Informacja

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

Wyszukujesz frazę "diameter increment" wg kryterium: Temat


Wyświetlanie 1-3 z 3
Tytuł:
The dynamics of the Taxus baccata L. population and the factors affecting its regeneration in the Jasień Nature Reserve
Autorzy:
Bujoczek, L.
Bujoczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/2078292.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
English yew
seedlings
saplings
diameter increment
diameter distribution
mortality
Opis:
Taxus baccata L. is a relict plant and has a scattered distribution in the entire species range. Yew regeneration may be affected by moisture conditions and tree stand characteristics – variables which change over time and which have not been sufficiently researched to date. The present study determined the size structure of yews, causes of yew mortality, the effects of tree stand characteristics and habitat conditions on yew diameter increment at breast height, the density of yew seedlings and saplings, and the likelihood of yew seedling occurrence. The study was conducted in central Poland, on 22 permanent sampling plots. The paper presents data col- lected in 2017 with reference to previous studies on these plots from 2001 and 2007. Stand volume, basal area, number of trees, canopy cover, and type of forest site were established for the tree layer. Saplings and shrubs were counted. Finally, the parameters determined for yew seedlings included density and percentage of individuals damaged by browsing, as well as soil moisture and percentage cover of herbaceous vegetation in the nearest neighborhood. In 2017, yew density in the tree layer was 70 individuals/ha, having increased by 15 individuals/ha over 16 years. During that period, 6.4 individuals/ha died in that layer. The predominant cause of yew mortality was wind. In the period 2007–2017, the mean diameter increment at breast height was 2.2 mm/year, and indicated a weak relationship only with tree diameter at the beginning of the studied period (R2 = 0.06). In 2017, the mean density of yew saplings and seedlings was 55 individuals/ha and 1005 individuals/ha, re- spectively. Two independent variables were found to be significant in the model of yew seedling occurrence: presence of mature yews on the sampling plot and soil moisture. The condition of the studied yew population is satisfactory, especially in the less moist areas. The number of seedlings is acceptable, but more active protection should be considered due to the scarcity of yew sap- lings. This is all the more important as seed-producing mature yews tend to die as a result of exposure to strong winds and periodic local flooding.
Źródło:
Dendrobiology; 2018, 80; 24-36
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie przyrostu pierśnicowego pola przekroju jodeł w drzewostanach rębnych
Modelling the basal area increment in mature silver fir stands
Autorzy:
Skrzyszewski, J.
Pach, M.
Krzysztof, R.
Szafroń, M.
Stenka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/989097.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany jodlowe
drzewostany rebne
jodla pospolita
Abies alba
przyrost drzew
przyrost piersnicowego pola przekroju
modelowanie
abies alba
diameter increment
tending
silviculture
mixed model
Opis:
Because of the very long regeneration period, final cuts in silver fir stands are always accompanied by the growing stock maintenance, which aims to maximize the revenue by increasing the share of harvest, trees with the highest timber value. We remove trees that have reached the maximum value and leave those whose value is still increasing. The remaining trees are the more valuable, the faster their value grows. The increase of a tree diameter is one of the factors that determines the value increment. The mature silver fir stand consists of trees that in youth grew in favourable light conditions and those that survived the long period of shade, achieving small dimensions. In such stands, the adjacent trees may vary greatly in diameter not related to their age. The aim of the study was to create a model describing the relationship between the increment of silver fir basal area (BAI) and the stand morphological features, age, and the dynamics of growth in early age. The research was carried out in the Brzesko Forest District and Forest Research Station in Krynica (S Poland). The sample size equalled 45 and 57 trees respectively. We used the composite form of linear mixed model. The significant positive effect on BAI (model 1) was found for the initial breast height diameter (dbh), the relative crown length as well as the age when trees reaches the 30 cm dbh. The negative impact was observed for Lorimer C18w index. The negative relationship with the relative BAI (model 2) was found for the initial dbh, slenderness, C18w index as well as the age when trees reaches the 30 cm dbh. Conditional and marginal determination coefficients reached 48 and 42% for model 1, and 62 and 38% for model 2 respectively. The results indicate the great possibility and purpose of growing stock maintenance in the pruned silver fir stands. Selecting the trees for the removal should be based on the target dbh. Had it been reached, the firs can still be characterized by a very good current BAI values. One should leave thinner firs with a relative crown length higher than average. Treatments releasing the crowns of the remaining firs, also at the cutting stage, are justified. Smaller growth at a young age (caused e.g. by shading), does not limit the possibility of obtaining trees with significant dimensions.
Źródło:
Sylwan; 2017, 161, 06; 467-475
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reakcja przyrostowa świerka w powiązaniu ze stopniem uszkodzenia korony
Increment reaction of Norway spruce in connection with the crown damage level
Autorzy:
Bruchwald, A.
Dmyterko, E.
Powiązania:
https://bibliotekanauki.pl/articles/1016122.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
korony drzew
stopien uszkodzenia
Picea abies
lesnictwo
piersnice drzew
przyrosty roczne
przyrost drzew
swierk pospolity
drzewa lesne
increment of the diameter at the breast height
increment reaction
criteria of the assessment
the damage to trees
defoliation
vitality
tree−top condition
norway spruce
Opis:
The study presents the analysis of the increment of tree diameter at the breast height in connection with two variants of the method of assessment the damage to Norway spruce stands. Variants utilise different assessment criteria. The first one is based on the tree's defoliation, the other one – on the damage index W that links defoliation, condition of the tree−top and branching in the middle part of the crown. Detected relations between damage criteria and type of the increment reaction show that index W characterises the damage to trees and stands better than feature A (defoliation). Therefore, method of assessment the damage to trees and stands based on this parameter is suggested for utilisation in the forestry practice.
Źródło:
Sylwan; 2007, 151, 11; 22-34
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