S.Yu. Grishin

Institute of Biology and Soil Science,
Vladivostok, 690022, Russia e-mail: grishin@ibss.dvo.ru

In this article are considered the after-effects of lateral eruption of Klyuchevskaya Sopka volcano (Tuyla group). In 1932 there was the first lateral eruption in history of the largest volcano of Russia at altitude about 500 m above sea level. The tephra (volcanic bombs, scoria and sand) was being erupted and lava flows were effused from three erupting centres during a year. Short field investigation of the area a few decades later allowed estimating the effect of the eruption and features of vegetation recovery. As a result of the eruption the forest vegetation was vanished from the area of 4.5 sq. km. Also the forest vegetation was vanished from the few hundred meters in a radius around the centres of eruption. The unusual feature of stone birch stand damage was destruction of trees under minimal level of deposited tephra about 1 cm thick, while the threshold of deposited tephra is 25 cm at the researched Kamchatka volcanoes. As well possible factors of vegetation damaged by eruption discussed here; most probable among them are: direct heat radiation from erupting centres, the eruption of tephra in the form of volcanic bombs, chemical poisoning.