Współczesne funkcjonowanie i perspektywy użytkowania stoków starasowanych w warunkach śródziemnomorskich na przykładzie Ikarii (Wyspy Egejskie, Grecja)

The paper presents results of the research on degradation of terraced slopes on the Ikaria Island (Greece). This issue is particularly important in connection with the abandonment of cultivation on terraces, which has been going on for many years. In 2010, 2016, and 2020, the authors conducted detailed field studies in 3 test areas including terraces built on slopes of different lithology, i.e. granite-gneiss, gneiss and crystalline schist and dolomite. They aimed at determining the internal structure of the terraces, assessing the state of preservation of the walls and calculating the volume of erosion and accumulation landforms formed within the terraces. Water permeability measurements on the terrace surface were also made. On their basis and on the basis of meteorological data, it was found that between 2010 and 2020, rainfall resulting in surface runoff could potentially occur in the study area 177 times. During this time, the degradation progressed most rapidly in the earliest abandoned terraces where grazing has taken place. Terraces in the best condition are those that are fully used all the time, regardless of the change of their use – the seasonal cultivation of vegetables was abandoned leaving the perennial cultivation of grapes and olive trees. The terraces abandoned during the study period experienced a relatively short period of non-use and even extreme rainfall events exceeding 200 mm / day contributed to a very slight erosion. The results of the research indicate that, due to the favourable lithology, the terraces on the Ikaria Island are among the most resistant to destruction. It can therefore be concluded that in the case of economic support for farmers, it would still be possible to maintain and use terraces on this island.