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Tytuł:
Zmienność proweniencyjna olszy czarnej w Polsce
Provenance variability of black alder in Poland
Autorzy:
Rożkowski, R.
Mejnartowicz, L.
Guzicka, M.
Dorobek, K.
Chmura, D.J.
Powiązania:
https://bibliotekanauki.pl/articles/979576.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewa lesne
olsza czarna
Alnus glutinosa
proweniencje
wysokosc drzew
piersnice drzew
piersnicowe pole przekroju
miazszosc drzew
zmiennosc proweniencyjna
alnus glutinosa
diameter
diversity
height
population
productivity
stem straightness
Opis:
European black alder (Alnus glutinosa (L.) Gaertn.) is a widespread tree species associated with wetlands and riparian ecosystems, thus it plays an important ecological role. Due to its fast growth and favorable wood properties it also has a potential to satisfy a growing demand for wood and fiber. However, its growth potential is not fully realized in Poland. In this study we investigated variation in growth traits, productivity, and stem straightness among 11 populations of European black alder originating from the lowland distribution of the species in Poland. The common−garden experiment located in 1968 in Kórnik (mid−western Poland) has been so far the only provenance experiment with this species in our country. We measured height and diameter of all trees at the site, assessed stem straightness in a 5−step scale (1−crooked; 5−straight), and calculated productivity at age of 50 years, which should be considered close to the rotation age. We found significant variation among populations in all investigated traits. The difference in productivity between the best and the worst provenance reached 75%. Using published and unpublished data from previous measurements at this site we also analyzed a trend in provenance ranking through time. The best and worst provenance could be identified at age 16 years, but many ranking shifts took place afterwards at the intermediate rank positions. We conclude that growth, productivity and stem quality of black alder could be improved through selection of favorable provenances within the species. Selection decisions can be made at the age below the half the rotation age, although decisions at 3/4 of rotation age would be more precise.
Źródło:
Sylwan; 2019, 163, 10; 830-838
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmienność wybranych cech potomstwa buka zwyczajnego (Fagus sylvatica L.) na powierzchni testowania w Nadleśnictwie Łosie
Variability of selected features in progeny of the common beech (Fagus sylvatica L.) grown on the experimental plot in the Losie Forest District
Autorzy:
Szeligowski, H.
Buraczyk, W.
Drozdowski, S.
Bielak, K.
Widawska, Z.
Będkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/979509.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
drzewa lesne
buk zwyczajny
Fagus sylvatica
proweniencje
drzewa potomne
zmiennosc cech
przezywalnosc
wysokosc drzew
piersnice drzew
fenologia
wartosc hodowlana
doswiadczenia proweniencyjne
Nadlesnictwo Losie
common beech
provenance
variability
silvicultural value
lesnictwo
hodowla lasu
Opis:
This paper presents the genetic variability in the growth parameters and morphological traits, as well as the silvicultural quality of progeny of 23 European beech (Fagus sylvatica L.) provenances from south−eastern Poland. The research was conducted on the experimental plot established in the Łosie Forest District in spring 2006. After 10 years, during the spring and autumn, we determined and measured the spring phenology and survival rate, the diameter at breast height (dbh), the tree height, and the straightness of trunk. The results obtained point out the considerable variability of analysed features, both within and between different beech populations (tab.). Highest and lowest survival rates are noted for the beeches from Lutowiska and Leżajsk (populations 451 and 461), respectively (fig. 2). Lowest mean height and dbh were achieved by beeches from Bircza (453), while the tallest and broadest trees were from the Kielce population (390) (fig. 3−4). The overall silvicultural assessment based on survival, height, dbh, spring phenological phases and straightness of the trunk revealed that the most valuable populations of beech are those originating from Kielce (390), Bircza (454), Strzyżów (459), Lesko (452), Rymanów (457) and Lutowiska (451). In turn, the analysis resulted in least favourable assessments for beeches from Bircza (453) and Gromnik (362). Thus, we confirmed also that trees of local origin are not always best−adapted to (and do not always grow best in) the place they originate from. The obtained results are highly relevant from the principles of creating the seed source regions for beech in Poland, as the proper selection of a population for the given place of growth may yield benefits for forest ecology and management.
Źródło:
Sylwan; 2019, 163, 03
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cechy biometryczne sosny czarnej i sosny zwyczajnej na wydmach nadmorskich w rezerwacie Mierzeja Sarbska
Biometric features of black pine and Scots pine on coastal dunes in the Mierzeja Sarbska Nature Reserve
Autorzy:
Szyc, K.
Kedziora, W.
Dominiecki, A.
Poniecki, M.
Lecyk, M.
Sagan, J.
Wojan, R.
Tomusiak, R.
Powiązania:
https://bibliotekanauki.pl/articles/881428.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
Tematy:
rezerwaty przyrody
wydmy nadmorskie
rezerwat Mierzeja Sarbska
sosna czarna
Pinus nigra
sosna zwyczajna
Pinus sylvestris
cechy biometryczne
piersnice drzew
wysokosc drzew
dlugosc korony
rozklad empiryczny
Źródło:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2018, 20, 2[56]
1509-1414
Pojawia się w:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
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:
Zmiana z wiekiem grubości, pola przekroju i wysokości robinii akacjowej z zachodniej Polski
Age-related changes of diameter, basal area and height of black locust from western Poland
Autorzy:
Bronisz, K.
Powiązania:
https://bibliotekanauki.pl/articles/880389.pdf
Data publikacji:
2018
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
Tematy:
lesnictwo
drzewostany robiniowe
robinia akacjowa
Robinia pseudoacacia
piersnice drzew
piersnicowe pole przekroju
wysokosc drzew
tablice zasobnosci drzewostanu
Nadlesnictwo Slawa Slaska
Nadlesnictwo Sulechow
Nadlesnictwo Glogow
Źródło:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2018, 20, 3[57]
1509-1414
Pojawia się w:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
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:
Dokładność stałych krzywych wysokości dla drzewostanów olszy czarnej (Alnus glutinosa (L.) Gaertn.)
Accuracy of the uniform height curves for black alder (Alnus glutinosa (L.) Gaertn.) stands
Autorzy:
Ochał, W.
Orzeł, S.
Siudak, K.
Zamyślewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/989648.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
dendrometria
drzewostany olszowe
drzewa lesne
olsza czarna
Alnus glutinosa
piersnice drzew
wysokosc drzew
stale krzywe wysokosci
h−d relationship
uniform height curve
forest inventory
black alder
Opis:
The study presents the assessment of the accuracy of two generalized height−diameter models, such as skwB [Bruchwald et al. 2001] and skwO [Orzeł et al. 2014], developed in Poland for black alder (Alnus glutinosa (L.) Gaertn.) stands. Verification of these models was conducted on empirical material that was collected in 127 alder stands located in the western part of Sandomierz Basin (southern Poland). Selected alder stands aged 6−89 years, while average breast height diameter ranged from 4.5 to 43.0 cm and average height from 6.3 to 32.7 m. The stand density varied from 222 to 4360 trees/ha. The accuracy assessment for uniform height−diameter curves was based on the analysis of single tree absolute error distributions. Synthetic indicators of goodness−of−fit, such as: average and standard errors, coefficients of variation and determination were calculated based on absolute errors. The final evaluation of the compared uniform height−diameter models results from the structure of the goodness−of−fit measures that was observed within all analyzed stands and within age classes of 20 years. The efficiency of uniform height−diameter models was also compared with stand height−diameter curve, which was developed based on the Näslund function. General height−diameter models overestimated height in alder stands on average from 0.26 (1.67) to 0.19 m (1.39%), based on skwB and skwO models, respectively. Bias depended on the age of stand and decreases from almost 3% in I age class to nearly 0.5% in IV and V age class. For both analyzed models, a positive systematic error was observed for the standardized breast height diameter. Bias in estimating the height of single stand depended on the accuracy of stand height estimations. In case of estimation based on the measurements of three trees height, bias in single stand can range from –13% to +14%. Due to the range and nature of observed systematic errors, uniform height curves should be applied to groups of stands that have different age and breast height diameter structure, as it allows for partial reduction of the error.
Źródło:
Sylwan; 2016, 160, 08; 635-646
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
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:
Symulacja serii przyrostów radialnych jodły Abies alba Mill. z wykorzystaniem modeli gamma
Simulation of radial increment series of Abies alba Mill. using gamma models
Autorzy:
Podlaski, R.
Powiązania:
https://bibliotekanauki.pl/articles/880927.pdf
Data publikacji:
2016
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
Tematy:
drzewa lesne
jodla pospolita
Abies alba
piersnice drzew
przyrosty radialne
rozklad gamma
Swietokrzyski Park Narodowy
Źródło:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2016, 18, 3[48]
1509-1414
Pojawia się w:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uproszczone wzory empiryczne do określania suchej biomasy nadziemnej części drzew i ich komponentów dla sosny zwyczajnej
Simplified empirical formulas to determine the dry biomass of aboveground components of trees for Scots pine
Autorzy:
Bronisz, K.
Zasada, M.
Powiązania:
https://bibliotekanauki.pl/articles/989260.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewa lesne
sosna zwyczajna
Pinus sylvestris
biomasa nadziemna
obliczenia
wzory empiryczne
wzory uproszczone
piersnice drzew
allometric equation
scots pine
biomass
seemingly unrelated regression
Opis:
So−far developed and published Polish equations for determination of aboveground biomass of Scots pine are based on two predictors: diameter at the breast height (DBH) and tree height. The main goal of the presented study were i) to build the simplified empirical biomass equations that use exclusively DBH as the independent variable, and ii) to compare the obtained results with values from equations based on both predictors (optimal model). The empirical material consisted of biomass data for 90 Scots pines growing on typical habitats in Bory Lubuskie (western Poland). The elaborated equations have a lower accuracy than the optimal ones. The R² value for all biomass components is higher than 0.69, and reaches as much as 0.976 in the case of dry wood biomass. The root mean square error (RMSE) for such components as dry biomass of bark and alive or dead branches and branches with needles is lower for the simplified model. However, for the dry wood biomass the optimal model has lower RMSE value. Because this component has the largest share in the total aboveground tree biomass (AGB), the resulting RMSE for the AGB is lower than for the optimal model. Optimal model is also more accurate when the mean error is considered. The simplified model can be used when there are no height measurement available or there is an anxiety that the use of height−diameter models significantly increases the uncertainty of results.
Źródło:
Sylwan; 2016, 160, 04; 277-283
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ rzeźby terenu na bonitację i cechy wzrostowe drzewostanów sosnowych na wydmach Kotliny Toruńskiej
Impact of land relief on site index and growth parameters of Scots pine stands on inland dunes in the Torun Basin
Autorzy:
Sewerniak, P.
Powiązania:
https://bibliotekanauki.pl/articles/989617.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Kotlina Torunska
rzezba terenu
ekspozycja terenu
drzewostany sosnowe
sosna zwyczajna
Pinus sylvestris
wzrost roslin
wysokosc drzew
piersnice drzew
smuklosc drzew
bonitacja drzewostanow
topography
pinus sylvestris
slope aspect
tree growth
forest site
soil
inland dunes
Opis:
The aim of the study was to determine the impact of land relief on site index and growth parameters (height, diameter, slenderness) of Scots pine (Pinus sylvestris) stands on inland dunes in the Toruń Basin (N Poland). The study was conducted on 150 plots situated on north− and south−facing dune slopes (54 pairs of twin plots) as well as in intra−dune depressions (42 plots). Height and diameter of ten the thickest pines per 0.1 hectare was measured, and next site index as a potential height of a stand at the age of 100 years was calculated. As the results of the used equation, site index was strongly (R²=0.58) negatively biased to age, so the bias was removed using an elaborated regression model. For stands older than ca. 20 years, the clear higher site index values as well as higher heights and diameters were found for intra−dune depressions than for slopes of the two studied aspects. This was explained by the occurrence of much more fertile and moister soils in depressions. The only age class for which the advantage of site index and growth parameters was not stated for depressions was the youngest class (≤20 years old). This was likely caused by the competitive impact on young pines of Calamagrostis epigejos which prefers intra−dune depressions on inland dunes and forms in forest floor usually dense cover in this position. Impact of contrasting slope aspect was clearly related in the study to age of a stand. For the youngest studied age class both site index values as well as heights and diameters were lower on north− than on south−facing slopes. This was explained by the effect of weeds which form more dense cover on slopes of this aspect than on sunny slopes. For older stands; however higher site index values as well as heights and diameters were revealed for north−facing slopes, due to pines likely took advantage of higher moisture of soils occurring in this place. With reference to slenderness, regardless stand age the parameter was regularly the highest for north− than both for south−facing slopes and depressions. Because of the revealed distinct higher productivity of intra−dune depressions in normally dry and poor in nutrients dune landscape, it could be reasonable to use the depressions to introduce admixtures of broadleaved tree species into pine monocultures on inland dunes.
Źródło:
Sylwan; 2016, 160, 08; 647-655
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:
Tempo wzrostu wysokości i pierśnicy jodły pospolitej (Abies alba Mill.) w Beskidzie Niskim
Height and diameter growth rates of silver fir (Abies alba Mill.) growing in Beskid Niski mountains
Autorzy:
Bruchwald, A.
Dmyterko, E.
Niemczyk, M.
Łukaszewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/989756.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewa lesne
jodla pospolita
Abies alba
wzrost roslin
wysokosc drzew
piersnice drzew
przyrost piersnicy
przyrost wysokosci
tempo wzrostu
Beskid Niski
height growth rate
diameter growth rate
spatial diversity of canopy layers
physical age
abies alba
Opis:
Silver fir is one of the main tree species of mountain and foothill forests in Poland that in optimal conditions forms pure stands with multi−layer structure. The study objective is to present differences in height and diameter growth rates of firs growing in upper stand layers and in the undergrowth. The research was conducted in 12 fir stands located in the Beskid Niski Mts. (southern Poland). In each stand height and diameter at breast height (dbh) were measured for 25 fir trees in order to develop a height curve. The first canopy layer included trees that were higher than ⅔ Hmax established from the height curve of the tree with the largest dbh. Height and diameter were measured on eight trees selected from the first canopy layer. An increment core was extracted at breast height in order to estimate the tree age. From the third canopy layer, which included trees higher than 2 m with dbh below 7 cm, five trees were selected. After cutting those trees, the length of the last ten branch whorls was measured. Five−year ring width measurements starting from the bark towards the pith were done at the stem cross−sections obtained at breast height. The number of rings was counted on remaining stumps. Height growth rate was defined as the height at the base age of 100 years (eq. 1). For the first canopy layer, the height growth rate was on average 31.8 m, while for the undergrowth it was 12.1 m. There was also large difference between diameter growth rate of the first stand canopy layer (55.7 cm) and undergrowth (18.3 cm). Both differences were significant at p=0.05. These discrepancies could result from low amount of light reaching the forest floor. The correlation between height and diameter growth rates and undergrowth tree age was negative in both cases. Long periods of shading result in smaller number of firs reaching the first canopy layer. Assuming that uneven−aged stand structure is optimal for that species, it should be characterized by a spatial variability (mosaic) of various canopy layers including even−aged patches with sparse canopy closure as well as gaps where fir regeneration will be initiated having favorable growth conditions.
Źródło:
Sylwan; 2015, 159, 10; 804-812
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakterystyka wybranych cech morfologicznych drzew w dojrzałych drzewostanach sosnowych eksponowanych na działanie wiatru
Characteristics of selected morphological traits of trees in mature pine stands exposed to the action of wind
Autorzy:
Tomczak, A.
Jelonek, T.
Pazdrowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/990957.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany sosnowe
wiatry
drzewa lesne
sosna zwyczajna
Pinus sylvestris
stabilnosc
cechy morfologiczne
piersnice drzew
wysokosc drzew
wysokosc osadzenia korony
srednica korony
dlugosc korony
wind
tree stability
biometry
scots pine
Opis:
The paper presents variability in morphological traits of trees in mature Scots pine stands exposed to wind. The analysed parameters included breast height diameter, tree height and length, diameter, lateral area and crown base area. Except for the crown base area and crown diameter, values of the other traits increased with an increase in the distance from the edge of the stand. Crown diameter in trees with average exposure to wind was smaller than diameters of trees growing on the edge of the stand (strong exposure) and within the stand (weak exposure).
Źródło:
Sylwan; 2014, 158, 03; 183-191
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 71

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