), applied on unpruned three-year-old plants of the hazelnut cultivar Nocchione, planted in the HD approach (740 plant ha⁻¹). Over five growing seasons (2019–2023), measurements included pruned wood removed, yield, vigor, yield efficiency, nut and kernel traits, and incidence of the main commercial defects. In general, treatment A outperformed other plant-shaping systems, maintaining high yield levels particularly in the two last growing seasons, and showing a mean kernel/nut ratio of 37.7 and a low incidence of defects. Treatment B achieved the highest yield efficiency in 2023 but had lower overall yields. Treatment A demonstrated the most balanced performance, combining high nut quality and stable production, making it the most promising plant training system for HD hazelnut orchards with planting densities above 700 plants per hectare. Future research will assess the long-term adaptability of this plant training system under varying environmental and management conditions. Full article

Starch is stored in thin-walled tissue of wood for several years or even decades. Starch reserves vary by anatomical structure, growth ring, and tree species. The spatial distribution pattern of starch in Catalpa bungei ‘Jinsi’ wood is unclear. We sampled three C. bungei ‘Jinsi’ trees at the end of the growing season and cut discs from their trunks to stain starch granules in wood ray cells with iodine–potassium iodide. We studied starch content in the ray cells of the trunks’ height position (stump, breast height, and crown base) from pith to bark in four directions (west, east, south, north) of the tree. There was a significant difference in starch content in three trunk height positions (p < 0.01), with stump (4.06 to 92.16%) > breast height (6.05 to 69.05%) > crown base (3.89 to 47.04%). There was a significant difference in starch content in different directions at the same height position. In the radial direction, the starch content of sapwood was much higher than that of heartwood, and the starch content showed an overall decreasing trend from bark to pith. The results indicated that starch distribution in tree trunks is uneven, which is related to energy metabolism processes, especially heartwood formation. This will contribute to further research on improving wood quality through the C. bungei ‘Jinsi’ tree breeding program. Full article

Comminution is performed by using two main types of machines: grinders and chippers. Grinders are commonly used to treat contaminated wood biomass. In South Korea, cut-to-length harvesting is the main salvage logging method, and felled trees and residues often become dirtied during extraction, where logs are moved from the stump to the roadside using a small shovel. Therefore, grinders are preferred for the comminution of wood biomass for conversion into hog fuel. This study aimed to evaluate productivity and hog fuel quality as outcomes of wood biomass sorting. The productivities for unsorted residues and logs were 11.2 ± 1.48 ton/PMH₀ and 12.4 ± 1.73 ton/PMH₀ at a moisture content of 24%, respectively. Between 33.5% and 46.0% of the total hog fuel mass passed through the screen and reached an acceptable size (3.15 mm to 63 mm). The bulk densities of the two materials ranged from 132.4 kg/m³ to 148.8 kg/m³ on a dry basis. The results of this study suggest that sorting the feedstock has the potential to reduce the number of oversized particles in the hog fuel without screening. Full article

Wood-decay fungi, including white- and brown-decay fungi, are well known for their ability to degrade lignin and cellulose, respectively. The combined use of these fungi can increase the decomposition of woody substrates. Research has indicated that these fungi also exhibit inhibitory effects against Bursaphelenchus xylophilus, the causative agent of pine wilt disease (PWD). In this study, we investigated a composite microbial formulation that efficiently decomposes pine wood while inhibiting B. xylophilus. We initially established a correlation between the degradation rate of wood blocks and fungal biomass, underscoring the necessity of optimizing biomass for effective treatment. A systematic approach involving a one-way test, a Plackett–Burman design, a steepest ascent experiment, and a Box–Behnken design, was employed to optimize the fermentation process. Validation trials were conducted in a 10-L fermenter. The bioagent’s efficacy and safety were assessed through field applications in a forest, with a focus on wood degradation capacity and B. xylophilus mortality rate. Additionally, the environmental impact of the microbial products was evaluated by analysing soil quality around treated areas to ensure that the formulation did not adversely affect soil health. Full article

Coppicing has been neglected in recent decades, leaving gaps in knowledge on silvicultural interventions, especially the long-term effects on coppices of Southeast Europe. The recent economic crisis, the sudden increase in energy prices, and the increased demand for assorted wood products have initiated higher interest in coppices in Croatia. Thus, our work aims to define the long-term effects of thinning in sessile oak (Quercus petraea (Matt.) Liebl.) and European beech (Fagus sylvatica L.) sub-mountainous thermophilic low coppices in the Croatian Dinarides. The experiment includes two localities with thinning and control plots. Thinning was performed in 2002, with 17.71% of wood volume removed in the European beech coppice and 26.09% in the sessile oak coppice. In 2020, 1276 trees were marked, measured (DBH, tree height, number of stems per stump), and assessed for vitality, origin, and six silvicultural features revealing tree quality. In 2022, trees were again measured (DBH, tree height) to gain data on tree growth. Conventional data analysis methods were used. The results show a statistically significant positive long-term effect of thinning on tree growth, stem, and crown features and support findings that thinning, by increasing growth and quality, is a necessary intervention in European beech and sessile oak low coppices. Thinning promoted the healthiest and best quality trees/stems, resulting in a more valuable range of wood products and the potential for higher income. It had a positive impact on tree growth regardless of the tree’s origin (seed or stump) and improved the growth and quality of trees among the supporting tree species. Short-term effects of thinning in trial plots suggested that thinning supported tree species diversity, but this effect diminished over time, showing no positive effect after twenty years. The study points to the need for more frequent thinning in coppices to support tree species diversity (i.e., to allow growth to less competitive tree species) but underlines the need for further research. Full article

Tropical forest management has a potential role in forest conservation if it is sustainable. This study of a forest under management in Bolivian Amazonia strongly suggests that the management project is not sustainable and that no potential changes in management would be likely to make it so. In a 216.41 ha harvested area, 278 commercial trees from 10 families, 15 genera, and 15 species were measured. The density of commercial species with diameter at breast height (DBH) ≥ 50 cm was 1.28 trees ha⁻¹, and the harvestable commercial volume was 12.40 m³ ha⁻¹. Due to market restrictions, the actual amounts harvested were much lower: 96 trees were harvested with commercial boles totaling 2.7 m³ ha⁻¹. Of the total impact on biomass and carbon (above- and belowground), the logs removed from the area represented only 13.4%, while 86.6% was from losses in the forest as follows: 14.5% from the stumps, crowns, and roots of harvested trees (DBH ≥ 50 cm) plus 72.1% from the trees (DBH ≥ 10 cm) in the forest lost to roads, log landings, and skid tracks and the gap openings caused by felling the harvested trees. The estimated expenses exceeded the gross revenue of the management company (USD 519.15 ha⁻¹), a fact confirmed by the company’s subsequent bankruptcy. The project’s low harvest intensity reduces the environmental impact per hectare but increases the impact per cubic meter of wood harvested because producing a given volume of wood requires disturbing a larger area and because more kilometers of access roads and skid tracks have to be installed to extract a given volume of wood. Because many costs are fixed regardless of harvest intensity, small harvest volume can render such projects financially unfeasible, increasing the likelihood that they will be abandoned and not provide long-term “sustainable” forest protection. However, this does not mean that higher harvest intensity results in sustainability, as other constraints apply to high-intensity projects. We conclude that conservation alternatives to maintain the forest would be more beneficial than management for timber. Full article

The European beech (Fagus sylvatica L.) is one of the most common tree species in Romania, with importance both economically and environmentally. Accurate methods of biomass assessment at the tree compartment level (i.e., stump, stem, branches, and leaves) are necessary for carbon stock estimation. Wood density (WD) is an important factor in determining biomass and, ultimately, the tree’s carbon content. The average tree density was found to be 578.6 kg/m³. For this study, WD was evaluated by the weighting method related to tree volume. Also, to investigate a practical approach to determining the weighted wood density (WWD_st), models were run using density at the base of the tree (WD_Base), density at breast height level using discs (WD_DBH), the wood core density (WD_ic), and the diameter at breast height (DBH) as predictors. The biomass assessment was conducted using different model evaluations for WWD_st as well as allometric equations using the destructive method. From the results, it was noted that using the WWD_st, the total biomass was underestimated by −0.7% compared to the biomass measured in the field. For allometric equations that included DBH and tree height as independent variables, the explained variability was around 99.3% for total aboveground biomass (AGB_total), while it was 97.9% for allometric function using just the DBH. Overall, the distribution of biomass across different compartments was as follows: 73.5% in stems, 23.8% in branches, 1.9% in stumps, and 1.3% in leaves. The study findings offer valuable insights into WD, biomass distribution among different components, and biomass allometric quantification in natural beech forest environments in mountainous areas. Full article

Real-time PCRs were developed to characterize Fomes fomentarius lineages occurring in the beech forests of the Ardennes (southern Belgium). A collection of F. fomentarius sensu lato isolates was built up in 2020 and 2021 from basidiocarps developing on beech trunks, stumps, or logs. Two of the 148 isolates tested (monokaryotic and dikaryotic) belonged to the species Fomes inzengae, while the other isolates corresponded to the species Fomes fomentarius sensu stricto. As far as we know, this is the first record of Fomes inzengae in Belgium. This fungus was also found in a mature tree not showing any signs of decay. This demonstrates its endophytic nature. Growth tests at different temperatures, as well as wood degradation tests in accordance with standard NBN EN113 showed different behavior between both species. Passive sticky traps were installed during two growing seasons at the two sites where F. inzengae had been reported. Spores were detected at all collection times between April and July, using the specific molecular test developed. Moreover, in 2023, the DNA concentrations measured were 100 times higher than in 2022. The implications of this new species in Belgium is discussed in the context of climate change. Full article

Efforts to enhance carbon storage in forest ecosystems through policy and management decisions rely on accurate forest biomass assessments. However, most forest inventories consider tree mortality the only form of aboveground biomass loss, overlooking other important factors, such as wood decay in living trees. In this study, using linear mixed-effects models, we delve into the sustainability of mature and over-mature deciduous forests in Latvia by conducting a comprehensive analysis of stem rot severity, identifying species for which the impact of stem rot on their carbon stock reduction was most significant. The analysis focused on determining the proportion of discolored wood, decomposed wood, and hollow spaces within the stems of 190 living deciduous trees commonly found in hemiboreal forests. The study reveals a greater extent of stem rot and more extensive decay in Populus tremula trees than in Betula spp., Alnus glutinosa, and Alnus incana. It emphasizes the influence of tree species, age, and diameter at breast height on stem rot proportions. The stump rot area significantly predicts the amount of decomposed and discolored wood within the stem. The study provides valuable insights for sustainable forestry practices and highlights challenges in estimating stem rot severity, emphasizing the need for comprehensive diagnostic methods. Full article

Burn severity is commonly assessed using Burn Ratios and field measurements to provide land managers with estimates of the degree of burning in an area. However, less commonly studied is the ability of spectral indices and Burn Ratios to estimate field-measured fire effects. Past research has shown low correlations between fire effects and Landsat-derived Burn Ratios, but with the launch of the Sentinel-2 constellation, more spectral bands with finer spatial resolutions have become available. This paper explores the use of several red-edge-based indices and Burn Ratios alongside more ‘traditional’ spectral indices for predicting fire effects, measured from the Maple and Berry fires in Wyoming, USA. The fire effects include ash depth, char depth, post-fire dead lodgepole pine (Pinus contorta; PICO) density/stumps, mean basal diameter, cone density on dead post-fire trees, coarse wood percent cover/volume/mass, percent cover of ghost logs and initial regeneration of post-fire PICO/aspen density. All-possible-models regression was used to determine the best models for estimating each fire effect. Models with satisfactory R² values were constructed for post-fire dead PICO stumps (0.663), coarse wood percent cover (0.691), coarse wood volume (0.833), coarse wood mass (0.838), ash depth (0.636) and percent cover of ghost logs (0.717). Red-edge-based indices were included in all of the satisfactory models, which shows that the red-edge bands may be useful for measuring fire effects. Full article