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The investigation was conducted in a 32-year-old pine stand, growing on a fresh coniferous site in western Poland. The strip roads in the stand had been designed and cut along tree rows 5 years prior to the investigation. The analysis focused on trees growing at 12 strip roads, in 3-meter-wide stripes on both sides of the strip roads and in control zones, half-way between each two neighbouring strip roads. The trees growing on the stripes along the strip roads were divided into three zones corresponding to tree rows. The first zone (I) was formed by trees growing in the row directly at the strip roads, while the zones two (zone II) and three (zone III) were formed by trees growing in the second and third rows of trees away from the strip roads, respectively, on both sides of the strip roads. The average distances of the zones two and three from the strip roads were 1.5 and 3 m, respectively. The diameters at breast height (DBH) of all the trees growing in the respective zones were measured. Moreover, the widths of the strip roads were measured, which resulted in dividing the strip roads into two groups: the wider strip roads (average width 3.6 m) and the narrower ones (average width 2.9 m). The statistical analysis showed significant differences in DBH values between the analysed zones, for nine of the strip roads. Both in the case of the wider strip roads, as well as in the case of the narrower ones, the trees growing directly along the strip roads were usually thicker than the more distant trees. A statistically significant difference between the DBH values of trees from zone I and II was found for one strip road. In most cases the trees from zone I were statistically thicker than the trees growing in the control zone.
W pracy wykazano, że po prawie 20-letnim okresie zmniejszenia się przyrostu bieżącego promienia na pierśnicy, w lalach 198 L 90 nastąpił wzrost jego wartości (regeneracja przyrostu) zasadniczo na przeważającej części objętego badaniami obszaru. Żywotne drzewostany, zapewniające normalny przyrost zbliżony do tablicowego, występują jeszcze głównie w południowo-wschodniej części kraju (od Beskidu Sądeckiego po Bieszczady) oraz częściowo w Górach Świętokrzyskich i na Roztoczu.
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.
The relative crown length, needle loss, and vitality of fir trees of older (above 160 years of age) and younger (from about 70 to about 130 years, with single trees up to 160 years of age) generations were significantly correlated with the current 10 year, (1985-1994), radial increment at breast height. In the case of trees of the younger generation the type of tree-top and the degree of crown deformation were also significantly correlated with the radial increment at breast height. The best growing fir trees of the younger generation were characterized by narrow conical (trees 41 to 60 years of age at breast height) to flattened (trees 101 to 120 years of age at breast height) tree-tops, well-proportioned or little deformed (loeses up to 20%) crowns, and a relative crown length amounting to at least 56%.
W pracy stwierdzono istotny wpływ pochodzenia sosny na wysokość drzew oraz grubość odkładanej kory. Badania nie wykazały natomiast istotnego wpływu pochodzenia na wielkość pierśnicy i miąższość strzał bez kory w badanej populacji sosen.
Oceniano dynamikę rocznych przyrostów oraz wzrostu wysokości i pierśnicy drzewek modrzewia europejskiego tworzących 10-letnie, rzędowe zadrzewienie śródpolne na glebach lessowych. Stwierdzono wyrównaną dynamikę wzrostu obu badanych parametrów zadrzewienia. Szybki wzrost wysokości (średnio rocznie 72 cm ) oraz pierśnicy (średnio rocznie 1,6 cm), a także wyrównane zwarcie i pułap koron predysponują modrzew europejski do zakładania przeciwwietrznych barier w krajobrazie rolniczym.
This paper presents the results of investigation into the variability of selected features of morphological structure of Douglas fir trees in Poland. The research was carried out in 28 Douglas fir stands, which were at least 80 years old. The mean values of studied features amounted: diameter at breast height — 54.8 cm, height — 32.4 m, bark thickness — 3.9 cm, crown length — 13.6 m, relative crown length — 41.6% and crown width — 5.4 m. The significant variability of studied features was stated, especially large diversity bark thickness and crown width was revealed. Four regions were distinguished in Poland. These regions were characterized by some distinction of the studied features.
The aim of this study was to determine the productive potentiality (stand volume, basal area, and their increments) of the natural little leaf linden stand 26.68 ha in area. This stand is a part of the Obrożyska nature reserve of the total forest area of 98.25 ha. Measurements were carried out in 1995 and 2005 on 26 4-are sample plots established according to the statistical-mathematical system of forest inventory and control, and in 1999 and 2000 on three permanent sample plots which represented different developmental stages and phases of the virgin forest. Between 1990 and 2005, the mean volume of the entire stand increased from 538 to 567 m3/ha. In the growing up stage it increased from 554 to 584 m3/ha, while in the optimum stage from 510 to 541 m3/ha. The volume increment in these two stages was 66 and 51 m3/ha/10 years respectively. Volume of the stand representing the growing up stage in transition to the optimum stage (Obrożyska I classical permanent sample plot) increased during the 10-year period from 700 to 768 m3/ha, while in the stand representing the initial phase of the optimum stage (Obrożyska II) it increased from 797 to 861 m3/ha, and in the stand representing the growing up stage (Obrożyska III) from 696 to 761 m3/ha. The volume increment in these three plots was almost 80, 96, and 82 m3/ha/10 years respectively. The stand volume per hectare of the little leaf linden forest in the Obrożyska reserve is one of the highest among stands of natural character in the Polish part of the Carpathians. A very high productive potentiality of the investigated little leaf linden stand permits to accept this tree species as the main species in stands of the submontane zone as well as in the lower part of the lower montane zone in the Poprad river valley and in the climate close to that of the surroundings of the town of Muszyna.
W pracy oceniono tendencję przyrostową badanych drzewostanów. Określono wpływ wybranych cech morfologicznych korony, żywotności, jakości pnia oraz masy systemu korzeniowego na wielkość 10-letniego przyrostu pola powierzchni przekroju pierśnicowego świerka i modrzewia.
The purpose of the paper is to report on the structure and the potential production of tree stands in the belt of dense forest in the locality of Pilsko, which were formed as a result of connecting natural processes with various methods of cuttings. In two stands single cutting harvesting was applied, corresponding to single tree selection cutting (Einzelplenterung in German). In the third stand there was cutting in the form of small gaps which corresponds to mountain selection cutting (Gebirgsplenterung in German). In the control period (1998-2008) the stand volume on two plots, Pilsko 1 and Pilsko 3 increased from 448 to 479 m3/ha and from 237 to 298 m3/ha respectively, however, in Pilsko 2 the stand volume decreased slightly from 401 to 397 m3/ha. The increase in the volume of the stand reached from almost 5 m3/ha in Pilsko 2 to approximately 8 m3/ha per year in the other plots. The stability of the stand is ensured mainly by the presence of trees in the thinnest classes in the lower and medium layer of the stand as well as the continuous process of regeneration. In this context the stand in which cuttings were taken in the past, characteristic of mountain selection, exhibited more beneficial features. All the researched stands exhibited great differences in the age of trees which enabled them to be classified as uneven-aged stands. The age at the breast height diameter of the oldest drilled spruce was 344 years and frequently the encountered specimens of this variety are of the age of 223 and 276 years. The uneven-aged structure of the stands, however, does not simultaneously ensure a complex and stable structure. In order to form, or to maintain, stable upper mountain spruces, which are under partial active protection (outside reservations with total protection) mountain selection cutting, or cutting by a method of group selection, should be recommended. These methods of cuttings ensure the variations within the structure of the stands, which minimises the risk of large-area disintegration.
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