Informacja

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

Wyszukujesz frazę "distribution dynamics" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
Zmiany składu gatunkowego i struktury drzewostanów w Roztoczańskim Parku Narodowym w okresie 2007-2017
Changes in the species composition and structure of forest stands in the Roztocze National Park in the years 2007-2017
Autorzy:
Łukaszewicz, J.
Zajączkowski, G.
Gil, W.
Tittenbrun, A.
Radliński, B.
Powiązania:
https://bibliotekanauki.pl/articles/979113.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
forest dynamics
species composition
dbh distribution
permanent plot
strict protection
Opis:
The aim of the study is to analyze changes in the species composition and in the diameter structure of the main forest−building species in the Roztocze National Park (central−eastern Poland). The research was carried out on 315 permanent monitoring plots. The range of collected data included: type of protection (strict and active protection), forest site type, tree species and their dbh (>7 cm over bark). Measurements and observations were made in 2007 and repeated in 2017. There was a significant reduction in the number of all tree species, except of beech Fagus sylvatica, regardless the protection status. Despite this, the basal area for the strict and active protection zone was similar both in 2007 (37.77 and 36.39 m2/ha, respectively) and 2017 (37.17 and 37.85 m2/ha, respectively). In the whole park, the number of large trees (mainly beeches) with high individual basal area increased, while the number of young generations of all species decreased. In the strict protection zone, the admixture species (decrease by 27.3%), as well as hornbeam Carpinus betulus (decrease by 22.8%), are not particularly competitive with beech. A similar tendency, although mitigated by active silvicultural treatments, was also observed in the active protection zone, in which admixture species have lost 24.8% while hornbeam 16.2%. In the strict protection area, there was a significant reduction in the number of fir Abies alba (by 14%). In the active protection zone fir increased its range and basal area, and maintains its population practically unchanged. There was also a decrease in the number of young generations, as evidenced by changes in the frequency in the 7−16 cm dbh class. The highest level of reduction in this class was found for pine Pinus sylvestris (by 64.8%), rare species (40.4%), hornbeam (31.2%), oak Quercus robur (26.6%), and spruce Picea abies (20.5%). Only beech increased the abundance in this class (by 1.4%) as well as in the next 17−26 cm class (even by 14.2%). The presented significant changes in the species composition and structure of basal area of the stands in the Roztocze National Park that occurred in the 10−year period, indicate a significant role of tending cuts in maintaining proper species composition, appropriate diameter structure of stands, their stability of natural richness and high level of diversity of forest ecosystems.
Źródło:
Sylwan; 2020, 164, 08; 683-694
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:
Zagrożone gatunki drzew Białowieskiego Parku Narodowego (Rezerwat Ścisły)
Threatened tree species of the Bialowieza National Park (the Strict Reserve)
Autorzy:
Brzeziecki, B.
Keczyński, A.
Zajączkowski, J.
Drozdowski, S.
Gawron, L.
Buraczyk, W.
Bielak, K.
Szeligowski, H.
Dzwonkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1007075.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
hodowla lasu
Bialowieski Park Narodowy
rezerwaty scisle
Obreb Ochronny Orlowka
stale powierzchnie obserwacyjne
sklad gatunkowy
drzewa lesne
grab
lipa
swierk
olsza
brzoza
dab
sosna
jesion
klon
wiaz
topola osika
zageszczenie populacji
liczebnosc
struktura grubosci
gatunki dominujace
gatunki zagrozone
diameter distribution
dynamic status
large−scale inventory
long−term trend
natural forest
permanent plot
population density
population dynamics
strict protection
Opis:
An assessment of the current dynamic status of tree species occurring in the Strict Reserve of the Białowieża National Park is presented. On the basis of long−term trends and analysis of large−scale inventory data, the three major groups of trees are distinguished: 1) ‘safe’ group, containing hornbeam and lime, 2) ‘presently safe, but declining in a long−term run’ group, involving spruce, birch and alder, and 3) ‘threatened and highly threatened’ group, consisting of oak, pine, ash, maple, elm and aspen.
Źródło:
Sylwan; 2012, 156, 04; 252-261
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

    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