Ocupación e impacto humano en la alta montaña durante la prehistoria. Un estudio arqueoambiental de Aigüestortes (8 – 4 ka cal BP) mediante el análisis de fitolitos

This Ph.D dissertation focuses on the prehistoric settlement at high mountain areas of the western Catalan Pyrenees, particularly, in Aigüestortes i Estany de Sant Maurici National Park (Lleida). More specifically, this research work is distinguished by an innovative methodological approach, which contributes to the study on human mountain occupation during Neolithic. The archaeological method is focused to detect the activities carried out by these agropastoral populations, the natural resources exploited and the impact caused on environment. Different sedimentary deposits were studied, in order to analyse silica phytoliths. They are siliceous bodies produced by plants, used as a proxy for detecting human activities on plants and their impact on landscape. Phytolith analysis is integrated as a tool for studying the prehistoric occupations in the high-altitude areas at the Pyrenees for the first time. In addition, into an integrated bioarchaeological approach, the results obtained are interpreted taken into account other biological remains analysed in sediments, such as charcoal, pollen, diatoms and organic matter.