Forest Roads Research Articles

The infrastructure contribution to the regional development and the environmental protection: Typologies of regional units based on forest operations engineering

The purpose of this article is to investigate the contribution of mountainous infrastructure and in particular forest operations engineering in its development, environmental protection, adaptation to climate change and policy making, in order to achieve more rational use of natural and financial resources.The research focuses on forest operations engineering funded by the Rural Development Program of Greece and were executed or will be executed by the Forest Services and Municipalities of the country during the Programming Periods 2007-2013 and 2014-2020 respectively. Data related to reforestation, fire protection, mountain waterworks and forest road projects constructed in the forest area are being analysed, followed by a description of their role in protecting the adjacent areas from fires, floods and in general effects of climate change, or contribute to regional and local development through assisting accessibility, upgrading the landscape aesthetically, creating jobs, etc. Finally, comparisons are made between the regional units and the clusters - clusters of regional units between the two program periods.The identification of clusters of regional units will contribute to the creation of a clearer understanding of the problems of the mountainous area and to the evaluation of the possibilities for a more rational development, creating the conditions for the choice of alternatives, depending on the general economic or social objectives.The data are taken from the Rural Development Program and relate to the funding that has been given or projected to be given for the execution of forest technical projects over two programming periods (2007-2013 and 2014-2020) at the level of regional unit. The data are processed by methods of descriptive statistics and multivariate analysis and in particular the cluster analysis of the executed and to be executed forest technical projects (especially projects related to reforestation, fire protection, mountain waterworks and forest road projects). This typology is particularly relevant, in the context of the effort for more rational mobilization and planned utilization of financial resources, based on the comparative advantages of each cluster-cluster of regional units.

Zoning and Field Study of Landslid es along Forest Roads of Darabkola-Sari

Zoning and Field Study of Landslid es along Forest Roads of Darabkola-Sari

Testing different isolation distances in woodpecker territory mapping in Central Hungary

Abstract Woodpeckers as cavity excavators are crucial in forest ecosystems, therefore, it is important to study their ecological needs, specifically at the territory scale, using mapping methodologies, of which there are uncertainties considering detection probabilities and the distances of the territory centres in different species and habitats. We studied the effects of the number of visits and isolation distance on detected woodpecker territories in the 1,000 ha forest mosaic of the Peszér forest in Central Hungary. We made territory mapping in 2020 along existing trails and forest roads on the present woodpecker species as Black, Eurasian Green, Great Spotted, Middle Spotted, Lesser Spotted Woodpecker and Eurasian Wryneck. We found a very low detection probability for single territories during one visit, while with the increasing number of visits it is more unlikely to overlook territories. Considering the isolation distances, by lowering the distance, more territories can be registered, which suggests that researchers should take great care choosing the proper distance for a given species whilst avoiding the over- or underestimation of territories. This paper has an actuality as BirdLife Hungary announced the Eurasian Green Woodpecker as the Bird of the Year in 2022, for drawing attention to this species’ habitat preferences and conservation.

Fluxes, patterns and sources of phosphorus deposition in an urban–rural transition region in Southwest China

Abstract. Understanding the patterns of atmospheric phosphorus (P) deposition is essential for assessing the global P biogeochemical cycle. Atmospheric P is an essential source of P in agricultural activities as well as eutrophication in waters; however, the information on P deposition is paid relatively less attention, especially in the anthropogenic influencing region. Therefore, this study chose a typical urban–rural transition as a representative case to monitor the dry and wet P depositions for 2 years. The results showed that the fluxes of atmospheric total P deposition ranged from 0.50 to 1.06 kg P hm−2 yr−1, and the primary form was atmospheric dry P deposition (76.1 %, 0.76–0.84 kg P hm−2 yr−1). Moreover, it was found that the monthly variations of P deposition were strongly correlated with meteorological factors, including precipitation, temperature and relative humidity. However, the fluxes of dry P deposition and total P deposition were more affected by land use, which increased with the agro-facility, town and paddy field areas but decreased with the forest and country road areas. These findings suggested that dry P deposition was the primary form of total P deposition, and P deposition could be affected both by meteorological factors and land-use types. Thus, proper management of land use may help mitigate the pollution caused by P deposition.

Factors contributing to rill erosion of forest roads in a mountainous watershed

Forest roads are a major source of and transport pathway for eroded sediments in mountainous watersheds. When rills develop on these roads' surfaces, they amplify sediment erosion. Best management practices can decrease sediment erosion, but in order to efficiently implement these practices it is necessary to determine which factors have the most influence on rill development on forest roads. Despite this need, there is scarce literature on rill development on forest roads. To fill this gap in knowledge, based on field survey and multivariate statistical methods including redundancy analysis (RDA) and variation partitioning analysis (VPA), we investigated unpaved forest roads in the Xiangchagou watershed in China and quantified the extent to which various factors influenced rill formation. Specifically, we studied how rill erosion intensity (REI) and rill morphological characteristics (like rill length, mean width and depth, density, and severity of fragmentation) varied along the slope of a forest road. We also introduced the concept of a road's hydrological constituents (its upslope catchment, surface, and cutslopes), and determined how much each constituent contributed to REI. We found that REI and morphological characteristics decreased moving from the upper portion of road segment downward, implying that rills developed more intensely uphill. Additionally, REI increased exponentially with rill width, density, and severity of fragmentation, and increase linearly with length and depth. Conversely, REI decreased exponentially with rill width-depth ratio. These relationships suggest that the morphological characteristics of rills could be used to predict the REI of a given road segment. Finally, we found that the road characteristics that best predicted rill formation included catchment area, cutslope area, and gravel bareness. Correspondingly, the upslope catchment, cutslopes, and road surface contributed 11.56%, 30.83%, and 8.23% of the variation in REI and morphological characteristics. The interaction between upslope catchment and road surface explained 19.89% of the variation. These results suggest that when best management practices are implemented to decrease erosion caused by forest roads in mountainous watersheds, they should integrate these hydrological constituents of a road.

Forest roads damage detection based on deep learning algorithms

ABSTRACT Currently, forest road monitoring reached a critical stage and need requires low-cost or cost-effective monitoring. Today, smartphones have been used on public roads to identify road deterioration due to benefits such as usability, cost, ease of access, and expected accuracy. The use of smartphones in forest road development by the proposed system is a distributed information system that converts data from enterprise mode to field mode by harvesting and assessing forest road conditions and image processing technologies. The technology proposed in this research allows different information YOLOv4-v5 with improvements to this version including mosaic data augmentation and automatic learning of enclosing frames. In this research, we applied a new hybrid YOLOv4-v5 to the dataset’s general applicability. We assessed the forest road dataset to run an experiment, smartphone images by various aspects of the smartphone images (SI) dataset which is specialized for detecting forest road deterioration. To enhance YOLO’s ability to detect damaged scenes by proposing a new technique that takes information into frames. We expanded the scope of the model by applying it to a new orientation estimation task. The main disadvantage is the provision of qualitative model information on forest road activity and the indication of potential deterioration.

Bearing Capacity of Forest Roads on Poor-Bearing Road Subgrades following Six Years of Use

The research was conducted on a forest road on the territory of the State Forests in Poland, in the Brzeziny Forest District, where eight test sections with a total length of 422 m were created with different pavement system on a low-bearing soil substrate (clay, silt loam) as part of the road reconstruction in 2016. The bearing capacity of the pavement was evaluated based on the static strain modulus ME MN·m−2 by measuring with a statistic plate (VSS), the dynamic deformation modulus Evd MN·m−2 obtained from lightweight deflectometer measurements, and the elastic deflection of the pavement Us mm evaluated from Benkelaman beam measurements. It has been shown that pavements made of crushed aggregate and common gravel on timber roller substructure maintain good bearing capacity parameters, where the average values of secondary modulus of strain are above 130 MN·m−2, and in the case of pine rollers, this modulus has increased. Pavements on low-bearing soils reinforced with willow brushwood mattresses have low bearing capacity parameters, with averages of 26.09 ≤ MEII ≤ 53.93 and 22.1 ≤ Evd ≤ 39.1 MN·m−2, but the technical condition of the pavement makes it possible to continue carrying out forestry-related transportation. The research confirms the possibility of reinforcing soils with poor bearing capacity with wooden rollers, and in the case of willow mats for roads with light truck movements.

Evaluating the Forest Road Systems Subjected to Different Loadings by Using the Finite Element Method

In the actual context, in which there is a trend of increasing the weight of the vehicles used to transport materials, checking the deformations of road systems as a response to dynamic and static loadings is necessary to better manage the road infrastructure. The goal of the study was to evaluate how the number and the thickness of layers, and the material types could influence the behavior of the road systems subjected to different loads, and to find out which of the road systems have the smallest deformations. The Romania forest roads are classified into three categories, and the most important are the principal forest roads. There were chosen road systems proper to this category. Consequently, nine types of road systems were considered, based on the materials used and the thickness of the layers, and the deformations were evaluated by considering loads of 25, 35 and 45 tons. For modeling the behavior of road systems under different loads, the Finite Element Method (FEM) was used taking into consideration the static domain. The models show that, in all the cases, the deformations depend on the number of layers, while the thickness of the ballast layer can reduce the deformations because of the rigidness of the structure. Those findings are very important because not all the modeled roads systems could provide suitable bearing capacity. Hence, an inappropriate thickness of the layers could negatively influence the behavior of road systems under the traffic with weight increased.

Prediction of Primary Deformation Modulus Based on Bearing Capacity: A Case on Forest Road with a Light Falling Weight Deflectometer Zorn ZFG 3000 GPS

Bearing capacity and compaction are among the most important and frequently used geotechnical parameters in road construction. The aim of this study was to determine the possibility of predicting the value of the primary deformation modulus E1 (obtained from measurements using a static plate load test—PLT) based on measurements with a Zorn light falling weight deflectometer (LFWD), type ZFG 3000 GPS, with a drop weight of 10 kg. A regression analysis was performed on 245 bearing capacity measurements that were taken on 46 forest road sections with various road surfaces. Different regression models were tested, from linear to logarithmic, polynomial, exponential and power models, but excluding polynomials of fourth and higher degree. The results showed that the prediction of E1 values (PLT) from the dynamic deformation modulus values Evd (LFWD) was possible. However, the reported unsatisfactory strength of the relationship between the two parameters was associated with a high risk of error (r = 0.64, R2 = 0.41, Se = 49.78). Neither the use of more complex non-linear regression models, nor the use of multiple regression by introducing an additional estimator in the form of the s/v ratio, significantly improved estimation results. The quality of the prediction of the E1 value was not constant. It varied, depending on the type of forest road, the use of geosynthetic reinforcement and the type of road subgrade. During the study, it was also found that the quality of the prediction of the E1 value could be improved by limiting the range of Evd values tested from above. It is advisable to continue this type of research, as the obtained results could form the basis for future development of national standards for the use of LFWDs to control the bearing capacity and compaction of forest road pavements.

Evaluation of Automatic Prediction of Small Horizontal Curve Attributes of Mountain Roads in GIS Environments

Road curve attributes can be determined by using Geographic Information System (GIS) to be used in road vehicle traffic safety and planning studies. This study involves analyzing the GIS-based estimation accuracy in the length, radius and the number of small horizontal road curves on a two-lane rural road and a forest road. The prediction success of horizontal curve attributes was investigated using digitized raw and generalized/simplified road segments. Two different roads were examined, involving 20 test groups and two control groups, using 22 datasets obtained from digitized and surveyed roads based on satellite imagery, GIS estimates, and field measurements. Confusion matrix tables were also used to evaluate the prediction accuracy of horizontal curve geometry. F-score, Mathews Correlation Coefficient, Bookmaker Informedness and Balanced Accuracy were used to investigate the performance of test groups. The Kruskal–Wallis test was used to analyze the statistical relationships between the data. Compared to the Bezier generalization algorithm, the Douglas–Peucker algorithm showed the most accurate horizontal curve predictions at generalization tolerances of 0.8 m and 1 m. The results show that the generalization tolerance level contributes to the prediction accuracy of the number, curve radius, and length of the horizontal curves, which vary with the tolerance value. Thus, this study underlined the importance of calculating generalizations and tolerances following a manual road digitization.

Open forest successional stages and landscape heterogeneity promote wild bee diversity in temperate forests

AbstractRecent studies have emphasized forests as crucial habitat for wild bees. In Europe, most forests are managed following the principles of close‐to‐nature silviculture, which combine timber production and nature conservation. However, open late and early successional stages within these forests are largely missing, which could be important for wild bees. This highlights that close‐to‐nature silviculture alone might not be sufficient to conserve bees within temperate forests. Open structures such as canopy gaps and road verges in forests could improve habitat for bees. To provide management recommendations for wild bee conservation in temperate forests, we analyzed how components of bee beta diversity varied between forest management types and tested how open structures, namely clear‐cuts, canopy gaps, and forest road verges influenced bee abundance, richness, and diversity. In addition, we analyzed the abundance and percent of red‐listed bee species at different scales. Bees were sampled using 90 pan traps on 45 (1 ha) plots in 2019 and 2020 in the Black Forest, Germany. Plots were selected in 15 triplets each consisting of three management types related to different successional stages: unmanaged, close‐to‐nature, and small clear‐cut. Beta diversity was not consistently nested highlighting the importance of different management and successional stages within the landscape to support bees in forests. Abundance, species richness, and Shannon diversity of bees were highest on clear‐cuts, compared to unmanaged‐ and close‐to‐nature plots. At landscape scale, wild bee abundance increased with canopy openness while wild bee diversity increased with landscape heterogeneity. Abundance‐ and percent of red‐listed bee species increased with the length of forest road verges. We advocate creating habitats at local scales which offer flowering and nesting resources by providing canopy gaps. At landscape scale, heterogeneity created through different forest successional stages is needed to conserve the entire community of wild bees.

Road Network Planning in Tropical Forests Using GIS

This study intended to develop a road network planning for timber harvesting in tropical forests in Peru using georeferenced and field data and Geographic Information System (GIS). The Digital Elevation Model (DEM) Alos Palsar 12.5 m was used. The DEM was processed to generate the hydrography and terrain slope maps. A weighted raster was created using overlapping weights of the slope raster and the hydrography map. We created a least cost path raster by using the weighted raster origin and destination points. We used a Triangular Irregular Network (TIN) to validate the Least Cost Path. In addition, histograms of the trajectory of each path with altitude and slope values ​​ were generated. We observed that the forest road planning using GIS provided better definition (economically and environmentally) of road networks in our forest site than those traditionally defined using conventional mapping techniques.

Changes within the roadbed and the cutslope of an abandoned forest road—A case‐study from the Tatra Mts. (Poland)

AbstractThe main aim of this paper was to determine the rate of erosion and aggradation within a forest road on different geological structures as well as a comparison of changes between roadbeds and road cutslopes. The research was conducted in the Lejowa Valley in the Tatra Mountains. The measurements of the forest road were performed using a Leica ScanStation C10 terrestrial laser scanner (TLS) with a set of six‐inch Leica High Definition Survey (HDS) targets. Based on the multi‐temporal digital elevation models (DEMs) two DEM of Differences (DoD) were created for the summer season of 2019 and the 2019–2020 period. The research has shown that there is a significant difference between the rate of relief change for roads constructed atop conglomerates and limestone. The net change for the road within conglomerates was an erosion of 432.37 m3ha‐1 yr‐1, while for the road within limestone it was a sediment deposition which amounted to 3.87 m3ha‐1 yr‐1. Research has shown that there exists a difference in the rate of erosion for road cutslopes and roadbeds constructed within conglomerates. It was shown that the erosion rate for the roadbeds was 1.7‐times larger than that for the studied road cutslopes in the period 2019–2020. Improperly designed and constructed forest roads may be subject to intensive relief transformations, even after they are no longer in use.

Assessment of forest road network alternatives in forest harvesting activity

One of timber harvesting purposes is moving wood from the forest to sawmills. Road network planning requires consideration for alternatives. This paper purposed to determine decision-making in the selection of alternative road networks with utility analysis by considering economic, ecological, and social criteria. The indicator used were the length of the road, open area, cost of road construction, felling, skidding, and empowerment of forest communities. The analysis showed that the first alternative was the best forest road network of the three alternatives designed. The results are used in the decision-making plan for implementation in the next rotation.

Effects of Structural and Diversity Attributes on Biomass in Different Types of Urban Forests in Changchun, Northeast China, and Suggestions for Urban Forest Planning

Understanding of the relationship between structural and diversity attributes and biomass is important for plant biodiversity conservation, ecosystem service function enhancement and sustainable development of urban forest ecosystems. In this study, road forest (RF), attached forest (AF) and landscape and relaxation forest (LF) were selected as research objects. We systematically evaluated the diversity attributes and above ground biomass (AGB) at two dimensions of different diameter at breast height (DBH) grades and different tree height grades of urban forests in Changchun, Northeast China. Structural equation modeling (SEM) analyses of the correlation between structure attributes, diversity attributes and biomass among different types of urban forests were carried out. The results showed that species richness (SR) and Shannon–Wiener index (H′) of shrubs were lower than those of trees. Under the DBH grades, H′ in each forest type was highest in the 0–10 m grades and SR was highest in the 10–20 m grades. Under tree height grades, both H′ and SR of each type were at the top of the list. AGB was highest in each forest type under 5–10 m height grades. The relationship between AGB and H′ was better in LF, but with no significant relationships in the other forest types. SEM highlighted that in the overall aspect, the effect of forest type on biomass was mediated by structure and diversity attributes. Particularly in LF, there were direct and indirect effects between structure attributes and biomass mediated by diversity attributes. The improvement of the H′, evenness index (J′) and SR could enhance urban forest services, especially for the biomass and diversity of LF.

Forest Road Wearing Course Damage Assessment Possibilities with Different Types of Laser Scanning Methods including New iPhone LiDAR Scanning Apps

Forests make up 34.1% of the Czech Republic total area and forest roads account for nearly the same length (47,465 km) as all other roads administered by the state and its regions (55,738 km). Forest roads are not as intensively used as other roads. On the other hand, as logging trucks carry the maximum permitted load on roads and forests create a specific microclimate, forest roads are subject to rapid wear. A road wearing course is generally designed for 20 years of service and for a maximum damage level of 25% before they are supposed to be reconstructed. To ensure this life cycle is adhered to, more efficient, faster, and more flexible surface damage detection adaptable for forest environment is needed. As smartphones and their optical devices, i.e., new iPhones with LiDAR sensors, become more advanced, the option arises to perform laser scanning on road surfaces using smartphones applications. This work aimed to test this technology and its precision applicability to assessing damage to a forest wearing course and compare it with another hand-held personal laser scanner (PLShh), represented in this study by GeoSLAM ZEB Horizon scanner, and more precise terrestrial laser scanning (TLS) technology, represented in this study by Faro Focus 3D laser scanner, which have started to replace tacheometric wearing course damage surveying thanks to their greater precision. So, this study involved a comparison of three alternative laser scanning methods focused especially on these, which are implemented in new iPhones for tacheometric surveying. First, a Faro Focus 3D laser scanner was used for the TLS method. Second, the PLShh method was tested on a GeoSLAM ZEB Horizon scanner. Third, another PLShh method using an iPhone 13 Pro with applications 3D Scanner and Polycam was evaluated. If we are comparing positional height accuracy of PLShh to tacheometric surveying on reference cross position height coordinates, ZEB Horizon achieved devXY and devZ RMSE 0.108 m; 0.025 m; iPhone 13 Pro with 3D Scanner app devXY and devZ RMSE 0.185 m; 0.021 m, and with Polycam app devXY and devZ RMSE 0.31 m; 0.045. TLS achieved the best results with devXY RMSE 0.049 and devZ RMSE 0.0077. The results confirm that only the TLS scanner achieves precision values in height differences applicable for an assessment of forest road wearing course damage measurement comparable with tacheometric surveying. Surprisingly, comparing the PLShh scanners to the TLS technology, they achieved interesting results, comparing their transverse profiles and 3D objects as digital surface models (DSM) of the road to TLS in height position. In transverse profiles, ZEB Horizon achieved devZ RMSE 0.032 m; iPhone 13 Pro with 3D Scanner app devZ RMSE 0.017 m, and with Polycam app devZ RMSE 0.041 m compared to the TLS method measured using a Faro Focus 3D static laser scanner. Comparing forest road DSM to Faro Focus 3D, ZEB Horizon achieved devZ RMSE 0.028 m; iPhone 13 Pro with 3D Scanner app devZ RMSE 0.018 m and with Polycam devZ RMSE 0.041 m. These results in height differences show that the height accuracy of PLShh achieves precision, which is applicable to determining the current shape of forest road wearing course compared to the required roof shape gradient. However, further testing provided the insight that such a kind of PLShh measurement is still only possible to use for the identification of a transverse profile shape, as in length measurement the length error increases. All PLShh are able to capture the current shape of forest road cross profile, but still they cannot be used for any design or calculation of material measurement needed for wearing course repair.

Analysis of Exhaust Emissions from Heavy-Duty Vehicles on Different Applications

Emissions from the road transport sector are a major contributor to the climate change. Commonly used heavy vehicles powered by diesel engines emit toxic and harmful compounds that adversely affect the environment. For this reason, increasingly newer Euro emission standards are being introduced. Therefore, the emission performance of heavy-duty vehicles used in the transportation processes of diverse loads was investigated. The first research object was a set of vehicles equipped with a crane used for loading and unloading timber. The measurements were carried out in a specially designed research test reflecting the way the vehicle is used. It consisted of the drive to the loading site, the transport of timber to the destination and the processes of loading and unloading timber. The test route included driving on both unpaved forest roads and asphalt roads. The second research object was a set of vehicles used in long-distance road transport. The research route characterizing the traffic of vehicles from the cited group was selected here. There were three stages of the route–urban, extra-urban and highway. The whole trip was carried out with a load of 24,800 kg. The testing equipment consisted of SEMTECH DS and AVL Micro Soot Sensor devices belonging to the PEMS (Portable Emission Measurement System) group. Based on the obtained results, the influence of the operating conditions on the exhaust emissions and fuel consumption was determined.

Assessment of slope failure susceptibility along road networks in a forested region, northern Iran

The risk of slope failure is always associated with the roads constructed in mountain regions. Estimation of the susceptibility of roads to slope failure is a part of the solutions for decreasing road maintenance costs. In this study, we modeled the susceptibility of slope failure along a forest road in northern Iran using the random forest (RF) method. The distribution of past failures was surveyed during field reconnaissance to produce an inventory map. Then the failures were randomly divided into two groups such that 70% (176 locations) were used for model training and the remaining 30% (75 locations) were used for model validation. Eleven geoenvironmental factors (i.e., altitude, slope degree, slope direction, plan curvature, flow accumulation, stream power index, topographic wetness index, topographic position index, topographic roughness index, slope-length, and valley depth) that thought directly or indirectly affected slope failure were selected and linked to the failure locations. The spatial associations between the influencing factors and the failure locations were assessed using the RF method and used for generating spatially explicit maps of slope failure susceptibility. The results showed that stream power index, flow accumulation, and plan curvature with Gini coefficients of 74%, 66%, and 51%, respectively, were the most influential factors in the occurrence and distribution of slope failures. The slope failure susceptibility maps were classified using the natural breaks and geometrical intervals classification methods and showed that nearly 38.11% and 42.42% of the study area are in high to very high risk classes, respectively. Model validation using the sensitivity (92.31%), specificity (85.68%), accuracy (88.54%), root mean square error (RMSE) (0.303), and area under the curve (0.902) proved the excellent performance of the RF model in elucidating the failure mechanisms and predicting future failures. The slope failure susceptibility maps produced in this study allow the development of mitigation strategies for road construction projects.

GIS Based Planning of Forest Road Alignment in Periyar Tiger Reserve, Kerala, India

In hilly places, constructing and building forest roads requires a variety of economic and environmental criteria. To develop a solution that minimize construction, maintenance, and adverse environmental effects, road management must take into account as many alternative alignment options as they can. The idea of this research was to plan the network of forest roads in the Periyar Tiger Reserve's mountainous region using Geographic Information Systems (GIS) based on Multi-Criteria Decision Analysis (MCDA). These techniques were applied using the study area's slope, aspect, Elevation, NDVI, drainage and susceptibility to landslides datasets. In addition, the road network created using the GIS-MCDA approach was contrasted with the existing road networks. The key elements that affect the road network in the research area were found, and the necessary maps were produced and categorized. The maps were graded using MCDA to determine the weight of both useful aspects as the next step in determining the significance and role of the aforementioned elements in the cost of road building. Second, using the Arc GIS 10.4 weighted overlay analysis tool, a forest potential map for road building was created by overlaying the weighted maps of the influencing elements. Thirdly, the competence of a map was divided into Six categories: very high, high, moderate, low, very low and Restricted roading Suitability. Finally, using a weighted overlay method to combine the road network and road planning potential map, the existing road network was analyzed. The findings of this study indicated that the majority of existing roads were located in high and moderate road Suitability. A small percentage was located in low road Suitability, which can be taken into account for alignment. These results suggested that the design of forest road planning in hilly areas can be more precisely accomplished using the multi-criteria evaluation method. Similar method as used in this study can be applied to other forested sites.

Optimal Forest Road Density as Decision-Making Factor in Wood Extraction

Forest road construction projects mainly depend on factors related to terrain physiography, watershed, and wood harvesting. In the whole tree system, wood extraction is the activity most impacted by the density of forest roads, influencing the extraction distance. One of the alternatives is the optimal forest road density approach, which allows for the minimization of wood extraction costs and the optimization of the productive area. Given the above, the objective of this study was to analyze whether the optimal forest road density in areas of forests planted with eucalyptus allows for maximum productivity and the lowest cost of the road-wood extraction binomial in a whole tree system. The technical and economic analysis of wood extraction was based on the study of time, operational efficiency, productivity, and the cost of wood extraction with a grapple skidder. For the optimal forest road density, the cost of the wood extraction activity was considered, as well as the cost of construction, reconstruction, and maintenance of roads. In addition, the cost of a loss of productive area and the cost of excess forest roads were weighted. The optimal forest road density was 30.49 m ha−1 for an average extraction distance of 81.99 m, with the cost of loss of productive area of 0.49 USD m³ and the excess road of 80.19 m, which represented a cost of 978.31 USD ha−1. It is concluded that the optimal forest road density allows for the identification of excess forest roads, allowing for a reduction in the total cost for the implementation of roads. Therefore, it can be considered an essential variable in the planning of the forest road network, providing improvements in productivity and the costs of wood extraction with a grapple skidder.