The flora and vegetation of an old solvay process tip in Jaworzno (Upper Silesia, Poland)

This paper demonstrates the flora, plant communities and substrates of an o ld solvay process spoil tip in Upper Silesia, Poland. In an area of 15 000 m(2) there are growing 136 vascular plant species. The flora is characteris ed by the preponderance of Asteraceae - species and long-lived perennial he rbs, many of them coming from meadows and grasslands. Ninety-five percent o f species are apophytes despite the anthropogenic origin of the site. A maj ority of species are associated with moderately dry, base-rich soils with l ow or moderate levels of nitrogen. The site is shown to be an important ref uge for some protected species, montane species and other elements uncommon in the local flora. An analysis of a series of samples used a methodology based on the assessme nt of percentage cover of particular species and multivariate analysis base d on TWINSPAN. Both suggested a relatively high overall similarity between the samples with minor variations associated with moister substrates. Elemental analysis and pH determinations of soil samples associated with th e releves revealed a narrow range of pH and an absence of any strong concen trations of heavy metals. A redundancy analysis of the soil-plant relations hips suggested that the strongest trend of differentiation was most closely associated with a phosphate gradient, and the next strongest was pH and po ssibly waterlogging. The most species-rich vegetation was associated with l ow phosphate and high pH levels. The results could be interpreted to suggest that processes of soil developm ent and plant succession are slow but nevertheless perceptible, with implic ations for future loss of diversity. The vegetation constitutes an assembla ge essentially of one type showing only weak relationships with described v egetation types such as Molinio-Arrhenatheretea meadow, Festuco-Brometea gr assland and Caricetalia davallianae mire. The results also suggest that the vegetation of the site is of considerable value for nature conservation. T he site should be protected and be the subject of further research.