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Wyświetlanie 1-6 z 6
Tytuł:
Określenie składu gatunkowego lasów Góry Chojnik (Karkonoski Park Narodowy) z wykorzystaniem lotniczych danych hiperspektralnych APEX
Identification of tree species in Mt Chojnik (Karkonoski National Park) forest using airborne hyperspectal APEX data
Autorzy:
Raczko, E.
Zagajewski, B.
Ochtyra, A.
Jarocińska, A.
Marcinkowska-Ochtyra, A.
Dobrowolski, M.
Powiązania:
https://bibliotekanauki.pl/articles/989774.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Karkonoski Park Narodowy
gory
Chojnik
lasy
sklad gatunkowy
metody badan
teledetekcja
pomiary hiperspektralne
skaner APEX
svm classification
apex hyperspectral data
species structure
Opis:
We used hyperspectral data from APEX scanner (288 spectral bands in 380−2500 nm spectral range; 3,5 m spatial resolution) to classify five tree species occurring in the area of Mt. Chojnik in the Karkonoski National Park (south−western Poland). Data used to delimit learning and verification polygons were acquired during field research in August 2013, when ground truth polygons were acquired using device equipped with GPS receiver. Raw APEX data went through radiometric and geometric correction at VITO office. To reduce processing time, 40 most informative bands were selected using information content analysis. The Support Vector Machines (SVM) algorithm was used for classification of the following tree species: Fagus sylvatica L., Betula pendula Roth, Pinus sylvestris L., Picea alba L. Karst and Larix decidua Mill. Final classification had 78.66% overall accuracy with Kappa coefficient equal to 0.71. The best classified species included beech (87.09%) and pine (83.96%), while the worst results were obtained for larch (60.29%). Low accuracy for larch could be caused by the fact that most of larch trees in the research area grow in small patches, which made it hard to specify large enough sample of training data. All classified tree species had producer's accuracy of at least 60%, with the highest value reaching 87%. User's accuracies were from 53% for pine to 85% for beech. It is possible to classify tree species using hyperspectral data with moderate to high accuracy even if the data used lacked atmospheric correction. Further work will focus on improving the classification accuracy and use of neural networks based classification methods. Results from this paper will serve as basis for tree species map of the Karkonoski National Park.
Źródło:
Sylwan; 2015, 159, 07; 593-599
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sprzedaż drewna w nadleśnictwach Puszczy Białowieskiej w latach 2008-2015
Sale of timber in forest districts of the Bialowieza Forest in 2008-2015
Autorzy:
Lachowicz, H.
Zastocki, D.
Sadowski, J.
Moskalik, T.
Nietupska, M.
Powiązania:
https://bibliotekanauki.pl/articles/985928.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Puszcza Bialowieska
gospodarka lesna
nadlesnictwa
Nadlesnictwo Bialowieza
Nadlesnictwo Browsk
Nadlesnictwo Hajnowka
surowce drzewne
drewno
sortymenty drewna
sprzedaz drewna
bialowieża forest
timber sales
assortment and species structure
Opis:
The structure of timber sales in forest districts of the Białowieża Forest in the years 2008−2015 is presented. The Białowieża Forest is one of the most valuable natural areas in Europe. The data from the reports generated by the State Forests Information System of the Hajnówka, Browsk and Białowieża forest districts were used for the research. The information contained in the forest management plans and nature conservation programs of the surveyed forest districts was also used. The volume of the sold merchantable timber in the Białowieża Forest amounted to 669,072 m3, of which 63.43% was softwood and 36.57% hardwood. Among the softwood assortment, sales of the large−sized timber amounted to 44.42%, while of the medium−sized timber to 55.58%. For the large−sized hardwood, the share of sales amounted to 30.66%, while for the medium−sized hardwood to 69.34%. The small−sized timber was sold at 22,389 m3, with the share of hardwood assortments being 82%, and of softwood 18%. A small share in the sales of small−sized timber is caused by the lack of FSC certification by forest districts, which excludes large industrial companies that buy predominantly the medium−sized coniferous timber assortments. The average price obtained from the sale of timber in the the Białowieża Forest in the analysed period was 134.7 PLN/m3. At a price higher than the average, wood was sold in the Białowieża and Hajnówka forest districts, while in the Browsk Forest District the timber was sold at a price lower than the average. The total volume of merchantable timber harvested in the forest districts of the Białowieża Forest in the analysed years, including the small−sized timber, amounted to 686,684 m3, with 691,461 m3 of timber being sold. The volume of the merchantable timber sold at that time was 669,072 m3, which constituted only 0.24% of the total timber sold at the State Forests in Poland.
Źródło:
Sylwan; 2018, 162, 11; 949-954
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rozpad drzewostanów świerkowych w Beskidzie Żywieckim
Dieback of Norway spruce stands in the Beskid Zywiecki Mts.
Autorzy:
Dmyterko, E.
Bruchwald, A.
Mionskowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/979601.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Beskid Zywiecki
drzewostany swierkowe
rozpad drzewostanow
swierk pospolity
Picea abies
struktura drzewostanu
struktura wiekowa
struktura gatunkowa
pozyskiwanie drewna
struktura pozyskania
zagrozenia lasu
wiatry
szkody od wiatru
forest dieback
picea abies
species structure
age structure
timber harvest
threat to forests by wind
Opis:
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.
Źródło:
Sylwan; 2019, 163, 02; 130-140
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena introdukcji Carya ovata (Mill.) K. Koch na siedlisku grądu w Nadleśnictwie Czerniejewo
Assessment of Carya ovata (Mill.) K.Koch introduction to the potential oak-hornbeam forest habitat in the Czerniejewo Forest District
Autorzy:
Paź, S.
Czapiewska, N.
Dyderski, M.K.
Jagodziński, A.M.
Powiązania:
https://bibliotekanauki.pl/articles/985838.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
ekosystemy lesne
rosliny
gatunki obce
introdukcja
orzesznik pieciolistkowy
Carya ovata
zmiany struktury drzewostanu
siedliska gradowe
Nadlesnictwo Czerniejewo
vegetation
species richness
light availability
tree stand structure
galio−carpinetum
Opis:
Alien tree species, due to their longevity, manifest their invasive potential after several decades from introduction. For the high threat to biodiversity, there is a need to analyze the risk of introduction connected with numerous alien tree species introduced in the various forest ecosystems. We aimed to assess the productivity potential and effect of alien Carya ovata on understory vegetation. Our study was conducted in the oldest (122 years old) tree stand of C. ovata in Poland, located in the Czerniejewo Forest District (western Poland). We analyzed C. ovata tree stand features and vegetation traits within the forest community and compared with natural vegetation – oak−hornbeam forest. We found that C. ovata trees had lower dimensions and standing volume than oaks (Quercus robur and Q. petraea) growing in the neighborhood. We also did not find the impact of C. ovata stands on understory vegetation species composition and light availability. Because of the low impact on forest floor vegetation and lack of spread we concluded that C. ovata cannot be classified as an invasive species. Moreover, its introduction was not successful in terms of tree stand productivity.
Źródło:
Sylwan; 2018, 162, 01; 41-48
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamika i główne kierunki zmian w drzewostanach zagospodarowanej części Puszczy Białowieskiej
Dynamics and main direction of change in forest stands constituting the managed part of Bialowieza Forest
Autorzy:
Bruchwald, A.
Dmyterko, E.
Brzeziecki, B.
Powiązania:
https://bibliotekanauki.pl/articles/985942.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Puszcza Bialowieska
drzewostany gospodarcze
dynamika drzewostanu
siedliska lesne
struktura drzewostanu
sklad gatunkowy
struktura wiekowa
miazszosc drzewostanow
przyrost miazszosci
abiotic and biotic threats
forest age structure
low−productivity stands
stand productivity
stand volume
stand stability
species composition
wind risk model
Opis:
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 human activities. The course of the succession processes is varied, depending, first of all, on local site conditions, consisting mainly of fresh sites (ca. 60%) – particularly fresh broadleaved forest, and encompassing exceptionally high fraction of wet and swamp sites (40%) – especially wet broadleaved forest site type. Most stands represent the intermediate, highly productive phase of succession, with spruce and oak as the dominant tree species. In particular, such stands are common in Białowieża and Hajnówka forest districts. Recently, the share of the mentioned stands is declining, most intensely in the Browsk Forest District. In 2017 alone, 430 ha of highly productive forest stands disappeared from the Białowieża Forest. The process of decay involved mixed stands; besides of spruces which were killed by a current bark beetle infestation, also many oaks, pines, birches, alders as well as rare and valuable minor tree species (such as ashes and maples) died. Dying spruce and, more often, oak stands are often replaced by low−productive hornbeam trees, occupying earlier lower stand strata in such stands. The resulting hornbeam stands are often distinguished by low crown closure and low productivity. Tree stands occurring in the Białowieża Forest are among the most endangered by wind damage stands in Poland. It means that in case of strong winds, several trees will be broken and/or uprooted. The intensity of such phenomena will be further increased by the high tree volume of stands as well as by the presence of many gaps in forest canopy, caused by a massive mortality of spruce trees. In general, one may expect that in the nearest future many stands occurring in the Białowieża Forest, built by different tree species, will be subject to a massive decay. The list of factors contributing to this process is long and involves, among other things, recurring droughts during the growing season, unfavorable changes in ground water table and increased frequency of strong winds. All these factors negatively influence the health status of trees, which further favours the development of parasitic fungi and insects. In consequence, there is a high probability that many areas in the Białowieża Forest will, for a long time, retain a treeless character and/or will be occupied by low−productive and single species hornbeam stands.
Źródło:
Sylwan; 2018, 162, 11; 897-906
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiany zachodzące w lasach Ziemi Kłodzkiej w latach 2001-2017
Changes in the forests of the Kłodzko Region in years 2001-2017
Autorzy:
Dmyterko, E.
Bruchwald, A.
Powiązania:
https://bibliotekanauki.pl/articles/985721.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Ziemia Klodzka
lasy
sklad gatunkowy
zmiany skladu gatunkowego
klasy wieku
struktura drzewostanu
pozyskiwanie drewna
zlomy
wykroty
posusz
miazszosc surowca drzewnego
zmiany w drzewostanach
dynamika zmian
zagrozenia drzewostanow
lata 2001-2017
species composition
stand age structure
timber harvest
damage caused by wind and drought
stand
growth model
Opis:
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 forests of four forest districts: Lądek−Zdrój, Międzylesie, Bystrzyca Kłodzka and Zdroje. The declining share of spruce stands (from 83.5% in 2001 to 75.5% in 2017) and the increasing share of beech and larch as well as sycamore stands indicate that these forests are systematically rebuilt. The average age of the stands is very high (81 years). The share of young (<20 years old ) stands is low (only 5%), while those older than 100 years constitute about 35%. The 21st century saw a serious damage to the investigated forests caused by frequent strong winds and long−lasting droughts in the growing seasons. The three hurricanes that took place in the analysed period were the cause of the removal of 1.1 million m3 of timber in the form of wind−broken and wind−fallen trees. The drought in the growing season in 2015 resulted in the salvage harvest of deadwood with a total volume of 1.6 million m3, which corresponds to the volume of four annual allowable cuts determined for the undisturbed growth conditions of trees in the area under research. Using the wind damage risk model, the threat measure Ms reaching a value of above 40 was calculated for the forests of the Kłodzko Region, which are currently among the most threatened in Poland. This threat results mainly from the high share of spruce stands in older age classes with high average height and gaps after previous hurricanes as well as from a large area of stands located at high elevations.
Źródło:
Sylwan; 2019, 163, 08; 675-684
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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