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Wyszukujesz frazę "species structure" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Rozpad drzewostanów świerkowych w Beskidzie Żywieckim
Dieback of Norway spruce stands in the Beskid Zywiecki Mts.
Autorzy:
Dmyterko, E.
Bruchwald, A.
Mionskowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/979601.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Beskid Zywiecki
drzewostany swierkowe
rozpad drzewostanow
swierk pospolity
Picea abies
struktura drzewostanu
struktura wiekowa
struktura gatunkowa
pozyskiwanie drewna
struktura pozyskania
zagrozenia lasu
wiatry
szkody od wiatru
forest dieback
picea abies
species structure
age structure
timber harvest
threat to forests by wind
Opis:
In the Beskid Żywiecki, the combination of abiotic, biotic and anthropogenic factors unfavourable for the growth of trees led to the dieback of spruce stands. The intensification of this process began after the hurricane in November 2004, followed by years of negative climatic water balance. The deterioration of tree growth conditions occurred after the drought in July 2006 and damage caused by the Kyril hurricane in January 2007. The weakened spruces were attacked by the bark beetles, the outbreak of which caused a massive dieback of spruce stands. In order to assess the volume of harvested timber in years 2004−2016, the volume of allowable cut (model volume) was calculated from the stand growth model for each forest district of Beskid Żywiecki. The comparison of the volume of harvested timber with the model volume allowed to determine the rate of dieback of spruce stands. The volume of harvested timber in 2007−2009 exceeded the model volume even 2.5 times. The cuts included mainly deadwood, wind−broken and wind−fallen trees, while the harvest of live trees was scarce. In the period 2010−2013, the harvested volume of live trees accounted for 50−70% of the model volume, the volume of deadwood in the same period was ca. 100% and additionally the volume of blown−down timber after the hurricane was 20−40% of the model volume, which taken together accounted approximately to 200% of the model volume. The execution of such harvesting operations, including silvicultural tasks, did not allow to carry out optimal forest management. The period 2010−2013 saw a downward trend. It was disrupted by the hurricane in December 2013, after which the volume of harvested timber, consisting mainly of wind−broken and wind−fallen trees, increased to 280% of the model volume. Again, the high volume of harvested timber was noted in 2016, (ca. 220% of the model volume). The process of damage to spruce stands in Beskid Żywiecki is likely to continue. A decline in its intensity may occur in the absence of old stands, which to a large extent already takes place in the forests of the Węgierska Górka Forest District. Currently, the most threatened by wind are forests in Ujsoły, Jeleśnia and Nowy Targ forest districts. The least threatened are forests in the Węgierska Górka. This forest district and in the future the remaining forest districts of Beskid Żywiecki, will face enormous challenges to obtain high yield and appropriate species composition.
Źródło:
Sylwan; 2019, 163, 02; 130-140
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gromadne noclegowiska błotniaków stawowych Circus aeruginosus w krajobrazie rolniczym na Wysoczyźnie Ciechanowskiej
Communal roosting of western marsh-harriers Circus aeruginosus in the agricultural landscape of the Ciechanów Upland
Autorzy:
Murawski, M.
Powiązania:
https://bibliotekanauki.pl/articles/2090097.pdf
Data publikacji:
2021
Wydawca:
Mazowiecko-Świętokrzyskie Towarzystwo Ornitologiczne
Tematy:
Ciechanów county
Przasnysz county
age structure
sex structure
North Mazovian Lowland
Montagu’s Harrier Circus pygargus
Pallid Harrier Circus macrourus
mixed- species roosting
Opis:
On 22 August 2020 field observations were carried out in the agricultural landscape of the Ciechanów and Przasnysz counties. A roost of 36 individuals of the Western Marsh-harrier Circus aeruginosus was found near Golany (Przasnysz municipality, Przasnysz county) in a sugar beet field Beta vulgaris subsp. vulgaris overgrown with the common lambsquarters Chenopodium album. Next controls documented the increase in the number of harriers and on 5th September there was a group of 62-65 birds. Several Montagu’s harriers C. pygargus and an adult male of the Pallid Harrier C. macrourus were also recorded at that roosting site. The latter stayed in the area for about 3 weeks and used two roosting sites alternatively. Another roosting site was also found nearby. There were12 western marsh-harriers, 1-2 Montagu’s harriers, and the aforementioned male Pallid Harrier. On 12 September the large roost near Golany disappeared due to a beet harvest and ploughing the field. The increase in the breeding population of the Western Marsh-harrier in Poland caused by inter alia development of field populations of this species, results in the increasing number of the records of communal roosting in the agricultural landscape. Therefore, efforts should be made to develop counting methods on such roosting sites and to protect the largest regional roosts of the Western Marsh-harrier and Montagu’s Harrier.
Źródło:
Kulon; 2021, 26; 43-48
1427-3098
Pojawia się w:
Kulon
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of dominant species on numbers and age structure of Iris sibirica L. population on blue moor-grass meadow in Southern Poland
Autorzy:
Kostrakiewicz, K
Powiązania:
https://bibliotekanauki.pl/articles/57143.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
generative reproduction
Iris sibirica
clonal plant
vegetative reproduction
Polska
dominant species
age structure
population
blue moor-grass meadow
seedling recruitment
plant ecology
Opis:
Two populations of Iris sibirica, a clonal species protected by law in Poland, occurring in patches of Molinietum caeruleae, of similar floristic composition although with different dominant species, were studied. In the Stanisławice locality, species with a high competitive potential prevailed, contrary to the Opatkowice locality, where the species of low competitive potential dominated. It was established that vegetative propagation ensures the continued presence of populations in both localities, although the proximity of plants with high competitive potential limits the vegetative propagation of ramet clusters of Iris sibirica. Despite the high level of seed production, the recruitment of seedlings in both patches is possible only in artificially created gaps. The field observations support the conclusion that creating gaps allowing for germination of seeds and development of seedlings, as well as eliminating expansive neighbours allowing proliferation of ramet clusters of Iris sibirica, is an affective way of protecting populations of this species.
Źródło:
Acta Societatis Botanicorum Poloniae; 2007, 76, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The population structure and regeneration of Sorbus torminalis in Hadecka planinka National Nature Reserve (Czech Republic)
Autorzy:
Madera, P.
Kohoutek, M.
Senfeldr, M.
Repka, R.
Powiązania:
https://bibliotekanauki.pl/articles/41463.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
population structure
regeneration
Sorbus torminalis
wild service tree
age structure
forest system
species protection
chequer tree zob.wild service tree
checker tree zob.wild service tree
Hadecka Planinka National Nature Reserve
Czech Republic
Opis:
We performed a detailed overall field survey of all specimens of the wild service tree Sorbus torminalis (L.) Crantz in the research area in the Hádecká planinka National Nature Reserve. This research area, with an area of 80 ha, contains one of the largest populations of the tree in Europe. In all, 1713 specimens were found. This study provides a detailed description of the wild service tree population in the area. The basic biometric parameters (height, GBH, social position, fertility) of thepopulation were assessed. The main emphasis of our analysis was to evaluate the population's age structure. We used estimates of age structure based on the Chapman-Richards growth function to perform this evaluation. During the past twenty years, the natural regeneration of the wild service tree in the nature reserve has decreased considerably. At an experimental plot where a high forest was converted to a coppice with standards, regeneration occurred over 75% of the area. Root suckers were found at the beginning of the observation period. After 2–3 years, generative regeneration occurred.
Źródło:
Dendrobiology; 2012, 68
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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