INSTYTUT DENDROLOGII

This contribution presents the results of the investigation of the Oyców birch (Betula oycoviensis Besser) population in Volyně, the Ore Mts., the only locality with its confirmed presence in the Czech Republic. The Volyně locality is situated ca 700 m ASL (mean temperature 6.5°C, annual precipitation 700 mm) mostly on nutrient-poor abandoned pastures. The aim of this paper is to present the results of geometric morphometric study on leaves and to summarize up to date knowledges on this tree species. We found and described altogether 58 individuals of Oyców birch during the field exploration. Dendrometric parameters, vitality and crown shape were analysed. To define characteristic morphological features of Oyców birch, we performed geometric morphometric method on leaves of selected 36 specimens. We found that 15 distinctive traits could be used to distinguish B. oycoviensis from Betula pendula Roth. The traits we considered most important are as follows: petiole length, number of major veins, blade length and blade width. These traits are in accordance with traits that common botanical field guides refer to. The appropriate management steps to support the natural regeneration of Oyców birch in the Volyně locality were recommended. To improve conditions for natural regeneration, grass sward removal in chosen spots is advisable. And finally, the artificial regeneration could be used to accelerate the propagation of the population.

Keywords: Oyców birch, geometric morphometrics, PCA analysis, threatened species, Ore Mts. (Krušné hory)