Potential of Wood Harvesting Residues and Residual Stand Damage due to Timber Harvesting: A Case Study at PT Austral Byna in Central Kalimantan, Indonesia

The practice of timber harvesting in natural forests which has been conducted up to now still leaves wood harvesting residue and residual stand damage. Most condition of wood harvesting residue is still good and can be utilized. The objective of this research was to determine the potency of wood harvesting residue and residual stand damage on timber harvesting in natural forests. The data on wood utilization, wood harvesting residue, and residual damage were collected from three sample plots. The sample plots were arranged in a systematic and purposive manner, and the data were processed with tabulation and average analysis. Research results showed that the average volume of wood being utilized was 9.212 m3 tree−1. The average volume of wood harvesting residues was 2.310 m3 tree−1, and the total average volume of wood harvesting residues which were good, defected, and broken was 2.121 m3 (80.952%), with an average volume for good wood harvesting residue condition of 1.038 m3 (34.808%). Proportions of wood harvesting residues were 2.154 m3 (94.444%) consisting of buttress as large as 0.102 m3 (5.159%), stumps as large as 0.375 m3 tree−1 (23.597%), butt as large as 0.855 m3 (35.930%), and end part as large as 0.821 m3 (29.758%). The average number of trees with a diameter of 20 cm which were damaged due to felling and skidding was 5 trees ha−1 (5.40%) and 6 trees ha−1 (6.58%), respectively.

Residual Stand Damage under Different Harvesting Methods and Mitigation Strategies

A major component of sustainable forest management are the stands left behind after the logging operation. Large mechanized harvesting equipment involved in current forest management can inflict damage on residual trees; and can pose a risk of mortality from diseases, natural calamities, and/or degrade future economic value. The primary objective of this study was to evaluate the residual stand damage under different harvesting methods and silvicultural prescriptions i.e., crop tree release (CTR), diameter limit cut (DLC), and overstory removal (OSR). The second objective was to evaluate the intensity and frequency of damage occurring on the bole, canopy, and root at tree and stand level. The third objective was to document strategies adopted globally to minimize stand damage due to timber harvesting. Five harvest blocks implementing three silvicultural prescriptions, were selected as the treatments across two different industrial timberlands in central and northern Maine (Study Site (SS) I and II, respectively). A hybrid cut-to-length (Hyb CTL) and whole-tree (WT) harvesting method were employed for conducting the harvest in SS I and II, respectively. Systematic transect sampling was employed to collect information on type, frequency, and intensity of damages. The inventory captured 41 and 8 damaged trees per hectare with 62 and 22 damages per hectare from SS I and SS II respectively. Bole damage was the most frequent damage across all treatments. The Hyb CTL had lower damage density (damage per ha) and severity compared to WT. The average number of trees damaged per ha was higher for CTR prescriptions compared to DLC. There were no significant differences in the height of the damages from the ground level between treatments within each study site; however, there was a significant difference between the study sites. Species damaged was directly related to the residual trees left behind and was dominated by American beech, yellow birch, sugar maple, and eastern hemlock. Finally, the study provides strategies that can be adopted at different forest managerial phases to mitigate residual stand damage.

Operational and Environmental Comparison of Two Felling and Piling Alternatives for Whole Tree Thinnings in Quercus Coppices for Bioenergy Use

A comparative study of motor-manual and mechanized felling and bunching was conducted when thinning dense coppice stands of the two most important oak species in Spain to obtain biomass for bioenergy use. In particular, the study matched chainsaw felling and manual piling against the work of a drive-to-tree feller-buncher in the very same sites. Productivity functions for felling and piling are fitted for each species. The derived unit cost functions show that the felling-bunching costs are lower for the motor-manual option in both species stands, particularly for the smaller tree sizes. Nevertheless, when the strongly reduced loading times in forwarding associated to the mechanization are taken into account, the total harvesting cost is often lower for the mechanized option. That is true for all tree sizes Q. ilex, and for trees larger than 13 cm diameter at breast height (DBH) for Q. pyrenaica. Residual stand damage was low to moderate, but always significantly greater for the mechanized option compared with the motormanual one. Soil damage was very low for both alternatives. The stumps experimented significantly greater damages in the mechanized felling and bunching, but further research is needed to determine if those damages have any impact on stump mortality, sprouting capability and future plants vigor. The greater productivity and level of tree damages found in Q.ilex when compared to Q. pyrenaica are likely due to the narrower and lighter crown of the latter.

Residual Stand Damage Due to Timber Harvesting in PT Tunas Timber Lestari, Papua

Timber harvesting activities can cause damage to residual stands, this can occur due to improper timber harvesting techniques. The study was conducted at one of PT Tunas Timber Lestari’s IUPHHK-HA in Papua Province. The results showed that: 1). The number of trees felled and skidded on 3 logging compartment with each of the 3 plot of observation sample has an area of 2 ha (the total area of the research is 18 ha) is 16 trees on average; 2). The average number of residual stand (trees with a diameter of ≥ 20 cm) damaged by logging is 26 trees (13.00%) per ha with details of damage to canopy of 4 trees (15.39%), broken branches of 13 trees (50.00%), the trunk wound of 2 trees (7.69%) and the collapsed/tilted of 7 trees (26.92%); 3). Damage to the residual stand in felling is caused more by the lack of skilled chainsaw operators in determining felling direction; 4) Damage to residual stands due to skidding is an average of 23 trees (9.99%) per ha, with details of 1 trees buttress (4.4%), wounds injuries of 7 trees steam (2.97) and collapsed/slanted 15 trees (65.2%); and 5). The cause of damage to the residual stand on skidding is that the skid trail has not been made and the skid tractor maneuvers too often.

Environmental Impacts to Residual Stand Damage due to Logging Operations in Hyrcanian Forest

The development of harvesting systems aims to provide physically feasible, economically viable, and environmentally sound solutions. Residual stand-damage data have been collected from a mixed broadleaved stand in Kheyrud area in Hyrcanian forest in the northern of Iran. After the harvesting operations, for all trees, damage to the bole, roots, extent of the damage, wounding patterns, size and distribution was assessed using stratified systematic sampling with a random start and fixed area plots. Results show that wounding occurred on 16.4% of the remaining trees, but the severity of wounding varied significantly by species. Forty-six percent of wounding for all species combined was considered as small size. The greatest average amount of damage, to a bole, occurred along the first 1m up from the ground and also within 3m of the skid trail centerline (86.4%). Gouges were present on 79% of all scars. The stratification of the study unit would effectively improve accuracy of stand damage surveys. Selection of the appropriate method for damage reduction to trees adjacent skid trails was crucial. According to the results, skidding damage cannot be completely avoided in practice. We suggest that the education and the entertainment of the foresters and workers in forest would be enhanced and the injuries could be explained before the harvesting to the workers. In such a way the damages would be less in the future.

A Comparison of Residual Stand Damage along Yarding Trails in a Group Selection Harvest Using Four Different Yarding Methods

A study of residual stand damage along yarding trails associated with four harvest methods—harvester/forwarder and cable skidder, tractor, and bulldozer with chainsaw felling—was conducted in a group selection harvest of a mixed hardwood stand in Maine. Tractive yardingmethods were associated with greater numbers of damaged trees per meter of trail length. In addition, the bulldozer method resulted in the largest number of damaged boles per 100 m2 of near-trail space, whereas the smallest number of damaged boles per 100 m2 was associatedwith the forwarder method. The tractor method resulted in the most root damage, and the forwarder method resulted in the largest trail width. These results have implications for equipment selection and the planning of harvests and harvest access systems.

Residual Stand Damage from Cut-to-Length Thinning of a Mixed Conifer Stand in Northern Idaho

We collected residual stand-damage data from a mixed conifer stand in northern Idaho that had been commercially thinned with a cut-to-length harvesting system. The stand composition after harvesting was 76% grand fir (Abies grandis); 14% Douglas-fir (Pseudotsuga menziesii var. glauca); 5% western redcedar (Thuja plicata); and 5% lodgepole pine (Pinus contorta), western white pine (Pinus monticola), and ponderosa pine (Pinus ponderosa). For all crop trees, damage to the bole, roots, and crown was assessed using systematic sampling with a random start and fixed area plots. Wounding occurred on 37.4% of the remaining trees, but the severity of wounding varied significantly by species (P < 0.05). Eighty-four percent of wounding for all species combined was considered as small size (<194 cm2). The greatest average amount of damage to a bole occurred along the first 2 m up from the ground (67.2%) and also within 4 m of the forwarder centerline (67.7%). Gouges were present on 41% of all scars. Tree location to forwarder trail appears to have a significant effect on the number and height of scars on a tree (P < 0.05). We estimated that throughout a 20-year period, volume losses for grand fir because of decay would be 2.57% compared to 1.31% in an undamaged stand of similar composition. West. J. Appl. For. 21(3): 142–148.