Producción y calidad de gramíneas en un gradiente de calidades de sitio y coberturas en bosques de Nothofagus antarctica (G. Forster) Oerst. en Patagonia

62-73The aim of the present study was to quantify the dry matter and crude protein concentration of grasses in different radiation levels and its variation over time, in Nothofagus antarctica (ñire) forests under silvopastoral use growing in contrasting environmental conditions in Southern Patagonia (Argentina). Biomass was clipped monthly for two growing seasons in five ñire stands corresponding to different site quality in three positions (radiation level) beneath crown, in between crown and in an adjacent area without trees. We additionally quantified photosynthetic active radiation, air and soil temperature, relative air humidity and soil moisture. Forage production varied between 135 to 1800 kg/ha, and was positively correlated with site quality. The effect of environmental variables over forage production depended on each site and year; however in most cases the aboveground biomass inside the forest was equal or higher than that of the adjacent areas without trees. The protein content of grasses was higher inside the forest, in the higher site quality stands, decreased throughout the growing season and was positively associated with soil moisture at all sites. The results suggest that silvopastoral use of ñire forests at intermediate crown covers may be desirable from the standpoint of forage production and quality