Informacja

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

Wyszukujesz frazę "forest expansion" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Wieloletnie zmiany składu gatunkowego drzewostanów o podwyższonym reżimie ochronnym w Puszczy Augustowskiej i Puszczy Knyszyńskiej
Long-term changes of tree species composition in high protective regime stands in the Augustow and Knyszyn Forests
Autorzy:
Paluch, R.
Gabrysiak, K.A.
Powiązania:
https://bibliotekanauki.pl/articles/979555.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Puszcza Augustowska
Puszcza Knyszynska
rezerwaty przyrody
drzewostany naturalne
zbiorowiska lesne
sklad gatunkowy
bor brusznicowy
bor mieszany trzcinnikowo-swierkowy
grad miodownikowo-grabowy
odnowienia naturalne
zmiany skladu gatunkowego
zmiany struktury drzewostanu
natural regeneration
forest reserve
natural stand
hornbeam expansion
Opis:
In the last decades, we observed significant changes in the tree species composition in all layers of close−to−natural stands. Since the 1970s, the Forest Research Institute has collected and stored dataset from stand measurements, phytosociological and other research that are the basis for the long−term monitoring of vegetation. The aim of the research was to determine the directions of changes in the species composition and structure of tree stands, and to analyze the changes in the species composition of natural regeneration growing without human interference in various forest communities in the period of about 40 years. From 2014 to 2017, 40 permanent plots of 0.25 ha were re−measured in the nature reserves of the Knyszyn and Augustów Forests (NE Poland). The diameter of all trees was measured and the trees of the natural regeneration and bushes up to 1.3 m high were counted. The stand similarity index (S) between successive measurements was calculated. The analysis of differences in the composition of tree stands in subsequent measurements was carried out using Student t and Kruskal−Wallis tests. In the species composition of fresh coniferous forest stands and fresh mixed coniferous forest, there were significant changes in the number and share of Scots pine and Norway spruce. In the Knyszyn Forest a significant decrease in the share of spruce was observed. However, an increase in the share of deciduous species was remarkable. An inhibition of the natural pine renewal process and increase in density of spruce regeneration was observed. It is necessary to emphasize the significant expansion of hornbeam in a fresh mixed deciduous forest in the Knyszyn Forest and expansion of hazel in the Augustów Forest. Mean basal area in the forest stands has increased. The similarity index between the beginning and the end of the research reached the value of 0.73−0.94. The species composition and density of natural regenerations created without human intervention are not satisfactory from the point of view of forest sustainability. The most important factor affecting the direction and rate of changes in the species composition of tree stands is the expansion of hornbeam and/or hazel. These species cause changes in the ecological conditions of the lowest forest layers, leading to the unification of the species composition of forest communities.
Źródło:
Sylwan; 2019, 163, 10; 846-854
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tempo i kierunki zmian składu gatunkowego drzewostanów naturalnych w wybranych zbiorowiskach leśnych Puszczy Białowieskiej
Rate and direction of changes in tree species composition of natural stands in selected forest associations in the Bialowieza Forest
Autorzy:
Paluch, R.
Powiązania:
https://bibliotekanauki.pl/articles/1313006.pdf
Data publikacji:
2014
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
lesnictwo
Puszcza Bialowieska
drzewostany naturalne
zbiorowiska lesne
sklad gatunkowy
bor swiezy brusznicowo-sosnowy
bor mieszany trzcinnikowo-swierkowy
grad miodownikowo-grabowy
grad typowy
grad trzcinnikowy
leg olszowo-jesionowy
zmiany skladu gatunkowego
podobienstwo skladu gatunkowego
stale powierzchnie obserwacyjne
hornbeam expansion
natural stands
permanent study plots
ash dieback
Białowieża forest
Opis:
The main aim of the study was to determine changes in the species composition and structure of natural tree stands in the Białowieża Forest (BF), which occurred in the years 1975-2012, as well as to evaluate their trends, directions and rate. The study was carried out on 121 permanent research plots (50×50m), which represented the most important forest phytocenoses in BF, i.e. fresh pine-whortleberry forest Vaccinio vitis-idaeae-Pinetum Sokoł. 1980, fresh mixed spruce-reed grass forest Calamagrostio-Piceetum Soko³. 1968, oligotrophic form of hornbeam - bastard balm forest Melitti-Carpinetum Soko³. 1976, different forms of linden- hornbeam forest: Tilio-Carpinetum Tracz. 1962, alder-ash forest Fraxino-Alnetum W. Mat. 1952 and sub-boreal spruce forest on bog moss Sphagno girgenshonii- Piceetum Polak. 1962. On the plots selected, there was measured the diameter at breast height (DBH) of all trees, as well as every tree and shrub up to 1.3 m high was counted and described with reference to species. The measurements and observations were regularly repeated every 10-15 years. The results showed that over the last period of nearly 40 years, there has increased a share of common hornbeam Carpinus betulus L. in the structure of forest stands in numerous BF associations. This tree species has expanded into different forest habitats including poor, medium fertile and wetland sites. The results obtained indicate a trend towards formation of linden-hornbeam forests in BF phytocenoses. The most evident changes were recorded in hornbeam - bastard balm forest. In natural conditions of the majority of forest associations analyzed, there prevailed hornbeam trees in forest regeneration, except for the stands in fresh mixed pine forest and spruce forest on bog moss. In the latter two cases, hornbeam showed signs of its presence in the last observation period. Norway spruce (Picea abies L.) retreated into oligotrophic forest associations. In the recent decades, spruce populations have been dramatically reduced in the stands in mixed coniferous and different kinds of broadleaved forests. There have also decreased a share of light-demanding tree species, such as Scots pine (Pinus silvestris L.), pedunculate oak (Quercus robur L.) and silver birch (Betula pendula L.) in BF tree stands, including their regeneration-layer. Especially, Scots pine regeneration has not been successful. In the short period of time (about 15 years) there has been observed rapid and outsized reduction of ash Fraxinus excelsior L. populations in natural conditions of alder-ash forests. All through the last 10-15 years, there has been also observed increased rate of change in stand species composition. The trend and rate of change in stand species composition point out to a possibility of human intervention towards stimulation of natural regeneration so as to preserve valuable populations of threatened tree species in the Białowieża Forest.
Źródło:
Leśne Prace Badawcze; 2014, 75, 4; 385-406
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    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