This is also some very important information regarding the Medieval Warming Period.
It connects the MWP to Peru and thus goes some distance to disproving the "hockey stick's" acertion that the MWP was a Eurpoean event and not global.
**edit** This paper is extremely important for one over riding reason. It shows that Maize was grown during the MWP above 3300 meters. That owerver ended during a cooling period in the late 16 century and has only in the last few years been reproducable. In other words, the current warming is just now approaching a level that existed for about 400 years starting around 1200 BC.
Quote:
For instance, the pollen in the cores says that there was maize being grown under the Incas around the lake at 3,300ms a.s.l. Until recently the upper level for maize around the Urubamba valley was 3,000-3,100ms. In the past few years the maize level has moved up and today there is maize being grown again above Marcacocha.
WUWT blog about the paper
http://wattsupwiththat.com/2009/07/0...u-picchu-inca/
copy of the paper
http://www.clim-past-discuss.net/5/7...5-771-2009.pdf