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Wyszukujesz frazę "vegetation change" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Effect of ecological factors on the zonation of wetland vegetation
Autorzy:
Hrivnak, R
Powiązania:
https://bibliotekanauki.pl/articles/58846.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
vegetation zonation
wetland
wetland vegetation
vegetation change
floristic change
hydrology
zonation
species-environment relationship
Opis:
The influence of some ecological factors to aquatic and marsh vegetation was studied during 1998-2000. Three basic vegetation units (Caricetum buekii, Typhetum latifoliae and Ceratophylletum submersi) and three transitional communities were defined in the belt transect, which was established along the moisture gradient. The content of available soil nutrients in individual vegetation types differed only in case of the Ceratophyllum submersum community, where a higher magnesium and nitrogen content accumulated due to specific environmental conditions. Water and marsh vegetation is usually characterised by a pronounced spatial and temporal dynamics. In the studied area, its zonation was dependent from the terrain morphology, and both depth and duration of floods. The fluctuation of ground and surface water table during a three-year period caused changes in the occurrence and cover of several species (e.g. Carex buekii, Typha latifolia, aquatic macrophytes). Pronounced changes in the cover of some species occurred even within a single vegetation season due to the long-term sink of water table below the ground surface.
Źródło:
Acta Societatis Botanicorum Poloniae; 2005, 74, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in vegetation and soil seed bank of meadow after waterlogging caused by Castor fiber
Autorzy:
Franczak, M.
Czarnecka, B.
Powiązania:
https://bibliotekanauki.pl/articles/57726.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
vegetation change
soil seed bank
meadow
water logging
Castor fiber
habitat moisture
abiotic stress
species composition
quantitative change
qualitative change
Opis:
Soil waterlogging is among abiotic stresses that influence species composition and productivity in numerous plant communities. The aim of the study was to find answer to the question of how waterlogging caused by beavers’ activity induces quantitative and qualitative changes of vegetation and soil seed bank levels of variable-moist meadows. An immediate effect of the waterlogging at the level of vegetation was the decline in species richness and a decrease in the values of the biodiversity index. Water stress inhibited growth and development of plants already present and, primarily, impeded recruitment of new individuals of species characteristic of variable-moist meadows, e.g. Cirsium rivulare, Filipendula ulmaria and Lythrum salicaria, which were replaced by Carex acutiformis. Prolonged waterlogging did not induce equally substantial changes in the soil seed bank as in the vegetation. Both in the waterlogged and control patches, slightly decreased species richness and biodiversity index were recorded. After waterlogging withdrawal, the reserves of the soil seed bank were slightly higher than the initial values. The differences were not statistically significant. In the waterlogged patch, the qualitative floristic similarity between taxa identified in the soil seed bank and vegetation cover declined, which was evidenced by the value of Jaccard’s index decreasing from 0.46 to 0.36. A reverse relationship was found in control patch, where the value of the similarity index slightly increased from 0.41 to 0.48.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial and temporal variability of seed bank resulting from overgrowing of xerothermic grassland
Autorzy:
Czarnecka, J
Powiązania:
https://bibliotekanauki.pl/articles/58295.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
vegetation
Polska
grassland
overgrowing
vegetation change
grassland vegetation
xerothermic grassland
structure
seed bank
bush encroachment
Roztocze macroregion
botany
burned seed flora
succession
Opis:
The aim of my study was to determine changes in the seed bank and vegetation during the process of overgro-wing of the xerothermic grassland situated on the slopes of the White Mountain (349 m a. s. l., the Central Roztocze Region, South-Eastern Poland). I also examined whether the changes of vegetation can be predicted if we know the structure of the burned seed flora. To achieve this goal I used two sets of data: one collected from three different environments (grassland, brushwood and woodland) at the same time (toposequence), and the other collected twice from the same place at the interval of seven years (chronosequence). I stated that the appearance of even a small number of ornitochorous seeds and their seedlings can be treated as a signal that the bush encroachment will accelerate. Seed number seems to decrease during succession in the analysed sequence of plant communities. The total number of species in the seed bank did not change in the most dynamic plant communities: grassland and brushwood, and it was significantly higher there than in the seed bank of woodland. During the time of observation, the most important quantitative and qualitative changes took place in grassland vegetation, which is more similar to brushwood vegetation now than it was at the beginning of the study.
Źródło:
Acta Societatis Botanicorum Poloniae; 2008, 77, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in the silver fir forest vegetation 50 years after cessation of active management
Autorzy:
Woziwoda, B.
Kopec, D.
Powiązania:
https://bibliotekanauki.pl/articles/58367.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
silver fir
Abies alba
forest vegetation
cessation
successional change
forest nature reserve
management
Polska
Opis:
Knowledge of the vegetation and the monitoring of its changes in preserved areas is an essential part of effective conservation policy and management. The aim of this study was to assess the effectiveness of traditional methods of conservation of silver fir forests. The study analyses the changes in the structure and species composition of a temperate forest excluded from the commercial silvicultural management for 50 years, and since then protected as a nature reserve. The study is based on a comparative analysis of phytosociological reléves made on permanent plots in 1961, 1982, 1994 and 2011. PCA and ecological indicator values were analyzed, as well as characteristic species based on an indicator value (IndVal) index. Results revealed significant and dynamic changes in the forest structure and composition. The mixed coniferous-broadleaved forest with Abies alba and diverse ground flora, considered in the 1960s as valuable and worthy of conservation, was found to have been anthropogenically transformed and unstable. Significant reduction in the human impact was followed by spontaneous regeneration of oak–hornbeam forest. However, the directional process of changes in vegetation was modified by such silvicultural treatments as selective cutting of trees and gap creation, all intended for silver fir maintenance. The results show that Carpinus betulus effectively outcompeted Pinus sylvestris, Picea abies, Quercus robur and A. alba. Changes in the forest overstory and understory caused temporal changes in the habitat conditions reflected in changes in the ground vegetation composition. The proportion of light-demanding and oligotrophic species significantly decreased, while the contribution of species with a wide ecological amplitude, i.e. more shade-tolerant and nutrient-demanding – increased. The share of A. alba was reduced. Species defined in this study as most valuable, should be actively protected, or selection of conservation targets should be re-evaluated.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temporal changes of aquatic macrophytes vegetation in a lowland groundwater feed eutrophic course [Klatovske Rameno, Slovakia]
Autorzy:
Otahel'ova, H
Hrivnak, R.
Valachovic, M.
Janauer, G.A.
Powiązania:
https://bibliotekanauki.pl/articles/58642.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
diversity
botany
aquatic plant
vegetation
lowland eutrophic stream
ecological status
distribution
Slovakia
Klatovske Rameno
temporal change
Opis:
Klátovské rameno is the lowland slow-flowing groundwater feed eutrophic tributary of the Malý Dunaj River (Danube Plain), where our study of temporal changes of aquatic macrophytes vegetation was realised in 1999 and 2005. For survey of aquatic vascular macrophytes the Kohler’s method (Janauer 2003) was used, which is compliant with European standard EN 14184. Altogether 35 aquatic macrophyte species were recorded during the survey. Nuphar lutea persisted as the most dominant species in 1996 and 2005. Species diversity increased slightly after the nine years: ten species immigrated to the watercourse. The changes in species abundance have shown weak differences, however the abundance of Sparganium emersum has increased markedly. Alien species Elodea canadensis and both S. emersum and Hydrocharis morsus-ranae significantly enlarged their distribution in the stream. The ecological quality of the river, based on the aquatic macrophytes assessment criteria, was slightly impaired after nine years, but still 90% of its studied course has a high or good ecological status.
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 spread of Impatiens parviflora DC. in Central European oak forests - another stage of invasion?
Autorzy:
Reczynska, K.
Swierkosz, K.
Dajdok, Z.
Powiązania:
https://bibliotekanauki.pl/articles/56626.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
Impatiens parviflora
spread
Central Europe
oak forest
invasive plant
long-term change
plant species
species composition
forest vegetation
small balsam
Opis:
In this study, we examine the pattern of occurrence of Impatiens parviflora in Central European oak forests over time and its ecological requirements within these types of communities. Research was based on phytosociological data collected in 3776 relevés. A modified TWINSPAN algorithm were used to distinguish the groups of oak forests. The ecological preferences of the I. parviflora and studied communities as well as differences between invaded and non-invaded vegetation plots were analyzed using mean weighted Ellenberg indicator values (EIVs). Finally, both the temporal pattern of I. parviflora participation and changes in its coverage in the studied communities were analyzed. Our study confirmed a high adaptability of this species with respect to temperature, moisture, soil reaction and nutrients and determined its broad ecological optimum in oak forests. However, it also revealed both a greater sensitivity of some communities within Central European oak forests to the invasion of I. parviflora and differences in habitat conditions between invaded and non-invaded vegetation plots. This suggests that the habitat niche of I. parviflora within oak forests is not accidental. The analysis of temporal changes in the frequency of I. parviflora confirmed a 20% increase in relevés over the last 50 years. However, we did not identify any statistically significant rise in the coverage of I. parviflora in oak forests specifically during the studied period.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 4
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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