Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "heterogeneity" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Modele struktury grubości w jednopiętrowych drzewostanach z udziałem jodły Abies alba Mill. i buka Fagus sylvatica L.
Models of diameter structure in single-storied stands with fir Abies alba Mill.and beech Fagus sylvatica L.
Autorzy:
Podlaski, R.
Pach, M.
Powiązania:
https://bibliotekanauki.pl/articles/989766.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany mieszane
drzewostany jednopietrowe
struktura grubosci
jodla pospolita
Abies alba
buk zwyczajny
Fagus sylvatica
piersnice drzew
rozklad piersnic
rozklad Weibulla
forest patches
structural heterogeneity
tree diameter distribution
weibull distribution
Opis:
The objectives of the study were (1) to determine the models of diameter at breast height (dbh) distributions in single−storied mixed stands with fir Abies alba Mill. and beech Fagus sylvatica L. as well as (2) to assess the usefulness of Weibull distribution to approximation of empirical dbh distributions for distinguished models. In the Carpathians (southern Poland) and in the Świętokrzyskie Mountains (central Poland) 36 sample plots ranging in size from 0.1 to 0.4 ha were established. To identify the dbh distribution models in single−storied stands with similar empirical dbh distributions, the hierarchical cluster analysis (HCA) with the Jaccard's measure and the Ward's minimum variance agglomeration method was used. To approximate dbh distributions, the Weibull distribution was employed. Single−storied mixed stands with fir and beech, with the mean age between 50 and 70 years at the dbh, were characterised by a large diversity of dbh distributions. Three groups of stands (I, II, III) differing, among others, in average dbh were determined (fig. 1). In these groups the average dbh ranged from 23.5 to 32.6 cm, from 18.9 to 25.1 cm, and from 13.7 cm to 19.6 cm, respectively. Within these groups, seven models of unimodal distributions were selected (figs. 2−4; tab.). The models are characterised by varying degrees of asymmetry with the highest number of trees from less than 30/ha to more than 300/ha which occurred mainly in the dbh classes between 9 and 33 cm (models AS1, SM1, AS2, AS3, AS4, AS5, SM2). The results of χ² test indicate the high flexibility and suitability of Weibull distribution for modelling of such types of dbh structures.
Źródło:
Sylwan; 2015, 159, 07; 586-592
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tekstura karpackiego dolnoreglowego drzewostanu mieszanego o charakterze pierwotnym
Texture of a primeval lower montane mixed forest in the Carpathians
Autorzy:
Kołodziej, Z.
Paluch, J.
Bartkowicz, L.
Pach, M.
Powiązania:
https://bibliotekanauki.pl/articles/989790.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Babiogorski Park Narodowy
regiel dolny
drzewostany mieszane
drzewostany swierkowo-bukowo-jodlowe
las pierwotny
tekstura drzewostanu
sklad gatunkowy
drzewa lesne
liczba drzew
piersnicowe pole przekroju
primeval forest
mixed stands
spatial pattern
structural heterogeneity
diversity index
forest dynamics theory
Opis:
The aim of this study was to characterize the texture of a primeval forest composed of Fagus sylvatica (L.), Abies alba (Mill.) and Picea abies ((L.) H. Karst). Empirical data were collected in the Babia Góra National Park (southern Poland) in the stand being under strict protection since 1934. 259 circular plots with a radius of 7.0 m and an area of 154 m² each were established in nodes of 20×20 m grid. For individual plots and blocks of the combined plots representing gradient of spatial scales between 0.015 and 0.640 ha, the number of trees, diameter at breast height (dbh) distributions, basal areas and the values of structural diversity indices of Gini (GI), Shannon (SH) and Staudhammer−LeMay (STVI) were determined. The indices were also calculated for several types of theoretical distributions. Based on the values obtained for the theoretical distributions, the individual plots and the blocks of the combined plots were classified as representing simple (GI≤0.30;STVI≤0.10), moderately diversified (0.300.45; STVI>0.30) dbh structure. For all the spatial scales analyzed the average values of GI and STVI indices reached the level typical for populations of a high structural diversity (i.e. exceeded the values of 0.45 and 0.30 respectively). According to the GI and STVI values, the portion of stand patches with complex dbh structure ranged from 70.9% and 68.2% at the individual plots scale, respectively, up to 100% in the blocks of 16 plots (4×4). In general, in all the spatial scales analyzed the spatial diversification of the dbh distributions and basal area levels was higher than in managed selection forests and much higher than in managed single−storied stands. The dominant frequency of highly diversified dbh distributions found in the analysed stand was not concordant with the predictions of the forest dynamics theory based on developmental stages, according to which in primeval forests with a significant partition of Abies alba and Picea abies should prevail stand patches of rather simple dbh structure, characteristic for the long−lasting optimum stage.
Źródło:
Sylwan; 2015, 159, 07; 600-609
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies