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Wyszukujesz frazę "Klaś, M." wg kryterium: Wszystkie pola


Wyświetlanie 1-2 z 2
Tytuł:
Wydajność aparatu asymilacyjnego sosny zwyczajnej (Pinus sylvestris L.) różnych klas wieku
Productivity of the assimilation apparatus of Scots pine (Pinus sylvestris L.) in various age classes
Autorzy:
Turski, M.
Beker, C.
Jaszczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/989700.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany sosnowe
klasy wieku
klasy Krafta
drzewa lesne
sosna zwyczajna
Pinus sylvestris
aparat asymilacyjny
wydajnosc aparatu asymilacyjnego
volume of leaved twigs
productivity of assimilating apparatus
age classes
kraft's classes
Opis:
Productivity of the assimilating apparatus is commonly defined as an increment in volume, most typically of the stem or trunk, per unit of crown size. In this paper the productivity of the assimilating organ (CPtwn1) is calculated as a quotient of the average annual increment in stem volume from a 5−year period (iv1) and the volume of twigs with needles (twnv), determined by xylometry methods (fluid displacement method). The experimental material comprised measurements taken on 200 Scots pines (Pinus sylvestris L.) in 8 pure pine stands growing in western Poland (tab. 1). Using the calculated sizes of assimilating apparatus, their arithmetic means and coefficients of variation were calculated for each stand (tab. 2, 3). Additionally, mean crown productivity within each Kraft's class comprising the dominant trees (classes 1, 2 and 3) as well as in the dominated trees (classes 4 and 5) were determined. The strength of the relationship between CPtwn1 and diameter at breast height (d1.3), height (h) and volume of leaved twigs (twnv) was calculated (tab. 4). Moreover, a two−way analysis of variance was conducted to assess the statistical significance of the effect of age of the stand and biosocial class of tree position in the stand (within the dominant trees and the dominated trees) on productivity of the assimilating apparatus. Mean productivity of analysed Scots pine crowns takes the highest values in the youngest stand (0.60 m³), while the lowest – in the oldest stand (0.34 m³). In the youngest, 25−year old pine stand, mean productivity of the assimilating apparatus in trees forming the dominated trees is by 124% greater than that of trees forming the dominant trees. An opposite situation is found in the oldest, 93−year−old stand, where mean productivity of the dominant trees is over 1.5 greater than that recorded in the dominated trees. Statistically significant effect of the stand age on productivity of the assimilating apparatus was observed (tab. 5). However, affiliation of a tree to the dominant or dominated trees does not result in such an effect. On the other hand, there is an interaction between age of the stand and its affiliation to the Kraft's classes. This means that the affiliation of trees to the dominant trees or the dominated trees and its effect on mean productivity of the assimilating apparatus depend on the age of stand.
Źródło:
Sylwan; 2015, 159, 01; 36-44
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena zgodności rozkładów empirycznych pierśnic drzewostanów bukowych różnych klas wieku z wybranymi rozkładami teoretycznymi
Goodness of fit evaluation of the breast height diameter distributions of beech stands differing in age with selected theoretical distributions
Autorzy:
Jagiełło, R.
Beker, C.
Jagodziński, A.M.
Powiązania:
https://bibliotekanauki.pl/articles/989389.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany bukowe
klasy wieku
buk zwyczajny
Fagus sylvatica
piersnice drzew
rozklad empiryczny
rozklad teoretyczny
ocena zgodnosci
diameter distribution
finite mixture distribution
beech stand
fagus sylvatica
Opis:
Modelling is one of the basic activities in the field of biological sciences. The main purpose of modelling is to illustrate relationships and phenomena of biological objects (and traits describing them) and present reality as close as it is possible with expected range of error. In the paper we presented results of approximation of the selected theoretical distributions, i.e. singular (normal, log−normal, gamma, two− and three−parameter Weibull, Johnsons SB) and finite mixture (normal, log−normal, gamma and Weibull) to tree diameter distributions in beech stands (Fagus sylvatica L.). The main aim of the study was to evaluate goodness of fit of selected distributions, prove legitimacy of using mixture distributions in even−aged, single−species beech stands and find the best distribution of model diameter distribution in a whole production cycle of this kind of stands. The study was conducted in 32 sample plots located in north−western Poland in stands at the age between 9 and 140. For the evaluation χ² test, a modified error index (e) and a root mean square error (RMSE) were used. We found that the RMSE and e are related in most cases with stand density. Mean values of used indicators show that finite mixture distributions are better in comparison to singular distributions. The best fitted distributions were Johnsons SB and mixture of gamma ones. Range of error index expressed with number of trees per hectare ranges 16.5−32.8% and 7.7−27.0% for this distributions, respectively. Conversely the worst results were obtained by fitting two−parameter Weibull distribution both in singular and mixture. Future diameter distribution model based on the probability distribution should be based on Johnson SB or 3−parameter Weibull distribution from singular ones or gamma from finite mixture. In case of age class apportionment unequivocal the best result were obtained with Johnson SB and partially with mixture gamma distributions.
Źródło:
Sylwan; 2016, 160, 02; 107-119
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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