Informacja

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

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "stand heterogeneity" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-3 z 3
    Tytuł:
    Regionalne zróżnicowanie potrzeb i pilności przebudowy drzewostanów
    Regional diversity of the need and the urgency of stands conversion
    Autorzy:
    Stępień, E.
    Kędziora, W.
    Orzechowski, M.
    Wójcik, R.
    Borecki, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/985680.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    drzewostany
    przebudowa drzewostanow
    potrzeby przebudowy
    zroznicowanie regionalne
    regionalne dyrekcje Lasow Panstwowych
    stand classification
    regional heterogeneity
    conversion necessity
    state forests
    Opis:
    Nowadays in forestry, we observe an increase in threats that rise the uncertainty and risk of the forest management. This is caused, inter alia, by increasing intensity of forest and environmental damage as well as by the conflict of expectations for the use of forest resources. As a result, there is a problem of achieving the goals of sustainable development and adaptation of the forest ecosystems to new challenges. The aim of the presented study was to assess the regional variety of the need and the urgency of stands conversion. The feature was determined for all stands of the State Forests older than 20 years. Three assessment criteria were selected: (A) silvicultural target (compatibility of the species composition with the planned one), (B) stands stability (resultant from 5 auxiliary sub−indices), and (C) stock level (including 2 auxiliary sub−indices). The majority of stands has consistent species composition (over 60% in total), however only a small fraction of stands was found with a species composition incompatible with the planned one (average 6.34%). Stands with medium stability accounted for about 70%, while those with poor growing stock status make up about 70% of stands under analysis. The regional diversification of the needs for stands reconstruction seems to be strongly correlated with the incompatibility of stand’s species composition with habitat conditions. The largest fraction of stands requiring conversion was observed in Wrocław, Kraków and Katowice regional directorates of the State Forests. This situation may change in the future due to dynamic changes resulting from modifications of the climate and the deterioration of health condition of dominant Scots pine stands in central and north parts of Poland. Private forests were not taken into consideration in this research. It may impact the overall picture in regions of the high share of private forest ownership.
    Źródło:
    Sylwan; 2019, 163, 04; 267-278
    0039-7660
    Pojawia się w:
    Sylwan
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rola sójki (Garrulus glandarius) w inicjowaniu przemian sukcesyjnych zbiorowisk leśnych z udziałem dębu (Quercus sp.)
    Role of jay (Garrulus glandarius) in initializing successional changes in forest communities with the participation of oak (Quercus sp.)
    Autorzy:
    Olszewski, A.
    Brzeziecki, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/980357.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Leśne
    Tematy:
    lesnictwo
    zbiorowiska lesne
    sukcesja roslin
    dab
    Quercus
    zoochoria
    sojka
    Garrulus glandarius
    acorn
    jay
    oak
    ornitochory
    seed dispersal
    stand heterogeneity
    tree succession
    zoochory
    Opis:
    The ability of spatial expansion and conquering of new locations, suitable for growth, is one of the most important properties enabling different plant species (including forest trees) a permanent existence in a constantly changing (in space and in time) environment. In the course of evolution, plants developed several adaptations and mechanisms enabling them to capture new localities appropriate for life. The key role in this process is played by so called propagules, i.e. differently built spores, seeds and fruits. The main sources of forces and major transportation vectors for propagules are such mechanisms as: power of gravity (barochory), wind (anemochory), water (hydrochory), animals (zoochory) and man (antropochory). Among them, in case of tree species producing large seeds, containing bulky amounts of food resources, the most important role is played by zoochory. The special variant of zoochory is ornitochory, i.e. dispersion of plant propagules by birds. One of the best known and documented examples of ornitochory is dispersal of oak acorns by jays (Garrulus glandarius). The contemporary research shows that during a vegetation period one single bird is able to deposit even several thousends of acorns within the area of 10 to 100 ha. The dispersal distance in case of acorns distributed by jays is variable and depends on several factors, first of all, climatic conditions and degree of environmental heterogeneity. On average, acorns are distributed within a distance of several hundred meters from seed trees; sometimes they are disseminated at a distance of several (4−8, maximum 20) kilometers. As a rule, only a part of deposited acorns is uncovered and consumed by birds, thus at least some of them can germinate and produce new oak seedlings. It was also recently demonstrated that jays preferably put down acorns under the stand canopies composed by tree species other than oak, for instance, under Scots pine trees. Under favourable conditions, this initiates natural successional processes and leads to a significant conversion of tree stand composition. Considering a large scale and commonness of this phenomenon, it deserves an interest and attention, not in the case of natural forests only, but in the case of managed forests as well, in which the quasi−natural, successional processes, initiated by jays, can considerably contribute to a greater compositional and structural diversity of tree stands.
    Źródło:
    Sylwan; 2019, 163, 06; 479-88
    0039-7660
    Pojawia się w:
    Sylwan
    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
      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