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1
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Metoda okreslania ryzyka uszkodzenia drzewostanu przez wiatr

100%
Bruchwald A., Dmyterko E.
Leśne Prace Badawcze
|
2010
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tom 71
|
nr 2
165-173
2
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Zagrożenie lasów Polski na podstawie modelu ryzyka uszkodzenia drzewostanu przez wiatr

100%
Dmyterko E., Mionskowski M., Bruchwald A.
Sylwan
|
2015
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tom 159
|
nr 05
On the basis of the wind damage risk model for forests using the data of the State Forests Information System, the stand damage risk factor Wr for each of the 430 forest districts in Poland and the threat measure Ms for a given forest district were determined. The measure of threat to forest Ms for a forest district is a methodical basis for assessing the potential damage to forests in Poland. Its value ranges from 8.1% for the Brzózka Forest District to 48.9% for the Ujsoły Forest District (fig. 1), giving the average value of 24.6% and standard deviation of 7.03%. The measure Ms was the basis for differentiating the levels of threat of wind damage to forest for forest districts. Level 1 (Ms 10%) indicates low threat, level 2 (10%Ms 20%) – elevated threat, level 3 (20%Ms 30%) – moderate threat, level 4 (30%Ms 40%) – high threat, level 5 (Ms 40%) – very high threat. Low threat to forests was found only in two forest districts located in the western part of the country. 113 forest districts, which form large concentrations particularly in western and central Poland, are exposed to an elevated threat. Most forest districts (233) are classified to a group of moderate threat. They are located across the country and are mostly concentrated in the northern and southern regions of Poland. 71 forest districts exposed to high threat are concentrated in the south of Poland in the Carpathians and the Sudetes, with scattered presence in the north of the country. Most of the 11 forest districts with a very high threat to forests are located in the mountains (tab., fig. 1). For the forest districts with a particularly high and very high threat, new silvicultural procedures and the basis for decision making in the field of forest management should be developed to reduce the risk of damage to forest.
3
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Nowy wariant modelu ryzyka uszkodzenia drzewostanu przez wiatr

84%
Dmyterko E., Bruchwald A.
Sylwan
|
2014
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tom 158
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nr 08
The paper presents a new variant of the wind damage risk model for forest stands in view of its application in the forests under private ownership. It was based on the following characteristics: average height, age and slenderness of the main tree species, stand density index, species composition, forest habitat type, as well as stand location in the region of the country and the volume of windbreaks, windfalls and deadwood in previous years. The latter characteristic in the new model variant is generated by the stand damage model. The new wind damage risk model variant determines the risk factor for individual stands ranging from 0 to 3. A higher value of the factor indicates a higher wind damage risk for the stand. The verification of the model was performed using the forest data from two counties (powiat) situated in the Podkarpackie Province. The wind damage risk factors obtained from the model are shown on numerical maps.
4
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Ocena funkcjonowania modeli ryzyka uszkodzenia drzewostanów przez wiatr w górach na przykładzie Tatrzańskiego Parku Narodowego

84%
Zieba S., Dolezuchowicz M., Banas J., Bujoczek L.
Sylwan
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2016
|
tom 160
|
nr 05
The paper assesses the performance of the risk models of the wind damage to the mountain forest stands located in the Tatra National Park (southern Poland). The models assume that the forest susceptibility to the damage from the wind depends on the characteristics of stands, their location and frequency of the occurrence of damage in the past. According to the methodology we built 5 variants of models, which take into account the following attributes: various stand features, forest type, regional factor of the damage to the the trees, thickness scrap, subversive and deadwood from the stand in the last 10 years, characteristics of the terrain: exhibition, slope inclination and altitude above sea level. The model output is a classification of the stand susceptibility to the wind damage expressed by a number between 0 and 3 (0.5 interval). The suitability of each variant was tested by comparing the in−class rate as well as the area and growing stock of undamaged and damaged stands. In this study we rated 2908 stands with a total area of 15,386.05 ha. Taking into account the risk class, it is possible to develop the appropriate procedures in order to limit the damage. The analysis conducted for the forests of the Tatra National Park showed high compliance of the developed risk models with the damages arising by the wind. This is confirmed by a particularly high proportion of damaged forest stands included in the class of high risk. Their fraction ranged from 43.8% (WR1) to 92.4% (WR5). Considering the position and stands characteristics the greatest damage arose at an altitude of 950 to 1000 m (70.2%) and the exposures NW, N and NE (60.2%).
5
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Zastosowanie modelu ryzyka uszkodzenia drzewostanu przez wiatr do oceny prawdopodobieństwa lokalizacji szkód w lasach Regionalnej Dyrekcji Lasów Państwowych w Białymstoku

84%
Bruchwald A., Dmyterko E.
Sylwan
|
2019
|
tom 163
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nr 08
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 damage risk model. The wind damage risk model determines the value of damage risk factor Wr for each stand ranging from 0 to 3; a higher value indicates a higher risk of damage to the stand. The damage risk factor allowed to create six damage risk classes, with a width of 0.5 each and to assign individual stands of the forest district to one of the classes. The areal share of damaged stands was calculated for each class. In 2015, i.e. before the hurricane, the share of stands in the highest damage risk class VI ranged from 0.1% to 3.5%. After the hurricane in 2016, the areal share of damaged stands was calculated for each class, the largest share (the largest damage) being in class VI, while the share of the most damaged stands were found in the following forest districts: Dojlidy – 71%, Supraśl – 79% and Żednia – 87%. In 9 other forest districts, the area of damaged stands in class VI also exceeded 70%. The wind damage risk model for the stand presented in the paper allows identifying stands where damage is very likely to occur, when the wind comes. This may limit the level of wind damage through, in the first place, the rebuilding of stands classified to the highest wind damage risk factor class.
6
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Ocena szkód w lasach Polski spowodowanych przez huragan w sierpniu 2017 roku

84%
Dmyterko E., Bruchwald A.
Sylwan
|
2020
|
tom 164
|
nr 05
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 two entities with over 1 million m³ each. The harvested volume was expressed as a percentage of allowable cut, calculated from the stand growth model. It showed possibile timber harvest in final and intermediate cuts in the absence of natural disasters (strong wind, intense drought, heavy snowfall, insect outbreaks, etc.). In many forest districts, timber harvest accounted for 100% of the allowable cut, with the maximum value approximated to 1100% of the allowable cut. The high salvage harvest of post−hurricane timber prevents the execution of other economic tasks, including plans of stand rebuilding. On the example of forest districts with the largest damage, the possibilities of selecting forests classified as the most threatened by wind were examined. The wind damage risk model for the stand was used to determine the value of wind damage risk factor Wr for each stand (values from 0 to 3; the higher value, the higher risk). The damage risk factor allowed to create six damage risk classes of a span of 0.5 each and to assign individual stands to one of the damage classes. The share of the area of stands and damaged stands in Wr classes was also determined. In the Lipusz Forest District the share of stands in VI class of Wr was 9.8%, and the area of damaged stands in this class was 98.3%. In the Rytel and Przymuszewo forest districts, the areal share of such stands was 10.7% and 5.1%, respectively, and almost all stands in this class were damaged by the hurricane. The areal share of forests in the highest Wr class was reported in the Gniezno Forest District accounting for 4.8% and the hurricane damaged 85% of their area. The wind damage risk model for the stand allows to identify forests where damage is very likely to occur. It is, therefore, possible to take action on the rebuilding of stands before the wind comes and thus reduce its negative effects. The cutting plan should include, in the first place, stands classified to the high wind damage risk factor.
7
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Zastosowanie modeli ryzyka uszkodzenia drzewostanu przez wiatr do oceny zagrożenia lasów nadleśnictwa

84%
Bruchwald A., Dmyterko E.
Sylwan
|
2011
|
tom 155
|
nr 07
8
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Zmiany zachodzące w drzewostanach Bieszczadów

84%
Dmyterko E., Bruchwald A.
Sylwan
|
2018
|
tom 162
|
nr 05
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 process is the encroachment of fir and beech under the canopy of pine stands, which is favoured by fertile habitats that meet the ecological requirements of these two tree species. As a result of economic activity supporting these processes, alder and pine stands are being rebuilt relatively quickly, turning into fir or beech stands, and sometimes into mixed stands with the participation of other tree species, including spruce (fig. 1). The decline of spruce stands occurs on the dominant area in Poland: in Beskid Śląski and Beskid Żywiecki, the Kaszuby Forest or the Białowieża Forest. The main causes of this process are abiotic and biotic factors, including frequent droughts causing the lowering of the groundwater level and insect outbreaks, especially of bark beetles. The proportion of spruce in the Bieszczady Mountains is relatively small (about 10%), and the high fertility of the habitats compensates, to some extent, the relatively high moisture requirements of this tree species and probably these factors determined the lack of decline of spruce stands in the analysed area. In the last 10 years, the average age of forests in the Bieszczady Mountains increased from 77 to 83 years (tab. 2), mainly as a result of too low volume of harvested timber (fig. 3). Comparing the total harvested volume with the volume of allowable cut determined by the stand growth model, the harvest of the wood raw material was understated by about 25%. The aging of forests is also confirmed by changes in stands in age classes (fig. 2). The aging of the Bieszczady forests is correlated with the process of increasing the threat to these forests by wind (figs. 4−5). The wind damage risk factor increased over the next 10 years in the two highest threat level, and thus the area of threatened stands increased. The forest threat measure in the Bieszczady forests increased in general as well as in individual forest districts (fig. 6). The forests in two of these districts are currently among the most threatened in Poland.
9
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Zagrożenie lasu przez wiatr na przykładzie nadleśnictw Puszczy Białowieskiej

67%
Bruchwald A., Dmyterko E.
Sylwan
|
2012
|
tom 156
|
nr 10
10
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Zastosowanie modelu ryzyka uszkodzenia drzewostanu przez wiatr do oceny procesu śmiertelności drzew w Sudetach w latach 2015-2017

67%
Dmyterko E., Bruchwald A.
Sylwan
|
2019
|
tom 163
|
nr 11
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 to identify stands, which may possibly be predisposed to mortality, after a long−lasting drought in the growing season. The studies concerned the forests of the Wrocław Regional Directorate of State Forests (tab. 1). Their area covers 245,000 ha, the timber volume amounts to 83 million m³ (338 m³/ha) and the volume increment to 2.3 million m³ (9.4 m³/year/ha). The fraction of spruce is the largest (50.3%), ranging from 7.1% (Pieńsk Forest District) to 84.8% (Lądek−Zdrój Forest District). The average age of stands is 74 years, ranging from 56 (Pieńsk Forest District) to 85 years (Jawor Forest District). The drought in 2015 caused an increase in the dynamics of spruce decline. The ratio of harvested to model deadwood volume at a level of up to 5% was assumed the ‘norm’ that characterizes the process of natural spruce mortality. Values higher than normal mean a more intense process of tree mortality caused by external factors (e.g. hurricane winds, floods, droughts). In 2014, the harvested deadwood was below the norm in 15 forest districts (fig. 1). In 2015, the highest ratio values (above 20%) were reported in the Wałbrzych and Szklarska Poręba forest districts (fig. 1). In 2016, the harvest of deadwood in each forest district exceeded the norm, and the highest values were found in the Jawor (102.3%), Bardo Śląskie (83.3%) and Świdnica (69.7%) forest districts. In 2017, the highest ratios of harvested to model deadwood volume were reported in the Bardo Śląskie (117.2%), Jawor (83.6%), Henryków (83.5%) and Świdnica (67.1%) forest districts. The model was found to identify also the stands that are most threatened by droughts. These are stands in the highest damage risk factor Wr class. The highest percentage of deadwood in this damage class was in Jawor (88.8%), Bardo Śląskie (81.9%), Miękinia (79.4%), Świdnica (76.7%), Henryków (73.8) and Złotoryja (73.6%) forest districts. It was also shown that the average value of the measure of threat to forests Ms was 35, qualifying them as highly threatened (fig. 3). Forests characterized by the highest level of threat Ms>40 was found in five forest districts, while in nine others the level of threat was high. The forests of the Sudety Mts. are threatened by the decline and the main direct causes of this process was the long−lasting drought in the growing season, causing damage to the stands earlier weakened by wind and other factors.
11
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Dynamika rozpadu drzewostanów świerkowych w Beskidzie Śląskim

59%
Dmyterko E., Bruchwald A.
Sylwan
|
2018
|
tom 162
|
nr 03
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) and by 89% in the 2011−2016 (later period) period. The highest volume exceed (503 and 307% for earlier and later period respectively) was recorded for the Wisła Forest District. For the deadwood, the harvested volume exceeded the modeled one by 45% (162 in earlier, and 59% in later period). In the Węgierska Górka Forest District the harvested volume amounted to 287% of the modeled one (438 in earlier, and 70% in later period). The largest amount of wind−broken and wind−fallen trees was found in Wisła. Their volume amounted to 48% of the modeled volume (59 in earlier, and 40% in later period). The highest exceed occurred in Węgierska Górka (89 and 70% in the later period respectively). The species composition in the analysed region changed significantly as the share of spruce decreased and share of beech and fir increased (tab. 1). Changes in the aeral fraction of stands in age classes in the Bielsko and Ustroń forest districts were insignificant (tab. 2). For Węgierska Górka, share of stands in age class <20 years increased from 11 to 40%, while the older stands fraction decreased. Major changes occurred in Węgierska Górka and Wisła as far as structure of the stands in the risk damage factor classes is concerned. Fraction for the risk factor classes I and II increased, while for class VI decreased (tab. 3, fig. 4). The highest dynamics of the wind threat measure was recorded especially in Węgierska Górka, where its value decreased from 42 in 2009 to 19 in 2016 (fig. 5). The biggest changes are likely to occur in Wisła in the next years due to the very high fraction of spruce. A significant damage caused by wind may also be expected in Ustroń, where the threat measure is high.
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