Abstract

CALABRIA, Cecilia  and  PUNTIERI, Javier. Leaf and stem development in extension units of Nothofagus dombeyi (Nothofagaceae) under high and low light conditions. Bol. Soc. Argent. Bot. [online]. 2008, vol.43, n.1-2, pp.19-30. ISSN 1851-2372.

The size of stem and leaves was studied for trunk, main branch and short branch extension units (EU) of young Nothofagus dombeyi trees growing in open areas (road verges) and understory communities in Patagonia. The surface area and outline (width/length ratio) of single leaves along EU, the specific leaf area, and the ratios leaf area/stem volume, stem length/stem mass and stem volume/stem mass were assessed. Trunk leaves were larger than main-branch leaves and main-branch leaves larger than short-branch leaves in similar positions on the EU. Stem developed proportionally more than leaves in trunk EU than in main-branch EU and, especially, short-branch EUs. Restrictions in stem development and increases in specific leaf area would allow N. dombeyi trees to survive under shaded conditions though limiting their height growth and, consequently, their chances to reach the canopy.

Keywords : Axis categories; Coihue; Extension unit; Leaf area; Nothofagaceae; Nothofagus.

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