For several recent years, foresters in Sumy region have been fighting against the top bark beetle that destroyed mature pine forests. Today, the population of this pest has decreased, but a new problem has emerged: ash dieback. To preserve ash plantations, specifically to determine the nature of infection spread and find practical methods to combat it, the forestry department of Sumy Regional Forestry and Hunting Management conducted a special seminar. It took place at Trostianets Forestry Enterprise with participation of chief foresters from forestry enterprises and scientists from the State Specialized Forest Protection Enterprise "Kharkivlisozakhyst".

The disease affecting the trees is called chalara ash dieback. It's a fungal infection that causes tree crown dieback and complete infectious drying. The first signs of the disease appeared in the 1990s, and now scientists state that chalara dieback has covered the entire range where common ash grows - all of Central and Western Europe, Great Britain, Canada, and the United States. Besides fungal pathology, ash plantations are also destroyed by an insect pest - the emerald ash borer, causing enormous financial losses to the forestry industry even in the most powerful countries of the world. "All this came from China. Forest pathologists from different countries are looking for ways to stop ash disease. The losses from emerald ash borer damage to ash are colossal - in America, in 35 states they are estimated at 3 billion dollars," says Kateryna Davydenko, a scientist at "Kharkivlisozakhyst".

Participants of the seminar in Trostianets Forestry Enterprise had the opportunity to visit forest areas where they could see firsthand the threat posed by this dangerous tree disease. "This area is infected with chalara dieback. It's designated for final felling. Six months ago there wasn't such drying here. We can see that the stock here is 510 m3 per hectare, meaning this is a well-maintained plantation that entered final felling in quite productive condition. But due to this disease, trees begin to dry out and lose their commercial qualities. Today, the forestry enterprise has 16 such compartments with 171 hectares of diseased plantations," comments Viktor Zubko, director of Trostianets Forestry Enterprise.

"This ash plantation is almost 120 years old, it's actually overmature. The cutting age for ash is 91 years. It has already lost 50% of its commercial qualities, but it's designated for final felling, so it will be cut down anyway. The losses will certainly be significant because the diameters are large. This is an obvious loss of commercial timber. At least 2000 UAH per cubic meter. We lose these funds due to tree disease," comments Anatolii Omelchenko, head of the forestry department of Sumy Regional Forestry and Hunting Management.

Ash infected with the fungus is noticeable in the forest from afar by its reddish bark color. Moreover, the diseased tree loses immunity to other pests: bark beetles and longhorn beetles. Ash wood turns blue, dries out, loses its qualities and turns from commercial into firewood. Scientists claim that the invasion of forest diseases and pests is a consequence of climate change in the world. They say that for the "emerald ash borer" the natural biological control method could be the parasitoid wasp. For chalara dieback - immediate cutting of diseased trees.

"Preliminarily, such areas were identified in Sumy Forestry Enterprise, but then there was no clear diagnosis that it was chalara dieback. In the region, the total area of ash plantations is almost 20 thousand hectares, concentrated in the forest-steppe zone. Middle-aged plantations prevail. Today it's necessary to examine these plantations for the presence of the disease in the shortest possible time. Sanitary measures are needed immediately, but legislative requirements are too lengthy," continues Anatolii Omelchenko.

"The problem with ash is quite serious. The emerald ash borer could lead to the complete disappearance of ash plantations if no measures are applied. The only method of fighting it is cutting down," says Denys Baturkin, acting director of "Kharkivlisozakhyst". According to the meeting participants, the seminar raised many questions for reflection, as it's necessary to act quickly on the ground and make certain adjustments at the legislative level. After the seminar, Sumy foresters will wait for scientific recommendations on how to fight dangerous diseases and pests to preserve healthy forests. But in order not to waste time waiting for conclusions, they will promptly conduct monitoring of ash plantations for infection with dangerous diseases and study options for replacing ash with other tree species more resistant to diseases.