Föhn, fire and grazing in Southern Tibet? A 20,000-year multi-proxy record in an alpine ecotonal ecosystem

Miehe, Georg; Hasson, Shabeh ul; Glaser, Bruno; Mischke, Steffen; Böhner, Jürgen; van der Knaap, Willem O.; van Leeuwen, Jacqueline F.N.; Duo, La; Miehe, Sabine; Haberzettl, Torsten (2021). Föhn, fire and grazing in Southern Tibet? A 20,000-year multi-proxy record in an alpine ecotonal ecosystem. Quaternary science reviews, 256, p. 106817. Elsevier 10.1016/j.quascirev.2021.106817

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The lithology, ostracods, palynomorphs and black carbon of a sediment core from a saline wetland in the southern Tibetan highlands (29°14′33.40″N/87°13′09.10″E, 4480 m a.s.l., A.R. Xizang, China) is analyzed and climate modelling applied with respect to core questions in Quaternary research: (1) Do meso-climatic effects of regional landscape structures like high mountains overrule the effects of global climates? (2) Did life persist during the LGM? (3) Which shifts in ecosystems can be detected? (4) Does the fire-record testify for the presence of humans and their environmental impact? (5) How old is Neolithisation in the world’s largest highlands?

The results of this integrated multi-disciplinary investigation revealed (1) the meso-climatic effect of the Himalayan arc’s relief channeled westerlies with West-Himalayan forest-pollen types into the southern Tibetan highlands, with (2) higher winter-precipitation, slightly lower summer precipitation, and the persistence of life for plants, and herbivores and therefore probably hunters. (3) The most arid period occurred between 17.8 and 15 cal kyr B.P., possibly synchronous with the Heinrich 1 event. Around 14.8 cal kyr B.P. humidity increased with torrential rains of high erosive power on sparsely plant-covered slopes and lasted until 4 cal kyr B.P. (4) The continuous fire-record proved the availability of combustible matter and a constant fire source which is believed to be human-attributed. Charcoal peaks around 17, 16 and 13 cal kyr B.P. remained sporadic until 11.5 cal kyr B.P. and attained the highest values since 8.7 cal kyr B.P. Black carbon increased steadily until 11 cal kyr B.P. and sharply peaked with high fluctuations around 10 cal kyr B.P., indicating high frequency intensive fires at the beginning of the Holocene. Between 10 and 6 cal kyr B.P. fire frequency decreases, with a slight peak around 4 cal kyr B.P. (5) The dawn of pastoralism in the early Mid Holocene Climatic Optimum dated back to 8.7 cal kyr B.P. with a decline of grass-pollen and the synchronous emergence of grazing weeds, leaving a perception gap of 5000 years between the palaeo-ecological and the archaeological state of the art.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Palaeoecology
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

van der Knaap, Pim and van Leeuwen, Jacqueline

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

0277-3791

Publisher:

Elsevier

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

11 Jun 2021 10:35

Last Modified:

13 Jun 2021 03:09

Publisher DOI:

10.1016/j.quascirev.2021.106817

Uncontrolled Keywords:

Qinghai-Tibet-Plateau; Palynology; Ostracods; Black carbon; Climate modelling; Last Glacial Maximum; Holocene; Anthropocene; Neolithisation

BORIS DOI:

10.48350/156440

URI:

https://boris.unibe.ch/id/eprint/156440

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