Badland erosion processes and their interactions with vegetation: a case study from Pisticci, Basilicata, Southern Italy

Abstract

The eastern part of Basilicata (Southern Italy) is characterised by the presence of Plio-Pleistocene clays, which are strongly affected by typical badland erosion forms. These landforms are the outcome of the recent uplift of a region of a clay bedrock and a mediterranean climate. The evolution of such features interacts with native or planted vegetation through several mechanisms. Resulting landforms show signs of more severe degradation on slopes exposed to the S. The geomorphological evolution includes the propagation of erosion process from the S to the N, with the result of the progressive demolition of the hills. Therefore, erosion control programs should focus on the stabilization of south-facing hillsides, a key to the stability of the whole system. The present work focuses on some of the relations between soil exposure, plant cover and soil vulnerability to erosive processes, through an analysis conducted on 10 sample areas with different exposure and cover: bare, herbaceous, or woods. The role of vegetation is of great importance for the stability of slopes, because it causes a higher content of organic matter, a lower level of salinity, especially at the soil surface, and a lower swelling of aggregates. Results suggest that the colonization of the south-facing hillsides with plants may be an important process of slope stabilization with regards to surface processes.