Kitaibelia vol. 5 – no. 1. (2000) p.209-215.
Sziklagyepek és lejtősztyeppek a Középdunai Flóraválasztó környékén II. Mészkő- és dolomitvegetáció a Cserhát-hegységben
Kun András – Ittzés Péter – Facsar Géza – Höhn Mária
Some results of a coenological and floristical research – carried out in the Cserhát Hills between 1994 and 1999 – are discussed. Limestone and dolomite areas form smaller and greater islands in the mainly adezite hills. The effect of these bedrocks is well expressed in their flora: according to their distance from calcareous rocky grasslands of neighbouring hills their rocky vegetation is getting richer or poorer.
The partial lack of forest cover in prehistoric times of dolomite and limestone horsts of South-Western- Cserhát, regarding their sharp forms, is assumed. As an effect of human deforestation the expansion and immigration of rocky species could have taken place on the eroded areas, forming rocky grasslands. The neighbouring calcareous rocky grasslands of Hungarian Mountain Range could have served propagules for this process.
Low lajta-limestone horsts of East-Cserhát are assumed to be completely covered by forests, considering the physical and chemical weathering feature of this bedrock. The forest canopy probably never could have closed on the steep, southish slope resulting in the survival of the steppe-slope vegetation and rocky species in the litter-eroded groundlayer. Therefore, at eroded surfaces caused by human deforestation, ancient rocky does not present. Instead, secunder vegetation of light-frequent and xero-frequent steppe species and few rocky species have occured at the new open sites. Hence the islands of lajta-limestone surfaces in the andezite Cserhát and Mátra Hills are far from the calcareous rocky grasslands of neighbouring hills, their species could not have immigrate into these areas.