Late glacial and early Holocene hydroclimate variability in northwest Iran (Talesh Mountains) inferred from chironomid and pollen analysis

Cyril Aubert, Elodie Brisset, Morteza Djamali, Arash Sharifi, Philippe Ponel, Belinda Gambin, Tayebeh Akbari Azirani, Frédéric Guibal, Hamid Lahijani, Abdolmajid Naderi Beni, Jacques Louis de Beaulieu, Ali Pourmand, Valérie Andrieu-Ponel, Alain Thiéry, Emmanuel Gandouin

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

We reconstructed the paleohydrologic and climatic history of the Lake Neor region, NW Iran, from the end of the late glacial to the middle Holocene (15,500–7500 cal yr BP). Subfossil chironomid and pollen assemblages in a sediment core from a peatland located south of Lake Neor enabled identification of four main hydrologic phases. The period 15,500–12,700 cal yr BP was characterized by a relatively dry climate with an open landscape, suggested by the abundance of Irano-Turanian steppe plants (e.g. Amaranthaceae, Artemisia and Cousinia). Dominance of several shallow-water and semi-terrestrial chironomid taxa (e.g. Pseudosmittia, Smittia/Parasmittia and Paraphaenocladius/Parametriocnemus) during this period is indicative of lower water tables in the wetland. Between 12,700 and 11,300 cal yr BP, chironomid taxa indicate higher wetland water tables, as suggested by the presence of Zavrelia, Chironomus anthracinus/plumosus-type and Micropsectra, which are inhabitants of open-water, lacustrine areas. The open-steppe vegetation remained dominant in the watershed during this time. Increasing wetland moisture could be explained by: (1) cool summers that reduced the evaporation rate; and/or (2) a decrease in duration of the summer dry season. The period 11,300–8700 cal yr BP was characterized by lower wetland moisture, contemporaneous with a delay in the expansion of deciduous forest, suggesting persistent dry climate conditions throughout the beginning of the Holocene, which may have been related to the intensified seasonality of precipitation. Around 8700 cal yr BP, higher wetland water levels, inferred from chironomids, occurred simultaneously with the onset of regional deciduous forest expansion, probably caused by a shortening of the summer dry period. We concluded that chironomids are appropriate paleoecological proxies to investigate global and local hydrologic variability in the Middle East.

Original languageEnglish (US)
Pages (from-to)151-167
Number of pages17
JournalJournal of Paleolimnology
Volume58
Issue number2
DOIs
StatePublished - Aug 1 2017

Keywords

  • Climate change
  • Irano-Touranian steppe
  • Lake Neor
  • Middle East
  • Paleohydrology
  • Seasonality

ASJC Scopus subject areas

  • Aquatic Science
  • Earth-Surface Processes

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    Aubert, C., Brisset, E., Djamali, M., Sharifi, A., Ponel, P., Gambin, B., Akbari Azirani, T., Guibal, F., Lahijani, H., Naderi Beni, A., de Beaulieu, J. L., Pourmand, A., Andrieu-Ponel, V., Thiéry, A., & Gandouin, E. (2017). Late glacial and early Holocene hydroclimate variability in northwest Iran (Talesh Mountains) inferred from chironomid and pollen analysis. Journal of Paleolimnology, 58(2), 151-167. https://doi.org/10.1007/s10933-017-9969-8