4000 years of human impact and vegetation change in the central Peruvian Andes - With events parallelling the Maya record?

A lake-sediment sequence from Marcacocha in the central Peruvian Andes provides a well-dated and continuous vegetation record from an area rich in Inca and pre-Inca remains over the last 4000 years. Climatic changes in this record at AD 1-100 and AD 900-1050 seem to be broadly contemporaneous with major arid events from Lake Chichancanab, Mexico, affecting the Maya civilization and corroborated by the Quelccaya and Huascaran ice cores in Peru.