Authors:M. Zeidler, M. Duchoslav, M. Banaš and M. Lešková
Dwarf pine (Pinus mugo) is a successful pioneer tree, but also an invader of the subalpine belt in Central-European mountains. In the Hrubý Jeseník Mts. (Czech Republic), dwarf pine was introduced at the end of the 19th century by humans into alpine communities. To analyse the influence of non-native woody species on species diversity, vegetation composition and the ecological bioindication of invaded alpine communities, three habitats (non-invaded alpine grasslands, gaps of alpine grasslands within dwarf pine stands and closed dwarf pine stands) were compared at two localities (Keprník, Tabulové kameny) using the space-for-time substitution approach. Plant species composition was assessed by means of phytosociological relevés, and bioindication by means of Ellenberg indicator values. At both localities, both beta and gamma diversity were lower, and species composition more uniform in dwarf pine plantations in contrast to the gaps within and alpine grasslands outside of dwarf pine stands. At Keprník, alpha diversity was lower in the dwarf-pine plantation than outside of it, while at Tabulové kameny no significant differences were found. This is probably due to the somewhat different spatial structure of the dwarf pine stands and the different timing of dwarf pine introduction at these localities. Bioindication showed that dwarf-pine stands were drier, more shaded and had a higher soil fertility than alpine grasslands. Dwarf pine colonisation of alpine grasslands causes the extinction of many endangered plant species, complicating conservation goals. Because of the limited size of alpine areas, changes caused by dwarf pine in medium-high mountains might be more significant than in mountains with large alpine forest-free areas.
Authors:M. Zych, J. Burczyk, M. Kotowska, A. Kapuścik, A. Banaś, A. Stolarczyk, K. Termińska-Pabis, S. Dudek and S. Klasik
Algal strains belonging to the
show significant differences in the extent of staining with the commonly used dye, crystalline violet. This seems to depend on the cell wall composition and on the occurrence of the acetolysis-resistant biopolymer algaenan in the algal cells.Eighteen algal strains were investigated using 24 h staining with 0.2% crystalline violet and it was confirmed that algal strains which did not contain algaenan and had a trilaminar structure in the cell wall showed strong staining ability, while non-algaenan strains were stained very weakly, if at all. The simple method presented here may be helpful to distinguish both kinds of algal strains.
Authors:M. Zych, A. Stolarczyk, K. Maca, A. Banaś, K. Termińska-Pabis, A. Kapuścik, S. Klasik and J. Burczyk
Differences in the assimilation of individual organic compounds (5 mM sugars and L-asparagine) under mixotrophic growth conditions were described for three naturally occurring
strains.The effects of assimilation were measured by the growth intensity and size of algal cells, and the effect of colour changes in the cultures was observed. Some compounds caused the cell colouration to change from green to yellow, being the result of chlorophyll disappearance and the accumulation of yellow secondary carotenoids. In the present experiment none of the cultures turned red, thus excluding the intense accumulation of the commercially interesting carotenoid, astaxanthin.