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Frankincense trees (Boswellia spp.) worldwide are affected by a number of threats, including global warming and changing land management practices. On the Socotra Archipelago (Yemen), which harbours eleven endemic Boswellia species, grazing is generally assumed to be one of the main threats preventing natural regeneration. To test the impact of overgrazing on natural regeneration, we established an in situ experiment on four different Boswellia taxa in different areas of Socotra Island. Mortality and the height increment of seedlings were measured for a period of two/three years in five plots excluded from grazing (fenced) and in five paired control (unfenced) plots. Each plot was 50 m × 50 m in size and contained several adult trees as a source of viable seeds. Our results show that seedling mortality was significantly higher, and seedling height increment generally (4 out of 5 sites) lower in open compared to fenced plots. In the fenced plots, the number of seedlings for all species reached up to 772, with 560 surviving seedlings. In comparison, the control plots reached up to 296 seedlings, with 176 seedlings surviving after 2–3 years. The results of our experimental study indicate that grazing directly threatens the natural regeneration of the endemic Boswellia on Socotra Island. However, seedling mortality remained relatively high inside the exclosures as well, which indicates that even without the pressure of livestock grazing, other impacts remain a challenge for the future conservation of the archipelago's unique frankincense trees.

In response to the decline of Central European spruce monocultures driven by various factors, the Demonstration Object of Reconstruction of Spruce Forests (DORS) was established in Husárik locality, Javorníky Mts., northwestern Slovakia. The area includes the Husárik trial site, where the applicability and efficiency of different artificial regeneration methods are studied. The trial was established on a 24-ha area cleared following the outbreak of spruce bark beetles in 2011. Its altitude is 800 m a.s.l., aspect NW, slope 30%, the soil is Ranker on the soft flysch sandstone bedrock. Our study covered 4 conifers – Norway spruce (spruce), European larch (larch), silver fir (fir), and Douglas fir (doug fir). Each species was regenerated using 4 different approaches: planting of commercial bareroot transplants (BR), planting of container transplants (CON), direct seeding (DS) and vegetative cell seeding using seed shelters (VCS). Results concerning the nine-year development of transplants and seedlings, along with the calculation of cost-efficiency, are presented. As to the species, BR and CON transplants of spruce and larch reached the best survival and height. The DS larch was the most cost-efficient method of establishment of a successfully established plantation (survival > 50%; stem height > 2/3 of the weed height; ratio of damaged individuals < 50%) with a total cost of 2 372 EUR·ha^–1. On the contrary, the slow initial growth of fir and Douglas fir and their extensive damage resulted in the incomparably higher cost of establishment of their successfully established plantation, such as 4 980 EUR·ha^–1 for five-years-old BR fir transplants. Our findings documented that current efforts related to the restoration of salvage-felled clearings remained difficult, especially in the case of introduction or reestablishment of coniferous tree species more vulnerable to open site conditions.

In today's forestry practices, integrated management is the prevailing approach. One method gaining traction is retention forestry, where certain trees, known as biotope trees providing microhabitats (TreMs), are preserved during harvesting operations. This article delves into hands-on training for marking interventions using marteloscope plots, focusing specifically on 'Pokojná hora,' a 1-hectare plot situated in the southeast of the Czech Republic. Field surveys were conducted using FieldMap technology, capturing essential data for all trees: coordinates, species, diameter, height, and health status. Additionally, details such as wood quality, economic value, microhabitats, and habitat value were documented for each tree. Forestry engineering students virtually mapped out interventions on the marteloscope plot, testing 11 solution variants across 2 scenarios to strike a balance between economic goals and biodiversity conservation. The plot hosts 155 microsites, predominantly on Fagus sylvatica (common beech) with 108 microsites. The likelihood of TreMs increases with tree diameter, while the correlation between a tree's economic value and its diameter was confirmed. Optimal management suggests maintaining 10 habitat trees per ha to reconcile economic and ecological objectives during harvesting operations. In essence, we contend that the adoption of retention forestry practices coupled with marteloscope training can play a pivotal role in arresting biodiversity decline within forest ecosystems.

Missouri Ozark woodlands are a unique, but imperilled ecosystem type due to fragmentation, lack of proper management and a changing climate. The management, restoration, and conservation of Ozark woodlands is a conservation priority. The Ozark woodlands contribute to the sequestration of carbon and nutrients through their robust productivity, effectively removing carbon dioxide from the atmosphere and storing it in the biomass and soil while cycling essential nutrients to support the ecosystem's health and vitality. We have assessed the over- and mid-storey leaf production, collecting leaves in baskets every autumn in a 1 200-ha conservation area in southwest Missouri since 2000. The leaf production data from 2000 to 2021 were compared among sites; control (not burnt for over 80 years), burnt (fire resumed in March of 1999 and repeated in 2001, 2003, 2008, 2010, 2013, and 2021) and reference (fire resumed in 1980 and repeated every 2 years). The average oak leaf production was statistically higher in the burnt site than the reference site, but only marginally higher than the control site. The leaf production varies statistically between the years. We applied a regression analysis among the productivity, temperature, and precipitation to associate the temporal variability in the weather with the productivity. The reference woodland showed statistical significance with the precipitation, but not with the temperature, while the other sites did not show any statistical significance with the precipitation. No statistically significance difference was observed between the productivity and temperature across any of the woodland burn histories. The March–June, March–May, and June–August precipitation statistically predicted the productivity. The results indicate that long-term burning is predictably associated with woodland leaf production and precipitation, but the precipitation is uncoupled with the productivity in woodlands that were more recently burnt or where burning has been suppressed. Sassafras saplings of approximately 1 m in height have emerged as the dominant species in the understorey of burnt woodlands while being completely absent from the control and reference woodlands. However, the productivity is the highest in the woodlands where burning has been suppressed and 20 years of prescribed fire does not significantly reduce the productivity. Oak regeneration over 20 years of burning is being suppressed by competition with sassafras, which may result in a significant shift in the ecosystem variables.

The subject of this study is to point out the issue of various impacts of musculoskeletal disorders in chainsaw operators and their impact on human health. The first goal was to find out whether the body mass index is responsible for excessive stress to individual parts of the body of chainsaw operators at work. The second goal was to determine whether the excessive load to the individual body parts is affected by the time of working with the chainsaw. Questionnaires created for the fulfilment of the goals were distributed to professional forest loggers working in the Czech Republic, which were filled in by 161 of them. Questions in the first part of the questionnaire were formulated in such a way that answers to them would clearly identify information on the individual respondents. The second part of the questionnaire was focused on the assessment of the load upon 12 body parts of the operators (each part being split into the right and left sides). The results of the statistical analysis showed that neither the body mass index (BMI) nor the length of time working with the chainsaw affect the load on the individual parts of the body of the chainsaw operators.

Riparian vegetation plays a major role in maintaining biodiversity and reducing the negative impact of nutrient leaching into aquatic ecosystems. However, the knowledge on the interactions between riparian vegetation and other environmental factors is still incomplete for planning sustainable riparian forest management. The aim of this study was to explore interactions between riparian forest ecosystem components along a small stream. Interactions between vegetation structure, chemical composition of soil and groundwater, as well as chemical element flows via litterfall and precipitation were studied in seven 50 m long transects located in the riparian forest of different characteristics along a 1.4 km river section in the northern part of Latvia. Our results showed that throughfall input of total nitrogen (TN) and potassium (K) was higher in transects with predominantly deciduous tree stands, but the concentration of TN in forest floor was higher in coniferous tree stands. At some soil layers, a positive correlation between organic soil carbon (OC) and the concentration of TN in groundwater was detected. The concentration of TN and nitrate-nitrogen (N-NO₃^–) in groundwater correlated positively with the deciduous tree basal area. The obtained results suggested that element flows are strongly dependent on tree species' composition and a comparatively small riparian area is able to provide diverse ecological conditions.

The objective of the presented research was to create an average image of a harvester operator in Poland and to identify factors influencing the degree of mental workload. We used a survey of environmental assessments of workload. The creation of an electronic survey and the support of a company that indirectly employs operators (State Forests) made it possible to reach a large group of surveyed people. The respondents indicated the occurrence of ailments typical of sedentary work at the researched workstation. These included mainly monotony, back pain and numbness in the upper limbs. Stress at work was felt by the majority of respondents; hence the analyses of mental stress, which also translates into other diseases, should indicate key responses to questions regarding comprehensive ergonomic assessments at the researched workstation.

Natural regeneration is a crucial factor in improving the economy of forest estates. The presented study analysed the economic parameters of three different approaches to forest regeneration: (i) artificial regeneration with Norway spruce, (ii) a 25% admixture of soil-improving and stabilising species (SSTS), and (iii) natural regeneration. The expenses for these specific operations related to individual regeneration methods were derived. These variants were investigated before the bark beetle calamity (2014) and after the outbreak (2023) for management sets (MS) 531, 551, 571, and 591, i.e. for acidic, nutrient-rich, gleyed, and waterlogged sites of higher elevations. In all cases, natural regeneration decreased expenses by approximately 2 000 EUR·ha^–1 (50 000 CZK·ha^–1) to 6 000 EUR·ha^–1 (150 000 CZK·ha^–1). The 25% admixture of SSTS increased the expenses. The proportion of natural regeneration subsequently decreased due to the bark beetle calamity from roughly 40% to 10% in recent years, which is comparable with the Czech Republic as a whole.

Scattered Greek juniper (Juniperus excelsa M. Bieb.) trees have ecological values, such as soil protection and soil erosion reduction in the Irano-Turanian region; however, intensive exploitation puts their habitats at risk. Therefore, knowing the soil characteristics of these habitats plays an important role in their management. The aim of this study was to investigate the soil quality of semi-arid woodlands dominated by a pure Juniperus excelsa community. At three sites in the Irano-Turanian region, soil samples were randomly taken from a depth of 0–20 cm in the eastern direction under the crowns of Greek juniper trees and from bare soil. The evaluated physical properties included bulk density (Bd), moisture, sand percentage, silt percentage and clay. Chemical properties included pH, electrical conductivity (EC), organic carbon (SOC), total nitrogen (TN), and nutrient concentrations of bare soil compared to the below-crown soil. Additionally, we investigated basal respiration (BR) and microbial biomass carbon (MBC) to evaluate the influence of Greek juniper trees on soil microbial activity. The bulk density value in samples taken under crowns was significantly lower by 42% compared to bare soil; however, significantly higher soil moisture (+39.8%) was obtained under tree crowns. Although clay and sand content under tree crowns was significantly higher than that of bare soil, sand content under tree crowns was significantly lower than in bare soil. According to our findings, soil pH under tree crowns and in bare soil was 7.13, which increased to 7.67 in bare soil. Soil EC (+15%), SOC (+76%), and TN (+29%) were significantly higher under tree crowns. The concentrations of magnesium and sodium were similar between bare and below-crown soils, but significantly higher phosphorus (+46%), potassium (+41%), calcium (+31.1%), iron (43.3), and zinc (+56.6%) were observed under Greek juniper crowns. Soil microbial activity was higher under tree crowns compared to bare soil, as evidenced by significantly increased BR (+49.1%) and MBC (+43.5%). Our findings indicate that scattered Greek juniper trees can improve soil properties, and their destruction leads to a significant decrease in soil quality. Generally, planting Greek juniper seedlings in degraded areas can help restore the soil quality.

Sandy soils represent an extreme environment for tree growth. Traditionally, site preparation before planting involves removing logging residues (LRR) and ploughing. An alternative method is incorporating logging residues (LRI) into the topsoil which may enhance tree regeneration and seedling growth. The aim of this study was to assess whether and how different site preparation techniques affect soil physico-chemical and microbial properties over the long term. The study was performed in the Záhorská nížina lowland (Slovakia) in September 2020. Soil samples were taken in two 25-year-old Pinus sylvestris (L.) plantations along five soil profiles in each stand, down to a depth of 30 cm. Results showed a significant increase in carbon and nitrogen concentration and soil moisture in the LRI plot. However, soil pH and phosphorus content significantly decreased. No significant differences were observed in calcium, magnesium, and potassium concentrations between the differently treated plots. The LRI plot also exhibited a significant increase in microbial biomass carbon, N-mineralisation, and catalase activity. The results indicate that different mechanical site preparation methods may impact soil properties over the long term, likely through improved seedling survival and tree growth.

Northern red oak (Quercus rubra L.) is an important introduced tree species in Hungary, particularly in the Nyírség region. This study investigates its diameter growth (DBH) in six forest subcompartments, with stand ages ranging from 20 to 71 years. 5- and 25-year diameter increments were calculated. The distribution of diameter and diameter increment values was also determined. The results show significant growth across all sites. For example, quadratic mean diameter (QMD) increased from 16.4 cm to 30.4 cm over 25 years in the forest subcompartment Encsencs 12A, and from 20.3 cm to 38.4 cm in Ófehértó 2A. Five-year DBH increments ranged from 1.8 cm (± 0.8) in older stands to 4.2 cm (± 0.5) in younger or middle-aged stands. The findings confirm Q. rubra's capacity for steady diameter growth in northeastern Hungary and contribute valuable growth data for future yield modelling and forest management strategies.

The forestry sector provides several social and economic benefits to the whole economy. It is based on the sustainable management of renewable natural resources and production of raw wood. It is therefore able of sustainable growth. The interest of the European Union is to build economy based on renewable natural resources, resulting in the need to pay increased attention to the development and support of the forestry. The aim of the paper is to evaluate the performance of forestry sector in the Czech and Slovak Republics for a period of five years. System of indicators measuring sectorial performance was set up to reach the goal. Obtained results in indicators have shown that the profitability and value added rate of Slovak and Czech forestry are at a high level and the performance is affected by high investment efficiency.

Juniper forests grow in mountain areas and many difficulties are encountered in their sampling. Sector sampling as an unbiased and cost-effective method was tested for the sampling of a 12.5-ha juniper forest. To begin with, a point-map of trees was created and 50 quadrats were determined systematically. Fixed area plots were measured within these 50 × 50 m quadrats. In each quadrat, eight sectors with 45° angle were determined. One-sector and two-sector scenarios randomly besides four-sector scenario systematically were conducted. Accuracy and precision of sampling methods were compared. Also, statistical analysis was conducted to compare sector sampling scenarios with fixed area plot (FAP) and real data. Results showed that four-sector scenario estimates were close to FAP method in precision and accuracy. Statistical analysis showed that there was no significant difference between sector sampling scenarios and FAP and in real data. But in correlation analysis only the four-sector scenario could compete with FAP method. Regarding consumed time and sampling error simultaneously, the efficiency of sector sampling was higher than that of FAP method for estimating density and close to FAP method for estimating crown cover. It can be concluded that in laborious situations such as in juniper forests, sector sampling can be competitive with FAP method with noticeable parsimony. But more study is still needed to decrease sampling error and optimize sector angle with the purpose of cost saving.

Climate change, biodiversity loss, and the increased occurrence of extreme weather events bring new challenges at a global level, not just in forestry. In response to the current situation, modified economic models such as circular economy, green economy, bio-based economy, or bioeconomy, are expected to move society towards a more sustainable future. The main aim of this paper was to evaluate forestry employment and its drivers within the bioeconomy labour market in the Czech Republic. The partial target was to provide a general view of the development of forestry employment within the bioeconomy labour market. The authors applied a mixed methods approach, using literature review, data analysis, correlation analysis, and regression analysis. A decreasing trend of the share of forestry employment in total bioeconomy employment and of the share of bioeconomy employment in the labour market in the Czech Republic was identified. Regarding the drivers of the forestry labour market, based on the results, employment in the forestry sector is positively dependent on wages/salaries and negatively dependent on GDP and forest land.

After 1989, Central and Eastern European countries with planned economies launched a process of transformation. In the Slovak forest policy, the main changes have been in the structure of forest ownership, increasing the share of governance mechanisms within the decision-making, and the organization of the sector. The aim of the paper is to analyse the current Slovak forest policy arrangement in relation to the socialistic political history, via the Policy Arrangement Approach. The analysis is based on literature search and consultations with forest policy experts. In total, 55 scientific publications were analysed. Subsequently, the results were consulted with four national forest policy experts. Despite the three decades-lasting transformation process, in Slovakia, forest policy is characterised by a strong influence of governmental actors, centralisation, and prevailing hierarchical use of policy instruments. Nature protection actors enter the policy arena, for instance, to expand protected areas. The top-down planning has an impact on the forest owners' performance of rights to use their forests. Non-governmental actors attempt to enforce their interests through participation mechanisms, inter-ministerial commenting procedures, and voluntary instruments. Public opinion is turning towards nature protection and forestry as such has come under pressure with its traditionalist approach.

Czech Academy of Agricultural Sciences (CAAS) is a professional and social institution whose basic mission is to influence the scientific level of research activities and education in its field of competence, to take care of its continuous development and to effectively popularize the acquired scientific knowledge. Within the CAAS and its Department of Forestry, the Commission of Forest Economics has been operating for a long time, focusing on forest and wood economics and policy. A total of 11 research directions are defined in the forthcoming Concept of Research, Development and Innovation of the Ministry of Agriculture for the period 2023+, the professional part of which is covered and guaranteed by the CAAS. The following directions are included in forestry and wood processing: "Forestry and related industries" and the direction "Forest and agricultural economics and policy" integrated with agriculture. The paper briefly describes the scientific focus of forest and wood economics and policy in this context and especially the activities of the Commission of Forest Economics of the Department of Forestry of the CAAS. In the temporal and factual context, it mentions the published monograph "Czech Academy of Agricultural Sciences and a Quarter-Century of the Commission of Forest Economics".

The Algeria forest, particularly in the northeastern region, has undergone profound changes in recent years. The Oued Bouhamdane watershed has a great forest potential, which is threatened by several factors of natural and human origin, resulting in a decrease in forest cover. It requires adequate forest monitoring to support the sustainable forest management of this watershed, which is possible thanks to satellite imagery. The objective of this research is to study the spatiotemporal dynamics of the vegetation cover of the Oued Bouhamdane watershed between 2013 and 2022 using remote sensing data. This study is based on the use of Landsat 8 and 9 images for two dates in 2013 and 2022, and the calculation of the Normalized Difference Vegetation Index (NDVI) to identify changes in vegetation cover between 2013 and 2022. The calculation of NDVI and the realization of the vegetation change map showed a regression of the forest cover between 2013 and 2022 with a rate of –5.53% of the total of the study area with a general negative change of 28.62% of the study area. This regression is essentially linked to natural and anthropogenic factors. This work can be a valuable tool for sustainable management of the forest of this watershed; moreover, the method is also adaptable to other watersheds of the northeastern region of Algeria.

Knowledge of mechanisms by which large mammals select rubbing trees (RT) is a major challenge for the effective management of forests and wildlife resources. In this study, we investigated this issue regarding the Wild boar (Sus scrofa) in the Moroccan forested site of Sidi Boughaba as a case study. We used data from four sets of variables, namely topography, forest type, landscape composition, and microhabitat, measured at 58 rub and control trees, to determine the factors associated with the occurrence of RT by means of generalized linear mixed models. Our results showed that the RT occurrence increased with a high density of red juniper trees and declined with distance to the nearest footpath. Variation partitioning analysis revealed that the pure fraction of microhabitat was the most robust in explaining this occurrence (adj. R² = 0.17, P < 0.001), followed by that of forest type (adj. R² = 0.05, P < 0.05). A scientific monitoring system must be set up to strike a balance between the availability of forest trees on the one hand and the pressure exerted by wild boars on this internationally importance site on the other. It is imperative to test the geographical generality of our results in other Mediterranean forests.

The Ellenberg quotient (EQ) is a climate index defined as a ratio of the hottest month's temperature and the average annual precipitation sum. The quotient indirectly expresses the relationship between climate and vegetation, and its application is related to the ecological niche of Fagus sp. Although the quotient was curated on the grounds of field research primarily on German vegetation, the possibilities of its utilisation are not limited to the Central European region. The objective of this study is (i) to compare the EQ values calculated for the forest vegetation zones in the Czech Republic with the published data using the ecological niche of Fagus sylvatica; and (ii) to compare the new EQ-based vertical model with field empirical mapping. The study area is the Czech Republic, Central Europe. We used climate data from 1970–2000 and the data of the National Forest Inventory, 2^nd cycle (2011–2015), representing an objective data design. Geospatial analytic methods, machine learning (boosting), and verification through statistical testing were performed. The results indicate higher EQ values between the two most substantial spatial frames – the Hercynicum and Carpaticum regions. By comparing empirical mapped units to their climatic potential (in the EQ), a match was found only within the Carpaticum region. The study presents a concretisation of the general climate index for a specific region, adds to the knowledge about the Fagus ecological niche in context with the Central European vegetation, and also points to the EQ's potential for evaluating the concept of vertical differentiation of forest communities, as well as a possible prediction tool for the vegetation migration in context with climate change.

Herbivorous ungulate diets affect population performance and overall forest health through balanced interactions on plant-herbivore relations; therefore, understanding them is critical. Faeces are frequently used in ungulate nutritional ecology because they can provide information about animals’ digestive efficiency. Roe deer (Capreolus capreolus) and red deer (Cervus elaphus) have different morpho-physiological and ecological constraints, and these differences should be reflected in their faeces. On the other hand, the lack of information about the animal (sex, age, reproductive status, diet selection, etc.) may be challenging for such studies. This study aimed to detect species’ different susceptibility to these factors reflected in animals’ faeces. Thus, we hypothesised that near-infrared reflectance spectrometry (NIRS) could distinguish between the faecal nutrients of two cervids. We collected 94 usable faeces from both species along the forest transect in Bohemian forests in the Czech Republic, covering 2 500 ha. Roe and red deer overlap was determined using the four faecal nutritional components on two axes. No discrimination occurred, refuting our hypothesis and highlighting that out-of-control variables are critical for faecal studies in uncontrolled settings. Fibrous parts explained the most variance (48%), indicating animals’ strong reliance on nutrition quality. Apparently, uncontrolled supplementary feeding produced similar faecal nutrient outcomes during the nutrition-limiting winter, which was theoretically supported by the animal’s response to predation and hunting pressure. The inability of NIRS to identify the source of N in faeces may also explain the lack of discrimination.

Poplar species such as aspen (Populus tremula L.) play a very important role in the forest formation process not only in Eastern European regions. Unfortunately, such aspen stands are often severely affected by fungal diseases, causing mainly core rot. In this study, the indirect effects of thinning on the phytosanitary condition of aspen by promotion of tree growth were investigated. Two thinning methods, manual (thinning from below) and mechanical thinning (schematic), were applied to young stands dominated by Eurasian aspen to study their effects on tree growth and health. All trees were measured at breast height and diameter frequency distribution was determined twice, i.e. three and 24 years after the beginning of the experiment. In addition, during the second measurement, tree-ring samples were obtained from individual trees to evaluate growth and wood decay damage. Neither manual nor mechanical thinning of aspen significantly increased its growth at the stand level, but positive effects on individual trees were observed in plots where mechanical thinning was applied. The thicker the trees, the less decayed they were. The analysis suggests that thinning in general should not be used to increase stand production, but the positive effects of mechanical thinning on individual aspens can be recommended to promote the growth of individual vigorous trees.

The presented study estimated the aboveground biomass (AGB) of Pinus roxburghii (chir pine) natural forests and plantations, and created biomass maps using a relationship (regression model) between AGB and Sentinel-2 spectral indices. The mean AGB and BGB (belowground biomass) of natural forests were 79.54 Mg·ha^–1 and 20.68 Mg·ha^–1, respectively, whereas the mean AGB and BGB of plantations were 94.48 Mg·ha^–1 and 24.56 Mg·ha^–1, respectively. Correlation showed that mean diameter at breast height (DBH) and mean height have weak relationships with AGB, and BGB has shown correlation coefficients (R² = 0.46) and (R² = 0.56) for polynomial models. Regression models between AGB (Mg·ha^–1) of Pinus roxburghii natural forest and Sentinel-2 spectral indices showed a strong relationship with Ratio Vegetation Index (RVI) with R² = 0.72 followed by Normalized Difference Vegetation Index (NDVI) and Atmospherically Resistant Vegetation Index (ARVI) with R² = 0.70. In contrast, the lower performance of spectral indices has been shown in regression with plantation AGB. Correlation coefficients (R²) were 0.41, 0.41, and 0.40 for RVI, NDVI, and ARVI, respectively. All indices showed that the distribution of AGB data was not the best fit with the linear regression model. Therefore, non-linear exponential and power models were considered the best fit for NDVI, RVI, and ARVI. A biomass map was developed from RVI for both natural forests and plantation because RVI has the highest R² and lowest P-value.

National parks (NP) are the last refugia of forests dominated by the Nothofagus species in Chile. However, frequent, careless human-caused fires are destroying these forests even within the national parks. After large-scale fires, N. pumilio stands are unable to recover naturally neither in generative nor in vegetative ways and artificial regeneration must be resorted to in order to maintain their extent. However, even artificial regeneration is not successful without protection against browsing. Therefore, the aim of this study was to experimentally test a range of repellents and other methods of mechanical protection of seedlings against browsing. Five replicates of plots were placed in Torres del Paine NP, in different habitat conditions and with different methods of protection against browsing (11 repellents, wire mesh, plastic tube and control). In each plot, 12 seedlings were treated with each type of protection. In our experiment, only 8% of the seedlings were damaged by browsing, while the mortality rate was 38%. The results indicate a more significant effect of abiotic factors (mainly frost, drought or wind) on seedling mortality than browsing. In parallel, however, it is clear that, compared with the control, six of the eleven repellents used in the experiment showed a significantly positive effect. We suggest the use of plastic tubes as the best option to protect seedlings, which, in addition to providing 100% protection against browsing, are likely to provide more favourable microclimatic conditions for seedlings, similar to leaving the burned snags.

Micropropagation has enormous potential in the forestry industry for the mass production of elite genotypes. A limiting factor that hinders a wider adoption of this technique is its high associated cost, dissuading small producers and laboratories from its use. Thus, it is important to develop low-cost protocols to increase the competitiveness of micropropagation. The goal of the present study was to elaborate a low-cost culture medium that would allow plant growth without diminishing plant quality and production. The replacement of laboratory sucrose with commercial sugar as a carbon source, and laboratory agar with locally produced agar as a gelling agent was tested. To validate the effects of the medium for woody species micropropagation, two relevant forest species, chestnut and birch, were used and several phenotypic characteristics were recorded. Our data indicated that the substitutions made in the media composition did not alter growth or rooting parameters. Substitution of laboratory sucrose and Bacto agar by table sugar and local commercial agar provides a valuable alternative for forest species micropropagation and for increasing their potential profitability.

Sap flow represents water transport from roots to leaves through the xylem and is used to describe tree transpiration. This paper proposed and tested a procedure to estimate sap flow by calculating global radiation in a digital model of the tree canopy surface obtained by unmanned aerial vehicle imaging. The sap flow of nine trees was continuously measured in the field. In the digital surface model, individual canopies were automatically delineated, their parameters were determined and the global radiation incident on their surface on specific days was calculated. A polynomial relationship was found between sap flow and the calculated incident solar radiation during the morning hours with a coefficient of determination of 0.98, as well as a linear relationship between the decrease in radiation and sap flow during the afternoon with a correlation coefficient of 0.99. Using the Random Forest machine learning method, a model predicting the sap flow of the trees was created based on the global radiation and canopy parameters determined from the digital surface model of tree canopies. The resulting model was deployed on additional days and compared to field measurements of sap flow, achieving a correlation coefficient of 0.918. In addition, two linear regression models were created for a tree group, achieving coefficients of determination of 0.66 and 0.90.

Assimilation (A) and photosystem II (PSII) efficiency value light response curves [A/PPFD and PSII/PPFD curves (PPFD – photosynthetic photon flux density)] of promising black locust clones (NK2 and PL251) and the registered Üllői clone were analysed to study the net assimilation rates and PSII efficiency within the function of PPFD levels. The natural logarithmic regression functions fitted well to the measured data points for A/PPFD, R² values varied between 0.9515–0.9884. For PSII/PPFD values, we used the exponential regression function with R² ranging from 0.9948 to 0.9989. Except for PL251, the A/PPFD curves of the tested clones increased steadily with increasing illumination levels but flattened at the 600 µmol·m^–2·s^–1 PPFD level due to the effect of photorespiration on the assimilation rate. For PL251, the A/PPFD curve decreased at the 1 200 µmol·m^–2·s^–1 PPFD level. Unlike A/PPFD results, the PSII/PPFD exponential curve decreased as the PPFD level increased. Europe is forecast to experience significant negative climate change factors, including increased drought, heat, and irregular precipitation. Under such conditions, relatively drought-tolerant tree species such as black locust will play a vital role in new afforestation and uninterrupted wood supply. Consequently, growing and improving newly bred black locust clones, including the ecophysiological studies of relatively drought-tolerant clones, is increasingly vital.

Forests cover almost one half of European land. Therefore, land taxes, including taxes from forests, are essential for a municipality's income. The land tax system is implemented on different levels, mainly nationally and locally. Therefore, many land tax features are settled by federal law, and others differ according to the local tax administrators. The objective of the paper is to compare the current laws and principles and the implementation process of forest land in Slovakia and Portugal. We have selected countries from different geographical areas of Europe. Even though the forest compositions and forest ownership differ, we aimed to identify whether the forest land tax systems can be similar. We analysed the legislation and strategic documents on the national level that helped us to describe the land tax system and its general features (e.g. taxpayer, tax rate, tax base, exemption options, tax period, or penalties). In both countries, the national tax law governs the tax implementation and settles any basic processes related to tax collection. The municipalities have the right to revise both the tax rates and exemptions. The results also show that forest owners in Slovakia have more options for tax exemptions than in Portugal.

Normal log lengths in Norway are 3–6 m (NL), but occasionally there is a demand for short timber with a 2.5 m log length (ST). There are concerns that ST could reduce the forwarders' productivity. Six type stands were created based on harvester data. Different assortment distributions, conditions, and forwarders were simulated in each type stand. It was found that an additional ST assortment almost always decreased productivity (from –15.5 to +4%). Increased forwarding distance (m), more difficult driving conditions, and increased log concentration [m³·(100 m strip road)^–1] decreased the productivity difference between sites with ST and NL and sites with only NL. Increased forwarder size increased the productivity difference between sites with ST and NL and sites with only NL. It is possible to load two stacks of ST on some forwarders. Such loading was more productive than loading one stack on longer forwarding distances, while the opposite was the case on short distances. However, loading two stacks of ST can lead to overloading.

The most crucial individual tree variables in forest management are diameter at breast height (DBH) and height of trees (H). Projection of stand development over time relies on accurate height-diameter functions. The main aim of this paper is to define the best usable model for tree height prediction from diameter at breast height. We explore the place where the Macedonian pine was discovered in the Baba Mountain in the Pelister National Park in North Macedonia. Thus, we established 48 experimental plots (EP) with a circle shape, a radius of 12.62 m and an area of 500 m² each. The EP were established in pure Macedonian pine stands in an elevation gradient between 950 m a.s.l. and 1 700 m a.s.l. Every tree in the EP was attributed with data for diameter at breast height, tree height, and stand characteristics data (elevation, slope, aspect, coordinate) as well. For predicting the tree height, we used 40 models from many authors which are the most usable in forest practice. Also, we prepared evaluations and tests for all models, in order to choose the best responsive model for the Macedonian pine forest. For predicting the best tree height model for Macedonian pine, we decided on Mamoun's equation, with a high correlation value of 0.85 with 73% out of the observed data. Also, this model showed a lower root mean square error of 32.65, a lower model prediction accuracy of 6.77, and a lower mean absolute percent error of 11.73%. Finally, it can be concluded that the nonlinear connection between DBH and tree height is the most responsive regression model.