Unusual decline in nearly 100 kilometres of forest shelter belts in Dobrudzha has been observed this year. Mainly ash stands are affected. Due to the lack of snow in the winter and the low amount of rainfall in the spring and summer, defoliation of the belts on the territory of the State Hunting Enterprise – Balchik has started. The management of the enterprise submitted a signal to the Forest Protection Station in Varna. A joint field check was conducted, and it was found out that not only individual trees, but also whole forest stands were affected. Teams from the University of Forestry, EFA and the Forest Research Institute at the Bulgarian Academy of Sciences were also invited to identify the causes of the dieback. 365 forest stands in the municipalities of Shabla, Kavarna and Balchik, where the trees are between 20 and 80 years old, were surveyed. The decline was observed all over the sites, but the most affected species were the common and American ash.
After the rainfall at the end of June, some of the belts improved their condition, but unfortunately this did not happen in all of them. The Director of the NESC, eng. Veselin Ninov, who oversaw the results of the inspections and daily checks, organized a meeting of experts from the Forest Research Institute, RFD – Varna, NESC and the affected forest enterprises to identify the cause of the decline and to plan short and long-term measures to deal with the problem.
New pest on trees
Prof. Georgi Georgiev from the Forest Research Institute and his colleagues have sampled the affected belts, but their final report is still expected. During the meeting, it was suggested that the decline process is due to an insect pest that was not known in our latitudes but has appeared here because of climate change and drought in the last two years. Scientists believe that the insect destroys the buds, young twigs and leaves of trees, leading to trees die-off. Prof. Georgiev said that once the results are out, a proposal will be made to combat this new pest in our country.
At the end of the meeting, it was decided that sanitary logging in the most affected belts was necessary so that the fallen trees do not create a problem for farmers, while reforestation of the affected areas will start in the spring of 2021. According to eng. Veselin Ninov, however, a long-term solution should be sought, because in 10-20 years this problem will escalate. A gradual replacement of tree species that need higher soil moisture, such as ash, with ones that are more drought-resistant should begin.
The reforestation of the affected belts in Dobrudzha will be carried out with European funds, within two projects – “Conservation measures for the Lesser Spotted Eagle and its habitats in Bulgaria”, which is part of the EU LIFE programme, with partners EFA, BSPB, NESC and SESC and the project “Removal of invasive alien species, restoration and conservation of priority forest habitats of the Natura 2000 network in North-eastern Bulgaria” LIFE19 NAT/BG/001133 – LIFE IASHAB. Partners of NESC in this project are SESC, EFA, Romsilva, Northcentral State Company, ABZ-2006 and WWF.