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    Wyświetlanie 1-36 z 36
    Tytuł:
    Struktura grubosci drzewostanow sosnowych wzrastajacych w roznych strefach przemyslowego uszkodzenia
    Autorzy:
    Orzel, S.
    Rutkowska, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/822222.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    drzewostany sosnowe
    tereny przemyslowe
    rozklad piersnic
    lesnictwo
    piersnice drzew
    Źródło:
    Sylwan; 2000, 144, 07; 55-63
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ocena zgodnosci rozkladow piersnic w drzewostanach jodlowych z niektorymi rozkladami teoretycznymi
    Autorzy:
    Zasada, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/816760.pdf
    Data publikacji:
    1995
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    rozklad rzeczywisty
    rozklad piersnic
    rozklad teoretyczny
    ocena zgodnosci
    lesnictwo
    drzewostany jodlowe
    Źródło:
    Sylwan; 1995, 139, 12; 61-69
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ocena zgodnosci rozkladow piersnic drzew drzewostanow brzozowych z niektorymi rozkladami teoretycznymi
    Autorzy:
    Zasada, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/813305.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    modele wzrostu
    dendrometria
    rozklad piersnic
    brzoza
    lesnictwo
    Betula
    drzewostany brzozowe
    drzewa lesne
    Źródło:
    Sylwan; 2000, 144, 05; 43-48
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Metoda okreslania grubosciowej struktury ciec w lasach roznowiekowych
    Autorzy:
    Poznanski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/821224.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    fazy rozwojowe
    drzewostany roznowiekowe
    rozklad piersnic
    lasy
    lesnictwo
    urzadzanie lasu
    grubosciowa struktura ciec
    Źródło:
    Sylwan; 2000, 144, 11; 23-32
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Model wzrostu dla modrzewia europejskiego (Larix decidua Mill.) wykorzystujący cechy taksacyjne drzewostanu
    A growth model for European larch (Larix decidua Mill.) based on stand characteristics
    Autorzy:
    Bruchwald, A.
    Dmyterko, E.
    Wojtan, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/45680.pdf
    Data publikacji:
    2011
    Wydawca:
    Instytut Badawczy Leśnictwa
    Tematy:
    lesnictwo
    drzewostany modrzewiowe
    bonitacja drzewostanow
    rozklad piersnic
    modrzew europejski
    Larix decidua
    modele wzrostu
    Źródło:
    Leśne Prace Badawcze; 2011, 72, 1
    1732-9442
    2082-8926
    Pojawia się w:
    Leśne Prace Badawcze
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dynamika zmian lasu o zroznicowanej strukturze w ciagu 26-letniego okresu kontrolnego
    Autorzy:
    Poznanski, R
    Banas, J.
    Zieba, S.
    Zygmunt, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/823891.pdf
    Data publikacji:
    2001
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    dynamika zmian
    drzewostany
    rozklad piersnic
    faza przedplonowa
    faza terminalna
    lesnictwo
    inwentaryzacja lasu
    zasobnosc drzewostanu
    Źródło:
    Sylwan; 2001, 145, 01; 73-84
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Możliwość zastosowania rozkładów mieszanych do modelowania rozkładów pierśnic drzew w naturalnych klasach biosocjalnych
    Potential of mixture distributions application for modelling tree diameter distributions by natural social classes
    Autorzy:
    Zasada, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1026820.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    drzewostany sosnowe
    rozklad piersnic
    klasy Krafta
    lesnictwo
    rozklad mieszany
    diameter distribution
    gamma distribution
    mixture distribution
    biosocial classes
    Opis:
    The aim of the presented study was to show an applicability of finite mixture distribution approach for estimating diameter distribution parameters of the dominant and suppressed stands on an example of one-layer, even−aged, pure Scots pine stands. This approach gave a good fit of compound distribution proportions, average d.b.h for the dominant and suppressed stands and standard deviations of d.b.h. for the analysed classes.
    Źródło:
    Sylwan; 2003, 147, 09; 27-37
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nowa metoda programowania rozwoju zasobow lesnych w przerebowym sposobie zagospodarowania
    Autorzy:
    Poznanski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/818730.pdf
    Data publikacji:
    1999
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    gospodarka lesna
    rozklad piersnic
    gospodarstwa przerebowe
    metody prognozowania
    zasoby lesne
    lesnictwo
    struktura drzewostanu
    urzadzanie lasu
    Źródło:
    Sylwan; 1999, 143, 02; 27-38
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Typy rozkladu piersnic a stadia rozwojowe lasow o zroznicowanej strukturze
    Autorzy:
    Poznanski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/822905.pdf
    Data publikacji:
    1997
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    rozklad piersnic
    gospodarstwa przerebowe
    lasy
    gospodarstwa lesne
    lesnictwo
    stadia rozwojowe
    gospodarstwa przerebowo-zrebowe z rebnia stopniowa
    zagospodarowanie lasu
    Źródło:
    Sylwan; 1997, 141, 03; 37-43
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wzorzec rozkładu pierśnic drzew wielowarstwowego drzewostanu jodłowego Gór Świętokrzyskich
    Pattern of breast height diameter distribution in a multilayer silver fir stand in the Swietokrzyskie Mountains
    Autorzy:
    Bruchwald, A.
    Dmyterko, E.
    Łukaszewicz, J.
    Niemczyk, M.
    Wrzesiński, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/989331.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    Gory Swietokrzyskie
    drzewostany jodlowe
    jodla pospolita
    Abies alba
    rozklad piersnic
    metoda BDq
    diameter distribution
    abies alba
    bdq method
    Opis:
    In Poland, the majority of silver fir stands is characterised by a single−layer stand structure. The current silvicultural activities aim at obtaining multilayer stands, which requires a clearer definition of the structure, and more precisely, a better knowledge of the pattern of diameters at breast height (DBH) distribution. The aim of the research was to develop a pattern of DBH distribution of trees in a multilayer silver fir stand in the Świętokrzyskie Mountains (central Poland) using the BDq method, through the mathematical determination of function parameters, including the productive capacity of the habitat. The application of this pattern will allow the selection of the management methods aimed to obtain and then maintain model stands with a different layer structure. The research was based on the empirical material collected in 56 stands that were characterized by both a single− and a multi−layered structure. They grew in coniferous forest habitats, mostly in the upland mixed coniferous forest, upland mixed deciduous forest and upland deciduous forest or mountain forest. One big (up to 1 ha) or 3−5 smaller (0.04 ha) sample plots were established in each stand in which diameters at breast height of all trees and heights of usually 25 trees, selected from the entire range of diameters, were measured. These were used to determine the height growth curve equation coefficients and then the height of each tree. For each stand the basal area was calculated and a graph for DBH distribution was prepared. Site index was established using the original empirical equation. In order to develop a model for multilayer fir stands, individual parameters of the equation 5, such as the basal area (B), the target diameter at breast height (D) and the coefficient q were to be determined using the BDq method. Taking into consideration only stands with one−tailed DBH, individual parameters of the function were found to be associated with site index. Empirical equations were developed for the determination of B and D, and, based on the DBH distribution graphs, coefficient q associated with site index was also calculated (tab.). The developed DBH distribution pattern is a mathematical description of the target fir stand. When the value of stand parameters approaches those of the model stand, it should be managed using the shelterwood cutting system, which results from the spatial variation in the stand height structure, and consequently from the need for different silvicultural treatments in different stand fragments.
    Źródło:
    Sylwan; 2016, 160, 09; 741-750
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aproksymacja rozkładów pierśnic w dwugeneracyjnych drzewostanach za pomocą rozkładów mieszanych. I. Estymacja parametrów
    Approximation of the breast height diameter distribution of two-cohort stands by mixture models. I. Parameter estimation
    Autorzy:
    Podlaski, R.
    Roesch, F.A.
    Powiązania:
    https://bibliotekanauki.pl/articles/994450.pdf
    Data publikacji:
    2013
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewostany dwupokoleniowe
    rozklad piersnic
    aproksymacja
    rozklad mieszany
    estymacja parametrow
    two−component mixtures
    tree diameter distribution
    weibull distribution
    gamma distribution
    starting strategy
    Opis:
    Study assessed the usefulness of various methods for choosing the initial values for the numerical procedures for estimating the parameters of mixture distributions and analysed variety of mixture models to approximate empirical diameter at breast height (dbh) distributions. Two−component mixtures of either the Weibull distribution or the gamma distribution were employed. The study plots, representing two−cohort stands, were located in the Świętokrzyski National Park (central Poland) and in the Southern Appalachian Mountains (eastern USA). A new strategy using three methods for choosing initial values (min.k/max.k for k=1, 5, 10; 0,5/1,5/mean; wp) for maximizing the likelihood during parameter estimation for mixture models for small and large plots is proposed.
    Źródło:
    Sylwan; 2013, 157, 08; 587-596
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modelowanie rozkładów pierśnic drzew z wykorzystaniem rozkładów mieszanych. I. Definicja, charakterystyka i estymacja parametrów rozkładów mieszanych
    Modelling tree diameter distributions using mixture models. I. Definition, characteristics and parameters estimation of mixtures distributions
    Autorzy:
    Podlaski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/973905.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    drzewostany
    modelowanie
    estymacja
    leśnictwo
    rozkład pierśnic
    rozkład mieszany
    rozkłady składowe
    finite mixture models
    tree diameter distribution
    maximum likelihood estimation
    initial values
    starting
    strategy
    Opis:
    The article presents an introduction to the theory of finite mixture distributions, discusses the ways of procedure in selecting the number and type of component distributions, the methods of assessing the initial values, and proposal of the procedure of estimating the parameters. The proposed procedure uses min.k/max.k (for k=1, 3, 6) and 0.5/1.5/average methods to select initial values for a numerical procedure (EM algorithm + Newton's method) allowing to calculate the extremum of the likelihood function. If at least two identical solutions for the extreme values are not obtained, the multistart method should additionally be applied.
    Źródło:
    Sylwan; 2011, 155, 04; 244-252
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aproksymacja rozkładów pierśnic drzew w dwugeneracyjnych drzewostanach za pomocą rozkładów mieszanych. III. Estymatory jądrowe a rozkłady mieszane
    Approximation of the breast height diameter distribution of two-cohort stands by mixture models. III. Kernel density estimators vs mixture models
    Autorzy:
    Podlaski, R.
    Roesch, F.A.
    Powiązania:
    https://bibliotekanauki.pl/articles/990995.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewostany dwupokoleniowe
    rozklad piersnic
    aproksymacja
    rozklad mieszany
    rozklad Weibulla
    estymatory jadrowe nieparametryczne
    two−component models
    kernel density estimator
    tree diameter distribution
    monte carlo simulation
    Opis:
    Two−component mixtures of either the Weibull distribution or the gamma distribution and the kernel density estimator were used for describing the diameter at breast height (dbh) empirical distributions of two−cohort stands. The data consisted of study plots from the Świętokrzyski National Park (central Poland) and areas close to and including the North Carolina section of the Great Smoky Mountains National Park (USA; southern Appalachians). Kernel density estimators belong to a class of nonparametric density estimators. Nonparametric estimators have no fixed structure and depend upon all the data points to reach an estimate. In this study the Weibull and the gamma mixture distributions were the most versatile models. The results also support the conclusion that there are only minor differences between the parametric models and the kernel density estimates.
    Źródło:
    Sylwan; 2014, 158, 06; 414-422
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Uproszczony model rozkładu pierśnic jednowiekowych niepielęgnowanych drzewostanów sosnowych (Pinus sylvestris L.)
    Simplified model of diameter distribution for even-aged unthinned Scots pine (Pinus sylvestris L.) stands
    Autorzy:
    Jagiełło, R.
    Beker, C.
    Powiązania:
    https://bibliotekanauki.pl/articles/986956.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    dendrometria
    sosna zwyczajna
    Pinus sylvestris
    drzewostany sosnowe
    drzewostany jednowiekowe
    drzewostany niepielegnowane
    rozklad piersnic
    rozklad uproszczony
    rozklad gamma
    diameter distribution
    gamma poisson
    scots pine
    unthinned stand
    Opis:
    Although modelling of the diameter at the breast height (DBH) distributions has long history, theoretical discrete distributions have not so far been used for this purpose. In this study we use measurements covering 25 years (six inventories) without silvicultural influence on 14 even−aged Scots pine (Pinus sylvestris L.) stands to develop the DBH distribution models. Analysed stands are located in Murowana Goślina Forest Experimental Station (W Poland). The objective of the study was to elaborate the most simplified model that applies stand variables easy to assess and uncomplicated theoretical distribution. We employed two−parameter Gamma Poisson (GP) distribution and compared it to Weibull (W) and Sb Johnson (SbJ) ones. When maximum likelihood estimation (MLE) was used, GP gave similar results to W and both were slightly worse than SbJ. We found that both DBH standard deviation and stand density have substantial impact for model bias when above distributions used. Stepwise regression analysis was used for obtaining linear equations for parameter prediction of GP distribution. Then, GP model was simplified by removing standard deviation of DBH (SDD) from equation for overdispersion parameter. Results showed slight increase in mean of error values (i.e. modified Reynolds e index and root mean square error) for simplified model (SGP) compared with those for model including SDD, but differences in means were insignificant. Minimal and mean DBH represent enough variability of diameter distribution to obtain appropriate model based on Gamma Poisson distribution. Error was only 5% greater from four−parameter SbJ (MLE) distribution with similar range: 8.2−28.8% against 5.1−25.5% for SGP and SbJ respectively. The presented model can be used in many branches of forestry for more accurate calculation of stand level variables, when additional allometric equations employed, for instance assimilation apparatus volume or below− and aboveground biomass.
    Źródło:
    Sylwan; 2017, 161, 10; 822-830
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aproksymacja rozkładów pierśnic drzew w drzewostanach dwugeneracyjnych za pomocą rozkładów mieszanych. II. Testy zgodności
    Approximation of the breast height diameter distribution of two-cohort stands by mixture models. II. Goodness-of-fit tests
    Autorzy:
    Podlaski, R.
    Roesch, F.A.
    Powiązania:
    https://bibliotekanauki.pl/articles/993354.pdf
    Data publikacji:
    2013
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewostany dwupokoleniowe
    rozklad piersnic
    aproksymacja
    rozklad mieszany
    testy zgodnosci
    two−component mixtures
    tree diameter distribution
    nonparametric goodness−of−fit tests
    discrete null distribution
    Opis:
    The goals of this study are (1) to analyse the accuracy of the approximation of empirical distributions of diameter at breast height (dbh) using two−component mixtures of either the Weibull distribution or the gamma distribution in two−cohort stands, and (2) to discuss the procedure of choosing goodness−of−fit tests. The study plots were located in the Świętokrzyski National Park (central Poland) and in the Southern Appalachian Mountains (eastern USA). The results of the goodness−of−fit tests (chi−squared, Kolmogorov−Smirnov, Cramér−von Mises, and Anderson−Darling), normalised bias and normalised root mean square error, indicate that dbh empirical distributions of two−cohort stands are compatible with the mixture models investigated. The chi−squared test and the generalization of the Anderson−Darling test to discrete distributions should be used to assess whether empirical dbh data are consistent with a hypothesized null distribution.
    Źródło:
    Sylwan; 2013, 157, 09; 652-661
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optymalizacja rozkładu pierśnic w lesie przerębowym
    Autorzy:
    Paluch, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1022248.pdf
    Data publikacji:
    2005
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    piersnicowe pole przekroju
    hodowla lasu
    rozklad piersnic
    przyrosty
    lesnictwo
    drzewostany przerebowe
    selection forest
    selection cutting
    target diameter
    equilibrium
    steady−state diameter distribution
    Opis:
    For a given target diameter and selection cutting intensity there is only one existing diameter distribution at which a stand can fully use the productive potential of the site. In typical market situations when the rise in market price of timber, at least to some extent, goes along with the increase of stem diameter, the enlargement of stand volume and target diameter results in the rise in stand value increment. Too heavy or too light cutting intensity brings about the reduction in the value increment of a stand.
    Źródło:
    Sylwan; 2005, 149, 02; 12-24
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kształtowanie zróżnicowanej struktury drzewostanów z wykorzystaniem metody BDq
    Application of the BDq method in uneven-aged stands silviculture
    Autorzy:
    Brzeziecki, B.
    Kornat, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/973764.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    struktura drzewostanu
    ksztaltowanie struktury
    rozklad piersnic
    metoda BDq
    diameter distribution
    stand conversion
    stocking control
    sustainable yield
    uneven−aged
    silviculture
    BDQ method
    Opis:
    The BDq method, a tool of stocking control in uneven−aged stands, with a special reference to the problem of determining diameter structure of cuttings, is introduced. Both theoretical foundations, as well as a practical application of the BDq method are presented on the example of conversion of two−storied stands, consisting of silver fir and Scots pine, to stands characterized by a plenter−like structure.
    Źródło:
    Sylwan; 2011, 155, 09; 589-598
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modelowanie rozkładów pierśnic młodocianych drzewostanów brzozy brodawkowatej na gruntach porolnych za pomocą dwuparametrowego rozkładu Weibulla
    Modeling dbh distribution of young silver birch stands on former agricultural lands with the 2-parameter Weibull distribution
    Autorzy:
    Zasada, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/991512.pdf
    Data publikacji:
    2013
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    dendrometria
    drzewostany mlode
    grunty porolne
    drzewostany brzozowe
    brzoza brodawkowata
    Betula pendula
    piersnice drzew
    rozklad piersnic
    modelowanie
    rozklad Weibulla
    betula pendula
    secondary succession
    diameter distribution
    weibull
    Opis:
    The paper presents the diameter distributions of young silver fir stands (Betula pendula Roth.) growing on former agricultural lands described using the 2−parameter Weibull distribution. Various methods of parameters' estimation were tested: maximum likelihood method, method of moments and percentile approach. It was found, that the diameter distributions in such birch stands can have various shapes and forms – from close to the exponential to almost normal. The shape parameter were not affected by the age of the stand, but the scale parameter was strongly correlated with age. The most efficient methods for the tree diameter distribution modeling using the 2−parameter Weibull distribution are the method of moments and the maximum likelihood method. However, the obtained results does not exclude the percentile method, which is relatively simple and can be further modified for obtaining better results.
    Źródło:
    Sylwan; 2013, 157, 04; 268-277
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Struktura rozkładów pierśnic w naturalnych górnoreglowych borach świerkowych Tatr i Beskidów Zachodnich w zależności od stadiów i faz rozwojowych lasu o charakterze pierwotnym
    Autorzy:
    Karczmarski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1022174.pdf
    Data publikacji:
    2005
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    Tatry
    Beskidy Zachodnie
    rozklad piersnic
    swierk
    Picea
    regiel gorny
    lesnictwo
    struktura drzewostanu
    bor swierkowy
    dbh distribution
    stand structure
    virgin type forests
    spruce
    Opis:
    The paper focuses on dbh distributions in the natural spruce stands at different stages and in different phases of virgin type forest development in the upper montane belt (according to developmental cycle by Korpel). The dbh distributions: normal, logarithmic−normal, Weibull and gamma that were found on 12 permanent study plots measured in 1991−1994 depended on the developmental stages and phases of the stands analysed.
    Źródło:
    Sylwan; 2005, 149, 03; 12-23
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Szerokość pasma jądrowego estymatora rozkładu pierśnic w drzewostanach olszy czarnej (Alnus glutinosa (L.) Gaertn.) z zachodniej części Kotliny Sandomierskiej
    Bandwidth of kernel estimator of DBH distribution in black alder (Alnus glutinosa (L.) Gaertn.) stands from west part of the Sandomierz Basin
    Autorzy:
    Pogoda, P.
    Ochał, W.
    Orzeł, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/985919.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    dendrometria
    drzewa lesne
    olsza czarna
    Alnus glutinosa
    piersnice drzew
    rozklad piersnic
    estymacja
    estymatory jadrowe nieparametryczne
    kernel estimator
    bandwidth
    dbh structure
    black alder
    Opis:
    Set of ‘nonparametric’ methods, that don’t make a priori assumption about functional form of empirical distribution was developed as an alternative to the parametric distribution modeling. The kernel estimators are one of such methods, that can be used to describe the frequency of data representing for example DBH records. Kernel smoothing requires the choice of weighting function and bandwidth also called as smoothing parameter or window. The lack of comprehensive analysis on the applicability of particular bandwidth selection methods to model DBH structure gave an impulse to present investigation aimed at determining value and variability of smoothing parameter in black alder stands. The optimal bandwidth was obtained according to six different variants of plug−in method proposed by Altman and Léger. Presented investigations were based on DBH measurements collected in 163 managed black alder stands aged from 6 to 89 years, growing in the west part of the Sandomierz Basin (S Poland). We measured in total 22,530 black alders, from 48 to 359 in individual stand. Stands were characterized by: age, quadratic mean diameter, basal area, mean height, Reineke’s stand density index and standard deviation of DBH. Smoothing parameter was obtained by means of plug−in method with the pilot bandwidth selected by: Silverman’s rule of thumb (nrd0), Scott’s method (nrd), unbiased cross−validation (ucv), biased cross−validation (bcv), method of Sheather and Jones (sj) and one−stage method of Wand and Jones (onestage). The bandwidth was first obtained to real data, then to 100 bootstrap samples of 5, 10, 15 ... and 100 trees from each stand. Smoothing parameters were characterized by mean and variance. Relationship between values of smoothing parameter and stand characteristics was determined. Finally the influence of sample size on value and variability of bandwidth was assessed. Value and variability of smoothing parameter in black alder stands are determined by stand age, sample size and method of bandwidth choice. There is a close relationship between bandwidth and the mean height (r from 0.75 to 0.83), quadratic mean diameter (r from 0.79 to 0.88) and standard deviation of DBH (r from 0.84 to 0.93). Potentially these stand features can be used to predict smoothing parameter values. Minor changes of bandwidth for samples containing above 50 trees together with persistence of standard error give an objective grounds for defining optimal number of diameters, that are necessary to kernel estimation of DBH distribution.
    Źródło:
    Sylwan; 2018, 162, 05; 411-421
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rozkłady teoretyczne najlepiej aproksymujące strukturę pierśnic w drzewostanach świerkowych regla górnego w rezerwacie przyrody "Śnieżnik Kłodzki"
    Theoretical distributions in approximation of breast height diameter structure in upper mountain zone Norway spruce stands in 'Snieżnik Klodzki' nature reserve
    Autorzy:
    Sinica, P.
    Tomusiak, R.
    Tkaczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/989425.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    regiel gorny
    rezerwat Snieznik Klodzki
    drzewostany swierkowe
    swierk pospolity
    Picea abies
    piersnice drzew
    rozklad piersnic
    aproksymacja
    rozklad teoretyczny
    dbh distribution
    stand structure
    native type forests
    picea abies
    Opis:
    The study on the structure of Norway spruce old−growth stands of original provenience in upper mountain zone was carried out in a nature reserve ‘Śnieżnik Kłodzki', located in the Lądek Zdrój Forest District (SW Poland). The fieldwork was conducted in three spruce stands located at the altitude of 1,215 and 1,235 m a.s.l. The breast height diameters (dbh) of living trees were characterized. The aim of this study is to characterize the structure of dbh of trees in spruce stands of subalpine forest. Implementation of the objective will be associated with the characteristics of empirical distributions dbh and an indication of theoretical distributions of continuous random variable best approximating the structure of dbh. The comparison of empirical dbh distributions with 36 theoretical distributions were carried out, but goodness−of−fit tests proven statistically significant compatibility with seventeen of them: beta (4−parameter), Cauchy, exponential power, folded normal, gamma (3−parameter), generalized logistic, Laplace, logistic, loglogistic, loglogistic (3−parameter), lognormal (3−parameter), noncentral chi−square, normal, smallest extreme value, triangular, Weibull and Weibull (3−parameter). The dbh distributions in upper mountain spruce stands are the best fitted with logistic distribution, and subsequently loglogistic (3−parameter), generalized logistic and Weibull (3−parameter) distributions. That four distributions can be used in individual tree growth models while generating structure dbh of trees in the stand. The knowledge of dbh structure in protected stands could be helpful in shaping spruce stand structure in planned silvicultural treatments, and shows the need for silvicultural treatments in upper mountain spruce stands.
    Źródło:
    Sylwan; 2016, 160, 11; 905-914
    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:
    Modelowanie rozkładów pierśnic drzew z wykorzystaniem rozkładów mieszanych. II. Aproksymacja rozkładów pierśnic w lasach wielopiętrowych
    Modelling tree diameter distributions using mixture models. II. Approximation the breast height diameter distributions of multi-storeyed forests
    Autorzy:
    Podlaski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/973657.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    modelowanie
    rozklad mieszany
    rozklad Weibulla
    rozklad gamma
    aproksymacja
    dynamika drzewostanu
    Swietokrzyski Park Narodowy
    leśnictwo
    rozkład pierśnic
    drzewostany wielopiętrowe
    finite mixture models
    weibull distribution
    gamma distribution
    irregularly descending distributions
    forest dynamics
    Polska
    Świętokrzyski National Park
    Opis:
    The aim of the study is to (1) test the procedure of estimating mixture distribution parameters proposed in Podlaski [2011] and (2) present the universality and usefulness of mixture distributions for modelling the empirical distributions of breast height diameters on the example of two−generation stands with an asymmetric breast height diameter distributions. The tested procedure of estimating mixture distribution parameters allowed to calculate parameters for all analysed plots. Weibull and gamma distributions correctly approximated empirical distributions of breast height diameters of all investigated stands. The results presented in the study show the usefulness of mixture distributions to model asymmetric unimodal and poorly developed bimodal distributions of breast height diameters.
    Źródło:
    Sylwan; 2011, 155, 05; 293-300
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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:
    Dokładność określania wybranych parametrów rozkładów pierśnic drzew w drzewostanach sosnowych za pomocą naziemnego skanowania laserowego
    Accuracy of the selected tree diameter distributions parameters assessed using terrestrial laser scanning in Scots pine stands
    Autorzy:
    Zasada, M.
    Sterenczak, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/994333.pdf
    Data publikacji:
    2013
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    dendrometria
    zasoby drzewne
    inwentaryzacja
    drzewostany sosnowe
    powierzchnie probne kolowe
    rozklad piersnic
    dokladnosc
    skanowanie laserowe
    forest inventory
    circular sample plots
    quadratic mean diameter
    percentile
    skewness
    kurtosis
    Opis:
    When using such methods as terrestrial laser scanning (TLS), one of the major factors influencing the accuracy of stand characteristics determination is the visibility of trees on a sample plot, which is often obscured by the shadow effect caused by trees located closer to the plot center. Because of this, the percentage of the identified trees and basal area depends on the distance from the plot center: the accuracy of stocking determination decreases as the plot radius increases. The values of such stand characteristics as average breast height diameter, standard deviation of tree diameters and percentiles of the tree diameters' distributions assessed based on all trees and the visible trees only are not significantly different from each other for circular sample plots with 20 m radius. Skewness and kurtosis are not significantly different in plots with radius of 5 and 10 meters. For the 15 m plot radius the difference was significant for about 15% of the analyzed plots. The obtained results correspond with previous findings that report that on the circular sample plots with radius up to 15 m the errors for the number of trees and basal area are relatively small and can be accepted in the practical inventory. The results support the circular sample plots size optimization, including measurements performed using a point cloud.
    Źródło:
    Sylwan; 2013, 157, 12; 883-891
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ocena przydatności wybranych funkcji do modelowania rozkładu pierśnic w drzewostanach olszy czarnej (Alnus glutinosa (L.) Gaertn.)
    Evaluation of usefulness of selected functions for modeling distribution of breast height diameter in black alder stands (Alnus glutinosa (L.) Gaertn.)
    Autorzy:
    Orzeł, S.
    Pogoda, P.
    Ochał, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/988989.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewostany olszowe
    struktura grubosci
    olsza czarna
    Alnus glutinosa
    piersnice drzew
    rozklad piersnic
    rozklad teoretyczny
    aproksymacja
    modelowanie
    funkcja gestosci prawdopodobienstwa
    test Kolmogorowa-Smirnowa
    diameter at breast height
    diameter distribution
    probability density function
    kolmogorov−smirnov test
    Opis:
    We evaluated the usefulness of ten theoretical probability density functions for the approximation of the breast height diameter distributions in managed alder stands growing in the western part of the Sandomierz Basin (southern Poland). The study material consisted of measurement results for 22,530 alders obtained for 844 circular sample plots, established in 163 stands aged 6−89. In the area of particular stands, from 2 to 10 age−dependent circular sample plots sized 0.01−0.10 ha were systematically arranged. We evaluated the following theoretical probability distributions: normal (N), double normal (P−N), Johnson SB (J), Weibull (W), beta (B), Burr (Bu), gamma (G), log−normal (L−N), log−logistic (L−L) and Birnbaum−Saunders (B−S). Additionally the usefulness of the W, B, Bu, G, L−N, L−L and B−S distributions with omitted location parameter was tested. The goodness−of−fit of each probability density function was assessed based on the Kolmogorov−Smirnov statistic, the root mean square error and ranks established on their basis. It was found that DBH distribution of majority stands is characterized by right−sided asymmetry and negative kurtosis. It was showed that the best distribution for the breast height diameter structure approximation of alder stands is the Johnson SB (J) distribution. To describe the frequency of thickness, normal (N) and log−logistic (L−L) distribution should not be used. Elimination of location parameter significantly affects usefulness of probability density functions to modeling empirical distributions of breast height diameter. Gamma and Burr distributions with omitted location parameter gave the best results in description the frequency of breast height diameter. In certain situations, these distributions can also be used to describe the structure of breast height diameter of alder stands.
    Źródło:
    Sylwan; 2017, 161, 02; 101-113
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kształtowanie zróżnicowanej struktury drzewostanów w warunkach nizinnych
    Promoting diverse forest stand structure under lowland conditions
    Autorzy:
    Brzeziecki, B.
    Drozdowski, S.
    Bielak, K.
    Buraczyk, W.
    Gawron, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/994357.pdf
    Data publikacji:
    2013
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    Puszcza Bialowieska
    drzewostany
    struktura drzewostanu
    struktura warstwowa
    struktura gatunkowa
    ksztaltowanie struktury
    postepowanie hodowlane
    struktura grubosci
    rozklad piersnic
    metoda BDq
    białowieża forest
    close−to−nature silviculture
    stand structure
    silvicultural planning
    stocking control
    Opis:
    The paper presents preliminary results and experiences concerning promoting diverse structures in forest stands dominated by light demanding tree species, i.e. those that prevail under conditions of Polish lowlands. Data was collected in the ‘Control Unit Browsk 28C', established in 2002 in the managed part of the Białowieża Forest (eastern Poland) and surveyed again in 2011.
    Źródło:
    Sylwan; 2013, 157, 08; 597-606
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Charakterystyka wybranych drzewostanów jodłowych o złożonej strukturze na obszarze rdLP Katowice i Krosno
    Characteristics of silver fir stands [Abies alba Mill.] with composite structure on the area of Krosno and Katowice Directorate of Sate Forests
    Autorzy:
    Niemtur, S.
    Zawada, J.
    Ambroży, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1015928.pdf
    Data publikacji:
    2007
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    RDLP Krosno
    wysokosc
    rozklad piersnic
    Abies alba
    przyrost grubosci
    lesnictwo
    piersnice drzew
    RDLP Katowice
    jodla
    liczebnosc drzew w klasach wieku
    drzewa lesne
    drzewostany jodlowe
    silver fir stands
    selection cutting
    continuous cover forestry
    stand structure
    regenerations
    Opis:
    The clear improvement in vitality of silver fir stands is being observed in recent years, they are also intensifying of aiming at increasing participation of the fir in Carpathians forests with simultaneous form of the selecting structure of stands. However suitable silviculture methods depend first of all on the current state of stands. Our results showed that all investigated fir stands need shorter or longer period of transformation for applying of selection cutting methods.
    Źródło:
    Sylwan; 2007, 151, 02; 7-18
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wpływ trzebieży przerębowej na zróżnicowanie strukturalne drzewostanu
    Autorzy:
    Bilski, M.
    Brzeziecki, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1022233.pdf
    Data publikacji:
    2005
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    dominacja wymiarowa
    rozklad piersnic
    trzebiez przerebowa
    lesnictwo
    struktura drzewostanu
    rozmieszczenie przestrzenne
    drzewa lesne
    drzewostany jodlowe
    abies alba mill.
    angle measure index
    bwinpro model
    differentiation thinning
    diameter distribution
    diameter spatial diversity
    liocourt−meyer curve
    spatial pattern
    stand structure
    Opis:
    The impact of differentiation thinning on various aspects of structure of exemplary Silver fir stand, including overall diameter distribution, diameter spatial diversity, dimension dominance and spatial distribution pattern, is analysed. Comparison of empirical diameter distribution (before and after thinning) with a the−oretical Liocourt−Meyer curve and the results of structural analysis, lead to the general conclusion that in case of relatively simple−structured Silver fir stands, achieving a desired, plenter−like structure is a longterm process, requiring a lot of consistency and patience.
    Źródło:
    Sylwan; 2005, 149, 04; 21-33
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Budowa, struktura i dynamika drzewostanow o charakterze pierwotnym w rezerwacie 'Dolina Lopusznej' [Gorczanski Park Narodowy]
    Structure and dynamics of stands of a primeval character in the 'Dolina Lopusznej' nature reserve [Gorce National Park]
    Autorzy:
    Jaworski, A.
    Kolodziej, Z.
    Lapka, M.
    Bartkowicz, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/45830.pdf
    Data publikacji:
    2006
    Wydawca:
    Instytut Badawczy Leśnictwa
    Tematy:
    drzewa martwe
    sklad gatunkowy
    rozklad piersnic
    drzewostany pierwotne
    Picea abies
    lesnictwo
    parki narodowe
    struktura drzewostanu
    nekromasa
    zasobnosc drzewostanu
    budowa drzewostanu
    fazy rozwojowe
    Gorczanski Park Narodowy
    zmiany skladu gatunkowego
    jodla pospolita
    buk zwyczajny
    Abies alba
    odnowienia naturalne
    Fagus sylvatica
    rezerwat Dolina Lopusznej
    swierk pospolity
    drzewa lesne
    Źródło:
    Leśne Prace Badawcze; 2006, 4; 35-59
    1732-9442
    2082-8926
    Pojawia się w:
    Leśne Prace Badawcze
    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
    Tytuł:
    Podstawy nowoczesnych zasad gospodarowania w różnowiekowych lasach górskich
    The foundations of modern management of uneven-aged mountain forests
    Autorzy:
    Poznański, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1009323.pdf
    Data publikacji:
    2010
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    lasy gorskie
    drzewostany roznowiekowe
    drzewostany przerebowe
    struktura drzewostanu
    rozklad piersnic
    inwentaryzacja lasu
    gospodarstwa przerebowe
    gospodarstwa przerebowo-zrebowe
    miazszosc drzewostanow
    gospodarka lesna
    postepowanie hodowlane
    uneven−aged forest
    multi−storied forest
    selection system
    dbh distribution types
    uneven−aged forest development stages
    new prescribed cut referring to silviculture needs
    new method of regulation of selection or near−selection forest type development
    Opis:
    In uneven−aged forests, age does not apply to the whole stand but to individual trees. Therefore age of individual trees is rather represented by their thickness, and dbh distribution types become the measure of their age. The distinguished dbh distribution types show individual uneven−aged forest development phases: type A – optimum phase, type B – initial phase, type C – future phase and type D – ageing phase. In the optimum uneven−aged forest development phase, 'prescribed cut according to silviculture needs' should be similar or equal to volume increment. In the initial development phase, such 'prescribed cut' should represent 60−80% of current volume increment, while in the future forest development phase, it should equal the current volume increment or exceed it by 20%. In the ageing forest development phase, 'prescribed cut according to silviculture needs' should be higher than the current volume increment by 10−30%. Selection−type forest management should be a model one for uneven−aged forests. Selection−type forests are close to the natural state and constitute a stable forest ecosystem with high resistance to biotic and abiotic factors and by reducing and dispersing the management risk they better fulfil their multiple functions.
    Źródło:
    Sylwan; 2010, 154, 09; 603-614
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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