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.

The relationship between height and diameter trees of Scots pine (Pinus sylvestris L.) and the extent of crown defoliation in the Kampinos National Park

Forests in Kampinos National Park contain some of the most valuable tree populations in Poland. Particularly interesting are stands of Scots pine (Pinus sylvestris L.) that are more than 130-years-old. Periodic observations of the health of tree crowns in these stands facilitates a wide range of research investigations. This article evaluates statistical relationships between allometric features of trees and the occurrence and severity of crown defoliation.Observations were made of 5 pine populations in 2017 and 2019, in which detailed data were collected for 250 trees. The percentage loss of the assimilation apparatus and level of stand damage were calculated.The results revealed a significant increase in defoliation between 2017 and 2019. The deterioration of crown condition was particularly evident on the most fertile sites. The degree of crown damage was not correlated with tree height or diameter. The greatest increase in defoliation between 2017 and 2019 was observed for the most severely damaged trees growing on fertile sites.This study contributes analyses aimed at correlating the allometric features of a stand with its health. Such information is valuable as it describes the status of the analysed stands, as well as providing information about how trees have responded to environmental conditions. In this study, crown defoliation coincided with a period of drought in Poland, which appears to have affected pine stands. For these reasons, the results are of both scientific and practical value.

Health condition of young spruce stands growing in Poľana in different altitudes

This paper presents the first results of chlorophyll fluorescence measurements on assimilatory apparatus of Norway spruce. Three young spruce stands located in various altitudes (600, 1,050 and 1,250 m above sea level) were selected for the measurements. Chlorophyll fluorescence a was measured by a portable fluorimeter PEA. These measurements were performed on three needle year-classes. We found greater stand damage on the areas which are located in higher altitudes, but only at the end of growing season.

Reduction of timber value from damaged spruce stands after their dieback

The paper presents a method for the derivation of total timber production and of increments in value units, particularly in net financial yield for spruce stands damaged by crown defoliation after their dieback. The value production was derived by means of value growth models of undamaged stands and models for the adjustment of volume and qualitative production of damaged and died stands. Changes in timber quality after tree drying and changes in the production of damaged stands compared with undamaged ones are illustrated in tables and graphs. The changes are expressed by means of the indexes of total mean increment and total current increment. They depend mainly on the degree of stand damage expressed by crown defoliation, age and yield class of stand, the age of stand when the damage started and duration of damage. The value of damaged stands after their dieback is lover minimally by 50% than before their dieback. It is caused mainly by deteriorated quality of timber from dead trees in stand.