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Wyświetlanie 1-6 z 6
Tytuł:
Changes in horizontal structure of natural beech forests on an altitudinal gradient in the Sudetes
Autorzy:
Vacek, Z.
Vacek, S.
Bilek, L.
Remes, J.
Stefancik, I.
Powiązania:
https://bibliotekanauki.pl/articles/41453.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
structural change
horizontal structure
natural forest
beech forest
European beech
Fagus sylvatica
forest dynamics
altitudinal gradient
Sudetes Mountains
Opis:
The article describes horizontal structure of the tree layer, natural regeneration, snags and crown projections of natural beech stands on three permanent research plots in the wide altitudinal range in the Krkonoše Mts (Czech Republic). The spatial structure was classified from 1980 to 2010 and subsequently the prediction of spontaneous development with an outlook for 30 years (to 2040) was done by growth simulator. Hopkins-Skellam index, Pielou-Mountford index, Clark-Evans index and Ripley’s K-function were calculated. Further, the vertical structure and total diversity index was evaluated. The horizontal structure of individuals in the tree layer had not changed significantly during the monitored years. Tree spatial pattern of the lowest altitude lying herb-rich beech forest was mostly regular to random, in acidophilous mountain beech forest predominantly random and in fragments of beech groups around the timberline aggregated. Juvenile growth on all investigated plots was distributed aggregated and snags randomly. The horizontal structure of crown projection centroids had always higher values toward the regularity than tree layer and was random to regular. The result of principal component analysis also confirmed that spatial pattern was dependent on the altitude, but also on the number of trees.
Źródło:
Dendrobiology; 2015, 73
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The dynamics and structure of dead wood in natural spruce-beech forest stand - a 40 year case study in the Krkonose National Park
Autorzy:
Vacek, S.
Vacek, Z.
Bilek, L.
Hejcmanova, P.
Sticha, V.
Remes, J.
Powiązania:
https://bibliotekanauki.pl/articles/41560.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
forest
natural forest
mixed stand
dynamics
structure
dead wood
spruce-beech forest
European beech
Fagus sylvatica
Norway spruce
Picea abies
Czech Republic
Karkonosze National Park
Opis:
The study deals with long-term dynamics of snags and fallen dead wood from 1970 to 2010 in an unmanaged forest ecosystem dominated by European beech in the Bažinky area, Krkonoše National Park (Czech Republic). The volume of dead wood was estimated from 1970 separately for fallen dead wood (logs) and standing dead wood (snags and stumps). Total dead wood volume on permanent research plot (PRP) 6 increased from 41.9 to 241.6 m3 ha–1 and on PRP 7 from 27.7 to 170.0 m3 ha–1. During 40 year case study the mean total volume of fallen dead wood was 193.3 m3 ha–1 (± 29.8 S.E.) and 96.2 m3 ha–1 (± 19.4 S.E.) and the mean total volume of standing dead wood was 17.4 m3 ha–1 (± 3.4 S.E.) and 12.6 m3 ha–1(± 1.4 S.E.) on PRP 6 and PRP 7, respectively. Comparing tree species, the mean volume of fallen dead wood was significantly higher for Norway spruce than for beech in the decomposition class 1 (F(1, 14) = 5.7, P = 0.03) and significantly higher for beech in the decomposition classes 4 (F(1, 14) = 20.4, P < 0.001) and 5 (F(1, 14) = 25.5, P < 0.001). Dead wood was distributed from randomly to aggregated spatial pattern. Despite the rapid decay of beech wood, the amounts of deadwood are likely to increase further during the next decades with continuing disintegration of the forest stand.
Źródło:
Dendrobiology; 2015, 73
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effects of climatic conditions and forest site types on disintegration rates in Picea abies occurring at the Modrava Peat Bogs in the Šumava National Park
Autorzy:
Krejci, F.
Vacek, S.
Bilek, L.
Mikeska, M.
Hejcmanova, P.
Vacek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/41583.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Opis:
A survey of mountain spruce stand development in the Šumava National Park on Modrava peat bogs on an area of 1,370 ha resulting from spruce bark beetle outbreaks was performedby means of visual evaluation of aerial photographs from the period 1991–2000. In addition, our study addressed the influence of climatic effects (period1984–2000) andthe effect of forest site (climax, waterloggedandpeaty spruce stands) on the dynamics of disintegration of forest stands. We showed that new infestations were predominantly foundat short distances from their source, the average value was estimatedto be 40–60 m, whereas the longest distance for annual progress in west to east direction was estimated to be 120 m. Differences in the dynamics of disintegration between waterlogged stands and drier stands were confirmed. There was a positive relationship between the average temperature in the 2nd quarter of monitoring years which was registered as the period of the onset of bark beetle development and the proportion of degraded area in Norway spruce stands. Moreover, pronounced winter desiccation in January 1993 was a triggering mechanism with crucial importance for the outbreak of bark beetle in the studied area.
Źródło:
Dendrobiology; 2013, 70
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gap regeneration in near-natural European beech forest stands in Central Bohemia - the role of heterogeneity and micro-habitat factors
Autorzy:
Bilek, L.
Remes, J.
Podrazsky, V.
Rozenbergar, D.
Diaci, J.
Zahradnik, D.
Powiązania:
https://bibliotekanauki.pl/articles/41443.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
gap regeneration
natural regeneration
Europe
beech forest
Fagus sylvatica
competition
stand
Central Bohemian region
heterogeneity
microhabitat factor
Opis:
Gap regeneration in a European beech (Fagus sylvatica L.) forest reserve was analyzed in relation to within-gap resource heterogeneity and ground vegetation competition. The study was carried out in two one-hectare permanent research plots (PRP) which included five smaller research plots (RP) encompassing two large gaps (500–700 m2), two small gaps (300–400 m2), and location under canopy. The coverage of woody regeneration, ground vegetation, dead wood, seedling density in eight height classes, characteristics of dominant trees of the beech regeneration, and the total thickness of holorganic horizons were measured. Soil moisture and light conditions were also assessed in selected sample plots. The relative direct and diffuse light was estimated by hemispherical photography. Small gaps showed both the highest cover of tree regeneration and the highest density of individuals per hectare. Slightly less regeneration was recorded in large gaps, while under closed canopy, regeneration densities were 5–10 times lower than in small gaps. Beech regeneration cover and the size (diameter and height) of dominant beech seedlings were positively related to relative diffuse light and negatively related to ground vegetation cover. The latter was positively related to diffuse light and soil moisture content. A pronounced statistically significant contrast in the cover and size of beech regeneration in relation to micro-site conditions (diffuse light, cover of graminoids) was only confirmed between sample plots located below canopy cover and those within gaps. Graminoids, in particular Calamagrostis epigejos L., occurred mainly in the large gap centre and along the southernmost edge of the large gap, increasing competition for resources here. The cumulative cover of ground vegetation and regeneration was relatively low (9–56%) compared with more mesic natural beech forests. The indicated negative influence of direct light at the northern gap edge suggests that extension of gaps on comparable sites in managed forest should not proceed in this direction.
Źródło:
Dendrobiology; 2014, 71
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stand dynamics in natural Scots pine forests as a model for adaptation management?
Autorzy:
Vacek, S.
Vacek, Z.
Bilek, L.
Remeš, J.
Hůnová, I.
Bulušek, D.
Král, J.
Brichta, J.
Powiązania:
https://bibliotekanauki.pl/articles/2077666.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Pinus sylvestris
forest dynamics
stands structure
air pollution
climatic factors
Central Europe
Opis:
The paper deals with the dynamics of structure, diversity and growth of natural pine stands without direct human impact during the ten-year period in Nature Reserve (NR) Kostelecké bory, Czech Republic. The objective was to determine the main characteristics of the spontaneous development of Scots pine (Pinus sylvestris L.) forest stands in relation to their naturalness, ecological stability and adaptation to climate change and air pollution stress. Horizontal and vertical structure and species diversity of the tree layer, dead wood and natural regeneration of each permanent research plot (PRP) were evaluated (n = 6, 50 × 50 m /0.25 ha/, Northern Bohemia, 410–425 m above sea level). The average ring series of PRPs were correlated with the climatic data (precip- itation, temperature) according to individual years from the Doksy climatic station, and the air pollution data (SO2 in 1988–2015, NOX and AOT40F – ozone exposure in 1992–2015) from Radimovice station. In 2016, the stand volume increased by 26.0% to 136 m3 ha−1 (108 m3 ha−1 in 2006) and the volume of dead wood increase by 127.2% to 27 m3 ha−1 (12 m3 ha−1 in 2006). The horizontal structure of tree layer and natural regeneration was predominantly aggregated to random. More distinct changes in biodiversity and structural characteristics occurred in the natural regeneration (21.5%) compared to tree layer (2.8%). The precipitation had a significantly higher effect on radial growth compared to temperature. The lack of pre- cipitation in growing season and high temperature in previous autumn and winter were limiting factors for growth. Climatic factors had significant effect on diameter increment in July of the current year (P < 0.01) and June of the current and previous year (P < 0.05). Radial growth was negatively correlated with SO2 con- centrations (P < 0.01) and ozone exposure (P < 0.05). NOX concentrations had low effect on radial growth. The natural stand dynamics had positive effect on biodiversity and functional integrity of natural pine eco- systems.
Źródło:
Dendrobiology; 2019, 82; 24-42
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zawartość wybranych składników mineralnych i anionów nieorganicznych w sokach drzewnych z terenu Podkarpacia
Content of selected minerals and inorganic anions in tree saps from Podkarpacie Region
Autorzy:
Bilek, M.
Stawarczyk, K.
Luczaj, L.
Cieslik, E.
Powiązania:
https://bibliotekanauki.pl/articles/827650.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Technologów Żywności
Opis:
Analizowano soki drzewne ośmiu gatunków drzew z Podkarpacia: brzozy zwisłej (brodawkowatej) – Betula pendula Ehrh., brzozy omszonej – Betula pubescens Ehrh., grabu pospolitego – Carpinus betulus L., klonu zwyczajnego – Acer platanoides L,. klonu jawora – Acer pseudoplatanus L., klonu polnego – Acer campestre L., klonu jesionolistnego – Acer negundo L. i klonu srebrzystego – Acer saccharinum L. Określono zawartość anionów nieorganicznych: chlorków, azotanów(V), siarczanów(VI) oraz fosforanów(V), a także składników mineralnych: miedzi, cynku, wapnia, magnezu, sodu i potasu. Największą średnią zawartość chlorków (32,68 mg·l⁻¹) i siarczanów (21,8 mg·l⁻¹) oznaczono w sokach grabowych, a magnezu (18,96 mg·l⁻¹) i wapnia (30,52 mg·l⁻¹) w sokach z klonu polnego. W sokach z klonu jesionolistnego stwierdzono największą średnią zawartość fosforanów (114,53 mg·l⁻¹), miedzi (1,45 mg·l⁻¹) i azotanów (25,99 mg·l⁻¹), a w soku z brzozy zwisłej – cynku (1,85 mg·l⁻¹) i sodu (0,59 mg·l⁻¹). Soki z klonu zwyczajnego odznaczały się z kolei największą średnią zawartością potasu (82,15 mg·l⁻¹). Otrzymane wyniki zestawiono z obowiązującymi w Polsce normami żywieniowymi. Wskazują one, że soki drzewne mogą być wartościowym źródłem składników mineralnych, szczególnie miedzi i cynku, w mniejszym stopniu wapnia, magnezu i fosforu. Jednocześnie stwierdzono znikome zagrożenie ze strony składników potencjalnie niekorzystnych dla ludzkiego zdrowia, tzn. anionów nieorganicznych: azotanów(V) i siarczanów(VI) oraz sodu.
There were analyzed tree saps of eight tree species: silver birch - Betula pendula, downy birch - Betula pubescens, common hornbeam - Carpinus betulus, Norway maple - Acer platanoides, sycamore maple - Acer pseudoplatanus, field maple - Acer campestre, boxelder maple - Acer negundo, and silver maple - Acer saccharinum). The contents of the following inorganic anions were determined: chlorides, nitrates (V), sulphates (VI), and phosphates (V) as well as of the following minerals: copper, zinc, calcium, magnesium, sodium, and potassium. The highest average content of chlorides (32.68 mg·l⁻¹) and sulphates (21.8 mg·l⁻¹) was determined in common hornbeam saps, whereas of magnesium (18.96 mg·l⁻¹) and calcium (30.52 mg·l⁻¹) in field maple saps. The highest average content of phosphates (114.53 mg·l⁻¹), copper (1.45 mg·l⁻¹), and nitrates (25.99 mg·l⁻¹) was detected in boxelder maple saps. The highest average contents of zinc (1.85 mg·l⁻¹) and sodium (0.59 mg·l⁻¹) were found in the silver birch saps,. The Norway maple tree saps, in turn, were characterized by the highest average content of potassium (82.15 mg·l⁻¹). The results obtained were compared with the nutrition standards in force in Poland. They indicate that tree saps could be a valuable source of minerals, especially of copper and zinc, and to a lesser degree, of calcium, magnesium, and phosphorus. At the same time, it was reported that the ingredients showing a potentially adverse impact on human health, i.e. inorganic anions: nitrates(V), sulphates(VI), and sodium, present a negligible risk.
Źródło:
Żywność Nauka Technologia Jakość; 2015, 22, 3
1425-6959
Pojawia się w:
Żywność Nauka Technologia Jakość
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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