Consequences of a major eruption of Shiveluch volcano (Kamchatka, April 11–13, 2023) for forest vegetation (preliminary report)

The strong eruption of Shiveluch volcano in April 2023 led to radical changes in the natural environment of a vast territory. Analysis of changes in the aff ected area using satellite images and during fi eld work in the summers of 2023 and 2024 revealed the features, depth and scale of the impact on forest vegetation. Multimeter layer of high-temperature pyroclastic deposits covered an area of more than 60 sq. km on the southern and southeastern slopes of the volcano. The main buried areas include a vast deposit fi eld measuring 38 sq. km, lying in the altitude range of 400–800 m and a series of pyroclastic fl ow tongues with a total area of 12.5 sq. km, descending to an altitude of 140–350 m, with a maximum length of 22 km from the eruption center. Before the eruption, there were coniferous (Larix cajanderi) and deciduous (Betula ermanii) forests, dwarf alder (Alnus fruticosa) covers, mountain meadows and volcanic badlands (legacy of previous eruptions). Woody vegetation, including valuable coniferous forests, was buried and destroyed over an area of approximately 24 km2. Burial of forests by thick (up to tens of meters) high-temperature strata occurred over an area of more than 20 km2. The pyroclastic surge and the peripheral parts of the pyroclastic fl ows turned forests and dwarf alder forests into dead stands over an area of several square kilometers. The cause of its death was powerful and rapid thermal damage by hot gas-sand vortices. Immediately after the eruption, surface watercourses begin to wash away pyroclastic deposits, transporting them, and burying forest areas with washed-out materials. As a result, the forest dies. Vegetation adjacent to pyroclastic deposit fi elds is aff ected by frequent and intense dust transports that occur in open areas above the tree line. The 2023 eruption was the largest explosive event in Kamchatka and the Kuril Islands in recent decades, and caused large- scale destruction of forests.