Dynamics of vegetation and fires in Gornaya Shoriya (north Altai mountains) in the late Holocene: according to palynological and charcoal researches of Maly Labysh peat mire
T. A. Blyakharchuk, M. A. Pupysheva
Institute of Monitoring of Climatic and Ecological Systems of SB RAS, Tomsk, Russia
Keywords: vegetation, pollen, the Holocene, mire, paleo fire, charcoal, Gornaya Shoriya, Altai
Abstract
In this work reconstruction of past vegetation and fire dynamics in north Altai was performed by pollen and charcoal investigation of peat deposits of Maly Labysh Mire located in the upper reaches of the Kondoma River in Gornaya Shoriya National Park (52.6306° N, 88.0829°E, 490 м a. s. l.). Lithology and radiocarbon dating has shown that the swamp is of lacustrine origin. The lake originated about 3000 years ago, and about 2200 years ago it turned into a swamp. Spore-pollen analysis of lacustrine and peat deposits revealed repeated changes in the vegetation cover, probably caused by climate instability during the last 3000 years. In general, 2 humid millennial periods (3000-1800 cal. yr. BP and 550-200 cal. yr. BP) were identified when the role of fir ( Abies sibirica ) increased in the forests, alternating with 2 drier periods (1600-900 cal. yr. BP and 200 cal. yr. BP - contemporary) when the fir gave way to birch ( Betula pendula and Betula alba ) forests. The article represents also data on the dynamics of paleo fires in the area of the Maly Labysh Mire based on micro- and macrocharcoal analyzes. It was found, that in peat deposits of Maly Labysh Mire the maxima of micro-charcoals record wetter periods, but macro-charcoals - drier periods, while periodical flooding of the bog with river waters took place. With transition of mire from the flooding regime to unflooding regime, the microcoals and macrocoals began to synchronously reflect drier periods. The results of the study showed that the frequency and intensity of fires in Gornaya Shoriya in the last two thousand years correlate well with previously identified periods of lowering of the groundwater level in the mire [Kuryina, Blyakharchuk, 2020] and with a decrease in the amount of atmospheric precipitation in the Holocene [Arkhipov, Volkova, 1994]. A conclusion is drawn about connection of paleo fires with dynamics of humidity of climate, which in complex influenced on vegetation change in Gornaya Shoriya.
|
