ORIGINAL ARTICLE Geological and Geomorphological Conditions Supporting the Diversity of Rock Landforms in the Pohořská Mountains (South Bohemia, Czech Republic) Jiří Rypl 1 & Karel Kirchner 2 & Lucie Kubalíková 2,3 & Jan Divíšek 2 Received: 13 March 2019 /Accepted: 7 January 2020 # The European Association for Conservation of the Geological Heritage 2020 Abstract The Pohořská Mountains, a geomorphological subunit of the Novohradské 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 Pohořská 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. Keywords Diversity of landforms . Geomorphological mapping . Lithology . Rock landforms . Spatial analysis Introduction Geodiversity is defined as “the natural range (diversity) of geo- logical (rocks, minerals, fossils), geomorphological (landforms, topography, physical processes), soil and hydrological features including their assemblages, structures, systems and contribution to landscapes” (Gray 2004; 2013). The definition integrates the three main abiotic components involved in landscape modelling: (1) geological parameters, (2) geomorphological processes, and (3) landforms and the resulting soil types, which represent starting conditions for biotic cycles. Zwoliński (2004) distin- guishes between two different approaches to geodiversity: (1) a holistic approach (as defined by Gray 2004, 2013), which con- siders geodiversity as a value-free entity and (2) quantitative approach, which considers geodiversity as a value or parameter determining the inner diversity of an area. In the last decades, these concepts have received increasing attention and stimulated research of various aspects of geodiversity. New methods have been developed for quantification of geodiversity (Serrano and Ruiz Flaño 2007; Zwoli ński 2009; Ruban 2010), mapping and modelling spatial geodiversity patterns (Marmion et al. 2008; Hjort and Luoto 2010; Zwoliński and Stachowiak 2012; * Jiří Rypl rypl@pf.jcu.cz Karel Kirchner karel.kirchner@ugn.cas.cz Lucie Kubalíková lucie.kubalikova@ugn.cas.cz Jan Divíšek jan.divisek@ugn.cas.cz 1 Department of Geography, Faculty of Education, University of South Bohemia, Jeronýmova 10, 371 15 České Budějovice, Czech Republic 2 Department of Environmental Geography, Institute of Geonics of the Czech Academy of Sciences, Drobného 28, 602 00 Brno, Czech Republic 3 Department of Geology and Pedology, Faculty of Forestry and Wood Technology, Mendel University, Zemědělská 3, 613 00 Brno, Czech Republic Geoheritage (2020) 12:2 https://doi.org/10.1007/s12371-020-00430-1