Can standardisation of the unit costs of wood extraction be applied in the financial system of the State Forests?

The paper presents a method for grouping forest districts that are characterised by similar natural and forest conditions and the results of standardisation of wood extraction costs for forest districts and regional directorates of the State Forests. The adopted standard costs referred to the costs which determine the reasonable level of costs necessary to perform a specific management task in the given natural, forest and economic conditions of forest districts. Forest districts were grouped based on the forest habitat types and the land diversity index (Wtri), which were determined with statistical methods to be the factors that shape wood extraction costs. In order to determine the standard unit costs of wood extraction, source materials for the year 2017 have been used, which had been obtained from the State Forests Information System for all forest districts in the country. The method of standardising wood extraction unit costs on the basis of forest district groups with similar natural and forest conditions was reduced in 2017 to the designation of eight uniform forest district groups in terms of forest habitat type structure and Wtri index. Standard unit costs of wood extraction, determined on the basis of the methodology presented in the paper, should be used in the State Forests’ financial system.

Comparison of Forwarder Productivity and Optimal Road Density in Thinning and Clearcutting of Pine Plantation in Southern Brazil

The prescription of forest management determines the number of trees to be cut and, consequently, the harvested wood volume, which directly influences the forest operations dynamic. The objectives of this paper were (i) to analyze the effect of process factors on wood extraction performance with forwarder in first thinning and clearcutting of Pinus taeda L. plantations; and (ii) to economically determine the optimal road density to manage these plantations. Time and motion studies at the cycle element level were conducted to quantify and model the time consumption, productivity, and operational costs of the extraction. The optimal road density (ORD) for both operation types (OT) was determined based on the transport geometry model, considering the minimization of the sum of unitary costs with construction and maintenance of roads, loss of productive area, and wood extraction. The extraction distance (ED), slope (SL), average log volume (LV), and OT had a significant effect on the time consumed in travels, and therefore, on productivity (PPMH). In clearcutting, the average PPMH was 12.17 m3ob PMH0-1, while, in thinning, it was 10.94 m3ob PMH0-1; however, as the ED increased, the difference of PPMH and the cost of extraction between the operations decreased, which highlighted a greater effect of this factor on forwarder’s work in clearcutting. For this reason, the ORD for clearcutting (37.76 m ha-1) was higher than for thinning (27.84 m ha-1). Therefore, we demonstrated in this study that the type of operation and forest management regime, as well as their interaction with process factors, affect the sizing of the number of roads per unit area, and also the costs of the forest activity.

Impacts of wood extraction on soil: assessing rutting and soil compaction caused by skidding and forwarding by means of traditional and innovative methods

Intensive forestry operations may cause soil compaction, plastic soil disturbances and rutting, which are responsible for undesirable effects on soils, vegetation and water bodies. Despite the numerous studies aimed to identify the main factors affecting soil damages, it still remains unclear whether wood extraction methods and driving direction (uphill or downhill) may affect the impacts of forest machines. This research analyses soil compaction and soil penetration resistance as well as rutting from forwarding and skidding using the same farm tractor in up- and downhill wood extraction. Rutting was estimated by 3D soil reconstruction derived by portable laser scanning (PLS) and close-range photogrammetry using structure for motion (SfM). Our findings showed that the direction of extraction did not affect soil damage severity during forwarding on a 25% slope. On the contrary, in order to reduce soil compaction, downhill skidding is preferable to uphill skidding. The results showed that the pressure on the ground caused by vehicles can be distributed horizontally, thus affecting also the soil between the wheel tracks. The soil bulk density inside the tracks after 10 forwarding passes increased by 40% and with 23% between the wheel tracks. The soil displacement in skidding trails (7.36 m3 per 100 m of trail) was significantly higher than in forwarding (1.68 m3 per 100 m of trail). The rutting estimation showed no significant difference between the PLS and SfM methods, even comparing the two digital surface models (DSMs) obtained, even if photogrammetry was preferred for technical and practical reasons.

Predicting productivity of timber loading operations: a literature review

Loading is considered a bottleneck of the forest harvesting system as it acts as a connection between primary transport and secondary transport (from roadside/ landing to mills or central yards). Any delay during the loading component can cause delay in the primary wood extraction and/ or secondary transportation. This article reviewed the current knowledge on loading productivity studies. Based on the results, the main variables impacting the loading productivity include log size, log lengths, load volume per truck, number of logs (or pieces) per truck and number of safety straps. The productivity of loading operations ranged from 3.4 m3/PMH0 in a manual loading to 168.9 m3/PMH0 using mechanised loaders. The results of this review can assist the academic and industrial users for predicting, controlling and managing the productivity of loading operations. 

Intermediate levels of wood extraction may facilitate coexistence of an endemic arboreal marsupial and Indigenous communities

Land-use change is a major driver of biodiversity loss. Large-scale disturbances such as habitat loss, fragmentation and degradation are known to have negative consequences for native biota, but the effects of small-scale disturbances such as selective logging are less well known. We compared three sites with different regimes of selective logging performed by Indigenous communities in the South American temperate rainforest, to assess effects on the density and habitat selection patterns of the Near Threatened endemic arboreal marsupial Dromiciops gliroides. We used structured interviews to identify patterns of wood extraction, which was 0.22–2.55 m3 per ha per year. In the less disturbed site only two tree species were logged, in the intermediately disturbed sites eight species were logged at low intensity, and in the most disturbed site seven species were logged intensively. The site with intermediate disturbance had the highest fleshy-fruited plant diversity and fruit biomass values as a result of the proliferation of shade-intolerant plants. This site also had the highest density of D. gliroides. These findings are consistent with Connell's intermediate disturbance hypothesis, suggesting that coexistence of people with nature is possible if wood extraction volumes are moderate, increasing plant diversity. Indigenous communities have sustainably used natural resources for centuries, but current rates of land-use change are becoming a significant threat to both them and their natural resources.

Time Consumption and Productivity in Wood Extraction Using Traditional Cable Car

Forests are a very important component for the environment in Albania considering the fact that they occupy more than 36% of the country's surface. The evaluation of the working time consumption and productivity of the various sub-phases of wood extraction work, in a beech forest in Albania, with traditional methods and old equipment’s, was considered of interest in this study to highlight the weaknesses to be corrected. Considering the slope in our study site, a traditional cable car Austrian Type R-Gander (A 6832 SULZ) manufactured in 1985 was used for the extraction of timber. Trunks from a distance of 800 - 900 m were extracted using this equipment. The operating team consisted of 3 workers. 10 - 15 working days are required for the assembly and disassembly of the equipment. During the work performed, data regarding working times were collected, paying special attention to dead times, where avoidable times are high 61,0 %. The extracted volume was 31.46 m3, which corresponds to a weight of 41.82 t.

Analysis of the Offering and Resale Prices on the Second-Hand Skidders Market

Skidders, as self-propelled machines designed to transport trees or parts of trees by trailing or dragging it from the woods to a landing area, are still extensively used as the main wood extraction equipment in most of the Europe and worldwide. The high price of new machines (and even higher for CTL technology) makes the second-hand skidder market very interesting and appealing, especially for small forest owners and forestry contractors. So, this paper reports on a survey of used skidders available for purchase on the European market. Up-to-date empirical data was gathered by the analysis of the offerings on the main online marketplaces, i.e., specialized websites. The study included skidder make and model, variation in their age, annual usage and resale prices. The survey identified a total of 163 second-hand skidders and the results pointed out the prevalence of small-size machines (<110 kW), the average annual use (after excluding 1 year old machines from calculation) of 863 hours per year and the average re-sale price of about 65,000 EUR. Skidders are most commonly re-sold at an age of 16 years and the calculated price models show that skidder age is a stronger predictor of their value, i.e., resale price, than the total machine working hours. In the concluding section, paper also includes some reflections on possible future trends and perspectives of skidding technology in forestry.

Green and Efficient Processing of Wood with Supercritical CO2: A Review

Wood processing is a crucial step of wood utilization, but the adding of environmentally hazardous feedstocks and the use of unreasonable technology allow it to harm the environment and human health. Supercritical CO2 (scCO2) is a non-toxic, odorless, and safe solvent, which is widely used in studies and industrial production, but there is no review summarizing wood processing with scCO2. The unique structure and chemical properties of wood combined with scCO2 technology produce positive results. In this paper, wood processing with scCO2 is summarized, including wood impregnation, wood drying, wood thermochemical conversion, and wood extraction. The green and efficient characteristics of wood processing with scCO2 are explained in detail for researchers, engineers, and investors to provide a clean wood processing method. Further study is needed to reduce its energy consumption and commercialize it eventually.

Analysis of the Current and Future Prediction of Land Use/Land Cover Change Using Remote Sensing and the CA-Markov Model in Majang Forest Biosphere Reserves of Gambella, Southwestern Ethiopia

This study aimed to evaluate land use/land cover changes (1987–2017), prediction (2032–2047), and identify the drivers of Majang Forest Biosphere Reserves. Landsat image (TM, ETM+, and OLI-TIRS) and socioeconomy data were used for the LU/LC analysis and its drivers of change. The supervised classification was also employed to classify LU/LC. The CA-Markov model was used to predict future LU/LC change using IDRISI software. Data were collected from 240 households from eight kebeles in two districts to identify LU/LC change drivers. Five LU/LC classes were identified: forestland, farmland, grassland, settlement, and waterbody. Farmland and settlement increased by 17.4% and 3.4%, respectively; while, forestland and grassland were reduced by 77.8% and 1.4%, respectively, from 1987 to 2017. The predicted results indicated that farmland and settlement increased by 26.3% and 6.4%, respectively, while forestland and grassland increased by 66.5% and 0.8%, respectively, from 2032 to 2047. Eventually, agricultural expansion, population growth, shifting cultivation, fuel wood extraction, and fire risk were identified as the main drivers of LU/LC change. Generally, substantial LU/LC changes were observed and will continue in the future. Hence, land use plan should be proposed to sustain resource of Majang Forest Biosphere Reserves, and local communities’ livelihood improvement strategies are required to halt land conversion.