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Wyszukujesz frazę "basal area" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Porównanie sposobów określania składu gatunkowego drzewostanów obrębu leśnego
Comparison of the methods of determining the tree species composition of stands in a forest district
Autorzy:
Bruchwald, A.
Miścicki, S.
Dmyterko, E.
Stereńczak, K.
Wysocka-Fijorek, E.
Powiązania:
https://bibliotekanauki.pl/articles/985705.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
sklad gatunkowy
struktura gatunkowa
metody badan
analiza porownawcza
obreby lesne
basal area
cover
diversity
sample plot
survey
volume
Opis:
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 method, may be different than that obtained from sample plots. The aim of the study was to compare three ways of determining the tree species structure of stands in a forest district. In Method 1, the species composition was estimated on the basis of the volume of trees measured on sample plots as part of a periodic forest inventory based on stratified sampling. The same data were used in Method 2, but the share of species was calculated on the basis of the basal area. In Method 3, the species structure was estimated according to the volume of trees estimated in each forest stand based on the cover of a given species. The empirical material was collected in 53 forest districts. In method 1 and 2, data from an average of 740 sample plots within the forest district were used. In Method 3, data from the forest stand descriptions contained in the database of the State Forests Information System were used. For each forest district, species composition was calculated, including 6 tree species and 8 groups of tree species. For all forest districts, the average shares of individual species and groups of species differed, depending on the applied method (tab. 1). In case of methods 1 and 2, the biggest difference was found for pine – the most numerous species – but it was also big for less numerous ones: birch and oak (tab. 2). In case of methods 1 and 3, the biggest difference in share was also found for pine (tab. 3). The greater the species diversity of a forest district (determined according to Simpson’s index of diversity), the greater was the average difference in the estimated share of an individual species (figs. 1 and 2). The method of determining the species structure in a forest district used in forest management practice nowadays was considered insufficient. It was proposed to establish it in larger units (subclass, age class, forest district) only according to the volume of trees measured on the sample plots (without rounding and ‘switching’ of species), using the stratified sampling method.
Źródło:
Sylwan; 2019, 163, 05; 365-372
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dokładność określania pierśnicowego pola przekroju drzewostanów bukowych na podstawie powierzchni próbnych
The accuracy of estimates of basal area in beech stands using sample plots
Autorzy:
Ochał, W.
Powiązania:
https://bibliotekanauki.pl/articles/1016133.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
drzewostany bukowe
dendrometria
piersnicowe pole przekroju
dokladnosc pomiaru
lesnictwo
powierzchnie probne
sample plot
sampling
stand basal area
beech stand
poland
Opis:
The paper presents the results of the research on the accuracy of estimates of basal area in beech stands using sample plots. The accuracy of estimates of the analysed characteristic was evaluated on the basis of variation coefficient value of the sums of tree basal areas on sample plots. The coefficient value was empirically determined for sample plots of various size, as well as for the secondary populations differing in plot number. The research was conducted in three beech stands of age class III, IV and VI growing in the territory of the Krzeszowice Forest District.
Źródło:
Sylwan; 2007, 151, 11; 10-21
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ zwiększania się wieku drzewostanu dwupiętrowego na zmienność sum powierzchni przekroju pierśnicowego i miąższości drzew na powierzchniach próbnych różnych wielkości
Effect of ageing on the variation of basal area and volume sums on sample plots varying in size in a two-storey stand
Autorzy:
Turski, M.
Andrzejewski, T.
Powiązania:
https://bibliotekanauki.pl/articles/1022959.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
suma powierzchni przekroju piersnicowego
dendrometria
suma miazszosci drzew
drzewostany dwupietrowe
wiek drzewostanu
lesnictwo
powierzchnie probne
zmiennosc
sample plot
basal area
volume
two−storey stand
pine
oak
Opis:
The paper provides an analysis of changes in coefficients of variation of basal area and merchantable volume sums on sample plots of various sizes 1, 2, 4, 10, 6, 25 and 50 ares in a two−storey stand (storey I – pine 195 years, storey II − oak 105 years) over the last decade. The authors established how many times the number of sample plots of a given size at a given age should be increased in relation to the last measurement to attain the same result accuracy. Moreover, the optimal size of small sample plots that can grant the most accurate results was calculated.
Źródło:
Sylwan; 2005, 149, 09; 15-23
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Długotrwałe efekty różnego nasilenia trzebieży selekcyjnej w drzewostanie sosnowym
Long-term effects of different thinning intensity in young Scots pine stands
Autorzy:
Zachara, T.
Powiązania:
https://bibliotekanauki.pl/articles/986702.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
hodowla lasu
drzewostany sosnowe
zabiegi pielegnacyjne
trzebiez selekcyjna
sosna zwyczajna
Pinus sylvestris
wzrost roslin
jakosc hodowlana
scots pine
silviculture
tending cuts
basal area increment
stand resistance
Opis:
The paper describes a case study of thinning experiment established in 1976 with a use of random block design in 21−year−old Scots pine stand in Janów Lubelski Forest District (south−eastern Poland). The stand was subjected to no thinning (control variant K), weak thinning with removal of 10% of basal area (variant S1), strong thinning with removal of 30% of basal area (variant S3) and extreme thinning, where only future crop trees and some reserve trees were left (variant TE). S1 and S3 treatments were repeated each 5 years, while in TE treatment the 20−year interval was applied. During the period of 40 years all trees were measured each 5 years and current basal area increment was calculated for the whole stand and for future crop trees population. The relative increment of future crop trees population calculated as a percentage of stand total increment was taken into account too. Data were subjected to ANOVA and differences were compared with Tukey test. The results showed that total stand increment was not influenced by thinning intensity. The future crop trees increment was significantly higher in a case of extreme thinning in comparison to weak thinning and to the control treatment during the first 20 years of experiment (age 21−41). During the second 20 years (age 41−61) only relative basal area increment of future crop trees population was significantly higher on the plots with extreme thinning in comparison to other treatments. The results suggest that a weak thinning brings no silvicultural effect meant as increased growth of previously selected future crop Scots pines. Strong or very strong thinnings give a long−term growth effect and they can be acceptable, but in healthy and well−tended young pine stands only.
Źródło:
Sylwan; 2017, 161, 09; 730-737
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Retrospektywna analiza wzrostu i przyrostu drzew w 30−letnim drzewostanie jodły kalifornijskiej (Abies concolor Eng.)
Retrospective analysis of growth and increment of trees in 30−years−old stand of white fir (Abies concolor Eng.)
Autorzy:
Beker, C.
Flieger, K.
Turski, M.
Powiązania:
https://bibliotekanauki.pl/articles/994778.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany sosnowe
sosna kalifornijska
Abies concolor
wzrost roslin
dynamika wzrostu
przyrost wysokosci
przyrost piersnicowego pola przekroju
przyrost miazszosci
white fir
growth
height
breast height diameter
basal area
volume
Opis:
The paper presents the results of the retrospective research on the height and diameter growth of trees in a 30−year−old white fir (Abies concolor Eng.) stand growing in the mixed broadleaved forest habitat in the Forest Experimental Station in Siemianice. The research concerned the volume and functionally related parameters including height, diameter at breast height and basal area.
Źródło:
Sylwan; 2012, 156, 12; 902-907
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Określanie wybranych cech drzewostanów sosnowych z wykorzystaniem chmur punktów pozyskanych w procesie automatycznego dopasowania cyfrowych zdjęć lotniczych
Estimating selected characteristics of Scots pine stands based on point clouds derived from automatic matching of airborne images
Autorzy:
Hawryło, P.
Powiązania:
https://bibliotekanauki.pl/articles/986689.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
fotogrametria
zdjecia lotnicze
automatyczne dopasowanie zdjec lotniczych
chmura punktow
drzewostany sosnowe
wysokosc Loreya
pole powierzchni przekroju piersnicowego
zasobnosc drzewostanu
dokladnosc szacowania
modele predykcyjne
area−based approach
forest inventory
lorey's height
basal area
growing stock volume
Opis:
Recent research show that image−derived point clouds (IPC) can be successfully utilized in the context of estimation of selected forest parameters. However there are still some topics for further investigation in the context of using archival data. Particularly, in case of forest stands in Poland the number of such studies is limited. This study investigates the usefulness of airborne IPC for estimation of Lorey's height (H), basal area (G) and growing stock volume (V) of Scots pine stands. Additionally, the accuracy of predictive models is analyzed for images acquired in the same year as the field reference data were collected (2015) and for archival images acquired in 2012. The study was performed in Janów Lubelski Forest District (south−eastern Poland) on approximately 7,800 ha. The measurements from 94 circular plots were used as the reference data. The Area Based Approach and multiple linear regression were used to create predictive models. For each analyzed dependent variable variety of IPC characteristics were evaluated to select the most accurate predictive models. The best model for each variable was selected based on Akaike Information Criteria and RMSE. The same predictor variables were used for both years of aerial images aquisition. For models comparison the one−sided bootstrap test was used. The RMSPE for H, G and V in case of images acquired in 2015 amounted to 5.3, 16.3 and 17.3%, respectively. Analogically, the relationship between predicted and observed values (R2) amounted to 0.96, 0.47 and 0.81. The finally selected models had three, one and two predictors for H, G and V, respectively. The difference between accuracy of models based on aerial images from 2012 and 2015 was not statistically significant for all analyzed variables. The obtained results show high potential of using airborne image−derived point clouds for forest inventory activities in Scots pine dominated stands.
Źródło:
Sylwan; 2017, 161, 09; 707-714
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ konkurencji na przyrost grubości buka (Fagus sylvatica L.) i sosny (Pinus sylvestris L.) w dwupiętrowych drzewostanach bukowo-sosnowych
Effect of competition on diameter growth of European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) in two-storeyed beech-pine stands
Autorzy:
Dudzińska, M.
Powiązania:
https://bibliotekanauki.pl/articles/991628.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany bukowo-sosnowe
drzewa lesne
konkurencja roslin
buk zwyczajny
Fagus sylvatica
sosna zwyczajna
Pinus sylvestris
przyrost grubosci
przyrost piersnicowego pola przekroju
przyrosty radialne
radial increment
basal area increment
competition indices
mixed stands
Opis:
The studies were based on the empirical material collected from 88 sample plots located in 78 beech−pine stands and 10 pine stands with beech undergrowth. The effect of the competition of beech trees from the understorey and pine trees on the radial increment (Δr) and basal area increment (Δg) was investigated. The strength of the competition was determined using distance−independent indices, which did not take into account the position of a tree in the stand. The effect of the competition on the basal area growth of both beech and pine trees was found to be greater than on the radial growth.
Źródło:
Sylwan; 2013, 157, 10; 730-736
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zróżnicowanie bieżącego przyrostu sosen w trzech klasach wieku
The current growth increment of pine tree stands comprising three different age classes
Autorzy:
Kaźmierczak, K.
Powiązania:
https://bibliotekanauki.pl/articles/1339817.pdf
Data publikacji:
2013
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
lesnictwo
dendrometria
drzewa lesne
klasy wieku
klasy Krafta
drzewostany I klasy wieku
drzewostany II klasy wieku
drzewostany III klasy wieku
sosna zwyczajna
Pinus sylvestris
przyrost drzew
przyrost biezacy
przyrost wysokosci
przyrost piersnicy
przyrost piersnicowego pola przekroju
przyrost miazszosci
height increment
dbh increment
basal area increment
volume increment
growth space
crown
age
biosocial position
Opis:
The study presents the results of an analysis of the pine tree growth increments (height increment, dbh increment, basal area increment and volume increment) for a 5-year period. The study involved Scots pine trees of Kraft's class 1, 2 and 3 (dominant stand) in stands of different age classes (II, III, V) growing in fresh mixed coniferous (BMoew) and fresh coniferous (Boew) forest habitats. The multivariate analysis of variance was performed to assess the statistical significance of age and dominance of trees within a stand on their increment. The dominance position was classified for each tree using Kraft's criteria. The following characteristics were also measured: dbh of the trunk in two directions (N-S and W-E), and crown projection area on the basis of the characteristic tree crown points, projected using of a crown projector, characteristic points in tree crowns (7 to 14 on average). The actual height was determined after trees were felled. The following measurements of the single tree growing space were selected and determined: crown projection area – pk (m2), crown diameter – dk (m), Seebach's growth space number – dk / d1. 3 , crown projection area to basal area ratio –d d k 2 1 3 / 2. , crown deflection coefficient –d h k / , single tree space ppd=pk·h (m3). We assessed the strength of the relationships between tree growth parameters and tree growth space, crown length, relative crown length and slenderness. Both the age and dominance position of trees within the stand affected the growth increments. The strongest correlation among measured traits was between the 5-year volume increment and decreasing slenderness.
Źródło:
Leśne Prace Badawcze; 2013, 74, 2; 93-100
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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