Four millennia of vegetation and environmental history above the Hyrcanian forest, northern Iran

Homami Totmaj, Leila
Ramezani, Elias
Alizadeh, Kammaledin
Behling, Hermann ORCIDiD

DOI: https://doi.org/10.1007/s00334-020-00813-y
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11796
Homami Totmaj, Leila; Ramezani, Elias; Alizadeh, Kammaledin; Behling, Hermann, 2020: Four millennia of vegetation and environmental history above the Hyrcanian forest, northern Iran. In: Vegetation History and Archaeobotany, 30, 5, 611-621, DOI: https://doi.org/10.1007/s00334-020-00813-y. 
 
Homami Totmaj, Leila; Department of Palynology and Climate Dynamics, Albrecht-Von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
Ramezani, Elias; Department of Forestry, Faculty of Natural Resources, Urmia University, Urmia, Iran
Alizadeh, Kammaledin; Department of Palynology and Climate Dynamics, Albrecht-Von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
Behling, Hermann; Department of Palynology and Climate Dynamics, Albrecht-Von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany

Abstract

Past vegetation, fire, and climate dynamics, as well as human impact, have been reconstructed for the first time in the highlands of the Gilan province in the Alborz mountains (above the Hyrcanian forest) for the last 4,300 cal yrs bp. Multi-proxy analysis, including pollen, spores, non-pollen palynomorphs, charcoal, and geochemical analysis, has been applied to investigate the environmental changes at 2,280 m a.s.l., above the Hyrcanian forest. Dominant steppe vegetation occurred in the study area throughout the recorded period. The formation of the studied mire deposits, as well as vegetation composition, suggest a change to wetter climatic conditions after 4,300 until 1,700 cal yrs bp. Fires were frequent, which may imply long-lasting anthropogenic activities in the area. Less vegetation cover with a marked decrease of the Moisture Index (MI) suggests drier conditions between 1,700 and 1,000 cal yrs bp. A high proportion of Cichorioideae and Amaranthaceae, as well as the reduction of trees, in particular Fagus and Quercus, at lower elevations, indicate human activities such as intense livestock grazing and deforestation. Soil erosion as the result of less vegetation due to dry conditions and/or human activities can be reconstructed from a marked increase of Glomus spores and high values of K and Ti. Since 1,000 cal yrs bp, the increasing MI, as well as the rise of Poaceae and Cyperaceae together with forest recovery, suggest a change to wetter conditions. The occurrence of still frequent Cichorioideae and Plantago lanceolata along with Sordaria reflect continued intense grazing of livestock by humans.