Geological and Geomorphological Conditions Supporting the Diversity of Rock Landforms in the Pohořská Mountains (South Bohemia, Czech Republic)

The Pohořska Mountains, a geomorphological subunit of the Novohradske Mountains in the southern part of the Bohemian Massif, represent a unique natural area situated on the border between the Czech Republic and Austria. The area was virtually inaccessible during the Cold War because of its localization close to the Iron Curtain. After 1989, the extensive geomorphological mapping with an emphasis on rock landforms has been carried out here in order to achieve increased protection status of this geomorphologically diverse area. In this study, we ask what geological and geomorphological conditions support the diversity of rock landforms in the Pohořska Mountains. The diversity of rock landforms in hexagonal grid cells (ca. 1 ha) was expressed as the number of rock-landform types and using the Shannon diversity index. The effects of lithology, slope, orientation, elevation, and relief curvature on the diversity of rock landforms were analysed using the Classification and Regression Trees. This analysis showed that the highest diversity occurs in grid cells with high mean relief curvature, elevation, and steep slopes. These conditions are met, especially on the summits of the highest peaks and their surroundings in the northern and southern part of the studied area. We conclude that this area deserves increased protection status because of its high geomorphological diversity.