Microclima y regeneración natural de Raulí, Roble y Coigüe (Nothofagus alpina, N. obliqua y N. dombeyi)

Abstract

En 74 sitios ubicados en las provincias de Bío-Bío, Malleco y Cautín (Chile) se estudió la regeneración natural de Nothofagus alpina, N. dombeyi y N. obliqua. Mediante análisis multivariados se examinan las relaciones entre presencia y brote de estados juveniles con diversas variables microclimáticas. N. alpina crece en condiciones de baja luminosidad relativa (< 27% de la luz a pleno sol), evaporación reducida y temperaturas ambientales (aire y suelo) moderadas. No soporta sitios con heladas durante el período de crecimiento vegetativo. En cambio, N. obliqua se comporta como típica especie heliófila prefiriendo sitios expuestos, con alta luminosidad y evaporación, e incluso aceptando temperaturas nocturnas cercanas al punto de congelación. Las demandas microclimáticas de N. dombeyi en la región investigada son muy similares a las de N. alpina. Se discute la clasificación ecológica de esta última especie.

Early performance of planted Nothofagus dombeyi and Nothofagus alpina in response to light availability and gap size in a high-graded forest in the south-central Andes of Chile

“…Seedlings of N. dombeyi performed better in larger gaps, and those of N. alpina in both medium-sized gaps (complete survival) and large gaps (bigger plants with significantly lower slenderness). These results support earlier suggestions that natural regeneration of N. dombeyi would respond better to larger gaps and that of N. alpina to relatively smaller gaps (Weinberger and Ramírez 2001). We have to consider, however, that the mean size of the large-gap category used for N. alpina had a rather small difference with that of the medium-gap category (only 102 m 2 ); hence, such small difference presents a limitation to interpret the effects of gap size upon the performance of N. alpina.…”

Determination of homogeneous edaphoclimatic zones for the secondary forests of Nothofagus dombeyi in central-southern Chile

“…These factors allowed for the permanent availability of soil moisture. The average temperature (10 °C or less) tended to be low for other Nothofagus species, also favoring N. dombeyi in this region, as reported by Weinberger and Ramírez (2001) for an elevation range from 700 to 800 m.a.s.l. At these elevations and above, N. dombeyi forest stands tend to be pure due to their greater tolerance to low temperatures compared with other species (Weinberger and Ramirez, 2001, Donoso et al, 1999), except when it meets with N. pumilio at elevations > 1000 m (Donoso et al, 2006).…”

Growth-unit structure in trees: effects of branch category and position on Nothofagus nervosa, N. obliqua and their hybrids (Nothofagaceae)

“…Both species regenerate from seeds under canopy gaps in native forests. The higher frequency of saplings of N. nervosa than N. obliqua under the canopy of older trees (Weinberger and Ramírez 2001) and their photosynthetic responses to different light levels (Read and Hill 1985) suggest that the former species is more shade-tolerant than the latter (see also Donoso et al 2006a, b). Among the architectural differences between N. nervosa and N. obliqua, only the more notable apical dominance and rectitude of the trunk and main branches in N. nervosa than in N. obliqua have been remarked (Destremau 1988;Tuley 1980).…”