Assessment of riparian forest vegetation of rivers supporting the Prespa trout in the Transboundary Prespa Park

The QBR (Riparian Forest Quality) index and the RMP (Riparian Macrophyte Protocol) were used to assess habitat quality and inventory riparian forests in four rivers sustaining the endemic Prespa trout (Salmo peristericus). Total QBR index and total riparian cover (first component of the QBR index) values were found significantly higher in the upper parts of Brajcinska and Kranska rivers, while lower values were recorded in the upper parts of Agios Germanos river and Leva stream. Cover structure, cover quality and channel alteration (the other three components of the QBR index) did not differ significantly between the four watersheds. The greater presence of Fagus sylvatica in the former rivers principally contributes to their increased total riparian area and riverbed cover compared to those of the two latter rivers. In the altitudes below 900 m.a.s.l., where gradients are gentle and human activities intense, vegetation types in all four systems change considerably with the participation of non-native species, while riparian area and riverbed cover are reduced.