High-resolution pollen and magnetic susceptibility (MS) analyses have been carried out on a sediment core taken from a high-elevation alpine bog area located in Sierra Nevada, southern Spain. The earliest part of the record, from 8200 to about 7000. cal. yr BP, is characterized by the highest abundance of arboreal pollen and Pediastrum, indicating the warmest and wettest conditions in the area at that time. The pollen record shows a progressive aridification since 7000. cal. yr BP that occurred in two steps, first shown by a decrease in Pinus, replaced by Poaceae from 7000 to 4600. cal. yr BP and then by Cyperaceae, Artemisia and Amaranthaceae from 4600 to 1200. cal. yr BP. Pediastrum also decreased progressively and totally disappeared at ca. 3000. yr ago. The progressive aridification is punctuated by periodically enhanced drought at ca. 6500, 5200 and 4000. cal. yr BP that coincide in timing and duration with well-known dry events in the Mediterranean and other areas. Since 1200. cal. yr BP, several changes are observed in the vegetation that probably indicate the high-impact of humans in the Sierra Nevada, with pasturing leading to nutrient enrichment and eutrophication of the bog, Pinus reforestation and Olea cultivation at lower elevations.
- Mediterranean area
ASJC Scopus subject areas
- Earth-Surface Processes
- Earth and Planetary Sciences(all)
- Arts and Humanities (miscellaneous)