ИСТИНА

Recent reviews of Holocene paleofire records evidence for the key role of climate in fire history. Soil archives of paleofires have been scarcely studied as compared to sedimentary ones, and regularities of their formation are not clearly understood until now. This study is aimed at correlation of local paleofire record with earlier studied milti-proxy paleoenvironmental records: geomorphic, sedimentary (lacustrine, lacustrine-boggy), and soil-sedimentary (alluvial fans), and soil (polygenic profiles). The study site is a small intermountain basin situated in Tyva Republic, Southern Siberia (51ºN., 97ºE., about 1300 m a.s.l.). Nowadays climate is ultra-continental, mean annual temperature is -6.1ºС, the amplitude of annual temperature variation makes up 55.5ºС. Mean annual precipitation is 230-323 mm. Bottom of the basin is occupied by permafrost affected steppes which surround the shallow fresh-water lake and its low boggy terraces. Mountain slopes around the basin are covered with larch taiga. Massive fires regularly occur in local taiga ecosystems nowadays. Archives of pyrogenic events were surveyed in a transitional zone between taiga and steppe ecosystems, within a local geomorphic "trap": a flatbottomed depression between the mountain slope and the narrow, elongated elevation (which is a residual of an alluvial fan) subparallel to the footslope. This position accumulates colluvium, particularly after fire-accelerated erosion. Two profiles were studied in different parts of this landform. One is located closer to the central axis of the depression under meadow-steppe vegetation. Another one was set right at the mountain footslope, under meadow-steppe vegetation as well, within a recent clearcut (rather fresh larch stabs surround the profile). Pedostratigraphy, morphology and micromorphology, LSC, and AMS 14C dating was applied. Earlier obtained paleoenvironmental reconstructions were based on paleosol studies, lithological, and geochemical data, data on pollen analysis, complex group analysis of biological composition applied for lake sediments and peats, C14 dating etc. Firefox https://b-com.mci-group.com/Abstract/Statistics/AbstractStatisticsViewP...