Historia de la vegetación, ambiente y evidencia de actividad humana de los últimos 6,000 años en el lago alpino La Luna, Nevado de Toluca

The sedimentary record from alpine Lake La Luna provided evidences of the vegetation dynamics and climate change during the last 6000 cal yr BP (calibrated years before present). A combination of analyses, including palynology, geochemistry and charcoal, allow inferring changes in the plants communities and the environment. The record starts with the establishment of alpine grasslands. According to the pollen spectra, coniferous and Quercus forests developed between 6000 and 4700 cal yr BP associated to humid conditions and low fire forests frequency events. By 4700 to 2000 cal yr BP drier environments with increases in fires frequency and high abundance of Pinus pollen is recorded. During the last 2000 cal yr BP changes in vegetation includes increases in Abies and reduction in Pinus pollen that point to humid environmental conditions during the Classic (1-650 AD), whereas during the Epiclassic (650-950 AD) and the Medieval Anomaly (950 a 1300 AD) the Pinus pollen increased suggesting drier conditions. Cold climates with reduced frequency of fires events are inferred during the Little Ice Age (1300-1850 AD). Presence of maize pollen in the pollen record gives evidence human activities in the area since 4680 cal yr BP.