Wyniki wyszukiwania - Biblioteka Nauki

1

Disappearing population of Betula humilis Schrk. on the Maliszewskie Lake, NE Poland

100%

Chrzanowska A. , Jadwiszczak K. A.

Biodiversity: Research and Conservation

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2015

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tom 37

2

Brzoza karłowata Betula nana w Polsce

100%

Jadwiszczak K. A. , Jadwiszczak P.

Chrońmy Przyrodę Ojczystą

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2014

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tom 70

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nr 2

PL

Brzoza karłowata Betula nana L. należy do gatunków zagrożonych wyginięciem w Europie Centralnej i Wschodniej. Jest to relikt glacjalny występujący w Polsce na trzech izolowanych stanowiskach: „Linje”, „Torfowiska Doliny Izery” i „Torfowisko pod Zieleńcem”. Analizy markerów molekularnych wykazały zmniejszony poziom zmienności genetycznej tego gatunku w porównaniu z brzozą niską, również objętą ścisłą ochroną. Czynnikami, które w przeszłości doprowadziły do spadku zmienności genetycznej u brzozy karłowatej, były redukcje liczby osobników na poszczególnych stanowiskach zachodzące w trakcie ekspansji polodowcowej, a także wywołane późniejszą melioracją torfowisk i ich zarastaniem przez rośliny konkurencyjne. Niski poziom zmienności genetycznej jest także skutkiem działania dryfu genetycznego oraz braku przepływu genów między populacjami. Brzoza karłowata rozmnaża się w Polsce głównie w sposób wegetatywny. Trudności z rozrodem generatywnym mogą być spowodowane: zacienianiem przez konkurencyjne drzewa i krzewy, zamieraniem starszych osobników na podtopionych częściach torfowisk oraz niszczeniem kwiatów i szyszek przez larwy owadów. Ochrona brzozy karłowatej wymaga działań konserwatorskich mających na celu intensyfikację rozrodu generatywnego we wszystkich populacjach

EN

Betula nana L. is an endangered species in central and eastern Europe. This is a glacial relict known from three localities in Poland: “Linje”, “Torfowiska Doliny Izery” and “Torfowisko pod Zieleńcem”. Analysis of molecular markers revealed the lower level of genetic diversity in the B. nana populations compared to the shrub birch Betula humilis, another threatened birch species in Poland. The reduced genetic variation is a consequence of “bottleneck effects”, which probably took place during postglacial recolonisation, and later, after drainage of mires resulting in expansion of competitive plants. Other factors reducing the genetic variation of B. nana in Poland are genetic drift, strongly operating in small populations, and a lack of gene exchange between different sites. B. nana reproduces mainly by vegetative layering. Generative reproduction is probably hindered by shading by forest and bushes, languishment of older ramets producing female and male catkins and browsing by larvae of butterflies. The conservation of species requires activities improving habitat conditions which would enable generative reproduction in the Polish populations of B. nana.

3

Low genetic diversity and significant structuring of the common hamster populations Cricetus cricetus in Poland revealed by the mtDNA control region sequence variation

80%

Banaszek A. , Jadwiszczak K. A. , Ratkiewicz M. , Ziomek J.

Acta Theriologica

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2009

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tom 54

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nr 4

289-295

EN

The genetic diversity of 12 populations in the present range of the common hamster Cricetus cricetus (Linnaeus, 1758) in Poland was established. The 366 bp of the mtDNA control region was sequenced for 195 individuals. As few as seven haplotypes were found and their distribution was geographically structured. The large geographic areas were fixed or almost fixed for a single haplotype and three groups of populations, that do not share any haplotypes, have been defined. Proportions of genetic diversity attributable to variation between groups of populations, between populations within groups and within populations were 93.64, 1.92 and 4.45% (SAMOVA: p < 0.001 for all estimates), respectively. Such pattern of variation is most probably the result of historical, postglacial bottlenecks and present genetic drift after the population decline in the last few decades.

4

Identification of the barrier to gene flow between phylogeographic lineages of the common hamster Cricetus cricetus

70%

Banaszek A. , Ziomek J. , Jadwiszczak K. A. , Kaczynska E. , Mirski P.

Acta Theriologica

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2012

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tom 57

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nr 3

EN

In anthropogenically disturbed habitats, natural barriers still exist and have to be recognized, as they are important for conservation measures. Areas of phylogeographic breaks within a species are often stabilized in inhospitable regions which act as natural barriers. An area of contact between phylogeographic lineages of the common hamster (Cricetus cricetus) was found in the Małopolska Upland in Poland. A total of 142 common hamsters were captured between 2005 and 2009. All hamsters were genotyped at 17 microsatellite loci and partial sequences of the mitochondrial (mtDNA) control region were obtained. No mixed populations with mtDNA haplotypes of both lineages were found. The distance between marginal populations was about 20 km; no hamsters were found in the area between. A principal components analysis (PCA) was performed on microsatellite data and the greatest change in PC1 scores was found between marginal samples. To define the habitat components responsible for the phylogeographic break, we compared the habitat composition of sites occupied by hamsters with those from which hamsters were absent. We found that hamsters avoided forested areas and sandy soils. The area of the potential barrier was characterized by a high proportion of woodland and unfavorable soils in comparison with neighboring areas inhabited by hamsters. They cannot settle in this area due to their high winter mortality in shallow burrows and high predation in the fields adjacent to forests.

5

Juniperus excelsa s. str. in Crimea - differentiation and history inferred from genetic and morphological markers

61%

Mazur M. , Jadwiszczak K. A. , Bona A. , Krasylenko Y. , Kukushkin O. , Marcysiak K.

Folia Forestalia Polonica. Series A . Forestry

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2021

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tom 63

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nr 4