Tree-length Logs Research Articles

Trial performance of the zero waste harvesting method in three forest concession companies, Central Kalimantan Province, Indonesia

Currently, natural forest management companies (concession permit of timber forest products utilization-natural forest/IUPHHK-HA) have implemented Reduced Impact Logging (RIL) technology but timber harvesting is still carried out using the conventional method. Tree length logging is an alternative method of harvesting wood in an effort to reduced waste and increases the efficiency of the utilization of timber forest products and the preservation of natural production forests. The potential for wood harvesting waste is estimated at 2.21 million m3year−1 and has remained left in the cutting compartment for decades. The purpose of this paper is to obtain technical and financial information about forest harvesting on a zero waste basis. Data collection was carried out by experimental methods. Productivity, efficiency, cost, and stand damage data were collected. The results of the research in three IUPHHK-HA in Central Kalimantan show that the zero waste logging method can reduced harvesting waste by 5.1% and increase the efficiency of wood utilization from 87.7-92.8%. Another advantage of the zero waste logging method is that the additional waste from the trunk above the first branch is about 5.8%. The productivity of the conventional method averaged 26.333 m3hour−1 at a cost of IDR 33,941 m−3 while the tree length logging method was 27.320 m3hour−1 at a cost of IDR 35,251 m−3. It is suggested that the tree length logging method be implemented in natural production forest harvesting.

Modeling the effect of skidded timber bunches on forest soil compaction

An increasing demand for forest products incites a large number of log transportation operations, which may lead to negative consequences for the soil and the ecosystem as a whole. This paper presents a mathematical model to estimate the soil deformation and compaction processes under the influence of individual components of the skidding system, such as the forwarder, limbs, butts, and tops of tree-lengths in high latitudes, permafrost soil, and forests of the cryolithic zone. The effectiveness of the proposed model was evaluated according to experimental results. Comparative analysis showed that the calculated data differ from the experimental data by no more than 10%. The deformation of the soil by the bunch of tree-length logs occurs due to shearing processes. It has been established that the initial vertical stress exceeds the radial stress by 30–40%. The result of estimating the dependency of the shelterbelt width on the number of tree-length logs showed that the limit values for logs amount to 4–6 units for the mild, medium, and solid soil categories. The obtained results and the developed model will allow for a qualitative and quantitative assessment of the technological impact on the soil during the projecting of maps for logging operations.

Labor productivity of full tree and tree length logging system using a self-propelled carriage introduced from Europe.

Labor productivity of full tree and tree length logging system using a self-propelled carriage introduced from Europe.

Productivity and cost of a small-scale cable yarder in an uphill and downhill area: a case study in South Korea

ABSTRACTTree diameter, topography, and stand accessibility have been major factors to consider when selecting the optimal equipment to extract logs from stump to landing area. In Korea, forest land has 6.4 million ha of forest, comprising 64% of its total land area. Small and medium (15–30 cm in diameter at breast height [DBH]) size of trees located on steep slopes (> 30°) is approximately 80% of total forest area. Therefore, there has been an increasing interest in the application of a small-scale cable yarding system. We performed uphill and downhill yarding experiments using an 80 hp farm tractor mounted tower yarder (HAM300) to evaluate productivities and costs associated with primary transportation of tree length logs in mixed conifer stands. In addition, sensitivity analyses were performed to find the effects of different yarding directions and distances on yarding productivities and costs. Results showed that uphill and downhill yarding productivities were 9.04 m3/PMH (Productivity Machine Hours) and 7.87 m3/PMH at a cost of US$9.06 and US$10.04/m3, respectively. The yarding direction greatly affected productivity and cost: decreasing productivity may be significantly affected by working conditions. Our results support the effectiveness of an HAM300 yarder in extracting logs for small-scale cable yarding operations.

Acoustic evaluation of loblolly pine tree- and lumber-length logs allows for segregation of lumber modulus of elasticity, not for modulus of rupture

Loblolly pine ( Pinus taeda ) logs can be evaluated using acoustic velocity whereby threshold acoustic velocity values can be set to ensure lumber meets specified mechanical property design values for modulus of elasticity. There is a need to better sort logs according to lumber quality for improved decision making and wood utilization because merchantable logs are being harvested from different stand types including natural forests, conventional plantations, and intensively managed plantations, all with differences in rotation ages, growth rates, and wood quality traits. This study aimed to link tree- and lumber-length log acoustic velocity with the resulting lumber properties as tested in static bending from five intensively managed loblolly pine stands in the Atlantic Coastal Plain of Georgia. Acoustic velocity was measured using the resonance-based approach on 87 tree-length logs and 244 lumber-length logs. The logs were then processed into 797 pieces of 38 mm by 89 mm (2×4), 140 mm (2×6), 184 mm (2×8), and 235 mm (2×10) dimension lumber, dried, and tested in static bending. Mean MOE of the lumber had moderate relationships with acoustic velocity of the logs (R 2 = 0.49) whereas MOR and acoustic velocity did not have a strong relationship (R 2 = 0.20). Accounting for log position increased the performance of the mean lumber MOE model (R 2 = 0.62) which was further increased by adding green density and small-end diameter (R 2 = 0.67). Utilization of acoustics was effective for segregating logs based on lumber modulus of elasticity and did not depend on knowing tree or stand information such as age, site quality, and silviculture history. Acoustic velocity evaluation of tree- and lumber-length logs could be employed to segregate logs within the supply chain to ensure that lumber would meet specified design values.

Harvesting Cost of Tree-length Thinning in a Larix leptolepis Stands

The purpose of study was to broaden our knowledge on the productivity and cost of thinning operations which has become increasingly practiced in Korea. The thinning operations were conducted in a 40-year old larch (Larix leptolepis) stand, including chainsaw felling and processing at the stump, followed by yarding tree-length logs using a Koller K301-4 tower yarder. The logs were further processed and sorted into 1.8 m and 3.6 m log piles at the landing. We used a standard time study method to evaluate key variables that affect the productivity of thinning operations. The total stump-to-pile operational cost was . The highest cost activity was the yarding phase which cost (48.2% of the total cost), followed by the costs of processing treelength materials into marketable log lengths (; 29.1%), and then by the costs of sorting/piling the processed logs (; 12.1%). It was interesting to see that felling and processing trees at the stump had low costs at (3.2%) and (7.5%), respectively. We used the detailed time study data to develop regression equations which were to predict yarding productivity. Our analysis showed that harvesting system cost was highly sensitive to the number of logs, yarding distance and lateral distance per turn, respectively.

Effects of tree-length timber skidding on soil compaction in the skid trail in Hyrcanian forests

Aim of study: The study was conducted to examine impact of skidding traffic, trail slope, traffic frequency, and soil depth on the soil bulk density.Area of study: This study was carried out in the Kheyrud Forest in Hyrcanian forest, Iran.Material and methods: The level of soil compaction at eight levels of traffic (1, 4, 8, 10, 15, 20, 25, and 30 passes), four levels of skid trail slopes (0, 10, -10, and -20%) and three soil depth (5, 15, 25 cm) were applied in three replicates consequently. Bulk densities were measured on the undisturbed surface (control) and within the tracks. Timbers were extracted in the tree-length logging method using rubber-tired skidder (Timberjack 450 C).Main results: About 5.2% of total area of harvesting unit were disturbed and compacted. Uphill skidding increases compaction more than downhill skidding. In the four different slopes, the highest increasing of the bulk density was occurred during the first few passes of skidder, although the bulk density continued to increase in amount and depth with the number of passes. The increases in bulk density were still important at the maximum sampling depth of 20-30 cm.Research highlights: The results indicated that slope steepness had a strong effect on the soil physical properties and soil disturbance. Designated skid trails should be used to minimize the influence on the forest soil.Key words: soil compaction; tree-length logging method; rubber-tired skidder; Hyrcanian forest.

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This study examined cost and productivity of tree length logging system in natural production forest. The study was conducted in several forest concession in Kalimantan. The results showed that the sytem is capable to extract the clearbole part as main production log and the wasted log above the first branch into the landing point. Skidding productivityof tree length syistem in PT Gunung Gajah Abadi 6,25 m3/jam/hm, PT Narkata Rimba 15,54 m3/hr/hm, PT Balikpapan Forest Industries 16,67 m3/hr/hm, PT Jatitrin Co Ltd 20,76 m3/hr/hm, PT Dwima Jaya Utama 36,69 m3/hr/hm dan PT Kayu Tribuana Rama 21,67 m3/hr/hm.The average cost of tree length logging system in PT Gunung Gajah Abadi is Rp 84.817,92 / m3, PT Narkata Rimba Rp 33.636,55/ m3, PT Balikpapan Forest Industries Rp 31.800,34/ m3, PT Jatitrin Co Ltd Rp. 25.535,26/ m3, PT Dmimajaya Utama Rp 14.155,19/ m3 and PT Kayu Tribuana Rama Rp. 25.207,41/ m3.

Removal of carbon and mineral nutrients upon clear felling of spruce forests in the middle taiga

We obtain an estimate of the influence of localized clear felling in a middle taiga spruce forest on the dynamics of organic mass and its content of carbon and elements of mineral nutrition. In an old-age myrtillus bilberry moist spruce stand, in which the reserve of organic mass is 180 t ha−1, there are concentrated 86 t of carbon, 508 kg of nitrogen, and 904 kg of ash elements. On the logging area of this spruce forest in the undercut (incomplete felling), roots, and logging slash, there are 112 t ha−1 of phytomass, where 53 t C ha−1, 308 kg of nitrogen, and 723 kg of ash elements are concentrated. Upon the localized clear felling with removal of tree-length logs, the loss of carbon is 44%, nitrogen 28.3%, and ash elements 22.3% of their overall reserve in the myrtillus moist spruce stand. In the spruce-sphagnum forest, the phytomass of the stand is 194 t ha−1 and contains 92 t ha−1 of carbon, 580 kg of nitrogen, and 974 kg of ash elements. Upon cutting of the stand in this spruce forest, 77 t ha−1 of organic mass were taken away, including 37 t of carbon, 140 kg of nitrogen, and 215 kg of ash elements, which are 39.5, 24.2, and 22% of their overall mass in woody plants of the cenosis, respectively.

Automated time study of skidders using global positioning system data

Time study is an important research tool used in comparing productivity of forest harvesting systems across varying conditions. Unfortunately, it has been an expensive tool to apply, involving travel and fieldwork by a crew of technicians plus time in the office to reduce raw data to usable information. In the interests of safety and cost reduction, it would be preferable to have a means of performing autonomous time study that did not involve fieldwork and that produced detailed summaries of machine or system performance over long periods of time. Automated tracking of machine productivity is currently possible on advanced harvesting equipment, notably cut-to-length harvesters, but is not for the predominant tree-length logging systems used in the US south. This paper reports on a data acquisition system used to convert movement and positional data collected using a GPS receiver mounted on tree-length harvesting equipment, primarily skidders, into time study information. The conversion was performed in two stages: reduction of raw position data to a set of measurable, simple events; interpretation of sequences of simple events as machine functions. Simple events were extracted from the raw position data along with time and distance accumulated since the previously occurring event, then passed to the interpretive stage of processing. The stream of simple events was evaluated using a pattern-matching system that combined events into machine functions. Patterns were rules specified using a regular expression syntax that defined machine-specific operational characteristics. Field trials with the data acquisition system on skidders showed it was capable of reproducing measurements obtained from field crews. In two tests measuring total skid cycle time (46 cycles), the automated time study system missed identifying fewer than 10% of the cycles, and of those identified, the difference in cycle time averaged less than 2% (5 s). Although small, the bias was consistent (automated system shorter) and significantly different from 0. Elemental time study was also possible. A three-element cycle (travel empty, grapple, and travel loaded) was identified in 33 of the 36 cycles with differences in element times between clock and automated system measurements being generally less than 10%.

Harvesting and comparative thinning alternatives in Gmelina arborea plantations

Harvesting of Gmelina arborea presents some unique considerations due to the environments in which it is grown and to the growing characteristics of the species. On low, wet sites, soil compaction is an important consideration when planning for harvests. Gmelina root systems tend to be superficial and special care is needed when thinning to minimize root damage. Clear felling for pulpwood is done primarily with chainsaws, moving the wood to roadside with forwarders, wheel tractors and trailers or small highlead cable systems. Pulpwood needs to be manually bunched for ease of collection by forwarders. Gmelina is an increasingly important species for solid wood products, both lumber and veneer, and plantation management for sawtimber requires thinnings to improve residual tree form and to increase sawlog diameters. Precommercial thinning along with early commercial thinning can significantly increase sawlog productivity when compared with the use of commercial thinnings only. Tree-length logging will become a common method for wood extraction in final harvests where both sawlogs and pulpwood are produced. Skidders mounted with logging arches are effective for wood extraction after felling trees with chainsaws. Comparative yield calculations are presented for veneer log production with two thinning systems.

Felling and Skidding Costs Associated with Thinning a Commercial Appalachian Hardwood Stand in Northern West Virginia

Abstract Detailed cost information on thinning operations is needed to develop economic guidelines for managing immature central Appalachian hardwood stands. Three thinning treatments were applied in a 50-yr-old mixed-oak, cove hardwood stand in northern West Virginia. A commercial logging contractor using chain saws and a rubber-tired skidder conducted the logging operations. Time-study data were used to compute production rates for felling marked trees and skidding tree-length logs to roadside landings for each thinning treatment. Production rates ranged from 2.7 to 3.0 cunits/hr depending on the residual stocking treatment. The cost of merchantable material at roadside ranged from $10.79 to $11.99 per cunit. Regression equations for predicting felling and skidding times were developed for each treatment. Data from these equations can be used in estimating production rates and costs for similar thinning operations. A nomogram is provided for estimating felling and skidding costs for a 60% residual stocking treatment, the current recommended silvicultural prescription for stands similar to the study area. North. J. Appl. For. 3:159-163, Dec. 1986.

Thinning Mountain Hardwoods with a Truck-Mounted Crane

Abstract The truck-mounted crane (TMC) is a cable yarder that shows promise for logging thinnings on moderate to steep slopes. A commercial thinning using the TMC yarder on moderate slopes in an overstocked stand of 60-year-old cherry-maple poletimber and small sawtimber showed that a 3-man crew could harvest 51 tons (21.5 cords) of tree-length logs per 8-hour day when extracting stems averaging 10 in dbh. The cost to fell, yard, and deck stems of this size averaged $9.60 per ton ($22.73 per cord), including cost of road construction. Truck-mounted crane yarding results in minimum damage to the residual stand, thus ensuring increased value of future crop trees. The environmental impact is light, because fewer roads are required, and forest soils and stream courses are disturbed less than with conventional logging methods. North J. Appl. For. 2:87-90, Sept. 1985.

Predicting Axle Loads on Trucks Hauling Tree-Length Logs

Abstract A methodology for predicting legal weight of loads of tree-length stems on tractor-trailer trucks is presented, with examples. The technique uses tree profile equations to predict center of mass and weight of stems. Load distribution on axles is accomplished by simplifying a formula based on the method of moments. One finding shows that with overhang longer than 15 feet, rear axles become overloaded before the maximum gross weight is reached.

Low-site class black spruce and jack pine nutrient removals after full-tree and tree-length logging

An old, merchantable, low-site class black spruce (Piceamariana (Mill.) B.S.P.) stand growing on a Lithic Humo-Ferric Podzol overlying a granite bedrock, and a younger but merchantable low-site class jack pine (Pinusbanksiana Lamb.) stand growing on a Ferro-Humic Podzol overlying a deep coarse sand near Baie Comeau, P.Q., were analysed for stand biomass and macronutrient contents of both stand and soil. The magnitude of the depletions of macronutrients from the site, in full-tree and tree-length methods of logging, are compared with their available and total quantities in the soil. The range of values from the literature for nutrient inputs are presented and discussed in relation to logging losses. The results suggest that full-tree logging in the dry jack pine stand could cause a severe loss of potentially mineralizable N supply; P, K, and Mg deficiency problems owing to export are not apparent, but a Ca balance problem is apparent. The implication is that full-tree logging should be avoided on such sites.

Effects of clearcutting and site preparation on stormflow volumes of streams in Pinus elliottii flatwoods forests

Three operational-sized watersheds in pine flatwoods of the Lower Coastal Plain in north Florida were isolated and continuously monitored for 3 1 2 years. Recording flumes assessed quantity of runoff water. After 1 year of calibration monitoring, two of the watersheds were, harvested, site-prepared, and planted under distinct harvest and regeneration practices. Minimum practices, imposed on one watershed, consisted of manual shortwood harvest of pinelands, roller drum chopping of harvest residues and residual understory, bedding, and planting. Maximum practices, imposed on another, consisted of tree-length logging of pinelands with heavy equipment, extraction of lightwood stumps, burning and windrowing of logging residue and residual understory, harrowing, bedding, and planting. Both silvicultural systems increased stormflow volumes; maximum practices moreso. Under both systems stormflow volumes apparently increased immediately following tree harvests. The increase persisted through site preparation, planting, and subsequently for 1 1 2 years without further detectable change. Results of this and two earlier reports on the effects of silviculture on hydrologic regimes of flatwoods forests are reviewed and summary conclusions drawn.

Effects of different harvesting and site preparation operations on the peak flows of streams in Pinus Elliottii flatwoods forests

Stream flows on three poorly drained and contiguous pine flatwoods catchments were monitored for 3.5 years. One was left untouched. Pine timber from another was manually harvested at the end of the 1st year, residues were chopped, terrain was bedded, and pine seedlings planted — a minimum series of forest operations. The third was subjected to a maximum series of forest operations — harvesting of tree-length logs with heavy equipment, lightwood stump removal, burning, windrowing, discing, bedding, and planting. Unlike the minimum series, the maximum series of forest operations significantly increased the peak outflows, particularly following windrowing. The increase was estimated to exceed sixfold immediately following windrowing and to decrease slowly and linearly with time thereafter (equation 3).

Effects of clearcutting and site preparation on water yields from slash pine forests

Three operational-sized watersheds in poorly-drained pine flatwoods forests on sandy soils of the Lower Coastal Plain in north Florida were isolated and continuously monitored for more than 3 years. Recording flumes assessed quantity of runoff water. After 1 year of calibration monitoring, two of the watersheds were harvested, site-prepared, and planted under distinct harvest and regeneration practices. Minimum practices, imposed on one watershed, consisted of manual shortwood harvest of pinelands, roller drum chopping of harvest residues and residual understory, bedding, and planting. Maximum practices, imposed on another, consisted of tree length logging of pinelands with heavy equipment, extraction of lightwood stumps, burning and windrowing of logging residue and residual understory, harrowing, bedding, and planting. Both systems increased water yields. Following minimum practices, yield increased intermittently depending on weather. Following maximum practices the increase in water yield was quicker, larger, and more persistent over various seasons and weather conditions. In both cases water yields returned to preharvest levels or less within the year following planting.

Understory biomass and nutrients 2 years after timber harvest in northern Minnesota

Adjacent areas within a 60-year-old Abiesbalsamea (L.) Mill. – Betulapapyrifera Marsh, stand in northern Minnesota, U.S.A., were clear-cut by whole-tree logging or tree-length logging followed by prescribed burning. Two years after harvest, understory biomass and nutrients were sampled on these sites and on an adjoining uncut control. All logged sites had significantly more total aboveground understory biomass than the control. However, biomass of woody species on the tree-length logged burn area did not differ from the control site. Because of the greater biomass on harvested sites, nutrient accumulations (N, P, K, Ca, Mg) by the understory were greater, with about 75% of these extra nutrients in herbs and shrubs. Although the quantity of nutrients in the understory is less than that removed with the overstory, it is important in maintaining the nutritional integrity of the system because it serves as a sink for available nutrients.

Phytosociological changes in understory vegetation following timber harvest in northern Minnesota

Impacts on the understory of a balsam fir (Abiesbalsamea (L.) Mill.) – paper birch (Betuiapapyrifera Marsh.) stand, caused by winter and spring full-tree logging and by winter tree-length logging which was followed by summer burning, were monitored for two growing seasons after overstory harvest. New species invaded full-tree logging sites, while compositional changes on the burned area were due primarily to the disappearance of species. Prescribed burning on the tree-length logging area prevented the quick increase in density of woody species that occurred on full-tree harvested sites. However, understory production increased on all sites, and by the end of the second season aboveground biomass was 3847, 4516, and 2604 kg/ha on the winter full-tree, spring full-tree, and winter tree-length plus burning sites, respectively, compared with 942 kg/ha on the uncut control.The major factors causing differences were prescribed burning and snow cover during harvest operations. Since our results concur with previous findings and appear predictable, resource managers can choose the technique best suited to specific objectives. However, no matter which system is used, the same core species will persist afterward, and if succession is allowed to continue, an understory will develop similar to that existing before harvest.