Climatic influences on the apical and radial growth of Nothofagus pumilio (Nothofagaceae)

MAGNIN AMARU; PUNTIERI JAVIER; VILLALBA RICARDO

Uspallata

Encuentro; Documenting, understanding and projectin changes in the hydrological cycle in the American Cordillera; 2013

Inter-American Institute for Global Change Research

The aim of this study is to evaluate the relationships between apical (primary) and radial (secondary) growth as well as the influences of climate variations on both apical and radial growth in a native forest of Nothofagus pumilio in the north Patagonia Andes. Ring widths and the lengths and number of internodes per annual shoot for the interval 2001-2010, were measured in 40 individuals of N. pumilio at the upper treeline. There are significant relationships between primary and secondary growth, and between these traits with climate over the 10-year interval of comparison. Ring width and the lengths and number of internodes per annual shoot are influenced by climatic variations in both the current and previous year of growth. Our results reveal that temperatures in winter and spring (June-October) preceding the period of shoot extension regulate stem elongation and thickening, whereas rainfalls during summer (December to March) also influence stem elongation.