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Research highlights: We used Dijkstra Algorithm (DA) to define optimal allocation of yards in order to minimize total skid-trail’s distance in the Amazon Forest. DA minimized trails’ distances and associated transportation costs, leading to an even smaller value when the current planning was disregarded and suggesting the reduction of deleterious e...
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Context 1
... connected with actual distances, considering the slope terrain information and eight possible walking routes from the center of each cell, were created with the 10 m DEM in model builder, a visual programing environment available on ArcGIS ® software. The processing is shown in Figure 6. ...
Context 2
... connected with actual distances, considering the slope terrain information and eight possible walking routes from the center of each cell, were created with the 10 m DEM in model builder, a visual programing environment available on ArcGIS ® software. The processing is shown in Figure 6. ...
Citations
... The trails are therefore designed to pass between the trees, approaching them at the maximum cable or grapple length. The design of secondary trails layout uses a Dijkstra algorithm with directed spatial weights (Sales et al., 2019) in order to minimise their length, according to RIL principles, while respecting longitudinal and transverse slope thresholds for reasons of human and mechanical safety. The allocation of a width to the trails allows to account for the mortality of all the trees situated on the trails. ...
Even where Reduced-Impact Logging (RIL) practices are applied, selective logging causes substantial damage to tropical forests. To further reduce selective logging damage, the practices that cause the most damage need to be identified and alternatives tested. To this end, we developed the R package LoggingLab, a spatially-explicit and individual tree-based selective logging simulator and demonstrated its functions using data from French Guiana. LoggingLab explicitly simulates damage during each stage of the selective logging process taking into account topography and hydrography, which are main constraints on logging. Most LoggingLab parameters can be easily adjusted to a wide range of local contexts. LoggingLab can also be coupled with forest dynamics models to simulate the long- term effects of different selective logging scenarios.
https://github.com/VincyaneBadouard/LoggingLab
... Also, Silva et al. [68] found that through optimization of operations using mathematical programming, this approach reduced the skidding area and time without changing the layout of operations in the field. In another approach using the Network Analyst Tool in ArcGIS® software, Sales et al. [69] reduced the skidding distance by up to 23%. Nonetheless, when reducing the road network for log hauling through optimization tools, Kazama et al. [70•] cautions that this should not come at the expense of additional watercourse crossings, or without consideration of the social impacts to local communities within the area. ...
Purpose of Review
The goal of this review was to determine what constitutes current challenges in effectively implementing sustainable forest operations in Amazonia. Next, succinctly characterize these challenges into comprehensive well-defined areas. Then ascertain the solutions provided in the literature. Lastly, after a thorough assessment, present potential directions to assist foresters, land managers, researchers, and loggers to build a consensus on what is necessary to achieve sustainable forest operations in Amazonia.
Recent Findings
Illegal logging is a pervasive threat to the credibility of the forest sector with 38% of all logged area in the Brazilian Amazon illegal, which undermines legitimate logging operations through an unfair competitive advantage. One solution is the application of near infrared spectroscopy which has shown promise in determining species and potentially the region of origin. This same technology is also being refined for utilization in species differentiation between logging residues used in green energy, as some industries are species averse, whereas the same species may still be viable for energy generation. Recent models reveal that in the Brazilian Amazon the logging cycle is too short and the cutting intensity too high. Moreover, tree age estimation, which is difficult in many Amazonian species, can now be determined through radiocarbon analysis to determine sustainable cutting cycles.
Summary
Without increased onsite forest inspections and determination of timber origin, illegal logging will continue unabated. Stand damage from logging can easily be reduced through new models and programs that reduce logging infrastructure coverage. To avoid the depletion of timber stocking, the logging cycle must be increased to coincide with the slow growth realities of many species in the Amazon.
... The partial disconnection between Amazonian diversity and the tools used in forest management planning, limit its economic and productive potential (BRAZ, 2010;SILVA et al. 2018). The management of natural forests has attracted very few investors, because they are not offered reliable and accurate management tools, that is, those that guarantee them to minimize costs and have greater productivity, with lower environmental impact (BRAZ, 2010;SILVA et al., 2018;SALES et al., 2019). ...
... Modern computational tools that use operational research are good allies in complex problems like this and meet this demand, supporting decision making and optimizing processes and operations (SILVA et al., 2018;SALES et al., 2019 Reallocate the log landings, considering the constraints: technical limit of 250m maximum extraction distance (MED) of logs; and forbidden overlapping of 250m radius extraction limit of log landings. ...
... Emmert (2014) Silva et al. (2020), using mathematical models to minimize the distances for infrastructure planning, the results demonstrated a higher productivity, a reduction of skidding distance (by an average of 17.16%), and reduced cost of log skidding (by 25.76%), strengthening the assumption of noticeable costs reductions from infrastructure's reduction. Also corroborated by Sales et al. (2019) that concluded reductions in costs and, possibly, environmental impacts of the logging. ...
Biodiversity is one of the main characteristics of tropical forests, distributed in micro sites with specific biophysical attributes. These factors are often poorly considered in forest management planning in the Amazon, through the spatial systematization of infrastructure for operations, generally not considering in decision making the distribution of forest stock of commercial species and other biotic factors. This study aimed to bring planning advances and contributions for the minimization of the infrastructure required in logging operations, through rational allocation of log landings and secondary roads, with use of environmental, operational and production constraints, keeping the same production capacity for the management of the Amazon Rainforests. Data granted by the company Precious Woods Amazon, which carries out large-scale forest management, were used, using a database of 06 consecutive logging UPAs (annual production units): 2013, 2014, 2015, 2016, 2017 and 2018. The data were analyzed in two stages: analysis and planning in digital geographic information system (QGIS) and infrastructure utilization improvements (QGIS qneat add-on package). In addition, a complementary analysis of climatic factors and costs of operations was performed. The geospatial analysis was intended to classify the restricted areas based on environmental and operational conditions that were excluded from the improvement step. Models for infrastructure improvements (roads, skid trails, and yards) were applied to minimize land use in operation support infrastructure subject to operational and environmental constraints. Finally, the results were included in planning maps with QGIS tools, demonstrating the process improvements. The reduction of infrastructure required in log landings ranged from 24.6% to 65.6%, with an average of 40.6%, which is relevant considering the agile planning improvement process applied to forest management in this study. The reduction in infrastructure required for secondary roads varied between 17.8% and 39.9%, with an average of 24.2% fewer roads (in meters), which is relevant when considering the area required for road construction (road width and removal of bordering vegetation), with great environmental and physical impact in tropical forests. Additionally, the highest expenses were concentrated between months July to November. This is the time when all operations are active. Cutting, which is one of the most crucial stages, ends in November, in order to avoid the beginning of the raining season in the region. The most expensive operations for the company were yard operations (27% of the total), transportation (18%) and pre-skidding (18%), respectively. We conclude that the study brought sensible contributions for the planning of logging in the Amazon, minimizing the necessary infrastructure while maintaining the same productive capacity. This work brings subsidies for the improvement of the processes of this activity in Amazon, as well as stimulates the replication of methods and contributes to new management enterprises in the region. We recommend the use, replication and dissemination of these rational methods presented herein for different logging contexts in Amazon, testing, if possible, different values for variables, especially those related to the maximum radius of skidding.
... Moreover, the workflow includes Dijkstra's algorithm (Step 3), which is a powerful computer solution for network analysis. While most forestry applications use this shortest path algorithm to find the optimal position of roads [37,38] or log yards [39], the TraDis tool uses Dijkstra's algorithm to find the nearest hauling place to the related skidding place (Step 3). ...
Knowledge about wood transportation distances is essential for sustainable forest management and related decision making in forest protection against fire or flood events. In this context, we developed the geoprocessing tool TraDis to allow for the calculation of two-dimensional (2D) and three-dimensional (3D) distance between a forest stand and the nearest forest road (i.e., pre-skidding distance) and the distance between this road and the nearest hauling place (i.e., skidding distance). The first aim of this study is to present the workflow for the calculation of the primary wood transportation distance using the TraDis tool. A detailed description, flowchart, and scheme are provided for these purposes. The second aim is to present the applicability of this workflow through a case study. The study area included 391 ha of forest stands, 58 km of forest roads, and 18 hauling places, and the transportation distances were calculated for various target objects, such as 366 forest stands, 10,341 square cells, 7220 hexagon cells, and 83,120 tree crowns. The results show that, while there is the ability to calculate the 2D distances for six forests, eight cells, and three crowns in one second, the calculation time for 3D distances is 1.6 times longer. Moreover, the pre-skidding distance and skidding distance at the 3D level were 3.6% and 0.9% greater than these distances at the 2D level, respectively.
... In a certain way, the management of natural forests for wood production is significantly questioned regarding the impact on species composition and richness [14,56], the provision and maintenance of ecosystem services [57], the frequency of silvicultural harvest and post-harvest operations [11,13] and the economic viability [12]. However, research on management in forests that were exploited in the past and that take into account the harvest criteria [58], techniques of harvest optimization and forest densification [11,33] and management compatible with the behavior of each species [59] has revealed great potential for the recovery and rational use of forests. ...
The existence of degraded forests is common in the Eastern Amazon. The maintenance of these forests standing and the recovery of their productivity play an important role in the conservation of biodiversity, storage and carbon sequestration. However, the management techniques currently employed are designed for natural forests in the first harvest cycle or lightly explored and do not apply adequately to forests that have gone through several harvest cycles. Therefore, adaptations and the establishment of new management criteria that take into account other characteristics of these types of forests are necessary to ensure their sustainability. The objective of this study was to propose a silvicultural management system that has the potential to recover and perpetuate the productivity of an intensively logged tropical forest. A forest census was carried out on 535.6 ha for trees with dbh ≥ 25 cm. With these data, the following two treatments were designed: (1) criteria: the BDq method was applied from B = 9.8 m2 ha−1, D = 100 cm and q = 2. The criteria for standing wood commercialization were, in this order, first, Health; second, Tree Stem; third, Tree Density and fourth, dbh ≥ 105 cm. (2) Control: the planning was in accordance with Brazilian regulations. For the cost–benefit and sensitivity analysis, the Net Present Value (NPV) was used and a projection of ±20% was made in the commercial price of standing wood. In the criteria treatment, a higher number of trees and species destined for the commercialization of standing wood was verified in relation to the control treatment, showing a greater diversity of species. In the criteria treatment, NPV was positive and superior to the control treatment in all scenarios. The proposed silvicultural management system with an object of an explored and enriched forest, with criteria for harvesting trees with a minimum cut diameter of 25 cm, proved to be viable to generate economic returns and with conservationist potential for the continuous supply of forest products and maintaining biodiversity.
... In the category for technical aspects, the density of the road network was the studied variable that has been highlighted in recent years. This variable is related to the haul roads, maximum skidding distance of skid trails, which in turn is linked to the planned quantity of log landings (Sales et al., 2019). In the Central Amazon, road density in timber management plans is dictated by law to be no greater than 1.75% of the area, and 0.75% for landings for a combined total of 2.5% (Brasil, 2018). ...
... In a logging area within the Amazon, the study by Aguiar et al. (2019) highlighted this algorithm as best for efficiency, when compared to 3 algorithms other for forest road layout (Integer Linear Programming, Variable Neighborhood Search and AS). Also, in this same forest, Sales et al. (2019) obtained satisfactory results using Djkstra's algorithm with support from GIS to minimize skidding distances, densities of skid trails and haul roads, which enabled an ideal skidding distance to a greater number of logs. ...
... The author outlined minimum cost trajectory problems, using the socalled minimum spanning tree road network, while considering environmental penalties. A heuristic solution was used for this problem, using the method of searching for the minimum cost paths for the flow of wood, based on the hydrological concept applied to a cost surface by GIS Based on Dijkstra's algorithm (Abdi et al., 2009;Babapour et al., 2014;Bont et al., 2018;Çalişkan et al., 2019;Eastaugh and Molina, 2011;Ghaffarian et al., 2009, Hayati et al., 2013a, 2013bHosseini et al., 2012;Jaafari et al., 2015;Ljubojević et al., 2018;Meignan et al., 2012;Parsakhoo, 2016;Parsakhoo and Jajouzadeh, 2016;Sales et al., 2019) 15 40.5 24.2 2 Least cost path analysis (LCPA) (Acar et al., 2017;Çalişkan, 2017;Çalişkan et al., 2019;Çalişkan and Karahalil, 2017;Kamarudin et al., 2014;Liampas et al., 2019;Picchio et al., 2018;Saito et al., 2013) 8 21.6 12.9 ...
Forest Management in the Brazilian Amazon has social, economic and environmental relevance, as it allows for the sustainable use of natural resources, while at the same time conserving a majority of the ecological processes of the forest. Among forest operations, the construction of new roads is essential for effective sustainable forest management (SFM). However, it is the most expensive part of forest infrastructure and has the greatest environmental impact. Several methods to optimize forest road planning (FRP) have been studied worldwide, although the literature is scarce on the subject of FRP in areas of SFM in Amazonia. Thus, the objective of this study was to carry out a systematic review of the global literature, on FRP optimization in the last decade (2009-2019), as a way to support future planning activities for road infrastructure in SFM in the Amazon. To guide this objective, three questions were raised to determine what the dominant factors affecting FRP in the study period, specifically what were the: (i) spatial variables; (ii) spatial decision analysis and; (iii) optimization methods for road layout. The bibliographic search was conducted according to the Prisma methodology where a set of keywords was entered into the Scopus, Science Direct and Web of Science indexing databases. In this study, all articles published in English-language journals between 2009 and 2019 were considered, resulting in 62 articles for analysis. There was a growing trend in publications, with most studies developed at the level of strategic planning (46.8%). Also, it was observed that the majority of studies occurred in the forests of Iran (33.9%). The results to the questions of this study found that: (i) there were 45 spatial variables, with slope the most studied (54.7%); (ii) Eleven methods of analysis for spatial decisions, with methods based on Analytical Hierarchy Process-AHP the most studied (36.6%) and; (iii) Thirty different methodologies for optimizing the design of forest roads, mainly methods based on Dijkstra's algorithm (40.5%). Some of the encountered methods have already been implemented in Amazonia to optimize the planning of infrastructure in areas of SFM. In this context, the combination of approaches, variables and analysis for FRP optimization that have been successfully tested in other forests of the world, could feasibly be applied in future planning of logging operations in the Amazon in order to verify the potential of these different procedures and methods, provided that they meet the objectives of the SFM.
This article addresses a case study on the application of criteria for harvesting, aiming at restoration and profitability in a degraded tropical forest in the Amazon. The objective is to provide technical and economic information to promote a truly sustainable silvicultural management system in forests with this profile and turn them into a desirable financial asset for conservation and social development. In the forest census, 85.907 trees ha−1 (100.8566 m3 ha−1) were inventoried with diameter at breast height (dbh) ≥ 25 cm, belonging to 106 commercial species. When applying the harvest criteria, 19.923 trees ha−1 (29.99 m3 ha−1), referring to 53 species, were destined for harvest. Some trees were selected by more than one criterion, totalizing 17.985 trees ha−1 by density, 1.831 trees ha−1 by compromised health, 0.212 trees ha−1 by maximum dbh, 18.933 trees ha−1 by minimum dbh, 1.385 trees ha−1 by tree stem (quality 3), and 0.080 trees ha−1 by species conservation. In all scenarios, the application of criteria for harvesting proved to be profitable with excellent cost–benefit ratios. The selection of trees with a minimum cutting diameter of 25 cm in shorter cycles tends to allow the promotion of new commercial species. The set of actions presented has the potential to favor the maintenance of biodiversity and expansion of low-density populations, health and the potential increment of the forest productivity. In addition, it is more feasible for the supply of forest products in a shorter time than provided for in Brazilian regulations; however, they must respect the specificities of the species and also of the site.
In Amazonian native forest management, forest road infrastructures, such as log storage yards and skid trails, are the most expensive attributes and are responsible for the significant environmental impacts with selective tree felling. Road optimization is crucial for reducing environmental impacts and production costs and is strongly linked to the optimal location of storage yards, which are essential to forest road planning. Considering the present problem and the current solutions available, this case study aimed to evaluate the efficiency and eventual gains of optimized forest planning (OFP), as compared to traditional forest planning (TFP). The TFP method is currently used most frequently by forest companies in the Amazon region. The study area of 126.41 ha belongs to the National Forest (NAFO) Saracá-Taquera, Forest Management Unit II (FMU-II), Annual Production Unit (APU) 04/2018, and Work Unit (WU) 2. For the analysis, two areas were defined for exploration: the first was explored using the OFP mathematical model (57.75 ha) and the second followed the TFP plan of the company (68.66 ha). Plans and executions for both areas were compared. The OFP model significantly reduced the Euclidean distances between tree and yards, with only 0.23 km difference in the amount of planned forest roads, when compared to TFP. Additionally, OFP demonstrated a higher productivity (trees.h-1 and m 3 .h-1), a reduction of skid distance (by an average of 17.16%), and reduced the cost of log skidding (m 3 by 25.76%). Thus, this study proved that OFP is a viable solution that can be adopted by companies to increase productivity.
