Climate And Human Impact On Vegetation In The Upper Part Of The Ussuri River Basin In Late Holocene, Russian Far East

Abstract

Changes in vegetation in the southern Sikhote-Alin Mountains, which are in the upper reaches of the Ussuri R., are shown respond to minor climatic fluctuations over the past 5.4 ka. The largest mountain, Muta mire, chosen for paleoenvironmental reconstructions, is located within the main regional watershed. The studies include diatoms and pollen analyses. Chronology is based on radiocarbon dating and position of B-Tm tephra of the Millennium eruption of Baitoushan volcano. The cooling and warming reconstructed from the regional data correlate with global paleoclimatic events. The regional humidity changes notably along with the temperature fluctuations. Fire chronology was established and its significance for vegetation was estimated. Periods of frequent forest fires coincided with reduced moisture supply during cooling events. The analysis per formed revealed a considerable human impact on the vegetation in the 20th century.

Keywords

• vegetation
• climate changes
• anthropogenic factor
• forest fires
• late holocene
• sikhote-alin