The Sirente Velino group forms a sort of belt used by the wildlife to go from one side to the other of the Apennines. It has a strategic topographical importance, because it represents a necessary connection between the mountains of Reatino, northern Simbruini, the area of Abruzzo, Lazio and Molise National Park
(in the south-east) and Gran Sasso e Monti della Laga National Park
in the north.
The two massifs show both similarities and differences for vegetation that is on their slopes and with reference to their origins. Even being separated by The Rocche Plateau, the two groups can be considered singly in reference to the same geological and tectonic origin.
The Velino Group is without spectacular vegetation and, with a predominance of semi-desert areas, while The Sirente chain (with the exception of some areas on the south and the peak) has extended formations of vegetation.