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Dendroclimatological Analysis of Wild Pear Pyrus Pyraster (L.) Burgsd. From Biedrusko Military Area (West Poland) — Preliminary Study

Cedro A., Antkowiak W.

Geochronometria

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2016

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Vol. 43, no. 1

18--23

EN

European wild pear (Pyrus pyraster, syn. Pyrus communis subsp. pyraster L.) is widely distributed in Europe, but rarely studied by dendrochronologists. This preliminary study was aimed to assess the age and effect of climate on tree-ring width in the largest Polish population of P. pyraster, in Biedrusko military area (western Poland). On the basis of samples from 21 trees, a chronology (BIE) was constructed, covering 45 years (1963–2007). Mean tree-ring width in the studied trees is 1.92 mm. The performed analyses (pointer years, correlations, and response function) indicate that tree-ring width is strongly dependent on weather conditions in the year preceding formation of the tree-ring. Annual rings of pear trees were wide after cold and rainy previous summer and after rainy previous October, while in the current year, ring width was affected by insolation in February and temperature in August (positive correlations) and precipitation in May (negative correlation). The low similarity of the ring-width pattern and effect of climate on tree-ring width between this population and a wild pear population from the Bielinek Reserve, located 200 km away, indicate that tree-ring width in this species is strongly dependent on habitat and there is a need to continue dendrochronological analyses.

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Success of wild pear Pyrus pyraster (L.) Burgsd. in colonization of steep sunny slopes : an interdisciplinary study in the Bielinek Reserve (NW Poland)

Antkowiak W., Cedro A., Prajs B., Wolko Ł., Michalak M.

Polish Journal of Ecology

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2012

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Vol. 60, nr 1

57-78

EN

A local population of Pyrus pyraster was studied in dry and warm habitats: xerothermic grasslands Potentillo-Stipetum capillatae and Adonido-Brachypodietum, as well as thermophilous oak forest Quercetum pubescentipetraeae in the forest-steppe Bielinek Reserve (NW Poland). Our aims were to assess: (1) the ability of this species to adapt to extremely dry sites, as a pioneer woody plant; (2) its phytosociological position; and (3) morphological variation and genetic diversity of the local population. The pear trees in Bielinek Reserve seem to reach an optimum in shrub communities of the class Rhamno-Prunetea, but tree age clearly indicates that the grasslands were colonized by wild pear trees already before the shrub communities developed. This indicates that P. pyraster can colonize very dry, eroded sites, such as steep sunny slopes covered by xerothermic grasslands. Wild pear trees form plant communities that are a seral stage followed by forest-shrub communities or thermophilous forests. The species in xerothermic shrub communities of the reserve shows a high constancy. It is also very resistant to extreme temperatures, insolation, drought, and erosion. Its tree-ring width (on average 1.1 mm per year) was strongly related to precipitation and temperature in spring and summer. High precipitation resulted in wider tree rings, while dry years (associated with high air temperature) caused a decrease in tree-ring width. Another significant factor is precipitation in winter, which had a positive influence on tree-ring width. Microsatellite markers revealed a high level of genetic diversity in this population. Our results suggest that wild pear can be recommended for afforestation of areas affected by droughts and disturbed sites in Central Europe. It can be used to increase the heterogeneity of the landscape, e.g. by creation of forest ecotones and for planting along roads and field margins, especially considering the predicted climate change.

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Issues in the protection of small river valleys: the example of the Kulawa River valley (northwest Poland)

Prajs B., Antkowiak W.

Oceanological and Hydrobiological Studies

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2010

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Vol. 39, No.3

129-136

EN

This paper presents the results of research relating to the vegetation of the Kulawa River valley and its flow lakes - Głuche Duże, Głuche Małe, and Sieczonek. Transformations observed in the flora examined were the result of two overlapping factors: 1. anthropogenic factors - among others, a high phosphorus content in the waters of the river and in nutrients accumulating in the lakes; 2. natural factors, such as a reduced level of subsoil waters. In the protection of river valleys, it is important to diagnose all threats. The diagnosis should be based not only on an evaluation of water quality, but also on the state of the whole environment of the valley.

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Tetrahydrofuran Ring Opening Initiated by a Catalytic Action of a Diazoalkanes/Boron Trifluoride Etherate Combination

Antkowiak W.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 6

875-878