Canopy structure analysis for estimating forest regeneration dynamics and growth in Nothofagus pumilio forests

MARTÍNEZ PASTUR G; PERI P.L.; CELLINI J.M.; LENCINAS M.V.; BARRERA M.; IVANCICH H.

ANNALS OF FOREST SCIENCE (PRINT)

EDP SCIENCES S A

Lugar: Paris; Año: 2011 vol. 68 p. 587 - 594

1286-4560

Silviculture proposals in Nothofagus pumilio forests are based on opening the canopy to stimulate natural regeneration modifying light and soil moisture. These two factors have been found the most critical affecting survival and growth. The objective was to evaluate regeneration dynamics of Nothofagus pumilio along different forest canopy structures and solar radiation transmissions. Regeneration data and seed production were obtained in 98 permanent plots established in old-growth and harvested stands along a crown cover gradient (19%-93%). Volumetric soil water content and basal area were also measured, while canopy structure and solar radiation transmission were estimated using hemispherical photographs. Saplings height was modelled using plant age, canopy structure and solar radiation transmission of the stands as explanatory variables. Natural regeneration dynamics was closely related to overstory canopy values, which determined the seed production and the successfully establishment, mortality and subsequent regeneration growths. Forest canopy structure and solar radiation transmission can be related to plant height growth through models, where regeneration founded their optimum at intermediate canopy covers (45% crown cover, 0.5 leaf area index, 26 W.m² global radiation and 65% percentage of global radiation).  These findings can be used to develop new silvicultural methods or to adjust the current practices that ensure regeneration establishment and maximize height growth at landscape level.