Micro-environmental changes induced by shape and size of forest openings: effects on Austrocedrus chilensis and Nothofagus dombeyi seedlings performance in a Pinus contorta plantation of Patagonia, Argentina

PAFUNDI L.; URRETAVIZCAYA M.F.; DEFOSSÉ G.E.

Forests systems

INIA

Año: 2016

Aim of the study: to analyze, within a Pinus contorta plantation, the effects of artificially created small rectangular and small and medium circular canopy gaps on: i) photosynthetic active radiation (PAR), and soil temperature and moisture, and ii) survival and growth of planted Austrocedrus chilensis and Nothofagus dombeyi seedlings, species which formerly composed the natural forest of the area.Study area: A 2 ha stand of  P.contorta in Los Alerces National Park, Argentina (42°43`S, 71°43`W, 490 m.a.s.l.).Material and methods: The Pinus contorta stand was 25 yr old, 22 m height and 26 cm DBH, presenting 1000 treesha-1 of density and 53 m2 ha-1 of basal area. In2009, rectangular and circular gaps were created within the stand and then seedlings were planted. During two growing seasons (2010-2011 and 2011-2012),PAR, soil temperature and moisture were measured in gaps and understory (control), and seedling survival and growth in gaps.Main results: During both seasons, soil temperature did not differ among gaps and control, whereas PAR and soil moisture were lower in control. Seedling survival was high in all gaps regardless of species and season. Seedlings showed higher diameter growth in rectangular than in circular gaps.