Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 34

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  Sphagnum
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Decomposition rates and changes of carbon and nitrogen contents of Sphagnum litter in mire vegetation can help to explore the ecological effects of climate change and the role of environmental factors from a local to an ecosystem scale. The objective of the study was to determine the relationship between mentioned parameters in small and isolated Sphagnum dominated mires. Measurements had been conducted throughout a year by placing litterbags filled with Sphagnum biomass in three vegetation types (open peat bog, poor fen, alder carr) of a mire ecosystem in Hungary. Peat decomposition rates differed to a great extent; the slowest decomposition rate (39.1±9.52%) was in the alder carr, indicating that slower decomposition could be characteristic for this kind of vegetation type of mire. Between Sphagnum dominated microhabitats, open peat bog showed medium (65.57±4.05) while poor fen the fastest (68.61±5.5) rates in decomposition. The C/N ratio of the Sphagnum litter showed significant decrease (P <0.005) in all studied micro-environments. Slower N release was observed from litter of Alnus dominated association (31.3±6.9%) compared to Sphagnum dominated ones (56.5±8.3%). Our findings showed that the decomposition rates were more dependent on vegetation type than C/N ratio and this relationship was also revealed at a small spatial scale.
The composition and abundance of microorganisms (testate amoebae and ciliates) dwelling in the water in the patches of Sphagnum palustre L. in three peatbogs with different pH values of the Poleski National Park (Eastern Poland) and their relationship to chemical parameters were studied. From April to October 2005 from each peatbog twice a month, eight samples were collected by washing 10 g of a wet mass of plant material in 50 ml of distilled water. A total of 11 testate amoebae taxa and 32 ciliate taxa occurred among Sphagnum palustre. Testate amoebae and ciliates richness and abundance were significantly greater (33 taxa and> 15 ind. g⁻¹, respectively) in low pH (4.5) peatbog. Generally, the moss dwelling testacean fauna was dominated by cosmopolitan and ubiquitous taxa. Only four testate amoebae taxa (Arcella vulgaris, Assulina muscurum, Hyalosphenia sp. and Euglypha sp.) showed a clear preference for a low pH. Ciliate communities were dominated by Colpodea, Cyrtophorida, Scuticociliatida and Suctorida. In all peatbogs bacterivorous protozoa occurred in the highest numbers (up to 60%), while algivorous and mixotrophic in the lowest (range from 3 to 10%). Moisture conditions appeared to play a key role in determining the distribution pattern of testacean communities, while pH and the content of total organic carbon in water correlated positively with the total numbers or biomass of testate amoebae and ciliates.
The lagg of ombrotrophic peatland studied is the ecotone connecting two contrasting in respect of trophic conditions ecosystems: acidic bog and fertilized arable fields. Differences of element content in the waters of these habitats concerns the concentration of Ca, Mg, Na, Cl and pH value. The periodical inflow of waters from agriculture catchment alkalize this zone and, as a result, threaten the ecological system of bog, what is realized by increasing lagg area at the cost of bog area and by decay of ombrotrophic flora components.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.