Forest Roads Research Articles

Rain-Driven Failure Risk on Forest Roads around Catchment Landforms in Mountainous Areas of Japan

Although the causes of and impacts against forest road failure differ according to the type of damage that occurs, the statistical understanding of the trends in the type of failure is insufficient. In this study, we collected data on 526 forest road failures due to heavy rainfall during 2006–2010 in the mountainous regions of Japan and statistically analyzed the characteristics. The forest roads covered in this study include those used primarily for timber extraction as well as those used for public purposes. Forest road segments were classified into four categories: streamside, stream crossings, zero-order basin, and others, and comparisons were made regarding the length of damage, the relative probability of occurrence, repair costs, and induced rainfall intensity in each category. Streamside segments accounted for only 15% of the total length of routes analyzed but 42% of all damaged segments. Furthermore, the relative risk of the streamside segments was about 6.0 times higher than that of the other categories of segments, indicating that they were the most likely to be damaged in this analysis. It is clear that the most important issue in the target area is to prevent damage to streamside segments.

Increasing the Durability of Tools for Forest Road Maintenance

To ensure the care of forests, it is necessary to make them sufficiently accessible by forest roads. The basic working tool are hammers, or round shanks of various shapes, composed of a body and a tip. They are subject to a strong abrasive environment, which often leads to damage up to the complete destruction of the functional part of the tool. For these reasons, it is necessary to deal with the possibilities for increasing their lifetime. One of the possibilities of increasing the service life of these tools is hardfacing by welding. The article deals with the abrasive resistance of the original material of the tool and the hardfacing materials. Based on the chemical analysis of the base material of the tool, we found that the tool is made of manganese steel 38Mn6. This material was used as a standard and was compared with the hardfacing materials Abradur 58, E DUR 600, UTP DUR 600 and OK 84.58. Electron microscopy was used to evaluate the microstructure. Next, the Rockwell hardness measurement was performed on the samples. The original tool material 38Mn6 reached the lowest hardness value, namely, 21 HRC. The highest value was reached by the hardfacing material E DUR 600, namely, 59 HRC. Subsequently, a test of resistance to abrasive wear was performed according to GOST 23.208-79. Based on this test, we can conclude that the highest value of resistance to abrasive wear was achieved by Abradur 58. Even though the hardness of this coating was slightly lower than the hardfacing material E DUR 600, specifically 56 HRC, we can state that this hardfacing material (Abradur 58) achieved the best results among the investigated materials.

Characterization of Vegetation Dynamics on Linear Features Using Airborne Laser Scanning and Ensemble Learning

Linear feature networks are the roads, trails, pipelines, and seismic lines developed throughout many commercial boreal forests. These linear features, while providing access for industrial, recreational, silvicultural, and fire management operations, also have environmental implications which involve both the active and non-active portions of the network. Management of the existing linear feature networks across boreal forests would lead to the optimization of maintenance and construction costs as well as the minimization of the cumulative environmental effects of the anthropogenic linear footprint. Remote sensing data and predictive modelling are valuable support tools for the multi-level management of this network by providing accurate and detailed quantitative information aiming to assess linear feature conditions (e.g., deterioration and vegetation characteristic dynamics). However, the potential of remote sensing datasets to improve knowledge of fine-scale vegetation characteristic dynamics within forest roads has not been fully explored. This study investigated the use of high-spatial resolution (1 m), airborne LiDAR, terrain, climatic, and field survey data, aiming to provide information on vegetation characteristic dynamics within forest roads by (i) developing a predictive model for the characterization of the LiDAR-CHM vegetation cover dynamic (response metric) and (ii) investigating causal factors driving the vegetation cover dynamic using LiDAR (topography: slope, TWI, hillshade, and orientation), Sentinel-2 optical imagery (NDVI), climate databases (sunlight and wind speed), and field inventory (clearing width and years post-clearing). For these purposes, we evaluated and compared the performance of ordinary least squares (OLS) and machine learning (ML) regression approaches commonly used in ecological modelling—multiple linear regression (mlr), multivariate adaptive regression splines (mars), generalized additive model (gam), k-nearest neighbors (knn), gradient boosting machines (gbm), and random forests (rf). We validated our models’ results using an error metric—root mean square error (RMSE)—and a goodness-of-fit metric—coefficient of determination (R2). The predictions were tested using stratified cross-validation and were validated against an independent dataset. Our findings revealed that the rf model showed the most accurate results (cross-validation: R2 = 0.69, RMSE = 18.69%, validation against an independent dataset: R2 = 0.62, RMSE = 20.29%). The most informative factors were clearing width, which had the strongest negative effect, suggesting the underlying influence of disturbance legacies, and years post-clearing, which had a positive effect on the vegetation cover dynamic. Our long-term predictions suggest that a timeframe of no less than 20 years is expected for both wide- and narrow-width roads to exhibit ~50% and ~80% vegetation cover, respectively. This study has improved our understanding of fine-scale vegetation dynamics around forest roads, both qualitatively and quantitatively. The information from the predictive model is useful for both the short- and long-term management of the existing network. Furthermore, the study demonstrates that spatially explicit models using LiDAR data are reliable tools for assessing vegetation dynamics around forest roads. It provides avenues for further research and the potential to integrate this quantitative approach with other linear feature studies. An improved knowledge of vegetation dynamic patterns on linear features can help support sustainable forest management.

일제의 부산·경남권 전쟁 시설 설치와 학생강제동원의 국제법적 불법성

This study explores the process of installing war facilities in Colonial Korea by the Japanese military when it designated the southern part of colonial Chosŏn as a rear base for its military actions during the Asia-Pacific War. Additionally, it investigates violations by Japan of international law, specifically ILO (International Labor Organization) principles, in its compulsory mobilization of students in Busan and other areas in Kyŏngnam Province into military service.
 After the United States entered the war., Pusan and Kyŏngnam Province became increasingly important as a strategic base for military operations. Students were forced to build aircraft bases and roads, including forest roads for war facilities, maintain park areas for constructing batteries, convert school playgrounds into agricultural plots to increase food production, and help in the recruitment of soldiers.
 Additionally, the study suggests that student mobilization should be treated as a category of forced mobilization. This becomes clear in two respects. First, the Japanese Government-General of Chosŏn legalized the forced mobilization of students via a National Mobilization Act enacted through two revisions to the Chosŏn Education Ordinance. Second, the Government-General beautified the practice under names like ‘education in labor’ and ‘physical training’, and reorganized students into ‘National Labor Groups’ (1938-1941) and ‘General Student Forces’ (1941-1945) which were collectively mobilized. After 1943, students were mobilized ranging in age from elementary pupils to college students, and after 1944, all classes were abolished and students were instead forced to engage in wartime labor.
 Furthermore, the study reveals that the mobilization of student labor promoted by the Japanese imperial government clearly violated International Labor Organization principles, as seen in the specific cases of Pusan and Kyŏngnam Province. This fact suggests that those students should be classified as victims of Japanese forced labor because they were routinely deployed through a separate organizational system.

Even minor logging road development can decrease the functional diversity of forest bird communities: Evidence from a biodiversity hotspot

Although the effects of major roads and highways on biodiversity have received considerable attention, there is a lack of research considering how smaller and less-used roads might also impact wildlife, especially during the initial re-used development phase of abandoned roads, despite these minor roads being much more extensive and pervasive. Here, we examined how even minor redevelopment of former-abandoned logging roads can impact bird community alpha and beta diversity indices at the taxonomic, functional, and phylogenetic levels in a biodiversity conservation hotspot in central China. The minor redevelopment (i.e., re-paved) of former-abandoned roads generally reduced bird alpha and beta diversity compared to undeveloped abandoned roads, especially at the functional level. Compared with continuous-use roads, minor road redevelopment shows only a slight impact on avian diversity. Notably, compared to old-growth forest reference stands and undeveloped abandoned roads, minor road redevelopments have negative effects on the recovery process of avian diversity. Furthermore, the structure and composition of the high tree layer significantly affected avian functional and phylogenetic diversity, and low shrub layer vegetation mainly influenced taxonomic and phylogenetic diversity. To mitigate the effects of minor forest logging roads on avian biodiversity in priority biodiversity conservation areas, we propose the following: (1) roads that have fallen into disuse should be allowed and encouraged to re-naturalise; (2) roads should only be paved, and cleared back as strictly necessary, allowing grassy or gravel roads to suffice where possible; and (3) if road development is necessary, key umbrella tree species should be planted deliberately to support maximal community diversity and to maintain ecosystem functions and processes.

Особенности проектирования деревянных мостов автомобильных лесовозных дорог

The supply of the national economy with forest resources is directly related to transport accessibility, the condition and development of the road network of forest-rich territories. Construction requirements for year-round and seasonal new forest roads are 2.1 and 9.3 ths km per year, respectively. The situation is complicated by the transfer of transport facilities to new heavier live loads. The previously used design shapes of transport structures are outdated and require new engineering solutions. This is especially relevant for wooden bridge structures, which are of primary importance to forest road builders. The research subject is the wooden bridge girder superstructures with spans of 12–18 m undergoing increased road loads compared to the previous ones. The research aims is the development of modern designs of wooden beam superstructures based on the composite girders made of logs, board-bar-dowel-nail blocks and factory-made laminated blocks. The research includes: superstructures with composite girders of logs combined by combdowel joints, a method for calculating superstructures with composite girders, design of a 15-meter experimental superstructure containing composite log girders in joint operation with roadway reinforced concrete slab; new designs of 15–21-meter superstructures with board-bar-dowel-nail blocks A11 and NK-80 for live loads, design procedure and technology of block manufacturing, examples of designed and built bridges with the 15-meter superstructures; designs of multi-ribbed superstructures made of prefabricated transportable one-piece laminated sections containing laminated beams and a multilayer laminated timber slab. The proposed designes with composite girders of logs (beams) and board-nail blocks can be manufactured on the sites and yards of logging organizations using commonly used equipment, local qualified staff and materials. The cost parameters of permanent bridges built in the Omsk region with the use of these designs are 1.5–2 times lower than those of reinforced concrete analogues. The use of these designs will be effective in the pilot method of forestry development. The use of laminated superstructures is related to the modern phase of forest infrastructure development.

Characteristics and causes of natural and human-induced landslides in a tropical mountainous region: the rift flank west of Lake Kivu (Democratic Republic of the Congo)

Abstract. Tropical mountainous regions are often identified as landslide hotspots with growing population pressure. Anthropogenic factors are assumed to play a role in the occurrence of landslides in these densely populated regions, yet the relative importance of these human-induced factors remains poorly documented. In this work, we aim to explore the impact of forest cover dynamics, roads and mining activities on the characteristics and causes of landslides in the rift flank west of Lake Kivu in the Democratic Republic of the Congo (DR Congo). To do so, we compile a comprehensive multi-temporal inventory of 2730 landslides. The landslides are of different types and are grouped into five categories that are adapted to study the impact of human activities on slope stability: old (pre-1950s) and recent (post-1950s) deep-seated landslides, shallow landslides, landslides associated with mining and landslides associated with road construction. We analyse the landslides according to this classification protocol via frequency–area statistics, frequency ratio distribution and logistic regression susceptibility assessment. We find that natural factors contributing to the cause of recent and old deep-seated landslides were either different or changed over time. Under similar topographic conditions, shallow landslides are more frequent, but of a smaller size, in areas where deforestation has occurred since the 1950s. We attribute this size reduction to the decrease in regolith cohesion due to forest loss, which allows for a smaller minimum critical area for landsliding. In areas that were already deforested in the 1950s, shallow landslides are less frequent, larger and occur on less steep slopes. This suggests a combined role between regolith availability and soil management practices that influence erosion and water infiltration. Mining activities increase the odds of landsliding. Landslides associated with mining and roads are larger than shallow landslides but smaller than the recent deep-seated instabilities, and they are controlled by environmental factors that are not present under natural conditions. Our analysis demonstrates the role of human activities on the occurrence of landslides in the Lake Kivu region. Overall, it highlights the need to consider this context when studying hillslope instability characteristics and distribution patterns in regions under anthropogenic pressure. Our work also highlights the importance of using landslide classification criteria adapted to the context of the Anthropocene.

Factors and thresholds determining sediment delivery pathways between forest road and stream in mountainous watershed

Road erosion is a global environmental issue. The transport of eroded sediment from road to stream can devastatingly impact water quality. Research efforts to combat this issue have prioritized maintaining roads and preventing erosion. Little research has explored the fate of eroded road materials in their transport from road to stream. Therefore, taking the Xiangchagou watershed in the Dabie Mountains of China as a case, this study investigated how local geography determines the formation and thresholds of different delivery pathways (gullied, partially gullied, and diffuse pathways) for road-eroded sediment through runoff, based on the binary logistic regression analysis, random forest model, and the lowest point data fitting methods. It explored how these different pathways have variable impacts on local plant and soil communities. Our results showed that soil D50, bulk density, shrub-grass coverage, and local plant diversity varied significantly (p < 0.05) between different delivery pathways. In particular, soil bulk density and local plant diversity varied significantly (p < 0.05) among different position of these delivery pathways. Specifically, the diffuse pathways are characterized by lower soil bulk density, looser soil structure, and higher species diversity, likely explained by the deposition of sediment-loaded runoff. Gullied pathways, conversely, had significantly more compacted surface soil and lower local plant diversity, likely as a result of scouring by sediment-loaded runoff. Slope gradient of upslope catchment (Us), road segment (Rs), and lower hillslope (Ds) and effective contributing area (Eca), which determine the intensity and kinetic energy of sediment-loaded runoff, are the main external drivers that determine the occurrence of gullied pathways. By contrast, the soil median particle size, surface roughness, and shrub-grass cover of lower hillslope, which contribute to erosion resistance of hillslope, are the primary intrinsic drivers promoting development of pathways from partial to full gully. Furthermore, we found that the critical topographic thresholds for the initiation of the gully pathways and the continued development of gully from partial to complete gully pathways could be expressed as Ds = 0.35Eca−0.13 and Ds = 0.41Eca−0.17, respectively. These results are expected to provide basis for understanding the formation and development mechanism of sediment delivery pathways from road to stream.

Artificial habitat – a chance for survival of a rare montane dragonfly (Odonata): case study on an alpine emerald (Somatochlora alpestris)

The mountain ecosystems of Central Europe are an important natural phenomenon. The character of small isolated islands also predetermines their vulnerability. Typical inhabitant of subalpine and alpine peat bogs, tiny montane habitats, is the endangered dragonfly Alpine Emerald (Somatochlora alpestris) a glacial relict surviving in restricted area of several mountain ranges within Central Europe. Species is threatened mainly by habitat loss and its transformation due to climate change, the expansion of tourist activities and plant succession. In our study from three mountain ranges in the Czech Republic, we bring the first ever evidence of successful development of S. alpestris in artificial habitats. Successful development of the species was recorded in peat pools created by the movement of heavy machinery on now almost abandoned forest roads. Some of the pools have been colonized in great numbers - up to tens of larvae of different instars, exuviae and imagoes have been found. Successful colonisation of the species was mainly due to: (i) proximity to source sites, (ii) suitable environmental parameters of the secondary habitat and (iii) the gradual abandonment of the paths´ use, leading to a reduction in the frequency of disturbance.

Factors Affecting Earthwork Volume in Forest Road Construction on Steep Terrain

Forest roads, as a prerequisite for high-quality forest management, should be optimally distributed in order to avoid negative environmental impacts and to best fulfill their task. In the design phase of forest roads, it is necessary to know which factors influence most the volume of earthworks to enable the designer to best adapt to the terrain requirements. In this paper the impact of an average cross terrain slope and carriageway value of a forest road on cut and fill volume is analyzed. The research was carried out in the area of the management unit Trovrh–Kik, characterized by irregular terrain with slopes ranging between 27 and 58%, and on some micro locations even up to 84%. On eight forest roads, based on standard cross-section profiles, the influence of the average cross terrain slope and carriageway value (difference between ground level and grade level) of the forest road on the cut and fill volume per 1 m of the forest road route was analyzed. The obtained coefficients of determination indicate a strong correlation between the cut volume and carriageway value (R2 = 0.6841), and a moderate correlation between the fill volume and carriageway value (R2 = 0.5619). Unlike the influence of carriageway value on the cut and fill volume, the correlation between the cross terrain slope and fill volume is weak (R2 = 0.2076) or moderate in the case of the cut volume (R2 = 0.3167). On the basis of the analyzed standard cross-section profiles, it was determined that the carriageway value was 0.051 m, where the difference between the cut and fill volume was minimum and the average actual carriageway value was determined to be −0.09 m. It can be concluded that, on terrains with large and varying slopes, there is no unique model or terrain factor that could describe the earthworks required in the construction of a forest road. However, it is beyond doubt that the increase in the carriageway value and cross terrain slope caused the increase in the aforementioned volumes.

Analysis of the quality of primary forest accessibility: the case study

Relative forest accessibility percent of accessible forest area by forest roads in comparison with total forest area is the most important indicator of the quality of primary forest accessibility. The accessible forest area by forest roads is determined by the bounded area around forest roads. Today, in the area with steep and variable slopes of terrain, a double targeted geometrical extraction distance of timber is used for the width of the bounded area around forest roads, and the forest road spacing is used in the area with a mild and uniform slope of the terrain. Both parameters depend on the targeted density of forest roads. Modern information technologies (IT) like geographical information systems (GIS) enable the quality spatial and statistical analysis of different kinds of data whose result is not accessible forest areas by current primary forest traffic infrastructure only, but also an insight into the spatial distribution of insufficient accessible areas into the forest area. The spatial distribution of these areas is significant for spatial distribution of the new routes of forest roads. The research is done in the area of Forest Management Unit (FMU) Prosara, for which the spatial analysis of a digital terrain model (DTM) determined the mostly hilly relief area. The average relative forest accessibility, based on double targeted geometrical extraction distance of timber, is 35% for the actual network of forest roads, and targeted forest road spacing is 60% for the upgraded network of forest roads.

Geology and vegetation control landsliding on forest-managed slopes in scarplands

Abstract. Landslides are important agents of sediment transport, cause hazards and are key agents for the evolution of scarplands. Scarplands are characterized by high-strength layers overlying low-inclined landslide-susceptible layers that precondition and prepare landsliding on geological timescales. These landslides can be reactivated, and their role in past hillslope evolution affected geomorphometry and material properties that set the framework for present-day shallow landslide activity. To manage present-day landslide hazards in scarplands, a combined assessment of deep-seated and shallow landsliding is required to quantify the interaction between geological conditions and vegetation that controls landslide activity. For this purpose, we investigated three hillslopes affected by landsliding in the Franconian scarplands. We used geomorphic mapping to identify landforms indicating landslide activity, electrical resistivity to identify shear plane location and a mechanical stability model to assess the stability of deep-seated landslides. Furthermore, we mapped tree distribution and quantified root area ratio and root tensile strength to assess the influence of vegetation on shallow landsliding. Our results show that deep-seated landslides incorporate rotational and translational movement and suggest that sliding occurs along a geologic boundary between permeable Rhätolias sandstone and impermeable Feuerletten clays. Despite low hillslope angles, landslides could be reactivated when high pore pressures develop along low-permeability layers. In contrast, shallow landsliding is controlled by vegetation. Our results show that rooted area is more important than species-dependent root tensile strength and basal root cohesion is limited to the upper 0.5 m of the surface due to geologically controlled unfavourable soil conditions. Due to low slope inclination, root cohesion can stabilize landslide toes or slopes undercut by forest roads, independent of potential soil cohesion, when tree density is sufficient dense to provide lateral root cohesion. In summary, geology preconditions and prepares deep-seated landslides in scarplands, which sets the framework of vegetation-controlled shallow landslide activity.

Performance of Skidding Operations in Low-Access and Low-Intensity Timber Removals: A Simulation of Productivity and Fuel Consumption in Mature Forests

Forest policies aiming for a greener future and decarbonization require scientific support to help in decision making on resource economy and sustainability of forest operations. Timber skidding is one of the most prevalent options in wood extraction around the world. While its operational and environmental performance is affected by several factors, of which the extraction distance, removal intensity, and machine capabilities are of first importance, there are few studies on the subject in low-access and low-intensity removals. Based on a time study which accounted for production and fuel consumption, this work modeled and quantified productivity and fuel consumption for such operational conditions. Dependence of fuel and time consumption on relevant operational factors was modeled by least square stepwise ordinary regression techniques. Then, the developed models and summary statistics were used to simulate productivity and fuel consumption for a wide range of extraction distances. The main results indicate that, for removal intensities in the range of 7 to 15 m3/ha, productivity of skidding operations in mature broadleaved forests depended heavily on the extraction distance. Taking as a reference an extraction distance of 200 m, productivity halved at 800 m, and decreased to one fourth at 2000 m. For the same conditions, fuel consumption increased linearly, being doubled at 800 m and four times higher at 2000 m. Although the unit fuel consumption increased linearly as a function of extraction distance, its magnitude of increment was much lower. The results of this study indicate that shortening the extraction distances may be the best option in increasing the operational and environmental performance of skidding operations. This may be achieved by developing further the forest road network, which, in addition to the benefits for harvesting operations, could support a more sustainable forest management.

On the Edge of Meshchera. History of Forest Roads. Some Facts about the History of Construction of Railway Lines Krivandino–Ryazanovka and Sazonovo–Pilevo. Part 2

The final part of the article, the first part of which was published in the previous issue of the journal.The article, based on the archived and other never published materials, discusses the history of design and construction of Krivandino–Ryazanovka and Sazonovo–Pilevo railways which belonged to Moscow–Ryazan branch of Moscow railway. The objective of the article was to clarify the circumstances of design, construction and operation of these lines, as well as to identify the reasons that led to their decline and closure in the mid-2000s. To achieve this objective, well-known publications in the press and the Internet were analysed. In addition to using data from these sources, written sources on the issue under study were searched for in archival institutions in Moscow. Some documents are published for the first time.The work carried out resulted in revealing previously unknown or questioned facts: Krivandino–Ryazanovka railway line was built in 1943–1944, Sazonovo–Ryazanovka section was built later than the rest of the line. The purpose of Krivandino–Ryazanovka line according to the project and in the first years of its existence was transportation of firewood for heating of Moscow. The date of commissioning of the entire Sazonovo–Pilevo line for servicing Kurovskaya distance of the railway was January 1, 1978. From the northern neck of Pilevo station, the access railway went to the construction yard of Meshcherskoye peat enterprise. According to information of Kurovskaya distance of the railway, the broad-gauge transshipment station of Meshcherskoye peat enterprise was called Torfyanaya.

The Impact of Road Investments on the Forest Environment—Case Study: The Impact of Asphalt Roads on the Health Condition and Growth of Trees

The study was conducted within the framework of the R&amp;D project entitled “Environmental aspects of reconstruction and construction of forest roads using selected asphalt binders”. The aim of this study was to determine the impact of an asphalt road segment located in the Przymuszewo Forest District, the Regional Directorate of the State Forests in Toruń, Poland (53°57′24.14″ N, 17°34′38.30″ E), on growth increments and health condition of trees in a 60-year-old pine stand. The first stage of the investigation required laboratory analyses and field observations to assess the impact of mineral filler and asphalt mixtures on roadside habitats. Chemical analyses were performed on samples of wood and soil collected from transects located at three distances from the asphalt road, as well as dendrological and dendrometric analyses in circular sample plots of 0.02 ha in analogous transects parallel to the selected asphalt pavement. Analyses of soils and wood showed no negative environmental impact associated with the road. Contents of all the assayed elements in wood were lower compared to their contents in soil, which indicates their markedly reduced phytoextraction. Statistical analyses showed that the asphalt road has an effect on the adjacent forest mass, but that this effect is statistically insignificant with respect to the mean annual increments diameter at breast height and the defoliation of trees growing at various distances from the road.

The effect of the forest road network on grassland ecosystems with the contribution of the SWOT-AHP method

Forest road edges are habitats for many grassland species because these species grow in open environments with sufficient light. The study area was the Regional Unit of Kavala (Eastern Macedonia and Thrace, Greece). The Strengths, Weaknesses, Opportunities, and Threats (SWOT) were recorded according to the literature review and the criteria were also ranked using the AHP (Analytic Hierarchy Process) method. According to the comparison of the SWOT criteria, Strengths occupy a percentage of 43.6%, followed by Weaknesses and Threats with a percentage of 24.5% and 17.3% respectively. Opportunities have the smallest percentage (14.6%). Regarding the sub-criteria of Strengths, the sub-criteria “The edges of forest roads protect high plant diversity, and a significant degree of endemism” ranks first with a percentage of 32.4%. From the comparison of the sub-criteria of Weaknesses, the sub-criteria “Forest roads create gaps by removing vegetation and divide the ecosystem” occupies the first place with a percentage of 37.9%. After comparing the sub-criteria of Opportunities, the sub-criterion “Through the forest road network there is access to new areas (grassland ecosystems)” receives the largest percentage (46.6%). The biggest Threat is the sub-criterion “The road network probably contributes to global macroclimate change” with a percentage of 52.4%.

The distribution of the tree of heaven (Ailanthus altissima (Mill.) Swingle) in the settlements and forests of Southern Börzsöny, Hungary

: In this study, we investigated the occurrence of the invasive alien tree of heaven (Ailanthus altissima) in the approximately 2,100-hectare area of Southern Börzsöny, along the road network in settlements Zebegény and Nagymaros and in forests. Th e survey was carried out according to the abundance and location of the species (for all occurrences), the maintained or neglected status of the area (for settlements), and the open or closed nature of the stand (for forests). Individuals or more coherent stands of the tree of heaven were recorded using handheld GPS. A new point was taken when the distance between two individuals or stands exceeded 10 m. We recorded 482 occurrences of tree of heaven in the two settlements and found that it occurs most frequently in neglected public green areas (38%) and neglected gardens (21%), and oft en shows up along railway lines (18%). In forested areas between the two settlements, we recorded 193 occurrences and found that the tree occurs mainly along regularly used forest roads (42%), and most frequently in open stands (especially in artifi cial gaps) (69%). Our study also points out that the Hungarian National Forest Inventory data indicate signifi cantly fewer occurrences (covering 23 subcompartments) than our forest mapping survey or earlier ones by other researchers (56 and 60 subcompartments, respectively). Based on our results, anthropogenic impacts are crucial for the spread of the species. Th e tree is expected to spread exponentially in the future, so in order to prevent this, we recommend that treatments are carried out as soon as possible, with the immediate eradication of seed-producing individuals. Th e issue of social perception and knowledge is also crucial, as the majority of the society generally has little knowledge of both the tree of heaven and the dangers posed by invasive plant species. Targeted education of the public can therefore be an important element of prevention.

Uzdužna i poprečna eksploataciona stabilnost traktora sa aspekta bezbednosti pri agrotehničkim operacijama

Abstract: In the Republic of Serbia, despite a certain decrease in the number of accidents with tractors in the period 2010-2020., the number of injured and killed people is still high. In previous analyzes of the causes of accidents with tractors, the reports were formally reduced to the following: the operator was under the influence of alcohol; unsafe and unsuitable driving on terrains with ups and downs as well as rural and forest roads; malfunctions of controls for: braking, steering, transmission (switching on and off to save fuel), malfunction of tires, etc.; malfunctions and lack of light signaling; failure to establish the necessary ballast in relation to the required stability of the tractor, especially when moving uphill and down slopes; exploitation of a tractor without a cab or a safety frame; weak distraction, non-observance of traffic regulations, tractor driving by minors etc. In this paper, stability was considered when the tractor was moving up a slope, as well as when moving on a side slope through the balance of forces and factors that affect stability, i.e. the angle of inclination at which the tractor could potentially overturn. Those data obtained by analyzing the forces acting on the tractor are very important from the aspect of safety during exploitation in agrotechnical and transport-specific conditions.

Measuring and Modeling Impacts of Gravel Road Design on Sediment Generation in the Southeastern U.S.

Highlights The erodibility of heavily trafficked gravel roads can be much greater than that of low volume forest roads. Improved designs of heavily trafficked gravel roads can decrease sediment generation by more than 90 percent. The WEPP Model can be successfully parameterized for high traffic gravel roads to reflect the effects of weather, road design, and topography. Abstract. The purposes of this study were to support a watershed modeling analysis by evaluating the ability to the Water Erosion Prediction Project (WEPP) model to estimate sediment generated by high traffic gravel roads, and to determine the erodibility of two designs of high-traffic gravel roads. In many watersheds, the road network can be a major source of sediment. The ability to predict erosion from roads, evaluate the effects of design and management on road sedimentation, and compare sediment from roads to other sources of sediment in the watershed is an ongoing need by watershed managers. The Water Erosion Prediction Project (WEPP) model is a widely used model for predicting sediment from forest roads. There has, however, been little information published on erosion from high traffic gravel roads and WEPP applications to such roads. To evaluate road erosion predictions, a study was conducted incorporating two road designs at Fort Benning, Georgia, U.S. One design followed a common practice of starting with a native material road and adding gravel and grading as required. Erosion and rutting on the road surface were common occurrences on this type of road. The improved design was a “graded aggregate base” design, built with compacted aggregate layers. To evaluate erosion risks for these two road designs, runoff and sediment delivery were measured from ten plots ranging in size from 63 to 150 m2. Runoff depths up to 50 mm occurred from daily rainfall amounts up to nearly 60 mm, with least square mean event runoff values of 6.5 mm from unimproved plots and 14.9 mm from improved road plots. Delivered sediment ranged from zero to 18 Mg ha-1 from individual storms with least square mean amounts of 2.27 Mg ha-1 of sediment delivered from unimproved road plots compared to only 0.026 Mg ha-1 delivered from improved road design plots for a given runoff event. Hydraulic conductivity was found by calibration to be 3.0 mm h-1 for unimproved roads and 1.3 mm h-1 for improved road segments. Rill erodibility was 0.09 s m-1 for unimproved roads and 0.0008 s m-1 for improved roads, values that were greater than had been measured on road erosion studies elsewhere that were typically less than 0.0004 s m-1. The critical shear for the unimproved roads was the minimum that the WEPP model would accept, 0.0001 Pa, but was a more typical value of 1.5 Pa for the improved road segments. When applying the calibrated erodibility values to a validation data set, the Willmott indices of agreement were 0.62 and 0.82 for runoff for unimproved and improved roads, respectively, and 0.67 and 0.66 for sediment delivery from unimproved and improved roads, respectively, indicating good agreement between observed and WEPP-estimated runoff and erosion rates. A sensitivity analysis and calibration analysis found that the WEPP model was not sensitive to interrill erosion for this application. A sensitivity analysis coupled with a WEPP validation analysis showed that WEPP could incorporate weather, topography, soil, and road design features to predict sediment delivery from highly erodible road segments. The study suggests that there is a need for a simulated runoff study to determine high values of rill erodibility more precisely on unimproved high traffic roads, and that there is a need to incorporate more erodible road erodibility values into the online WEPP:Road interface for the WEPP model. The road erosion rates and effectiveness of improved road designs for reducing off-road sediment reported in this study will be useful to managers seeking to quantify and reduce road erosion rates from high-traffic gravel roads in sensitive watersheds. Keywords: Erodibility, Gravel Roads, Soil Erosion, WEPP.

Белая и тундряная куропатки в заповеднике «Басеги» . Виды на южной границе ареала

The article analyzes the long-term (1984-2023) dynamics of registrations of white and tundra partridges on the territory of the Basegi Reserve (Middle Urals, Perm Krai). The author systematizes the available materials on the frequency and content of encounters of these species in Basegas, summarizes his own long-term field observations on the specifics of the territorial distribution of white and tundra partridges in the areas of their joint habitat, draws conclusions about the existing trends in the development of these species of grouse birds of the extreme southern boundaries of their range on the western macroscline of the Ural Mountains. Rare, but fairly regular meetings of white partridges observed over the past 40 years on all three massifs of the Basegi ridge (the Northern, Middle and Southern Baseg mountains), as well as on the upper marshes and forest roads in the adjacent taiga zone, allow us to determine the status of this species in the reserve as rare, small, periodically nesting birds. Reliable facts of registration of tundra partridge on the Northern Baseg Mountain noted in May and September 2023 make it possible to include this species in the list of inhabitants of the protected area. However, the status of this bird's stay in Basegi is unclear and requires clarification.