Traditional mule logging method in Hyrcanian Forest: a study of the impact on forest stand and soil

We inventoried plant regeneration and soil compaction along mule trails to evaluate damage to forest stands and regeneration follow-ing mule hauling before and after operations in Kheyrud Forest in the...     

Feasibility of a harvesting system for logging residues as unutilized forest biomass

The concept of a “harvesting system for unutilized forest biomass by a processor and a forwarder” is examined for the purpose of constructing a system to harvest logging residues (or slashes) as a new resource for energy. The rate of slash harvesting, α, and the energy input rate of hauling slashes,p (%), are defined as indices of the possibility of harvesting slashes and the utilization of slashes for energy, respectively. From an analysis of the field experiment, both the volume of logs hauled by the forwarder per day,E _F (m³/day), andp are expressed as functions of the hauling distance,L(m). The productivity of the processor,E _P (m³/day), andL were used to calculate α. Results showed that α was approximately 0.95 for the experiment site, indicating that almost all the slashes could be hauled. It was recognized that the energy utilization of slashes was feasible for this site becausep was less than 1 %. The hauling cost per unit weight of slashes was calculated as 15.4 yen/kg on an oven-dry weight basis. This high cost clarified that the cost must be reduced by taking measures such as enhancing the hauling efficiency of the forwarder. A part of this paper was orally presented at the 5th Annual Meeting of the Japan Forest Engineering Society (1998).     

A Comparison of Productivity in Five Small-Scale Harvesting Systems

The use of small-scale harvesting equipment continues to grow in forestry in many regions of the world. This equipment includes various devices and methods used to harvesting that generally are smaller, less expensive and less productive than advanced forestry machines. The objective of this study is to compare the efficiency of five alternative extraction methods implemented in a harvesting unit located in a mixed beech and oak forest ecosystem in northwestern Turkey. A continuous time study was conducted during primary transport operations that included skidding with animal power, skidding with farm tractor, hauling with farm tractor, hauling with forest tractor, and extraction by skyline. Timber was skidded uphill on a skid trail, and an average skidding distance of 100 m for all haulage methods was considered. Average slope of the harvesting unit ranged from 20 to 40 %. Average productivities for respective haulage methods were 3.80, 6.25, 2.80, 5.25 and 10.09 m³/h. Significant differences were found between productivity of haulage methods using one-way analysis of variance. The extraction by skyline, skidding with farm tractor, and hauling with forest tractor were determined to be the most statistically different methods, the productivity of these methods was found significantly higher than the other methods. Skid trails are useful for shortening distances during forest operations and skidding with farm tractor is a productive method in small-scale forestry of Turkey.     

Optimal road spacing of cable yarding using a tower yarder in Southern Austria

Cable yarding systems are widely used in mountainous forests of Austria. The goal of this paper is to determine optimal road spacing (ORS) of yarding operations by tower yarder in Styria to help logging planners minimize logging costs. A total of 591 working cycles were used to develop the multiple regression model using stepwise method to predict yarding time per cycle. The production and cost in whole tree uphill yarding were 6.70 m³/PSH and 27.60 Euro/m³, respectively. The roading, yarding and installation cost per cubic meter were computed for different yarding distances and graphed as a function of road spacing. The minimum total cost and ORS were 42.88 Euro/m³ and 261 m, respectively for one-way yarding. For two-way yarding, the minimum estimated total cost, ORS and optimal road density would be 38.48 Euro/m³, 373 m and 26.8 m/ha, respectively. The results showed increasing harvested volume decreases ORS and that increased roading cost increases ORS. The load volume has a significant effect on ORS.     

Energy wood resources availability and delivery cost in Northwest Russia

Availability of solid by-products from wood harvesting and mechanical wood processing was estimated as sources for energy production based on recent actual harvesting, sawmill, and plywood production in Northwest Russia at 30 million m³. Nearly 70% of the energy wood, 20 million m³, was from harvesting, consisting of non-industrial round wood, unused branches and tops, defective wood resulting from logging, and spruce stumps removed after final felling. Over 30%, 10 million m³, of the available volume was from sawmills and plywood mills, i.e. wood chips, sawdust, and bark. Due to current low utilization of energy wood for bioenergy in Northwest Russia, delivery cost of energy wood to the potential border-crossing points in Finland was analyzed for three means of transport: railways, roadways, and waterways. Nearly 28 million m³ of the energy wood could be transported by railways and 2 million m³ by roadways and waterways. The costs were lowest by roadways from the nearby border areas (10–15 €/m³ for wood processing by-products and 16–22 €/m³ for forest chips). The costs by railways varied from 12 to 27 €/m³ on shorter distances to 47–58 €/m³ on longer distances. Waterway transportation was the most expensive, about 28–48 €/m³. It should be emphasized that we have estimated availability and delivery costs of energy wood, not prices which are defined by the market based on supply and demand.     

Costs for thinning and final felling operations in Sweden, 2000–2017

ABSTRACT

Wood supply is one of the most significant cost items for most forest industries, and costs of forest operations and sale prices of wood is vital information for forest owners. Cost trends between 2000 and 2017 in Swedish forestry is analysed, separately for final felling and thinning, and subdivided into ordinary and salvage operations. Data on costs for operations totalling 821 million m³ harvested roundwood were analysed, both as actual costs and after adjustment for the consumer price index. Adjusted costs for ordinary harvesting operations declined between 2000 and 2007, increased during 2008 and 2009 and have since been relatively constant. Costs of salvage logging operations performed as thinning were 21% higher than ordinary thinning, and when performed as final felling costs were 64% higher than in ordinary final felling. The relative logging cost trends in Sweden and Finland were similar during the period, and there are similarities with the US. However, while logging costs in Sweden and Finland increased in 2008 and 2009, they declined in the US and did not reach the same relative level as in Sweden until 2013. Results can be used for benchmarking logging costs between regions or larger buyers of logging services.     

Uncertainty in timber assortment estimates predicted from forest inventory data

Uncertainty factors related to inventory methodologies and forest-planning simulation computings in the estimation of logging outturn assortment volumes and values were examined. The uncertainty factors investigated were (1) forest inventory errors, (2) errors in generated stem distribution, (3) effects of generated stem distribution errors on the simulation of thinnings and (iv) errors related to the prediction of stem form and simulation of bucking. Regarding inventory errors, standwise field inventory (SWFI) was compared with area-based airborne laser scanning (ALS) and aerial photography inventorying. Our research area, Evo, is located in southern Finland. In all, 31 logging sites (12 clear-cutting and 19 thinning sites) measured by logging machine in winter 2008 were used as field reference data. The results showed that the most significant source of error in the prediction of clear-cutting assortment outturns was inventory error. Errors related to stem-form prediction and simulated bucking as well as generation of stem distributions also cause uncertainty. The bias and root-mean-squared error (RMSE) of inventory errors varied between −11.4 and 21.6 m³/ha and 6.8 and 40.5 m³/ha, respectively, depending on the assortment and inventory methodology. The effect of forest inventory errors on the value of logging outturn in clear-cuttings was 29.1% (SWFI) and 24.7% (ALS). The respective RMSE values related to thinnings were 41.1 and 42%. The generation of stem distribution series using mean characteristics led to an RMSE of 1.3 to 2.7 m³/ha and a bias of −1.2 to 0.6 m³/ha in the volume of all assortments. Prediction of stem form and simulation of bucking led to a relative bias of −0.28 to 0.00 m³ in predicted sawtimber volume. Errors related to pulpwood volumes were −0.4 m³ to 0.21 m³.     

A study on the productivity and cost of cable logging in Turkey

Tower yarders have recently been introduced to forestry in Turkey. Clarification of the productivity and cost of logging using the tower yarder is often requested because the cost for machinery is a significant factor in all calculations concerning mechanized operations. Machines are often extremely expensive compared with the low cost of labor in developing regions. In this study, a new logging system using a tower yarder was compared with a conventional system using a stationary yarder in terms of productivity and cost. The research was conducted in the northeast of Turkey, in 1989 and 1992. The productivity of the tower yarder and the stationary yarder was found to be 5.655 m³/h and 5.002 m³/h, respectively. Harvesting cost was analyzed based on observed productivity. The harvesting costs of the tower yarder and the stationary yarder were found to be 47,410 TL/m³ and 17,553 TL/m³, respectively. With the tower yarder, the machine cost reached 93.1 % of the harvesting cost while the machine cost using the stationary yarder reached 71.1%. A part of this paper was orally presented at the 3rd Annual Meeting of the Japan Forest Engineering Society (1996).     

Development of wood procurement in Northwest Russia: round wood balance and unreported flows

This paper analyses industrial round wood flows into, within, and out of Northwest regions of Russia. We examine sawlogs, pulpwood, and fuelwood used for industrial purposes obtained from logging, and chips obtained from the wood-processing industry. We attempt to clarify different recent trends in wood harvesting, industrial round wood export, and forest industries development that have an influence on unreported wood in Russia. Our method, which uses wood balance diagrams, provides an interpretation of data from different Russian sources in order to offer better transparency regarding wood flows from forests to mills. It also helps to explain the apparent imbalance between round wood supply and demand and it helps one to assess the possible share of unreported industrial round wood production in Northwest Russia. Based on annual forest-related statistical data available from the Ministry of Natural Resources, the State Committee of Statistics, and the Russian Federation’s Customs Department, unreported round wood flows can be estimated to be 23% of the total industrial round wood production, or approximately 9 million m³ u.b. per year. Unreported round wood flows are more common in export oriented regions that have poorly developed forest industries.

Time consumption, productivity, and cost analysis of the motor manual tree felling and processing in the Hyrcanian Forest in Iran

An empirical time study was conducted to evaluate the per- formance of the current felling and tree processing methods used in Northern Iran’s Hyrcanian forest. Motor-manual felling is done mostly in winter, while tree processing starts when the felling season ends. We identified the elements of felling and processing work phases, and 142 cycles and 110 cycles were respectively recorded for felling and proc- essing. On the basis of data analysis (time study), we developed statisti- cal models of effective time consumption in the respective work phase and for its total productivity. The production rate of felling with and without delay time was 9.7 and 11.65 trees per hour (0.17 USD·m -3 and 0.21 USD·m -3 ), and the average production cost with and without delay was 1.21 USD and 1.45 USD per tree, respectively. The average produc- tivity of processing was 35 m 3 per effective hour and the average unit cost of processing was 0.22 USD·m -3 .     

Estimating fuelwood production and yield in regrowth dry miombo woodland in Zambia

A combination of destructive and non-destructive samples was used to develop regression models for estimating fuelwood production and yield in regrowth dry miombo stands aged 6–34 years. Fuelwood yield from understorey species was estimated from girth at stump height (gsh) data while gsh and stem height data were necessary for estimating yield from canopy species. Mean fuelwood production was estimated at 1.93 m³ ha⁻¹ year⁻¹. It was found that canopy species had a greater sustained stem growth than understorey species. Enhancement of regeneration of canopy species is therefore recommended for the management of miombo woodland for fuelwood production.     

Loan financing of smallholder treefarming in the provinces of Ilocos Norte and Ilocos Sur,the Philippines

Following the model of a credit program for pulpwood production and agroforestry by smallholders in another region of the Philippines, the World Bank financed a similar scheme to produce fuelwood for the small-scale tobacco-curing industry in the Ilocos region. This project proved to be unsuccessful due to local cultural attitudes toward borrowing money, inadequate forestry extension services, and the dispersed characteristics of the fuelwood market.     

Growing situation of afforested trees and damage to lower-story trees caused by felling in multi-storied forest management in Peninsular Malaysia

The growing condition of afforestation trees and damage to lower-story trees caused by felling and hauling of upper-story trees in a multi-storied forest in Peninsular Malaysia was surveyed. Seventy months have passed since the planting ofAcacia mangium upperstory trees, which have grown 233 m³/ha in volume. The growth ofShorea leprosula thirty-five months after planting of lower-story trees have reached 5.54 m in height. However, as the ratio of height to basal diameter exceeds 100:1, trees are tapering to a considerable degree. A backhoe was installed in order to fell the upper-story trees. From the results of logging, the damage ratio estimation of the lower-story trees was simulated by using the Monte Carlo method. The damage ratio differed considerably depending on planting patterns, height of upper-story trees and felling skills. The results of this survey proved that the felling and hauling of upper-story trees would be technically feasible in the future, except when one row upper-story trees and one row lower-story trees method were employed.     

Optimal Rotation Age of Larix kaempferi Pulpwood Plantation by Real Options Approach

The differentiation process including somatic embryogenesis in different Ginkgo explants in vitro culture were studied by cytological observation.The results are as follows:1) two complete cotyledons and a embryo bud were observed in mature embryos and several secretory acavitives appeared in maturation region of embryo buds,hypocotyls,cotyledons and radicles after culturing 20 days;two incomplete cotyledons and a embryo bud primordia were found in large cotyledon embryos.The proembryo of two cells,four cells, multi-cellular,and globular embroy were developed from the callus of the small cotyledon embryos.2) The differentiation of cotyledon explants started from epidermal cells,and gradually formed meristematic cell mass in the cortical cells,and eventually adventitious buds were observed.3) The adventitious roots of Ginkgo originated in the cells at the cross of vascular cambium and vascular rays. 4) The type of rooting belongs to induction type by root primordium.The formed adventitious roots were observed after 20 days.     

A Case Study on the Productivity of Forwarder Extraction in Small-Scale Southern Italian Forests

Most timber harvesting operations in the southern Mediterranean area of Italy can be considered to be in an early stage of mechanization. It is mainly based on agricultural tractors that are sometimes equipped with specific forest-related accessories such as winches, hydraulic cranes, or log grapples. In recent years, there has been an increase of specialized forestry machines working in Calabria, southern Italy, including forwarders, skidders and cable yarders. This study assesses the efficiency and costs of extraction using forwarders, as a mechanized alternative to agricultural tractors and horse logging. Time studies were conducted to quantify the productivity and operational cost of log forwarding for two John Deere forwarders in two different coniferous stands: (A) Calabrian pine and (B) silver fir. The empirical time study included 100 forwarding cycles (i.e., 50 for each site) that were broken down into four different work phase elements. Models for cycle time, total productivity and individual work phases were calculated. The average load per cycle was 11.8 m³ in stand A and 9.97 m³ in stand B and the average one-way forwarding distance was 306 m in A and 597 m in B. The average productivity per scheduled machine hour (SMH) was 14.4 m³ in A and 15.7 m³ in B, while the costs, calculated to be 3.60 €/m³ in A and 4.90 €/m³ in B, were considered lower respect traditional methods.     

Influence of Log Characteristics on Drum Debarking of Pulpwood

Properties of 200 poorly debarked softwood logs were studied in order to examine how different log characteristics affect drum debarking of mixed pine (Pinus sylvestris L.) and spruce [Picea abies (L.) Karst] pulpwood during the summer. The definition of a poorly debarked log and the sampling criterion was that >10 dm² bark remained on the log surface. The average share of poorly debarked logs was 8% and the most frequent log type was breakage logs. The main species among the poorly debarked logs was spruce and the mean wood moisture content was considerably lower than for the pulpwood chips. Many logs were affected by root rot or were damaged by harvesting equipment, resulting in reduced moisture content and, consequently, in increased bark/wood shear strength. Bark from the poorly debarked logs contributed to approximately 68% of the bark content in the chips. By avoiding air-drying of pulpwood, or by sorting pulpwood prior to debarking, the bark content in chips might be substantially reduced, which would improve the purity of the pulp and decrease production costs.     

Spatially explicit assessment of forest road suitability for timber extraction and hauling in Switzerland

Efficient forest management, and wood production in particular, requires a forest road network of appropriate density and bearing capacity. The road network affects the choice of a suitable extraction method and the length of the transport route from the forest, while the road standard defines the truck type that can be used.

We evaluate the forest road network’s economic suitability for harvesting operations in the entire Swiss forest, an area of about 13,000 km² covering a range of topographies, based on the Swiss National Forest Inventory’s (NFI) forest road dataset. This dataset is based on information from an interview survey with the local forest services and includes all forest roads in Switzerland capable of carrying trucks. Extraction options and hauling routes are analysed together; thus, the entire logging process is examined.

Model results include maps of the most suitable extraction method; extraction costs; hauling costs; and a suitability map based on a combination of the results. While the larger part of the Swiss forest is classified as “suitable” for economic harvesting operations, significant portions also fall into the “limited suitability” and “not suitable” categories. Our analysis provides an objective, country-wide, spatially explicit assessment of timber accessibility. The resulting suitability map helps identify areas where timber harvesting is economic using the current forest road network, and where it is not. The model results can be used in road network planning and management, for example, by comparing road-network re-design scenarios, and compared to the spatial distribution of available wood volume.

     

Time Prediction Models and Cost Evaluation of Cut-To-Length (CTL) Harvesting Method in a Mountainous Forest

Time equations are derived for felling with chainsaw, skidding with cable wheeled skidder, loading with grapple hydraulic loader and trucking of logs within a cut-to-length harvesting method. The continuous time study method was applied to collect data for felling, skidding, loading and a transportation model. Multiple regression analysis via SPSS software was applied to develop the time models. Felling time was found to be highly dependent on diameter at breast height. Skidding distance, winching distance, slope of the trail and piece volume were significant variables for the skidding time prediction model. The loading time model was developed considering piece volume. Transportation distance and load volume were used as independent variables in modeling the transportation time. The net production of felling was estimated at 12 trees/h (56.65 m³/h). The net production rates for skidding, loading and traveling averaged 18.51, 41.90 and 3.32 m³/h respectively. The total cost of harvesting from stand to mill was estimated 19.70 €/m³. The skidding phase was the most expensive component of the cut-to-length method. The bucking and delimbing components were less costly than the other logging phases. The results of this study can be used for harvesting planning and productivity optimization.     

Stochastic simulation of forest fuel sourcing models under risk

Abstract

Climate change effects such as storms and droughts are leading to increased risk of forest damage in central Europe. The aim of this paper was to evaluate forest fuel sourcing models including climate change-induced risks on forest fuel supply. Stochastic risk events, such as storms and bark beetle infestations, were modelled by means of a Monte Carlo simulation, and the economic performance was evaluated for two fuel-sourcing models supplying a single combined heat and power plant (CHP). The first sourcing model depicted a common sourcing model for Austrian CHPs, where only forest chips provided by long- and short-term suppliers were stored. The second sourcing model additionally enabled the storage of salvaged pulpwood to supply forest fuel from the plant's own inventory during shortage periods. Simulation results showed that storing salvage pulpwood as feedstock considerably reduced supply chain risks and resulted in lower procurement costs (1–3% less than normal delivered cost without storing salvaged pulpwood).     

The Ankasa Forest Conservation Area of Ghana: Ecosystem service values and on-site REDD + opportunity cost

The Ankasa Forest Conservation Area is one of the most important protected areas (PA) in West Africa. This study aimed at estimating the economic values of selected ecosystem services of the PA and the direct on-site REDD + opportunity costs to communities. We found that the PA stocks 32.8 million m³ (627 m³/ha) of standing trees with a stumpage value of about $ 19.1 million (364 $/ha), 64.3 million tCO₂e (1230 tCO₂e/ha) of carbon worth of $379.5 million ($7257/ha), and 6380 tons of nutrients worth of 0.64 million USD. The direct on-site REDD + opportunity cost for conserving the PA until 2042 was about 6.7–24.1 $/tCO₂e (0.22–0.80 $/tCO2e per year) in net present value. From our field observation of the PA, we did not see a buffer zone that separates the PA from the surrounding land uses. Establishing a buffer zone is very important for the sustainability of the PA. Such an effort, however, should take in to account the opportunity costs to the rural communities associated with possible displacement. Thus, the results of the study could be used as important input for designing policies that will reinforce the sustainability of the Ankasa PA and other conservation sites in Ghana.