Tree rings point to drought as trigger of social conflict

This fact sheet describes research using Polylepis tarapacana tree rings to reconstruct precipitation on the Bolivian Altiplano, linking a severe drought starting in 1316 to a shift from vulnerable valley villages to fortified hilltop settlements (Pukaras) due to social conflict over water.

• Analysis of Polylepis tarapacana tree rings, which are highly sensitive to rainfall, allowed researchers to reconstruct annual precipitation on the Bolivian Altiplano back to 1290, revealing a history of severe droughts in the 14th century.
• A long drought period between 1316 and 1371, the longest recorded in the past 700 years, coincided with the abandonment of vulnerable valley floor villages in favor of fortified hilltop sites known as Pukaras, suggesting that water scarcity for irrigation and consumption triggered social conflict.
• Current trends on the Altiplano since the 1950s include persistent warming and unprecedented glacier shrinkage, which, combined with population growth and increasing water demands from mining and agriculture, increase the risk of future water shortages and potential political and economic conflict.

APA

Inter-American Institute for Global Change Research (2012). Tree rings point to drought as trigger of social conflict. https://iai.int/admin/site/sites/default/files/uploads/2014/06/snapshot11_EN.pdf

Chicago

Inter-American Institute for Global Change Research. Tree rings point to drought as trigger of social conflict. 2012. https://iai.int/admin/site/sites/default/files/uploads/2014/06/snapshot11_EN.pdf.

Wikipedia

{{cite report |author=Inter-American Institute for Global Change Research |title=Tree rings point to drought as trigger of social conflict |date=2012 |url=https://iai.int/admin/site/sites/default/files/uploads/2014/06/snapshot11_EN.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{interamericaninstituteforglobalchangeresearch2012tree, author = {{Inter-American Institute for Global Change Research}}, title = {{Tree rings point to drought as trigger of social conflict}}, institution = {Inter-American Institute for Global Change Research}, year = {2012}, url = {https://iai.int/admin/site/sites/default/files/uploads/2014/06/snapshot11_EN.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }