Late Holocene environmental changes as recorded in the sediments of high Andean Laguna Chepical, Central Chile (32°S; 3050 m a.s.l.)

Abstract

© 2016 Elsevier B.V. We present a reconstruction of environmental changes from sediments of high-altitude Laguna Chepical in the subtropical Andes of Central Chile (32°16′S; 70°30′W, 3050 m a.s.l.) for the past 3100 years. Based on subfossil pollen, microscopic charcoal and diatoms, we inferred changes in moisture (related to precipitation) and ice-cover/ice-free season (related to summer temperature) at decadal to millennial scales. Sustained wetter and colder summer temperatures than today prevailed between 1100 BC and ca. AD 1. Afterward, decreasing pollen accumulation rates and increased fire activity suggest drier conditions and possibly enhanced seasonality and/or inter-annual climate variability. Frequent changes between cold and warm summers were observed, particularly for the last 1000 years. About AD 1250 (during the Medieval Climate Anomaly), wet years and early break up of ice-cover occurred in central Chile, which is today typical for El Niño-like mean conditions. Converse