**6. Concluding remarks**

The area of the Carpathian Basin is characterized by a large-scale environmental mosaicity present on the scale of the basin. This complexity increases downward to the regional and local scales. The major driving factor on the scale of the basin is the regional overlap of various climatic influences ranging from the Atlantic, Alpine, and Continental influences to the Sub-Mediterranean-Pontic climatic effects. According to our data, this type of mosaic-like complexity of the environment developed even during the ice age and controlled the evolution of the mollusk fauna both on the regional and local scales. Geomorphology, bedrock, groundwater table, exposition, as well as soil conditions further increased the macro-scale mosaicity on the regional and local scales. These regional environmental mosaics functioned as the ice age refugia for terrestrial and freshwater warmth-loving gastropods. Long-term conservation of these is the key to the preservation of the natural biota of the basin among changing climatic conditions.
