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Hodowlane aspekty ochrony drzewostanów przed szkodami od wiatru i śniegu

100%

Zachara T.

Postępy Techniki w Leśnictwie

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2019

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tom 144

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Warunki meteorologiczne powstania szkód wiatrowych w dniach 11-12 sierpnia 2017 roku w lasach środkowo-zachodniej Polski

100%

Chojnacka-Ozga L., Ozga W.

Sylwan

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2018

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tom 162

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nr 03

Climate change, which was particularly marked at the turn of the 20th and 21st centuries, was accompanied by unfavourable weather phenomena. One of whose effects cannot be prevented is hurricane. Much of the most devastating storms (e.g. Kyrill in January 2007, Carmen in November 2010), which crossed over Poland, was associated with low pressure systems. The occurrence of high wind speeds in the cold season is a natural feature of Polish climate. Hurricanes in the summer are generally characterized by more complicated origin. The cause of the damage at this time of year may be squall fronts and tornados (e.g. July 4th, 2002 – Puszcza Piska; July 20th, 2007 – Częstochowa region). An important issue is to develop a category of winds for the forest district, which can have destructive effect on the stands. Current research shows that gusty winds exceeding 11 m/s may cause first damage to the trees, while blows with velocity exceeding 30 m/s result in severe damage. Knowing and monitoring the mechanisms that leads to strong winds, assessing their impact, and managing risk in the context of their effects is one of the important elements of a forest management strategy. On August 11th, 2017, after the influx of hot tropic air, much cooler polar air began to flow from the west. In the afternoon and evening storm cell and supercell began to form in the south−west of the country. Later on, they moved in the north direction forming a squall line. With a Mesoscale Convective System (MCS) moving to the north, there was a gusty wind exceeding 40 m/s in some places. A gust of wind occurred around 18.30 (EET) in Dolny Śląsk (SW Poland) and after about 2 hours in Pomerania (N Poland). The pressure tendency during the transition reached 4−5 hPa. In the northern part of the country, gusts of wind were the largest and occurred several times in 2−3 hours. The system was accompanied by heavy precipitations, which in north Poland determine more than 60% of the average monthly rainfall. The effect of moving MCS was the damage of almost 80 thousand hectares of forests in Poland, which of more than 39 thousand hectares were classified to complete restoration.

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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

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tom 160

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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%).

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Rozpad drzewostanów świerkowych w Beskidzie Żywieckim

67%

Dmyterko E., Bruchwald A., Mionskowski M.

Sylwan

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2019

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tom 163

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nr 02

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 Kyril hurricane in January 2007. The weakened spruces were attacked by the bark beetles, the outbreak of which caused a massive dieback of spruce stands. In order to assess the volume of harvested timber in years 2004−2016, the volume of allowable cut (model volume) was calculated from the stand growth model for each forest district of Beskid Żywiecki. The comparison of the volume of harvested timber with the model volume allowed to determine the rate of dieback of spruce stands. The volume of harvested timber in 2007−2009 exceeded the model volume even 2.5 times. The cuts included mainly deadwood, wind−broken and wind−fallen trees, while the harvest of live trees was scarce. In the period 2010−2013, the harvested volume of live trees accounted for 50−70% of the model volume, the volume of deadwood in the same period was ca. 100% and additionally the volume of blown−down timber after the hurricane was 20−40% of the model volume, which taken together accounted approximately to 200% of the model volume. The execution of such harvesting operations, including silvicultural tasks, did not allow to carry out optimal forest management. The period 2010−2013 saw a downward trend. It was disrupted by the hurricane in December 2013, after which the volume of harvested timber, consisting mainly of wind−broken and wind−fallen trees, increased to 280% of the model volume. Again, the high volume of harvested timber was noted in 2016, (ca. 220% of the model volume). The process of damage to spruce stands in Beskid Żywiecki is likely to continue. A decline in its intensity may occur in the absence of old stands, which to a large extent already takes place in the forests of the Węgierska Górka Forest District. Currently, the most threatened by wind are forests in Ujsoły, Jeleśnia and Nowy Targ forest districts. The least threatened are forests in the Węgierska Górka. This forest district and in the future the remaining forest districts of Beskid Żywiecki, will face enormous challenges to obtain high yield and appropriate species composition.

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Szacowanie szkód spowodowanych przez wiatr w drzewostanach przy wykorzystaniu zobrazowań satelitarnych i danych Systemu Informatycznego Lasów Państwowych

67%

Ciesielski M., Balazy R., Hycza T., Dmyterko E., Bruchwald A.

Sylwan

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2016

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tom 160

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nr 05

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, Jodłów and Smreczyna. To evaluate the area of the windthrow in particular forest stands, the remote sensing data were used, whereas to estimate the total wood volume we applied the growth model and the average volume of the particular forest stands, gathered in the State Forests Information System (SILP) database. The volume of the windthrow evaluated by the forest rangers during some local investigation equaled 103 thousands m³, while one calculated using the SILP database – 161 thousands m³ and with the growth model – 168 thousands m³. The forest service estimations were underestimated. According to the model of the wind damage risk, most of the forest stands in the Międzylesie Forest District were highly or very highly endangered by the strong winds. The presence of the windtrhow is very dangerous either for people or the surrounding forest (due to the risk of pests outbreak). Therefore it demands immediate decisions and actions from the forest service, which need reliable and quickly accessible data. The information provided with the satellite imagery, the risk model and the growth model may accelerate the decision−making process and optimize the damage disposal. Satellite imagery also enables to estimate the amount of damage on the areas, which are hardly available for the foresters and their vehicles. Due to their high usefulness, growing availability and declining prices, these tools should be introduced to local forestry as quickly as possible.

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Dynamika rozpadu drzewostanów świerkowych w Beskidzie Śląskim

59%

Dmyterko E., Bruchwald A.

Sylwan

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2018

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tom 162

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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.

Ograniczanie wyników

5 Sylwan

1 Postępy Techniki w Leśnictwie

3 Bruchwald A.

3 Dmyterko E.

1 Balazy R.

1 Banas J.

1 Bujoczek L.

1 Chojnacka-Ozga L.

1 Ciesielski M.

1 Dolezuchowicz M.

1 Hycza T.

1 Mionskowski M.

1 Ozga W.

1 Zachara T.

1 Zieba S.

2 2019

2 2018

2 2016

Hodowlane aspekty ochrony drzewostanów przed szkodami od wiatru i śniegu

Warunki meteorologiczne powstania szkód wiatrowych w dniach 11-12 sierpnia 2017 roku w lasach środkowo-zachodniej Polski

Ocena funkcjonowania modeli ryzyka uszkodzenia drzewostanów przez wiatr w górach na przykładzie Tatrzańskiego Parku Narodowego

Rozpad drzewostanów świerkowych w Beskidzie Żywieckim

Szacowanie szkód spowodowanych przez wiatr w drzewostanach przy wykorzystaniu zobrazowań satelitarnych i danych Systemu Informatycznego Lasów Państwowych

Dynamika rozpadu drzewostanów świerkowych w Beskidzie Śląskim