Landscape changes in the mainland of the south of the Far East during the Little Ice Age
N.G. RAZJIGAEVA1,2, L.A. GANZEY1, T.A. GREBENNIKOVA1, T.A. KOPOTEVA3, L.M. MOKHOVA1, T.R. MAKAROVA1, E.P. KUDRYAVTSEVA1
1Pacific Institute of Geography, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
2Geographical Institute, Russian Academy of Sciences, Moscow, Russia
3Institute of Water and Ecological Problems, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk, Russia
Keywords: climate changes, floods, paleolakes, mountain bogs, mountain landscapes, Primorye
Abstract
The manifestation of the Little Ice Age in the south of the mainland of the Russian Far East is analyzed. The study is based on a synthesis of paleogeographic data, which, in the absence of historical records, are the most informative for reconstructing changes in the natural environment. The main natural archives were deposits of mountain lakes and bogs located in different landscape zones of the low- to mid-mountain areas of the Sikhote-Alin and East Manchurian Mountains (at absolute elevations from 300 to 1600 m). Based on changes in the composition of diatom flora, as well as components of forest and bog ecosystems, abrupt climatic changes that occurred from the 12th to 13th centuries, including the transition period from the Medieval Warm Period, were reconstructed. It has been established that the medieval cooling in the south of the Far East was humid, with increased precipitation, including winter precipitation, and frequent floods. In this context, short-term periods of decreased humidity and seasonal droughts were observed. Typically, drier conditions coincided with solar activity minima. The cooling had an impact on the development of mountain landscapes, resulting in a change in the ratio of forest-forming species, a shift in the boundaries of landscape zones, widespread development of sphagnum bogs, and the emergence of species of northern regions among peat-forming plants. At the end of the Little Ice Age, settlement and active development of the territory became the leading factor in landscape transformation.
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