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The oldest scientific journal of forestry
Issue: 2020_4

Indukcyjna metodyka prognozy rozwoju zasobów drzewnych
Inductive methodology of the forecast of wood resources development

Abstract: For effective forest management, comprehensive information on the condition and structure of wood resources is needed, as well as a forecast of their development and the possibility of harvest cutting in the long term. The paper objectives is to present a methodology of predicting the development of wood resources and the possibility of main cutting based on the current state of the forest. Presented methodology of the forecast preparation is based on the inductive type of prediction in which future directions of changes are predicted based on past events. Such forecast finds expression of conscious human activity in actively shaping the future, while it does not seek to determine the target state of the forest, but it is assumed that shaping the state of the forest can be subject to constant evolution. The forecast of the development of wood resources in individual forest areas may be based on the data contained in the forest management plans, and these data may be compiled either for individual forest districts (or other forest units), or for groups of forest districts (e.g. for regional directorates of the State Forests, or the State Forests in total). The initial data, necessary to make forecasts, are primarily: a tabular comparison of the stands area and volume in age classes and subclasses; projected afforestation area; intensity indicators of final cutting and intermediate felling determining the harvesting intensity in relation to the size of wood resources in individual classes and age subclasses; and the expected volume of current volume increment over the adopted forecast periods. Additional data contains: approximate share of clear− and complex cutting in final felling; adopted distribution according to the age classes of the young generation after removal cuts in stands kept in complex cutting; average length of the regeneration period; and average age of stands in regeneration classes – used to determine the average age in forest areas for which a forecast is made. Presented methodology makes it possible to determine and analyse anticipated changes in area and volume in age classes, average age and average stand volume as well as possibilities of final and intermediate cutting, and the harvesting intensity in relation to the size of wood resources and the current volume increase in the adopted forecast periods.

Key words: harvest growth increment, volume, area, resource modelling

Sylwan 164 (4):267-279, 2020. DOI:

Modelowanie wielkości użytkowania rębnego drzewostanów w zależności od przyjętych metod prognozowania rozwoju lasu
Modelling of the size of allowable cutting based on adopted methods of forest development forecast

Abstract: Many attempts have been made to develop a strategy for regulating forest use consistent with the multifunctional forest model. In this paper we present two proprietary methodologies of regulation of the allowable cutting size in a multifunctional forest in the 60−year time perspective. We assumed that all restrictions of nature protection and non−productive functions of the forest would still be in force. We based the first method on age class tables (TKW), which is faster but less exact in terms of spatial order of felling. The tree stand method (D−STAN) is based on stands spatial order and the cutting direction basis. In both cases, we based the temporal felling order on species rotation age. Comparing the results, we noticed that they present similar trends in the age structure of tree stands in younger age classes. The main discrepancies of the forecast concerns the share of forest stands in a complex structure: the TKW method gave approximately 12,4%, while the D−STAN one produced 5,1%. The latter approach shows that much smaller areas of stands are used for reconstruction. That marker is influenced by the spatial order of cutting used in the D−STAN model. In conclusion, we suggest to return to the big−area clear−cutting system on fresh coniferous habitats. Medium−area clear−cuttings should be brought back on the least fertile fresh mixed coniferous forests and possibly even fresh mixed deciduous forests.

Key words: forestry use, forest development, modelling of usage regulation

Sylwan 164 (4):280-291, 2020. DOI:

Zastosowanie biostymulatorów w hodowli i ochronie sadzonek dębu szypułkowego (Quercus robur L.) w gruntowej szkółce leśnej
Application of biostimulators in the growth and protection of pedunculate oak (Quercus robur L.) seedlings in bare−root nursery

Abstract: Pedunculate oak is a species of major economic importance in Polish forests. This species seedlings constitute 18.9% of the nursery production in the country. One of the most widespread fungal disease these oaks face is the oak powdery mildew induced by Erysiphe alphitoides. Nursery production is on the lookout for environment−friendly means of plant protection as well as growth simulators capable of raising levels of productivity. Our objectives was to assess two preparation treatments regarded as biostimulators (registered as fertilisers under the names Apol−Humus and Apol−Hum Chelat) in the raising of seedlings of pedunculate oak in bare−root nursery conditions. The experiment included 6 variants with seedlings treated with the above agents, protected against mildew in the traditional way using Falcon 460 EC, treated with fertiliser and fungicide at the same time, or left as control specimens with no measures taken. All preparations were applied by means of foliar spraying 5 times in the course of the season. Survival of seedlings was then assessed at the season end, along with biometric features like root−collar diameter, length of main root and stem, dry mass of leaves and stem, and degree of oak powdery mildew attack. Results indicated curtailment of mildew infection of oak seedlings thanks to both of the biostimulators, albeit to a more limited extent than when fungicide was applied. No stimulation of seedling growth was achieved, however, though the most favourable biometric parameters characterised the oaks supplied with both biostimulator and fungicide. Significantly higher survival rate was noted for oaks offered effective protection against mildew, in the variants with the fungicide or with simultaneous application of Apol−Humus or Apol−Hum Chelat with Falcon. The research points to the two biostimulators under study (based on natural components) being suitable for use in the nursery production of pedunculate oak seedlings, with it being presumed that either or both can allow for reduction in amount of fungicide necessary to be used to safeguard seedlings against mildew.

Key words: plant biostimulants, chitosan, humic acid, fulvic acid, silicon, pedunculate oak

Sylwan 164 (4):292-299, 2020. DOI:

Rozwiązywanie konfliktów związanych z gospodarką leśną – ekonomiczny punkt widzenia
Resolving the environmental conflicts in forestry – economical point of view

Abstract: The paper focuses on the discussing adversarial and cooperative institutions for resolving environmental conflicts relating to forests. Using the term of production possibility curve, we identified cases, in which those two different kinds of institutions are appropriate for resolving conflicts between timber production and environmental goods. It is found to be essential how sensitive the environmental goods are to changes in timber production. The choices concerning the institutions are mostly governed by the attitudes towards risk and chances for conflict resolution.

Key words: adversarial or cooperative institution, conflict resolution, timber production, production possibility curve, indifference curve

Sylwan 164 (4):300-310, 2020. DOI:

Czasochłonność zrywki drewna skiderem z drzewostanu do szlaku operacyjnego
Time consumption of log extraction from the stand to the skid trail using the skidder

Abstract: Skidders are used at two stages of log extraction: when pulling logs to a skid trail and for further semi−suspended log skidding along the trail to a landing. The aim of the study is to characterise the working time structure of a skidder operator performing timber extraction from the stand to the trail, and to develop time−consumption models depending on terrain slope and skidding distance. The research was done in stands situated in central and southern Poland, where late thinning and cutting in areas between tree groups (group clear cut) were performed. The timber was transported to skid trails by means of LKT 82 cable skidders. The timber was pulled to the trail on slopes with inclinations ranging from –30° (up the slope) via 0° (on a flat surface) to 38° (down the slope) at a maximum distance of 70 m. Time study of work cycles was performed and the volume of timber harvested in each package was calculated. Analyses of working time and its time consumption were performed for the operational working time. The measurements covered a total of 269 log extraction cycles with a total duration of over 20 hours. Altogether 752 logs with a total volume of over 520 m³ were extracted. The large share of time was devoted to load attaching and detaching (40%). Quite a large share of log extraction (24%) was associated with the long skidding distances. The time of stretching the collecting rope in the case of skidding up the slope (an average of 60 s) was significantly shorter than in the flat terrain or skidding down the slope (70 s). The average duration of a skidding cycle was also affected by the direction of the slope. Rectilinear relationships were determined between the duration of a skidding cycle and the terrain slope, as well as the skidding distance. The combined effect of these features on the duration of skidding was described. The duration of a skidding cycle was influenced by distance (61% of the general variability) more than the slope (16%). The time consumption of the skidding amounted to ca 12 min/m³. Two homogeneous groups were determined: uphill skidding as well as skidding in flat terrain and downhill. The relationship between the time consumption and the number of logs extracted along with their volume took the form of an exponential regression. The time consumption standard of log extraction performed with the use of a skidder along a skid trail should be supplemented with the time of forming timber packages in the stand and pulling them to the trail, with an additional distinction between the direction of skidding and terrain slope.

Key words: timber harvesting, skidding, working time, time consumption, modelling

Sylwan 164 (4):311-320, 2020. DOI:

Ekonomiczne konsekwencje wichury w 2016 roku w Nadleśnictwie Supraśl
Economic consequences of the 2016 storm in the Supraśl Forest District

Abstract: The purpose of the article is to determine the value of losses resulting from salvage cutting of stands and to estimate the amount of extraordinary costs and profits from the sale of removed wood in forests damaged by a wind−storm that occurred on June 17, 2016 in the Supraśl Forest District (NE Poland). We obtained the following data from the State Forests Information System: the size of disaster area, the volume and structure of harvested wood in the affected area, extraordinary costs as a result of damage caused by a wind−storm, average sales price of downed or broken wood separated into individual recipients and entrepreneurs. The renewal of the disaster area has not been completed as for June 5, 2019. To determine the value of losses due to salvage felling of stands, formulas included in the Regulation of the Minister of the Environment of 20 June 2002 on one−time compensation for salvage felling of stands were used. Tables of stand value indicators developed by the Forest Research Institute in 2013 were used for the calculations. The total area of forests damaged by a wind−storm in the Supraśl Forest District was 329 ha. The area in which harvesting was carried out using a clear−cutting method covered 284 ha, the removal of damage in the remaining area was performed in accidental cuts. The total extraordinary costs incurred by the Supraśl Forest District as a result of a wind−storm amounted to over PLN 10.9 million, the largest group were costs related to harvesting and skidding of trees in disaster areas (nearly PLN 9.5 million). The total value of sales of large− and medium−sized wood assortments to retail customers was approximately PLN 1.93 million and to entrepreneurs over PLN 44.7 million. The value of small−sized assortments was at the level of PLN 37.5 thousand for retail customers and PLN 39.8 thousand for entrepreneurs. The value of forests damaged by a wind−storm was estimated at over PLN 20.3 million. A comprehensive analysis of the economic effects of the natural disaster in the Supraśl Forest District has not been completed; it requires research conducted in subsequent years, as the consequences and related costs of the hurricane will be experienced in the near future.

Key words: extraordinary costs, timber price, value of stand, timber of disaster

Sylwan 164 (4):321-330, 2020. DOI:

Zmiany bogactwa gatunkowego runa borów sosnowych na pasach wydmowych Kampinoskiego Parku Narodowego na początku XXI wieku
Changes of the herb layer species richness within Scots pine forest of the dune belts in the Kampinos National Park (central Poland) at the beginning of XXI century

Abstract: Scots pine forest are of the main economic importance to the forest management in lowland Europe. Large areas of spontaneous pine forest, including old−growths, are located on two vast dune belts of the Kampinos National Park (central Poland). These forests grow on oligotrophic sandy soils with deep groundwater level. This makes the area unique to study long−term changes in this type of pine forest communities. The aim of the work was to assess the changes in the species composition and richness of undergrowth of Scots pine forests at the beginning of the XXI century. The study was conducted on 10 permanent and 53 semi−permanent plots located within stands of Peucedano−Pinetum and Querco−Pinetum associations on both dune belts of Kampinos National Park. The fieldworks were performed in 2001 and 2002, and repeated in 2015 and 2018. Based on Ward’s cluster analysis we described five local forms of plant communities. Seven species groups were distinguished and changes in their richness assessed using one sample Wilcoxon test. Each species group included species characteristic and/or differentiating for a given set of syntaxonomical units. The results confirmed the hypothesis of gradual decrease of the total species richness. The median of species richness change was –0.308 species per year and was statistically significant. The changes were bigger within the local forms of the Querco−Pinetum association in comparison to Peucedano−Pinetum. The decrease was connected especially with dry grassland and heathland species (characteristic for syntaxons of Koelerio−Corynephoretea and Nardo−Callunetea classes) as well as with coniferous forest generalist species (characteristic for syntaxons of Vaccinio−Piceetea and Cladonio−Vaccinietalia). The results suggest that the two main processes shaping the species composition at the beginning of XXI century within pine forest located on the dune belts of Kampinos National Park may be identified as (i) fluctuation, and (ii) simplification, manifested by species richness decrease. This is probably connected with forest regeneration after past human use and disturbance.

Key words: Peucedano−Pinetum, Querco−Pinetum, permanent plots, semi−permanent plots, old−growth pine forest, fluctuation, species richness decrease

Sylwan 164 (4):331-342, 2020. DOI:

Opinie przewodników beskidzkich na temat kształtowania krajobrazu leśnego w Bieszczadach
Forest landscape management in the Bieszczady Mountains in the opinion of the mountain guides

Abstract: The article presents the results of a survey conducted in 2018−2019. The research aimed to determine the opinion of the mountain guides on forest landscape management in the Polish part of the Bieszczady Mountains (SE Poland). The survey included questions related to selected aspects of forest landscape management such as: timber acquisition, engineering forest landscape management with particular regard to the communication accessibility of forests and nature protection. Statistical analyses showed that according to the investigated mountain guides excessive tree felling is carried out in the forests of the Bieszczady Mts. Most of the respondents were of the opinion that in the Bieszczady only manual timber acquisition should take place. The vast majority of the surveyed guides negatively referred to activities related to hardening of the forest roads. Most of them were against the establishing of a new national park in the region. The frequency of guides’ visits to the forests differentiates their views on the establishment of new and extension of existing landscape parks, as well as on the aspect of levelling forest road surfaces.

Key words: Carpathian Primeval Forest, foresters, guide associations, mountain tourism

Sylwan 164 (4):343-351, 2020. DOI:

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