Resumo

REQUENA-ROJAS, E. J.  e  TAQUIRE ARROYO, A.. Wood anatomy and characterization of tree-rings in individuals of Polylepis tarapacana in the Altiplano – Tacna - Peru. Quebracho (Santiago del Estero) [online]. 2019, vol.27, n.2, pp.66-66.  Epub 01-Mar-2019. ISSN 0328-0543.

The objectives of this work were to describe the log and characterize anatomically the growth rings of individuals of P. tarapacana that grow at 4400 m of altitude in the Tacna Highlands. The samples were collected from Kallapuma, district of Tarata, the Tacna region. Three trees were selected randomly and a slice of the trunk at 0.30 m in height obtained from each. In describing their wood, the methodology of the IAWA Committee was used. The Standard List Inferential statistics, the Student's "T" test at 95 % confidence interval, were used to compare the vascular elements of both the heartwood and the sapwood. The woods showed growth rings made up of very thick walled, and radially shortened cells (fibers) which conforms the latewood, darker in color. In turn, the earlywood appeared as thick to medium thick light-colored cells (fibers) and oval, polygonal or circular in shape. The fibers were short and of medium diameter; the pores were excessively numerous; the radii wide and the vessel elements presented simple perforation plate. A highly significant statistical difference was found between the lengths of the late- and early-wood fibers (P-value = 0.0001) as much as that between fiber diameter (P-value = 0.03) and wall thickness (P-value = 0.02) was observed. The characteristics concerning porosity, vessels and fibrotracheids suggest that P. tarapacana adapted to grow in arid places. This study could pave the way for eco-physiological studies and give answer to the differences in growth as response to precipitation and temperature in different sites of the Altiplano.

Palavras-chave : anatomy; wood; dendrochronology; growth-ring.

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