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Wyświetlanie 1-4 z 4
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:
Modele struktury grubości w dwu- i wielopiętrowych drzewostanach z udziałem jodły Abies alba Mill. i buka Fagus sylvatica L.
Models of diameter structure in two- and multi-storied stands with fir Abies alba Mill. and beech Fagus sylvatica L.
Autorzy:
Pach, M.
Podlaski, R.
Powiązania:
https://bibliotekanauki.pl/articles/989729.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany mieszane
struktura grubosci
drzewostany dwupietrowe
drzewostany wielopietrowe
jodla pospolita
Abies Alba
buk zwyczajny
Fagus sylvatica
rozklad piersnic
rozklad Weibulla
rozklad mieszany
tree diameter modelling
forest complex structure
weibull mixture model
Opis:
The objectives of the study were (1) to determine the models of diameter at breast height (dbh) distributions in two− and multi−storied mixed stands with fir Abies alba Mill. and beech Fagus sylvatica L. as well as (2) to assess the usefulness of single Weibull distribution and two−component mixture of Weibull distribution to approximation of empirical dbh distributions for distinguished models of dbh structures. In the Świętokrzyskie Mountains, 21 sample plots ranging in size from 0.2 to 0.4 ha were established. To identify the models of dbh distributions, in two− and multi−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 were used. To approximate dbh distributions, the single Weibull distribution and the two−component mixture of Weibull distribution were employed. In two− and multi−storied mixed stands with fir and beech, with the mean age between 50 and 70 at the dbh, four models of dbh distributions were determined (fig. 1). Two of them were decreasing, strongly asymmetric (OS and OJ models; fig. 2) and the other two were increasing in the initial phase and decreasing in the final, having two maximums (DM1 and DM2 models; fig. 3). In the stands with the complex structure mixed distribution should be used to approximate empirical data. The analysis revealed high suitability and versatility of Weibull distribution both as single form and two−component mixture.
Źródło:
Sylwan; 2015, 159, 08; 632-638
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stan wielogatunkowego lasu naturalnego (Abies, Fagus, Picea) regla dolnego w rezerwacie Oszast na tle monokultur świerkowych w Beskidzie Żywieckim i Beskidzie Śląskim
A comparison of lower montane natural forest (Abies, Fagus, Picea) in Oszast Reserve and spruce monocultures in the Zywiecki Beskid and Slaski Beskid
Autorzy:
Jaworski, A.
Pach, M.
Powiązania:
https://bibliotekanauki.pl/articles/1316186.pdf
Data publikacji:
2014
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
lesnictwo
lasy gorskie
regiel dolny
rezerwaty przyrody
rezerwat Oszast
las naturalny
drzewostany wielogatunkowe
sklad gatunkowy
swierk pospolity
Picea abies
buk zwyczajny
Fagus sylvatica
jodla pospolita
Abies alba
klon jawor
Acer pseudoplatanus
jarzab pospolity
Sorbus aucuparia
zmiany skladu gatunkowego
zasobnosc drzewostanu
struktura drzewostanu
rozklad piersnic
smiertelnosc
odnowienia lasu
stand volume
dbh distribution
mortality
regeneration
Opis:
The aim of this research was to find out what changes occurred between 1999-2009 in Oszast reserve in the volume, species composition and diameter at breast height (dbh) distribution of the forest stand, and the number and height of regeneration. The objective was to determine what would be condition of these managed lower montane multispecies forest stands (Swiss irregular shelterwood method or selection cuttings) and what role spruce would play in them if they have not been replaced by spruce monocultures. The research was conducted on three permanent circular sample plots (s.p.), each had size of 1/3 ha. Over 10 years, standing volume of the forest stand increased on s.p. 1 (from around 562 m3 ha-1 to 649 m3 ha-1) and s.p. 3. (from 653 m3 ha-1 to 660 m3 ha-1), while decreased on s.p. 2. (from 421 m3 ha-1 to 378 m3 ha-1). The species composition, defined on the basis of volume share (averaged for the three s.p. jointly), did not undergo consistent changes. However, the relative dominance of beech over spruce was determined based on tree numbers. The average spruce mortality (averaged from three s.p.) did not exceed 10% and was slightly higher than that of beech (6%), and lower than fir mortality (15%). Nevertheless, spruce did not show any symptoms of dieback. The reasons behind its mortality were fallen trees and windbreaks. In regeneration, on the whole, beech or sycamore predominated, and the proportion of spruce and fir was small. In the future spruce and fir may even decrease further by competitive ability of dynamically regenerating beech. Abandonment of forest management to promote greater diversity of species, may favour the formation of beech monocultures, or forest stands dominated by beech, everywhere that beech is already present or will be introduced. The maintenance of stable, multispecies forest stands, with co-dominant fir, beech and spruce of native origin, requires natural or artificial regeneration of spruce and fir, manipulated to restore fir up to about 30%, and reduce spruce down to about 40%. This would be possible through the use of the Swiss irregular shelterwood method and selection system, and by continuous tending of regeneration.
Źródło:
Leśne Prace Badawcze; 2014, 75, 1; 13-23
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakterystyka lasów przerębowych w wybranych nadleśnictwach Regionalnej Dyrekcji Lasów Państwowych w Krakowie
Characteristics of selection stands in selected forest districts of the Cracow Regional Directorate of State Forests
Autorzy:
Jaworski, A.
Paluch, J.
Pach, M.
Kołodziej, Z.
Majerczyk, K.
Powiązania:
https://bibliotekanauki.pl/articles/1016254.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
sklad gatunkowy
rozklad piersnic
Nadlesnictwo Gromnik
Nadlesnictwo Limanowa
lasy gorskie
Karpaty Wschodnie
struktura wysokosci
lesnictwo
zasobnosc drzewostanu
drzewostany jodlowe
Nadlesnictwo Stary Sacz
ciecia przerebowe
Nadlesnictwo Gorlice
RDLP Krakow
Nadlesnictwo Nawojowa
odnowienia naturalne
drzewostany przerebowe
LZD Krynica
Nadlesnictwo Losie
selection system
west carpathians
natural regeneration
annual cut
cutting intensity
target dbh
liocourt−meyer distribution
Opis:
Research was carried out in 13 fir stands representing a spectrum of typical Carpathian selection forests. In most of them, no selection cutting was applied except for Krynica I and II stands. The stand volume oscillated between 384 m3/ha and nearly 628 m3/ha. The maximum dbh age of the stands ranged from 100−120 to over 200 years. Dbh distributions attained the form of a J−shaped curve with the highest number of trees in the smallest diameter class, however, none of these curves showed conformance with Liocourt−Meyer's theoretical distribution. From the analysis of the undergrowth, it can be concluded that three stands showed unsatisfactory amount of undergrowth. In general, the intensity of cuts in the majority of sites was high. This is related to the specifics of these stands which, in most cases, have not yet been managed under the selection system.
Źródło:
Sylwan; 2007, 151, 06; 34-52
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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