Resumo

ARGOLLO, Jaime; SOLIZ, Claudia  e  VILLALBA, Ricardo. Dendrocronological potential of Polylepis tarapacana in the Central Andes of Bolivia. Ecología en Bolivia [online]. 2004, vol.39, n.1, pp.5-24. ISSN 1605-2528.

In this paper we have investigated the dendroclimatological potential of Polylepis tarapacana (queñoa), a small tree growing in the Bolivian Altiplano and adjacent areas of Peru, Chile and Argentina (16-22°S) between 4.000 and 5.200 m elevation. Dendrocronological samples were collected on slopes of four volcanoes: Sajama, Tunupa, Caquella and Soniquera. Presently, the chronologies range between 98 and 705 years in length, and represent the highest tree-ring records worldwide. In order to determine the climatic variables controlling P. tarapacana growth, interannual variations in tree growth were compared with regional records of precipitation and temperature. Correlation functions indicate that the radial growth of P. tarapacana is influenced by precipitation during the summer previous to the ring formation. In the sampling sites, precipitation explains around 50% of the total variance in growth. Summer temperatures that increase evapo-transpiration and reduce soil water supply, are negatively correlated with tree growth. These records offer the unique opportunity for reconstructing precipitation variations across the Altiplano during the past 5-7 centuries.

Palavras-chave : Dendrochronology; tree rings; Polylepis tarapacana; Bolivian altiplano; correlation function.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )