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Wyszukujesz frazę "Recruitment" wg kryterium: Wszystkie pola


Wyświetlanie 1-2 z 2
Tytuł:
Odnowienie naturalne drzew w Puszczy Białowieskiej
Natural regeneration of trees in the Bialowieza Forest
Autorzy:
Brzeziecki, B.
Andrzejczyk, T.
Żybura, H.
Powiązania:
https://bibliotekanauki.pl/articles/985949.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Puszcza Bialowieska
odnowienia naturalne
drzewa lesne
topola osika
Populus tremula
brzoza brodawkowata
Betula pendula
brzoza omszona
Betula pubescens
olsza czarna
Alnus glutinosa
sosna zwyczajna
Pinus sylvestris
dab szypulkowy
Quercus robur
jesion wyniosly
Fraxinus excelsior
klon pospolity
Acer platanoides
wiaz gorski
Ulmus glabra
swierk pospolity
Picea abies
lipa drobnolistna
Tilia cordata
grab pospolity
proces dorastania
ekosystemy lesne
dynamika lasu
active approach
deer browsing
long−term study
multifunctional forest management
natural recruitment
nature conservation
silvicultural treatment
strict protection
tree competition
tree diversity
Opis:
Since several years already, a massive infestation of bark beetle has taken place in the Białowieża Forest, decimating a local Norway spruce population. In consequence, many open areas appeared, practically deprived of trees and other forest vegetation. The existence of such areas has a very negative impact on multiple values of the Białowieża Forest: natural, social, economical and landscape−aesthetic values. The local forest administration prepared a strategy aimed at active restoration of diverse woodland communities typical for the Białowieża Forest in all places, where bark beetle infestation wiped up the spruce stands. Those plans were criticized by representatives of the environmental organizations who blamed the foresters for transforming the Białowieża Forest into ‘plantation’ and claiming that such measures are inconsistent with the existing forest management and protection plan. The postulate of environmentalists is that the recovery of woodland communities should proceed completely naturally. Taking into account the above mentioned controversies, in this paper we examine the issue of natural regeneration in the Białowieża Forest in detail. In particular, we try to determine to which extent this method of forest reproduction enables re−establishment of compositionally diverse woodland communities, distinguished by a high level of biological diversity and able to provide a wide range of commodities and benefits important for today’s society. Based on an extensive literature review we show that a combination of different (abiotic and biotic) factors, influencing establishment and subsequent growth of seedlings and saplings in the Białowieża Forest has long been strongly unfavorable for many tree species. In this regard, one should particularly emphasize the negative role of large herbivores, especially red deer, which is present in the Białowieża Forest since the end of 19th century, when it became a private hunting ground for Russian tzars. The devastating effect of deer browsing on natural regeneration is a well−documented phenomenon and widely recognized problem in the forestry practice. The fencing of young forest generation against game pressure is an indispensable measure, needed to secure the continuous existence of several tree species (first of all those palatable and vulnerable to browsing). Very strong arguments for an active approach to the described problem delivers also a long−term study on natural forest dynamics conducted since 1936. It shows that under conditions of strict protection the regeneration capacity of the Białowieża tree species is very variable. These differences lead to the compositional simplification and impoverishment of many tree stands, with numerous negative consequences for local biodiversity. We underline that an active management strategy is a basic prerequisite for maintaining a diverse character of the Białowieża stands and their ability to provide all important ecosystem services on a sustainable basis. Such a strategy should include, beside of the phase of establishment, also the subsequent developmental stages of new forest generations. The general goal of such a strategy should be to secure a possibly high diversity of tree composition and to enable the development of tree species representing a full range of life−history strategies and playing different successional roles: from typical pioneer species, through intermediate, to climax species.
Źródło:
Sylwan; 2018, 162, 11; 883-896
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Struktura i dynamika wielogeneracyjnych starodrzewów sosnowych występujących w obszarach ochrony ścisłej Kaliszki i Sieraków w Kampinoskim Parku Narodowym. Część 2. Procesy zamierania i dorastania oraz ich wpływ na rozkład grubości drzew
Structure and dynamics of uneven−aged, Scots pine−dominated, old−growth stands in Kaliszki and Sieraków strict reserves in Kampinos National Park. Part 2. Tree mortality and recruitment processes and their effects on tree diameter distributions
Autorzy:
Brzeziecki, B.
Zajączkowski, J.
Olszewski, A.
Bolibok, L.
Andrzejczyk, T.
Bielak, K.
Buraczyk, W.
Drozdowski, S.
Gawron, L.
Jastrzębowski, S.
Szeligowski, H.
Żybura, H.
Powiązania:
https://bibliotekanauki.pl/articles/979128.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
demographic non−equilibrium
diameter structure
long−term study
old−growth forest
permanent study
plot
scots pine
strict protection
Opis:
Two fundamental demographic processes (tree recruitment and mortality) are analyzed for forest stands growing on permanent study plots located in strictly protected Scots pine−dominated, old−growth stands of Kampinos National Park (central Poland). The major implications of the observed demographic trends for the general shape of tree size distributions are determined, as well. During the past ca 30 years, in the stands sampled, there was a pronounced lack of balance between mortality and recruitment processes. Mortality rate was eight times higher than recruitment rate. Eventually, there was a net significant decline in population density, observed for all major tree species, including Scots pine, pedunculate oak, silver and downy birch, and black alder. As mortality processes affected mainly smaller trees, there was also a significant deterioration of the general demographic status of most important tree species. This effect was shown by the change of the overall shape of diameter distributions over the study period: from reverse J−shaped to flat curves running nearly parallel to X−axis. The values of recruitment rates were markedly lower, and the values of mortality rates – significantly higher, than analogous values characterizing comparable forests (e.g., those obtained for the natural stands of Białowieża National Park). Low recruitment rates, as obtained for Kampinos stands, suggest that presently, in the local, Scots pine−dominated, old−growth stands, the general conditions for forest regeneration and for maintaining a long−term demographic stability are unfavorable. Most probably, the regeneration of this type of forest has an episodic, ‘wave−like’ character and corresponds to the ‘catastrophic’ model, according to which the successful regeneration of current dominants (especially Scots pine, silver and downy birch, black alder) must be preceded by a stand−initiating (stand−replacing) disturbance, leading to total or partial, but heavy, destruction of the currently existing stand. At the moment, it would be difficult to predict, however, if and when such a disturbance will affect the stands under investigation. Thus, we predict that in the nearest future at least, the state of overall demographic unbalance will continue or even increase.
Źródło:
Sylwan; 2020, 164, 06; 443-453
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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