Badlands vegetation on dolomitic substrata: a comparison between Central and Southern Apennines. La vegetazione dei calanchi su substrato dolomitico: confronto tra Appennino centrale e meridionale

Badlands are a group of landforms with some common features but diverse dynamics, depending mainly on climatic and lithological drivers. The evolution of such features interacts with native vegetation through several mechanism involving especially exposure, slopes and soil features. Interest about badlands historically focused on some issues, like erosion rates, runoff generation and on the role of lithology and soils in landforms evolution, in particular for land reclamation. Nevertheless we argue that they are also hot spots of landscape and biological diversity that merit protection rather than reclamation. In the Italian Peninsula they are typical landforms of loose soils characterized by strongly dissected slopes widespread on Plio-pleistocenic marine clay and marly substrata. Their vegetation features has been subject of various geobotanical studies revealing relationships with soil type, landforms and human activity. However, badlands can also occur on other incoherent substrata (e.g. sandstones, limestones, dolomites) where specific vegetation studies are until now incomplete. As a consequence, we investigated the vegetation features of badlands on Apennines dolomitic substrata, generally developed on cataclasites formed by fracturing and comminution during faulting. We gathered 146 phytosociological data, mainly original, from Central (Simbruini Mountains) and Southern Apennines (M. Picentini, M. della Maddalena, Lucanian Apennine, M. Pollino). Multivariate analysis revealed a similar pattern of relationship between plant communities and landform but different species assemblage in the two regions. Two main plant communities were identified in Central Apennines (Globularia meridionalis garrigues and Calamagrostis varia stands and two in the Southern one (Lomelosia crenata garrigues and Achnatherum calamagrostis stands) showing similar features in the environmental parameters as phytoclimate, slope and exposure. Syntaxonomical classification at lower and higher ranks will be discussed in terms of structure, ecology and chorology of the identified communities.