Modelo de simulación de producción de materia seca y concentración de proteína bruta de gramíneas creciendo en bosques de Nothofagus antarctica (G. Forster) Oerst. bajo uso silvopastoril

Ecología Austral, 24:111-117 (2014) Nothofagus antarctica (ñire) occupies a significant fraction of the Southern Patagonian forests and are often used as silvopastoral systems. It lacks, however the information to make optimal and sustainable use of these systems. In this work we modeled the production of dry matter (DM) and the variation in the concentration of crude protein (CP) of grasses in silvopastoral systems in ñire forests, considering environmental variables (air and soil temperature, air humidity, soil moisture, site quality, crown cover, including) and applying existing and own information. The model was focused on the scale of stand considering a homogeneous and coeval population of ñire under conditions of southern Patagonia (Santa Cruz and Tierra del Fuego). Model sensitivity analysis showed that the most important parameter were the stand site quality on DM and the soil temperature on the CP. We found a significant lineal correlation for DM (R=0.52; P<0.001, average underestimation 22%) and CP (R=0.47; P<0.001, average overestimation 24%) when real and estimated values from the model were compared. The results of the simulations were coherent with empirical data in regard to the environmental variables and management of the stand affecting DM and CP of the understory, and suggest that the model is acceptable for use as a guiding tool in the management of understory grasses in ñire forests.