Arkadiusz Tomczak

Mass and density of pine pulpwood harvested in selected stands from the forest experimental station in Murowana Goślina

The aim of this analysis was to determine the mass of pine pulpwood, harvested from fresh-cutting trees. Analyses were made in four pine stands (aged 45, 47, 55 and 56). In each plot a total of 30 model trees were selected from among trees to be felled as a part of planned intermediate cutting. The average mass of one log of 2.5 m length ranged from 26.3 kg to 44.0 kg, at a mean of 33.9 kg. The total volume of timber harvested was 21.68 m3 with a total mass of 21 222.4 kg. When converted to 1 m3 the mass of timber was assessed at 979 kg. The ratio of actual density (979 kg/m3) to tabular density (740 kg/m3) was thus 1.3:1. As a result the actual mass of timber is approx. 30% higher than the mass that may be estimated based on the tabular density of wood assessed for the purpose of road transportation. At the stem profi le the mass of logs decreases (which is the result of stem diameter decreasing with height), while green density increases. The increase in green density of logs is probably the result of changes in porosity and moisture content of wood, as well as changes in the proportion and properties of bark.

Radial variation in the wood properties of Scots pine (Pinus sylvestris L.) grown on former agricultural soil

Abstract The soil of former farmland greatly differs from forest soil, and significantly influences tree growth and development compared with other site factors. The effect may also be reflected indirectly in radial variability of wood. This study compared radial variation of wood density, compressive strength along the grain and static bending strength of wood of Scots pine trees growing on former farmland and forest soils. The analyses were conducted in eight mature pine stands. On the basis of the stand description, four stands were classified as growing on forest soil (L) and four as growing on former farmland soil (P). A total of 24 model trees were selected, twelve on each soil type. Analyses of wood properties were conducted along four axes from the cross sectional radius of the trees at breast height. Our analyses showed that radial variation in wood properties of Scots pine (from selected locations in Poland) growing on former farmland is similar to the variation among the control trees growing on forest soils. In both groups of trees, the lowest density and the lowest strength were in the pith (juvenile) zone. Wood with the highest density and greatest strength was located in the central part of the radius. Wood of Scots pine trees growing on former farmland soils in comparison to that of trees growing on forest soil was characterised by a statistically lower basic density, lower compressive strength along the grain and static bending strength.

Modelling needle biomass in Scots pine (Pinus sylvestris L.) stands on former farmland and forest soils

Model biomasy igliwia sosny zwyczajnej (Pinus sylvestris L.) wyrosłej w warunkach gruntów porolnych i leśnych Modelling needle biomass in Scots pine (Pinus sylvestris L.) stands on former farmland and forest soils The relationship between the biometric traits of Scots pine (Pinus sylvestris L.) trees and their total needle biomass was analysed and the foliage of these trees growing in 38 stands in northern and western Poland was modelled. Productive pine stands were chosen on former farmland and forest soil providing locally optimal conditions for growth. A total of 114 trees aged between 32 and 114 years old were felled and their total biomass of fresh needles was calculated. Out of all the traits measured, diameter at breast height (DBH) was the best predictor of foliage biomass. Since the two models produced to describe this relationship on forest soils (Mi = 0.093614 D1.31.679398), and farmland (Mi = 0.060302 D1.31.819009) were very similar, they may be used interchangeably. However, as they aged, needles of pines growing on former farmland deteriorated faster than those on forest soil with respect to their assimilation capacity. This suggests that the assumptions of Pipe Model Theory need to be verified.

Selected properties of wood in Scots pine (Pinus sylvestris L.) growing on post-agricultural land in northern Poland

Właściwości drewna sosny zwyczajnej (Pinus sylvestris L.) na gruntach porolnych w północnej Polsce Selected properties of wood in Scots pine (Pinus sylvestris L.) growing on post-agricultural land in northern Poland Analyses were conducted on wood of Scots pines collected from timber stands growing on post-agricultural land and forest land in the fresh coniferous (Bśw) and fresh mixed coniferous (BMśw) forest habitats located in the territory of the Miastko Forest District. The wood of pines growing on post-agricultural land in the BMśw habitat conditions had the highest basic density and lowest compression strength along the grain among the tested sample groups. The arrangement of wood properties was not typical with regard to the social position of trees in a stand. The obtained results have shown the lack of a direct relationship between wood basic density and compression strength along the grain. The analyses performed pointed to differences in the properties of wood tissues between pines growing on post-agricultural land and pines growing on typical forest soils.

The use of wood and the possibility of planting trees of the Paulownia genus

The aim of the study was to approximate the empirical distribution of diameter at breast height, height and crown length using theoretical distributions: normal, log-normal, Weibull, Gaussian mixture and Johnson’s SB. For the distribution of all characteristics in the stands in the fresh mixed forest site and additionally for crown length in the fresh mixed coniferous forest site, the distribution of the Gaussian mixture was best matched, in other cases the most accurate approximation was provided by Johnson’s SB distribution. The obtained relationships may be helpful in predicting stand development and in forest management planning, while in the future they may be an important step in the development of a local model of pine stand growth.Several hydrological objects have been erected in the Nadwarciański Landscape Park as ecological compensation measures to mitigate the effect of habitat destruction caused by the construction of the A2 highway. In permanent experimental plots established in those objects a vegetation cover survey was performed in 2010, 2011 and 2016 and ecological indicators were calculated. The effectiveness of these measures to restore nature value was analysed, showing the hydrological objects to be ineffective. Water conditions in the Warta river valley have not improved, while a decrease in species richness and simplification of plant communities have been observed.The work presents a review of the literature concerning the industrial use of the Paulownia genus. The purpose of the study was to analyse the current state of knowledge and potential for planting industrial hybrids of Paulownia. The paper presents botanical affiliation, a brief historical outline, the use of wood, climate requirements and experience with young hybrid crops. Based on the literature review, it may be concluded that the main purpose of cultivation in short cycles is to produce wood pulp for the needs of the pulp and energy industry rather than the other branches of the wood industry. It is worth noting that the provided technical parameters, chemical composition, requirements for growing conditions and biomass production, differ for the other species of Paulownia as well as various hybrids. It cannot be definitely stated that Paulownia is a universal species and gives the same effects under various conditions, but an attempt should be taken to determine the suitability of selected species or their hybrids for specific purposes.

Does body posture during tree felling influence the physiological load of a chainsaw operator

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) working postures occurs in tree felling by chainsaw. MATERIAL AND METHODS A group of 10 experienced fellers aged 47.5±7.3 (37 - 59-years-old) was studied. Heart rate (HR) was measured during simulation of felling activity in 4 working postures: back bent forward with straight legs (stoop), back bent forward with bent legs (flexed-stoop), squat and kneeling on one knee (half-kneel). RESULTS The lowest value of HR was noticed for squatting - 114.1 bpm, then for kneeling on one knee - 116.3 bpm. HR during felling in a standing posture with straight legs amounted to 121.5 bpm and for standing with bent legs 125.3 bpm. For all studied postures the differences in average HR values were statistically significant at p<0.01. CONCLUSIONS A working posture during tree felling by chainsaw has influence on the level of physiological workload of an operator. Standing bent forward body postures cause higher heart response than squatting and half-kneeling.

The infl uence of the selected ratios of trees stability on the wall thickness of tracheids in the Scots pine (Pinus sylvestris L.)

The study comprised an analysis of two tree stability indexes, i.e. slenderness factor (H/D1.3) and crown inclination index (DK/H) of thirty six pines coming from twelve mature stands growing at diff erent sites. Apart from stability for each tree tracheid wall thickness was determined at breast height in early and late wood. Results showed that examined trees belong to a group considered to be stable (Figs. 2, 3), while investigated stability indexes are negatively correlated (−0.64). Next tracheid wall thickness was determined in early wood to be 2.11 ±0.21 μm and for late wood at 6.84 ±1.08 μm. No signifi cant diff erences were found between examined plots in terms of investigated indexes or tracheid wall thickness in late wood. In contrast, statistically signifi cant dependencies were observed between the analysed indexes and tracheid wall thickness in early and late wood. Slenderness factor was most strongly correlated with tracheid wall thickness in late wood. Moreover, a dependence was also found between crown inclination index and tracheid wall thickness in early wood, which most probably may be explained by the relationship between the tree crown, which width was one of the variables in DK/H and hydraulic functions of anatomical elements. With an increase in the crown inclination index the mean tracheid wall thickness decreased, most probably leading to an increase in their lumen, which has a positive eff ect on their effi ciency in conductivity of water and minerals.

Correlation between selected elements of wood macrostructure and maturity of Scots pine (Pinus sylvestris L.) growing on post-agricultural land

Wybrane elementy budowy makrostrukturalnej drewna a dojrzałść sosny zwyczajnej (Pinus sylvestris L.) wyrosłej w warunkach gruntów porolnych Correlation between selected elements of wood macrostructure and maturity of Scots pine (Pinus sylvestris L.) growing on post-agricultural land The study was an attempt of comparing quantitative changes over time in selected wood macrostructural elements of Scots pines growing on former farmland, with those in trees growing on typical forest soils. The analysis was conducted on the basis of easily-determinable quality indexes taking into consideration average width of annual rings and the proportion of latewood in 5-year increment periods, the proportion of juvenile wood (Vm) and the proportion of heartwood (Vt). The study also compared selected biometric characteristics of trees, i.e. height (h), diameter at breast height (d), length (lk) and width (dk) of live crown; total stem volume (Vc) and determined a total of 48 model trees from 16 sample stands in age classes II, III, IV, V and higher. The radial dynamics of changes in annual ring widths was higher in trees from former farmland. In contrast, the proportion of latewood was similar in trees in all age classes and in trees growing on both soil types. In three out of four age classes analyzed in this study, the proportion of juvenile wood was higher in trees growing on typical forest soils, while the proportion of heartwood was higher in trees from former farmland. Taking into consideration the above observations it may be assumed that the Scots pine trees growing on former farmland reached technical maturity faster. However, this conclusion needs to be verified on a larger sample of model trees.