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Stand density changes due to aging and thinning interventions. At the same time, the social status of trees develops and varies due to different genetic conditions as well as access to nutrients and light. Trees growing in diverse conditions gain their social status in the stand, which, in the end, influences their development and biomass allocation. The objective of this research was to discover if stand density or tree social status has an impact on a tree’s aboveground biomass allocation. The study was carried out in five premature and five mature pine stands, growing in the same soil conditions. The selected sample stands had a different growing density, from low to high. In each sample stand, 10 trees were selected to represent a different social status, according to the Schädelin classification. There were 100 trees felled in total (50 in the premature stands and 50 in the mature stands), for which the dry biomass of the stem, living and dead branches, needles, and cones was determined. The results showed that stand density only had an impact on the branches’ biomass fraction but not the stem and foliage fractions, while social status had an impact on all the fractions. Dominant and codominant trees, as well as those with developed crowns, had a smaller share of the stem and higher share of branches in comparison with trees of a lower social status.
Bogdan Wertz; Mariusz Bembenek; Zbigniew Karaszewski; Wojciech Ochał; Maciej Skorupski; Paweł Strzeliński; Andrzej Węgiel; Piotr S. Mederski. Impact of Stand Density and Tree Social Status on Aboveground Biomass Allocation of Scots Pine Pinus sylvestris L. Forests 2020, 11, 765 .
AMA StyleBogdan Wertz, Mariusz Bembenek, Zbigniew Karaszewski, Wojciech Ochał, Maciej Skorupski, Paweł Strzeliński, Andrzej Węgiel, Piotr S. Mederski. Impact of Stand Density and Tree Social Status on Aboveground Biomass Allocation of Scots Pine Pinus sylvestris L. Forests. 2020; 11 (7):765.
Chicago/Turabian StyleBogdan Wertz; Mariusz Bembenek; Zbigniew Karaszewski; Wojciech Ochał; Maciej Skorupski; Paweł Strzeliński; Andrzej Węgiel; Piotr S. Mederski. 2020. "Impact of Stand Density and Tree Social Status on Aboveground Biomass Allocation of Scots Pine Pinus sylvestris L." Forests 11, no. 7: 765.
Thinning is one of the most important tools of forest management, although thinning operations require the use of machines which ultimately cause damage to the remaining stand. The level of damage largely depends on the human factor, and a tired, less focused operator will create more injuries in the forest. With this in mind, the objectives of this research were to find out whether the probability of tree damage caused by an operator is also affected by: (1) the part of the day (dawn/day/dusk/night), and (2) the cumulative shift time. The research was carried out in pure pine stands of different ages, density and thinning intensities. Sample plots were selected that had an increasing number of trees per hectare and growing thinning intensities were applied. The same Komatsu 931.1 harvester was used for the thinning operations in each stand. In all the age classes combined, 5.41% of the remaining trees were wounded. There was a significant influence of the part of the day on the percentage of damaged trees, which was positively correlated with the cumulative shift time. Stand conditions, such as age class and stand density, as well as thinning characteristics—thinning intensity, number of harvested trees and productivity—have different effects on the distribution of damage intensity and on probability. The results may improve the planning of operators’ work shifts in forests of various ages and densities, allowing harvester productivity to be maintained while at the same time inflicting the lowest possible level of damage.
Mariusz Bembenek; Petros A. Tsioras; Zbigniew Karaszewski; Bogna Zawieja; Ewa Bakinowska; Piotr S. Mederski. Effect of Day or Night and Cumulative Shift Time on the Frequency of Tree Damage during CTL Harvesting in Various Stand Conditions. Forests 2020, 11, 743 .
AMA StyleMariusz Bembenek, Petros A. Tsioras, Zbigniew Karaszewski, Bogna Zawieja, Ewa Bakinowska, Piotr S. Mederski. Effect of Day or Night and Cumulative Shift Time on the Frequency of Tree Damage during CTL Harvesting in Various Stand Conditions. Forests. 2020; 11 (7):743.
Chicago/Turabian StyleMariusz Bembenek; Petros A. Tsioras; Zbigniew Karaszewski; Bogna Zawieja; Ewa Bakinowska; Piotr S. Mederski. 2020. "Effect of Day or Night and Cumulative Shift Time on the Frequency of Tree Damage during CTL Harvesting in Various Stand Conditions." Forests 11, no. 7: 743.
Obtaining high harvester efficiency in young pine stands during early thinning is achallenging management practice. One of the difficulties lies in achieving the optimal use of the tree trunk for assortments and obtaining satisfactory timber quality. The objective of this research was to find out 1) how much of the tree trunk can be processed by a harvester to produce logs, and 2) the quality of the assortments in terms of log length accuracy and delimbing quality. The work was carried out in a 31-year-old pine stand in northern Poland with the Vimek 404 5T harvester with the Keto Forst Silver head for early thinning. Eighty sample plots were set up within the stand for detailed tree analysis after harvesting. The total length of the assortments from each tree was measured as well as the minimal top diameter (under bark). Additionally, the lengths of the bottom, middle and top logs were measured as well as the height of the knots after delimbing. On average, 70% of the total tree height was used for assortments and logs were processed up to a mean top diameter of 5.3 cm under bark. The length accuracy was very high: 90% of the logs had the expected length, more than 9% had a commercially acceptable length, while only 0.7% of the logs were too long. After delimbing, the knots were of a maximum height of 2 cm. Using the Vimek 404 5T harvester in the 31-year-old pine stand was an effective solution for trunk processing and obtaining quality assortments.
Piotr S. Mederski; Konrad Werk; Mariusz Bembenek; Zbigniew Karaszewski; Mariusz Brunka; Kwiryn Naparty. Harvester efficiency in trunk utilisation and log quality of early thinning pine trees. Forest Research Papers 2019, 80, 45 -53.
AMA StylePiotr S. Mederski, Konrad Werk, Mariusz Bembenek, Zbigniew Karaszewski, Mariusz Brunka, Kwiryn Naparty. Harvester efficiency in trunk utilisation and log quality of early thinning pine trees. Forest Research Papers. 2019; 80 (1):45-53.
Chicago/Turabian StylePiotr S. Mederski; Konrad Werk; Mariusz Bembenek; Zbigniew Karaszewski; Mariusz Brunka; Kwiryn Naparty. 2019. "Harvester efficiency in trunk utilisation and log quality of early thinning pine trees." Forest Research Papers 80, no. 1: 45-53.
In forestry interventions such as thinning or selection cutting, appropriate road and skid trail networks are essential for efficient forest operations, but also for limiting damage to the residual stand and soil. Recently, multiple studies have shown the advantage of precision forestry and the use of a geographic information system (GIS) in forest road network planning, replacing time-consuming manual measurements and skid trail design directly in the forest. The objective of this research was to test the accuracy of three GIS-based methods, the correct distance method (CDM), real distance buffer method 12 (RDBM12) and real distance buffer method 10 (RDBM10), in estimating the area accessible for winching along skid trails. The study was carried out in two mountain areas, Fibbino and San Martino al Cimino (Italy). All the methods for determining the winching area were based on GIS and digital terrain model (DTM) maps. Additionally, control distances were measured manually in both areas and the results were compared with the distances measured using the GIS methods. The initial results showed that all the methods were useful for determining the winching area in mountain conditions. However, in conclusion, the CDM and RDBM10 methods were more accurate and can be recommended for further use and development.
Rodolfo Picchio; Francesco Latterini; Piotr S. Mederski; Rachele Venanzi; Zbigniew Karaszewski; Mariusz Bembenek; Michele Croce. Comparing Accuracy of Three Methods Based on the GIS Environment for Determining Winching Areas. Electronics 2019, 8, 53 .
AMA StyleRodolfo Picchio, Francesco Latterini, Piotr S. Mederski, Rachele Venanzi, Zbigniew Karaszewski, Mariusz Bembenek, Michele Croce. Comparing Accuracy of Three Methods Based on the GIS Environment for Determining Winching Areas. Electronics. 2019; 8 (1):53.
Chicago/Turabian StyleRodolfo Picchio; Francesco Latterini; Piotr S. Mederski; Rachele Venanzi; Zbigniew Karaszewski; Mariusz Bembenek; Michele Croce. 2019. "Comparing Accuracy of Three Methods Based on the GIS Environment for Determining Winching Areas." Electronics 8, no. 1: 53.
Stand density changes during forest growth. Various types and intensities of thinning operations can be applied in order to improve the volume of the remaining trees. It is not clear whether or not thinning results in better total volume increment although timber value is usually higher when thicker logs are obtained from trees. The objective of this study was to determine if Scots pine (Pinus sylvestris L.) stands of lower density would produce timber of a higher value than stands with a higher density and thinner trees. The research was carried out on 20 experimental plots in 81–90-year-old Scots pine stands, located in north-western Poland. The data obtained were used to simulate the logging of the trees into either 2.5-m logs or tree tops, which were classified into five quality classes of timber. The volume of each assortment was calculated, based on its dimensions, and the value in EUR was calculated. It was found that the correlation between stand density and the total value of the wood was very weak and not statistically significant. However, taking each assortment separately, the values of sawmill wood, pulpwood and energy wood were significantly correlated with stand density. It was concluded that lower densities were more profitable for sawmill wood production, while higher densities might be more beneficial in biomass production.
Andrzej Węgiel; Mariusz Bembenek; Agnieszka Łacka; Piotr S Mederski. Relationship between stand density and value of timber assortments: a case study for Scots pine stands in north-western Poland. New Zealand Journal of Forestry Science 2018, 48, 12 .
AMA StyleAndrzej Węgiel, Mariusz Bembenek, Agnieszka Łacka, Piotr S Mederski. Relationship between stand density and value of timber assortments: a case study for Scots pine stands in north-western Poland. New Zealand Journal of Forestry Science. 2018; 48 (1):12.
Chicago/Turabian StyleAndrzej Węgiel; Mariusz Bembenek; Agnieszka Łacka; Piotr S Mederski. 2018. "Relationship between stand density and value of timber assortments: a case study for Scots pine stands in north-western Poland." New Zealand Journal of Forestry Science 48, no. 1: 12.
The application of a harvester for thinning operations in young stands can pose several dilemmas. Firstly, the value of the timber obtained should be higher than the cost of the thinning operation—this is especially difficult with young stands, where the timber is of a small size and productivity is low. In addition, small harvesters used for thinning usually have short cranes, less than 10 m in length, which is rather impractical in stands where the distance between strip roads is a standard 20 m. The aim of this research was to select the best mechanised thinning operation, taking into account economic suitability and some environmental aspects (damage to the remaining stand and density of strip roads). The research was carried out in a 31-year-old pine stand (11.27 ha) in which three different harvester thinning (T) operations were designed: TM1) with midfield and one harvester pass, TM2) with midfield and two harvester passes and TWM) without midfield and one harvester pass. In all the proposed operations, a Vimek 404 T5 harvester (with a 4.6 m-long crane) and a Vimek 606 TT forwarder were used. The most economic operation was TWM, with a total cost of €13.73 m−3, while TM1 was 13% more expensive at €15.51 m−3. The lowest level of damage, 1.5%, was recorded in TWM, while in TM1 the level was 2.1%. The TWM operation required a net of strip roads twice as dense as in TM1. Taking into account all the analysed aspects, a thinning operation with midfield and one harvester pass is recommended when using the Vimek 404 T5 harvester and the Vimek 606 TT forwarder in the first thinning of a pine stand.
Piotr S. Mederski; Rachele Venanzi; Mariusz Bembenek; Zbigniew Karaszewski; Martyna Rosińska; Zenon Pilarek; Irene Luchenti; Michał Surus. Designing Thinning Operations in 2nd Age Class Pine Stands—Economic and Environmental Implications. Forests 2018, 9, 335 .
AMA StylePiotr S. Mederski, Rachele Venanzi, Mariusz Bembenek, Zbigniew Karaszewski, Martyna Rosińska, Zenon Pilarek, Irene Luchenti, Michał Surus. Designing Thinning Operations in 2nd Age Class Pine Stands—Economic and Environmental Implications. Forests. 2018; 9 (6):335.
Chicago/Turabian StylePiotr S. Mederski; Rachele Venanzi; Mariusz Bembenek; Zbigniew Karaszewski; Martyna Rosińska; Zenon Pilarek; Irene Luchenti; Michał Surus. 2018. "Designing Thinning Operations in 2nd Age Class Pine Stands—Economic and Environmental Implications." Forests 9, no. 6: 335.
Introduction and Objectives: Holding determined body postures during work is connected with muscles activity. The more forced the posture, the larger the number of muscles taking an active part in holding and stabilizing the work posture. During logging, the greatest share of awkward (forced)...
Witold Grzywiński; Tomasz Jelonek; Arkadiusz Tomczak; Marcin Jakubowski; Mariusz Bembenek. Does body posture during tree felling influence the physiological load of a chainsaw operator? Annals of Agricultural and Environmental Medicine 2017, 24, 401 -405.
AMA StyleWitold Grzywiński, Tomasz Jelonek, Arkadiusz Tomczak, Marcin Jakubowski, Mariusz Bembenek. Does body posture during tree felling influence the physiological load of a chainsaw operator? Annals of Agricultural and Environmental Medicine. 2017; 24 (3):401-405.
Chicago/Turabian StyleWitold Grzywiński; Tomasz Jelonek; Arkadiusz Tomczak; Marcin Jakubowski; Mariusz Bembenek. 2017. "Does body posture during tree felling influence the physiological load of a chainsaw operator?" Annals of Agricultural and Environmental Medicine 24, no. 3: 401-405.
In this paper the values of energy expenditure obtained with estimative methods (tables of energy expenditure, Lehmann’s method) were compared to the data obtained with a method based on pulmonary ventilation measurements. Thereby, the usefulness of estimative methods for determining energy expenditure on work stations in forestry was tested. We compared energy expenditures for 30 forestry workstations within which 59 different activities were distinguished. For each activity the energy expenditure was determined utilizing the three following methods: pulmonary ventilation measurement, tables of energy expenditure and Lehmann’s method. The percentage error in energy expenditure for particular activities determined with tables ranged from -44.47% to 42.31%. The highest representation of error value (52.8%) varied between -19.9% and 5.0%. The error in energy expenditure estimation determined with Lehmann’s method is characterised by a smaller variability ranging from -31.35% to 34.13%. The highest density of error values was found in the range from -4.9% to 10.0%, which comprises 44.1% of the results. To conclude, the use of tables resulted in an underestimation of the energy expenditure value for 64.1% of activities, whereas the use of Lehmann’s method resulted in an underestimation in 49.1% of the cases.
Witold Grzywiński; Piotr S. Mederski; Mariusz Bembenek. Comparing methods of energy expenditure estimation using forestry as an example. Forest Research Papers 2015, 75, 417 -421.
AMA StyleWitold Grzywiński, Piotr S. Mederski, Mariusz Bembenek. Comparing methods of energy expenditure estimation using forestry as an example. Forest Research Papers. 2015; 75 (4):417-421.
Chicago/Turabian StyleWitold Grzywiński; Piotr S. Mederski; Mariusz Bembenek. 2015. "Comparing methods of energy expenditure estimation using forestry as an example." Forest Research Papers 75, no. 4: 417-421.
Mariusz Bembenek; Piotr Mederski; Zbigniew Karaszewski; Agnieszka Łacka; Witold Grzywiński; Andrzej Wegiel; Dieter F. Giefing; Jörn Erler. Length accuracy of logs from birch and aspen harvested in thinning operations. TURKISH JOURNAL OF AGRICULTURE AND FORESTRY 2015, 39, 845 -850.
AMA StyleMariusz Bembenek, Piotr Mederski, Zbigniew Karaszewski, Agnieszka Łacka, Witold Grzywiński, Andrzej Wegiel, Dieter F. Giefing, Jörn Erler. Length accuracy of logs from birch and aspen harvested in thinning operations. TURKISH JOURNAL OF AGRICULTURE AND FORESTRY. 2015; 39 ():845-850.
Chicago/Turabian StyleMariusz Bembenek; Piotr Mederski; Zbigniew Karaszewski; Agnieszka Łacka; Witold Grzywiński; Andrzej Wegiel; Dieter F. Giefing; Jörn Erler. 2015. "Length accuracy of logs from birch and aspen harvested in thinning operations." TURKISH JOURNAL OF AGRICULTURE AND FORESTRY 39, no. : 845-850.
Damage to the remaining stand is an unavoidable consequence of thinning operations. The different machines used for timber extraction differ in the level of damage of trees they cause, mainly through wounds to the bark and cambium which can make a substantial impact on the remaining trees. Three different methods of timber harvesting with a chainsaw were analyzed: the short wood system (SWS), the long wood system (LWS) and the full tree system (FTS) in which an agricultural tractor is used for timber extracting. All systems were analyzed in stands containing three different age classes: 2nd (21-40 years), 3rd (41-60 years) and 4th (61-80 years). The level of damage to the remaining stand was assessed considering the percentage of trees exhibiting wounds (scratched bark and/or damage to the cambium) to calculate an index of stand damage (WDI) which incorporated the volume of harvested timber per hectare. The SWS produced the lowest damage to trees in stands of all age classes: average 5%, with the less damage in the oldest stand. After using the LWS, 9% of trees were wounded; in this method there was no statistical difference in frequency of wounding across all the analyzed stands. The highest level of damage was incurred after the FTS, causing 11% of trees to be injured. In stands of the 2nd age class, the method of timber harvesting had no statistically significant effect on the amount of wounding endured. The WDI was lowest in SWS: 0.08, higher in LWS: 0.15 and the highest, 0.23, when FTS was applied.
Zbigniew Karaszewski; Dieter F. Giefing; Piotr S. Mederski; Mariusz Bembenek; Anita Dobek; Anastasia Stergiadou. Stand damage when harvesting timber using a tractor for extraction. Forest Research Papers 2013, 74, 27 -33.
AMA StyleZbigniew Karaszewski, Dieter F. Giefing, Piotr S. Mederski, Mariusz Bembenek, Anita Dobek, Anastasia Stergiadou. Stand damage when harvesting timber using a tractor for extraction. Forest Research Papers. 2013; 74 (1):27-33.
Chicago/Turabian StyleZbigniew Karaszewski; Dieter F. Giefing; Piotr S. Mederski; Mariusz Bembenek; Anita Dobek; Anastasia Stergiadou. 2013. "Stand damage when harvesting timber using a tractor for extraction." Forest Research Papers 74, no. 1: 27-33.
Mariusz Bembenek; Dieter F. Giefing. Strip road impact on selected wood defects of norway spruce (Picea Abies (L.) H. Karst). 2013, 63 -76.
AMA StyleMariusz Bembenek, Dieter F. Giefing. Strip road impact on selected wood defects of norway spruce (Picea Abies (L.) H. Karst). . 2013; (190):63-76.
Chicago/Turabian StyleMariusz Bembenek; Dieter F. Giefing. 2013. "Strip road impact on selected wood defects of norway spruce (Picea Abies (L.) H. Karst)." , no. 190: 63-76.