Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 28

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  zywotnosc drzew
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The study assesses the damage to silver fir from the canopy layer in the stands of the Świętokrzyskie Mountains (central Poland) using three methods. The suitability of these methods was also analysed by calculating the correlation between increment of the diameter at breast height (DBH) and the level of damage. In total we investigated 240 trees. The first analysed method involves tree defoliation. The mean defoliation of sample accounts for 47.8%, while majority of the trees were found to be within 2nd damage class (fig. 1). Absolute and relative DBH increment does not correlate with tree defoliation strongly (tab.). The next method is based on the assessment of the average tree damage index W that takes into account defoliation, top condition and vitality. In general, analysed trees were found to have reduced height growth and both branching in the top (fig. 2) and central (fig. 3) section of the crown. Inclusion of the secondary crown in the assessment of tree damage resulted in an increase in the vitality of the whole crown (fig. 3). The assessment of damage based on index W showed that largest proportion of trees was within moderate damage and the value of the damage index was lower than in method based exclusively on defoliation. The last method (morphological−incremental) combines the method based on damage index W with DBH increment (index Wz, formula 3). In the period 1971−1985, most of the fir trees reacted negatively to the environment changes (growth reduction), while the proportion of trees with positive responses decreased. In the period 1976−2000, the proportion of trees with negative response decreased, while the proportion of firs with positive and neutral responses increased (fig. 5). The period 2001−2015 faced the dominance of trees showing neutral growth responses, the proportion of trees with positive responses was fairly high, while the proportion of trees with negative responses was the smallest. The highest value of the correlation coefficient (r=–0.661) was found for the correlation between the relative 10−years DBH growth and damage index Wz2(tab.). Of the three discussed damage assessment methods, this method is therefore considered the most accurate.
This paper describes the variability of Scots pine (Pinus sylvestris L.) provenances in the IUFRO experiment located in Rogów (central Poland). The silvicultural quality and growth of 17 European provenances at the age of 28 years were examined, including height, diameter at breast height, standing volume, straightness of stem and health status. Populations from Poland (Spała, Miłomłyn, Rychtal), Germany (Betzhorn, Lampertheim), France (Haguenau) and Hungary (Pornóapáti) characterized by the best growth parameters. In contrast, pines from Northern (Russia, Sweden) and Southern (Turkey, Montenegro and Bosnia and Herzegovina) Europe were smaller and thinner and, as a result, with lower standing volume. The smallest differences of pine populations were found in tree height. The highest mean tree height (11.68 m) was reported for Rychtal (Poland) provenance, while the lowest (6.77 m) for Çatacik (Turkey). The overall mean tree height in the whole experiment was 9.83 m. Diameter at breast height (dbh) varied more than the tree height. The highest mean dbh (129.91 mm) was reported for Haguenau (France) provenance, while the lowest (72.85 mm) again for Çatacik (Turkey). The overall mean dbh for all provenances equaled 107.12 mm. The highest differences of pine populations were found in the standing volume. The highest standing volume (19.05 m³/ha) was obtained for Pornóapáti (Hungary) provenance, while the lowest (163.72 m³/ha) again for Çatacik (Turkey). In terms of silvicultural quality, the northern provenances were classified as the best ones because of high proportion of trees with straight stems. The largest share of tress with straight stems occurred in the population of Serebryanskoe from Russia (60.8%), while the smallest of Haguenau from France (6.9%). The populations from Southern Europe (Maočnica, Prusačka Rijeka and Çatacik) show poor adaptation to environmental conditions of central Poland.
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Zdrowotność a żywotność - próba definicji

83%
Sylwan
|
1995
|
tom 139
|
nr 02
105-118
W pracy określono cechy biomorfologiczne (względna długość korony, typ wierzchołka, zniekształcenie korony) oraz żywotność jodeł wykazujących w latach 1981-90 regenerację przyrostu bieżącego promienia pierśnicy w stosunku do 10-lecia sprzed załamania przyrostu, tzn. do okresu 1951-60.
Chances of growing conditions have major impact on vitality of trees and their surviving on construction site. In this article was analyzed impact on trees of unfavorable biotical habitat conditions, with taking under consideration infectious agents, but also characteristic of microclimatic changes connected with human activities. All listed factors connected with knowledge about their importance and ability to assess the impact on tree condition, allows to take responsible and rational tree management decisions on the area of investment and urban areas.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.