Monitoring of the phytosanitary condition of Larix decidua Mill. plants in the Modryna tract of the Zviahel Forestry branch of the State Enterprise Forests of Ukraine

Abstract

Phytosanitary monitoring of forest stands is currently a relevant and important area of scientific research that ensures observation, assessment, and forecasting of the dynamics (changes) of the quantitative and qualitative (including sanitary) state of forests and underlies the development of an effective system of tree protection. The purpose of this study was to identify the species composition and distribution of dominant phytopathogen species in the Modryna tract of the Zvyagelske Forestry branch and to identify the primary factors of Larix decidua Mill. decline. This study employed phytopathological, entomological, forest inventory, and comparative methods. The study identified and registered typical symptoms of damage and the consequences of the harmful effects of pests of L. decidua trees in the Modryna tract, leading to a general weakening of their sanitary condition. Symptoms of larch needle cast (meria needle blight) and browning were recorded on the needles; on the trunks – typical manifestations of cankers and fruiting bodies of a unique basidiomycete – Lariciphomes officinalis. Apart from infectious pathologies, sporadic wind and storm damaged larch trees, as well as other negative effects of wind exposure, were recorded in the study areas. The species composition of the pests of the surveyed larch trees included the following insect species: Cephalcia lariciphila, Sacchiphantes viridis Ratz., Coleophora laricella, Zeiraphera diniana Gn., Lasiomma laricicola Karl. It was generalised that the main threat to the centuries-old larch trees is the complex effect of anthropogenic, abiotic, and biotic (including parasitic) environmental factors that constantly and to varying degrees affect the sanitary and physiological state of ancient larch trees. The findings of this study provide information for predicting the risks of spreading pathogens and pests, which allows managing these risks and preventing their further spread