The research objective was studying humus and its fractional structure as important diagnostic sign of gen-esis on the example of paleoploss of floodplain and the first floodplain terrace of middle watercourse of the Ye-nisei. The objects of the research were geological cuts of sedimentary deposits of the floodplain and the first floodplain terrace of the Yenisei River with containing horizons paleoploss, entering the "Evolutions of Envi-ronment of the Holocene of Siberia" Database, located in the territory of the South of the Yenisei Siberia in for-est-steppe and steppe natural zones. The main method of research was paleoecological monitoring. Paleopedo-logic method was one of the methods of paleoecological research when studying paleoploss, buried in the thick-ness of rainfall. Depending on environment conditions the part of organic substances as a result of "transfor-mations" forms difficult specific organic compounds which received the name of humic substances. The most characteristic part of humus also consists of them. For diagnostic purposes and conditions of paleoploss formation the complex of indicators is used. Complex technique of studying of organic substance included both general characteristic of humus, and separate re-searches of humic acids, i.e. the component, the least subject to diagenesis. Some properties of humus, such as humus carbon size, its group and fractional structure, are diagnostic to genesis indicators paleoploss and are poor subject to secondary changes. The percentage size of carbon of humus in paleoploss allows diagnosing soil profile in analytical way. Humic horizons paleoploss are allocated (Ah) in humus carbon size about 0.40-2.98 %. This size increases from Ah horizons paleo-ploss forest genesis to Ah horizons paleoploss steppe genesis. Paleoploss (humus, group and fractional struc-ture) as components of natural complexes of the last periods of soil formation, have diagnostic signs showing dynamics of climate change during the periods of the Holocene occurring at different times. The ratios of change of climatic indicators and humus (group and fractional structure) paleoploss show the range of fluc-tuation of climate and vegetation in the Holocene of the floodplain and the first floodplain terrace of middle wa-tercourse Yenisei.
Holocene, paleoploss, organic sub-stance, humus, fractional structure (Cgk: Cfk), climatic indicators, climate, floodplain, floodplain terraces, the Yenisei River
1. Velichko A.A. Paleogeografiya sovremennogo sostoyaniya prirodnoy sredy i prognoz // Byul. komissii po izucheniyu chetvertichnogo perioda. - M., 1980. - № 50. - S.12-23.
2. Velichko A.A. Sovremennoe sostoyanie koncepcii pokrovnyh oledeneniy Zemli // Izv. AN SSSR. Ser. «Geografiya». - 1987. - № 3. - S. 21-34.
3. Velichko A.A. Vvodnoe zamechanie otvetstvennogo redaktora // Razvitie landshaftov i klimata Severnoy Evrazii. Vyp. 1. - M.: Nauka, 1993. - S. 36-37.
4. Demidenko G.A. Rekonstrukciya prirodnyh usloviy Prieniseyskoy Sibiri v golocene. - Krasnoyarsk, 1996. - 100 s.
5. Demidenko G.A. Evolyuciya prirodnyh kompleksov Sibiri v golocene. - Krasnoyarsk, 2002. - 160 s.
6. Demidenko G.A., Turygina O.V. Izmenenie klimata Sibiri v pozdnepleystocenovoe - golocenovoe vremya. - Krasnoyarsk, 2017. - 248 s.
7. Demidenko G.A., Hizhnyak S.V. Vliyanie global'nogo izmeneniya klimata na fluktuaciyu pri-rodnyh zon i podzon Prieniseyskoy Sibiri // Vestn. KrasGAU. - 2017. - № 7. - S. 97-106.
8. Evseeva N.G., Zhilina T.N. Paleogeografiya konca pozdnego pleystocena i golocena (kor-relyaciya sobytiy): ucheb. posobie. - Tomsk: Izd-vo NTL, 2010. - 180 s.
9. Zykina V.S. Struktura lessovo-pochvennoy posledovatel'nosti i evolyuciya pedogeneza pleystocena Zapadnoy Sibiri: avtoref. dis. … d-ra geol.-mineral. nauk. - Novosibirsk, 2006. - 36 s.
10. Pianka Z.E. Evolyucionnaya ekologiya. - M.: Mir, 1981. - 399 s.
11. Vaganov E.A., Hughes M.K., Shashkin A.V. Growth dynamics of conifer tree rings // Ecological studies: analysis and synthesis. - 2006. - T. 183. - R. 23-27.
12. Zykina V.S., Zykin V.S. The loess soil seqvence of the brunheschron from west Siberia and its corre-lation to global and climate records // Quaternary International. - 2008. - T. 179, № 1. - R. 171-175.
