Wyniki wyszukiwania

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Size variation and peculiar behaviour of nucleolar organizer region in Quercus species

100%

Papes D., Zoldos V., Besendorfer V., Silajak-Yakovlev S.

Prace Naukowe Uniwersytetu Śląskiego w Katowicach

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1998

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tom 1696

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Differential responses to neutral red uptake of mating type Iand mating type II cells in Paramecium primaurelia. I. Cell size variation

86%

Ramoino P., Delmonte Corrado M. U.

Acta Protozoologica

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1992

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tom 31

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nr 1

3

Ecological strategy at cell size level to respond to stressed environments

72%

Wang H., Liu Y., Chen H.

Polish Journal of Ecology

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2016

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tom 64

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nr 2

The cell size variations in woody plants in various environments are not well known, and the underlying mechanism has not been fully analyzed. 2. The current study focused on the intraspecific and interspecific size variations in palisade cells occurring in 76 woody species along an elevation gradient (1800–4500 m a.s.l.) on Gongga Montain (1400–7552 m a.s.l.) in southwest China, which included tropical and subtropical genera of broad-leaved forest flora including Salix hyperba as the species occurring on all elevations. We hypothesized that cell size is regulated by alterations in width-length scaling (L-D ratio) to mediate a surface-to-volume ratio (S/V) most suitable for the prevailing environmental conditions. 3. It was observed that cell size co-varied similarly with environmental conditions at the conspecifics, congenerics, and interspecifics levels investigated. Cell sizes decreased among conspecifics, or increase among congenerics and interspecifics via negative or positive scaling of width-length ratio at the cellular level. However, this dichotomously differing tendency may be ecologically constrained by both a cost-increasing and benefit-diminishing mechanism of cell dimension with increasing elevation at the species level, implying a ‘middle way’ strategy for species to stressed environments. 4. The implications of the results for regional floristic evolution are discussed.

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Egg size variation in Blue Tits Cyanistes caeruleus and Great Tits Parus major in relation to habitat differences in snail abundance

58%

Banbura M., Sulikowska-Drozd A., Kalinski A., Skwarska J., Wawrzyniak J., Kruk A., Zielinski P., Banbura J.

Acta Ornithologica

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2010

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tom 45

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nr 2

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Egg size variation and breeding characteristics of the Black-winged Stilt Himantopus himantopus in a Saharan oasis

58%

Adamou A.-E., Kouidri M., Chabi Y., Skwarska J., Banbura J.

Acta Ornithologica

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2009

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tom 44

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nr 1

Different aspects of the breeding biology of the Black-winged Shit were studied in a natural oasis wetland area in the Sahara Desert, the Chott of Aïn El Beïda, near Ouargla, E Algeria in 2004-2007. In this wetland the water level is independent of rainfall and Stilts start egg laying when average daily temperature increases to ca. 15°C, mostly in April-May, with no significant differences between years. Complete clutches usually consist of 4 eggs but 3 egg clutches happen with low frequency (2.9-5.6%). Egg size traits (mass, length, breadth and volume) tended to decrease from 2004 to 2007, probably due to deteriorating hydrological conditions of the wetland. Within-clutch variability showed both significant repeatability and laying-sequence-dependent differences among eggs, with the final egg being smaller than the clutch mean value. We found that all egg traits studied showed a negative correlation with the date of laying, which seems to be a phenomenon analogous to the seasonal decrease in clutch size, typical of birds with more variable clutch sizes. Hatching tended to be asynchronous, with average clutch hatching time being 1.84 days. The small final egg and hatching asynchrony are typical components of the adaptive brood reduction, the phenomenon not being recorded so far and remaining for future studies on the Black-winged Stilt. These are the first published data on breeding characteristics for any N African population of the Black-winged stilt.

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Size-structured interactions and the dynamics of aquatic systems

58%

Persson L., De Roos A. M.

Polish Journal of Ecology

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2006

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tom 54

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nr 4

Size variation within species as a result of individual growth and development over the life cycle is a ubiquitous feature of many aquatic organisms. We review the implications of this size variation for the dynamics of aquatic systems. Ontogenetic development results in differences in size dependent competitive abilities between differently sized individuals giving rise to cohort cycles that are qualitatively different from traditional predator prey cycles. Size-dependent interactions also mean that the type of interaction – competitive or predatory – changes over the life cycle as a result of an increase in size. At the intraspecific level, cannibalistic interactions may, depending on the life history characteristics of the cannibal, give rise to either equilibrium or cycles driven by a mixture of inter-cohort cannibalism and competition. In multispecies contexts, size variation and particularly food dependent growth lead to the presence of alternative states involving catastrophic collapses. These sizestructured interactions have so far been mainly demonstrated for fish and cladocerans, but do have whole lake food web ramifications.

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Unarmoured dinoflagellates collected during the cruise of the r-v Oceania to the European Arctic, in June-August 1992 and 1993

51%

Okolodkov Y. B.

Polish Polar Research

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