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ECOTONE SHIFT AND MAJOR DROUGHTS DURING THE MID–LATE HOLOCENE IN THE CENTRAL TIBETAN PLATEAU
Author(s) -
Shen Caiming,
Liu Kam-Biu,
Morrill Carrie,
Overpeck Jonathan. T.,
Peng Jinlan,
Tang Lingyu
Publication year - 2008
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1890/06-2016.1
Subject(s) - ecotone , holocene , plateau (mathematics) , geography , physical geography , ecology , climatology , geology , biology , archaeology , habitat , mathematical analysis , mathematics
A well‐dated pollen record from a large lake located on the meadow–steppe ecotone provides a history of ecotone shift in response to monsoonal climate changes over the last 6000 years in the central Tibetan Plateau. The pollen record indicates that the ecotone shifted eastward during 6000–4900, 4400–3900, and 2800–1600 cal. yr BP when steppes occupied this region, whereas it shifted westward during the other intervals when the steppes were replaced by meadows. The quantitative reconstruction of paleoclimate derived from the pollen record shows that monsoon precipitation fluctuated around the present level over the last 6000 years in the central Tibetan Plateau. Three major drought episodes of 5600–4900, 4400–3900, and 2800–2400 cal. yr BP are detected by pollen signals and lake sediments. Comparison of our record with other climatic proxy data from the Tibetan Plateau and other monsoonal regions shows that these episodes are three major centennial‐scale monsoon weakening events.