ESTUDIOS DENDROCRONOLÓGICOS EN LOS AMBIENTES HÚMEDOS DE LA PUNA BOLIVIANA

FIDEL A. ROIG; GARECA LEON, E.E.; FERNÁNDEZ, M.; MONGE, S.

Revista Boliviana de Ecología y Conservación Ambiental

Fundación Simón I. Patiño

Lugar: Santa Cruz; Año: 2001 p. 3 - 13

1997-1192

The development of tropical dendrochronology has advanced substantial during the last decade. Yet, dendrochronology has just begun to be applied in the study of Bolivian forests with this being the first tree-ring chronology for a Polylepis pepei forests. In Bolivia, Polylepis pepei occurs between 3 700 - 4 350 m in the transition zone between humid mountain forests and Puna grassland. Increment cores of P. pepei were taken from 30 trees, growing on a boulder screen at 4 000 m on the eastern side of the San Jacinto river catchment on the Cochabamba Cordillera. Growth rings in P. pepei were clearly identifiable by observation of the circular band of vessels in earlywood and fibers with radial flattened walls in latewood. A 135 year-long tree ring chronology was developed by cross-dating 29 radii from 19 trees. The average correlation between ring width series was r= 0.55, indicating a high correlation between tree growth and a common response to a single, dominant growth limiting factor. The correlation analysis between the tree-ring chronology and climate records revealed a strong dependence of the annual wood formation of P. pepei to summer temperature variability. The results demonstrate the potential of P. pepei growth rings for reconstructing environmental conditions in the cold-humid tropical environments of the Bolivian Puna.