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The first issue of ‘Sylwan’, the world’s oldest forest scientific journal and the press organ of the Polish Forest Society, was published in 1820. The main goal of its founders was, as it is today, to promote forest knowledge among employees of every tier of forest administration, as well as among academia and students interested in forestry. In the last 30 years, ‘Sylwan’ has become a modern, peer−reviewed...
On August 11−12, 2017, a hurricane passed from south to north of Poland causing considerable damage to forests, especially in regional directorates of the State Forests in Wrocław, Poznań, Toruń, Szczecinek and Gdańsk. By the end of 2018, the volume of wind−broken and wind−fallen trees and deadwood approximated to 9 million m³. In 9 forest districts the harvested volume exceeded 440 thousand m³, including...
Climate change creates a big challenge for forest science. One of several problems calling for urgent solution concerns the elaboration of the scientific foundations for determination of the species composition of forest stands under changing environmental conditions. This problem is particularly acute in case of declining Norway spruce stands in the Sudety Mountains (SW Poland). The paper presents...
We developed functions that describe the relationship between the stand top height and age for Scots pine (Pinus sylvestris), Norway spruce (Picea abies), silver fir (Abies alba), European larch (Larix decidua), English oak (Quercus robur), European beech (Fagus sylvatica), black alder (Alnus glutinosa) and silver birch (Betula pendula). We applied model proposed by Cieszewski for that purpose. The...
A dynamic process of mortality of Norway spruce stands in south−west Poland, mainly in the Sudety Mts. was observed in 2015. It was associated with an insufficient amount of precipitation in the growing season. This process was intensified by the outbreak of insects, especially bark beetles. The aim of the paper was to verify the hypothesis that the application of the stand damage risk model allows...
The aim of the study was to present two issues concerning forests in the Sudety Mts. (SW Poland): 1) the process of tree mortality in individual years in the period between 2002 and 2018, as well as 2) the analysis of the radial growth of the main tree species (i.e. spruce, larch, beech, fir and Douglas fir). The intensity of the process of tree mortality is evidenced by the volume of wind−broken...
In June 2016, a hurricane damaged the forests of the Regional Directorate of the State Forests in Białystok (eastern Poland), resulting in the removal of approximately 1.9 million cubic meters of wind−fallen and wind−broken trees and deadwood by the end of 2018. The research material was obtained from the database of the State Forests Information System and used to assess the functioning of the wind...
The aim of the study was to assess the changes occurring in the forests of the Kłodzko Region in the recent period (2001−2017), with particular emphasis on the species composition of the stands, their share in age classes and the structure of harvested timber, including live trees, deadwood, wind−broken and wind−fallen trees. The Kłodzko Region located in the Sudety Mountains (SW Poland) covers the...
Like in the Beskid Śląski and Żywiecki Mts., the dieback of Norway spruce stands takes place also in the Beskid Mały range. This process is clearly more intensive and occurs over a longer period of time. The conversion of these forests during the study period (2004−2016) resulted in a significant increase in the proportion of beech and fir as well as other, mostly deciduous tree species (tab. 1)....
In Polish forest management planning, the species composition of stands in a forest district is established by adding up the volumes of tree species from individual forest stands. These volumes are calculated according to the estimated share of species cover and the estimated volume of the entire forest stand. The species structure of stands in a forest district, established on the basis of such a...
In the Beskid Żywiecki, the combination of abiotic, biotic and anthropogenic factors unfavourable for the growth of trees led to the dieback of spruce stands. The intensification of this process began after the hurricane in November 2004, followed by years of negative climatic water balance. The deterioration of tree growth conditions occurred after the drought in July 2006 and damage caused by the...
The paper describes current (in years 2007−2017) changes of basic parameters of forest stands that constitute the managed part of Białowieża Forest (ca. 53,000 ha), divided into three forest districts: Białowieża (12,600 ha), Hajnówka (19,700 ha) and Browsk (20,400 ha). The investigated tree stands represent different phases of ecological succession, modified by silvicultural treatments and other...
The dynamics of decline of Norway spruce forests in the Beskid Śląski Mts. (S Poland) in a 2007−2016 period was analysed based on data from the State Forests Information System. For that purpose we used modified growth model and wind damage risk model. The harvested timber volume (salvage cuts) exceeded the allowable harvest modeled with the stand growth model by 270% in years 2007−2010 (earlier period)...
The aim of the study was to analyse (on the basis of the data from the State Forests Information System) the changes occurring in the Bieszczady forests in the period of 2007−2016. One of the processes taking place in the study area is the withdrawal of grey alder stands and the appearance of natural regeneration of mainly beech and fir, and in a smaller proportion spruce (fig. 1). Another natural...
The purpose of the research was to develop and evaluate the accuracy of various methods for determining the volume of the butt−end (from 0 to 6 m) and middle (from 6 to 12 m) logs of silver birch. The material was collected on 84 samples plots established throughout Poland. On each plot, 2 to 10 trees (722 in total) were felled and measured using a cross−section method. The average age of the measured...
Knowledge of diameter at the breast height (DBH), tree height and form factor allows to estimate tree volume, which is one of the most important measures in forestry. The paper presents empirical equations for the determination of DBH form factor of different species and hybrids of Populus sp. The study was set up on short−rotation plantation in Wichrowo Forest District (northern Poland). Four poplar...
The aim of the research was to assess the accuracy of the stratified sampling method used to estimate the standing volume of a forest district and to compare it with the accuracy of simple random sampling methods. The paper presents the variability of the variables affecting the accuracy of the stratified sampling method. We attempted to find the ways to increase this accuracy. The research was based...
The aim of the study was to evaluate the area and volume of the windthrows caused by a downburst, which occurred early morning on July 8th , 2015 in the Międzylesie Forest District (south−western Poland). The wind velocity reached 270 km/h and the phenomenon caused damages similar to those observed after the hurricane. The most affected forest ranges included: Różanka, Nowa Wieś, Lesica, Goworów,...
In Poland, the majority of silver fir stands is characterised by a single−layer stand structure. The current silvicultural activities aim at obtaining multilayer stands, which requires a clearer definition of the structure, and more precisely, a better knowledge of the pattern of diameters at breast height (DBH) distribution. The aim of the research was to develop a pattern of DBH distribution of...
The study presents a method of planning species composition of forest stands in mountain areas on the example of Beskid Niski Mts. (south−eastern Poland). The focus was on the species composition of forest stands growing in different conditions, taking into account the type of forest habitat and terrain characteristics: altitude, exposition and slope. The research was based on data stored in the Information...
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