Situation of common ash (Fraxinus excelsior) in Latvia of the active phase of forest destruction. Forest stand dynamics and distribution in the last 80 years (1940 2020)

At the beginning of the 19th century, common ash was a rare species in the forests of Latvia. Back then, the first ash plantations were cultivated in Western Latvia (Cīrava), but the attempt was not successful. After that, the ash spread gradually, with a particularly sharp increase during the second half of the 20th century. In 58 years (1940-1998), as a result of intensive natural regeneration and planting efforts, the area of ash stands in forests increased 9.2 times, reaching 0.79% of the forest area, a large proportion of which (62%) was covered by young stands (up to 40 years old). In the first twenty years (2001-2020) of the 21st century, with the onset of the pandemic of fungal pathogen Hymenoscyphus fraxineus, the area of ash stands has decreased 1.9 times. During the pandemic, ash young stands and pure ash stands have suffered the greatest loss. Therefore, when growing future ash stands, it is necessary to maintain a balanced age structure of stands and to create ash mixed stands.