Climate change on the northeastern Tibetan Plateau during the past ∼ 600 years inferred from peat pollen records

A 600-year high-resolution pollen record from a peat core (FS-2010) on the Zoige Plateau was obtained to reconstruct vegetation and climate changes on the northeastern Tibetan Plateau. Surface pollen data reveal that vegetation differences are reflected in different modern pollen assemblages. Fossil pollen data indicate that alpine meadow was the dominant vegetation type on the Zoige Plateau during the Little Ice Age (LIA) from similar to 1400 to similar to 1900 AD. Pollen-based climatic reconstructions indicate climatic fluctuations during this period consistent with records from neighboring areas. Specifically, relatively "warm-wet" conditions persisted from similar to 1400 to similar to 1500 AD and similar to 1800 to similar to 1900 AD, but generally "cool-dry" conditions from similar to 1500 to similar to 1800 AD. The reconstructed temperature variations during the LIA (i.e., similar to 1400 to similar to 1900 AD) were attributed to variations in total solar irradiation. This study casts further doubt on the FG/MG (subalpine forest and shrub group/alpine meadow group) ratio as a reliable indicator of temperature reduction during the Current Warm Period (CWP; post similar to 1900 AD) due to significant anthropogenic impacts including deforestation and swamp drainage. The reconstructed patterns of precipitation in the Zoige Plateau including Flower Swamp are shown to be contingent on variations in the strength of the Asian Monsoon. (C) 2020 Elsevier B.V. All rights reserved.