Early anthropogenic change in western Mediterranean mountains (Sierra Nevada, SE Spain)

Human impact on western Mediterranean mountains is gaining more attention, as they harbour a rich plant diversity threatened by global change. This paper presents an analysis of two pollen records from both sides of Sierra Nevada, the prime plant-diversity centre of the Mediterranean, spanning the last 5400 years. The analysis sought to answer the following key questions: When did natural systems transform to cultural landscapes? What was the intensity and extent of alterations driven by the diverse civilizations? A compilation of archaeological and paleaeoclimatic data supported this analysis, as well as a multi-proxy palaeoecological study using pollen, non-pollen palynomorphs and microcharcoal, searching for the imprint that diverse societies left on these mountains. Results suggest that human influences started earlier than expected, with a strong impact on forest cover, oriented more towards crops on the southern face and towards livestock on the northern one, whereas mining and metallurgy were initial key drivers of population dynamics. Irrigation has supported farming since at least the Islamic period. More recent anthropogenic control and land-use management have allowed a further spread of the tree cover. Proper conservation strategies need long-term perspectives, including palaeoecological studies. The preservation of traditional human activities like grazing, high-elevation cropping or irrigation systems become essential to maintain current biodiversity. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study analyzed two pollen records from both sides of Sierra Nevada in the western Mediterranean, revealing the early human impact on these mountains, including changes in forest cover, agriculture, livestock, mining, and metallurgy. The results suggest that human activities started earlier than expected and have had significant influences on the landscape and biodiversity of the region. Proper conservation strategies should consider long-term perspectives and the preservation of traditional human activities to maintain current biodiversity.