The favorable climate conditions, the rich water sources, and the topographic diversity which is alternated between valleys, plateaus, low hills and high mountains, have supported the growth of a rich variety of plant types in the valley.
The first river terraces of the valley up to 700 m of altitude are covered by dense vegetation, consisting mainly of Mediterranean shrubs, including also the olive trees, vineyards and a selection of fruit types. The territories from 700-1200 m high are occupied mainly of forests of oak, ash and maple trees; while on the altitudes above 1200-1800 m grows the coniferous plants such as the firs and pine trees. In these highlands, deep inside the east-north side of the valley, extends the National Park of Hotova Fir, populated by one of the oldest Mediterranean species of coniferous tree. These highest altitudes are occupied by the alpine meadows and are also the home for a number of seasonal animal enclosures.
After the 90’s of the last century, an intensive deterioration of the vegetation is noted in the area, which is mainly a result of the inappropriate and unsustainable land-use and water sources of the Valley, such as the massive forests fires and illegal clear-cutting, abandonment of agriculture lands, decay of irrigation and drainage systems, etc.