Late Holocene vegetation dynamics of the Muravyev-Amursky Peninsula (on the basis of soil-profile palynological data)

1 Far Eastern Federal University, Vladivostok, Russia
3 Pacific Geographical Institute FEB RAS, Vladivostok, Russia

In order to explore vegetation dynamics of Muravyev-Amursky Peninsula in late Holocene, we sampled the Southern, Western, and Eastern areas using a test pit in each area (5-09, 7-09, 3-09 respectively). Analysis of spore-pollen spectra of genetic horizons was carried out for polygenetic burozems or PB (the burozem profile comprises one modern and one buried elementary soil profile). Palynological data allowed us to reconstruct paleoclimatic conditions of Muravyev-Amursky Peninsula by Klimanov's (1981) informational-statistical method, based on statistical correspondence between the percentage of different taxon pollens in present-day pollen complexes and climatic conditions, under which the said complexes were formed. Spore-pollen spectrum compositions of PB genetic horizons in each sample area give evidence of anthropogenic influence on vegetation dynamics, resulting from intense logging of coniferous-broadleaved forests when the Peninsula was cultivated. Subsequent fires and developing erosion and solifluction contributed to formation of polygenetic burozems; PB formation was also due to severe climatic conditions of the final phase of the Short Ice Age. The age of PB buried humus-accumulative horizon [AY] fully agrees with this thesis (test pit 5-09 - 150±60 years old (Ki-16630)). Spore-pollen spectra of horizons BM[AY] (test pit 5-09), [AYBM] (test pit 3-09), and [BM] (test pit 7-09) indicate colder-than-modern climatic conditions which gave rise to birch forests with fern-herb ground cover. These horizons are characterized by high content of soil skeleton matter and stone material, which is the result of severe climatic conditions, prevailing at the time of horizon formation. Overall, our research data show that the Peninsula vegetation dynamics in late Holocene is due to both anthropogenic and climatic factors. This research is supported a grant of the Russian Foundation for Basic Research, project no. 12-05-00017 and by grants of the Far Eastern Branch of Russian Academy of Sciences, project no. 12-III-A-09-208, 12-III-B-09-200.

© 2012 Organizing Committee