An ecological framework to establish management boundaries for silvopastoral systems. 1- The case of ñire forests of northern Patagonia, Argentina

RUSCH, VERÓNICA; LÓPEZ, DARDO; CAVALLERO, LAURA; RUSCH, GRACIELA; PERI, PABLO; CARDOZO, ANDREA; HANSEN, NIDIA; VON MÜLLER, AXEL; GARIBALDI, LUCAS A.; SARASOLA, MAURO

Iguazú

Congreso; 3º Congreso Nacional de Sistemas Silvopastoriles / VIII Congreso Internacional de Sistemas Agroforestales; 2015

Native forests and silvopastoral systems are shaped by anthropogenic use, so it is necessary to understand their dynamics and the consequences of management to keep the system between desired conditions. The aim of this study is to develop a State-and-Transition-Model (S&TM) for northern Patagonia ñire forests. Under silvopastoral use. We reviewed the literature describing vegetation communities of northern ñire ecological sites and historical information about natural disturbances and case studies of management practices, The model was further built in an experts workshop and ground-truethed with field surveys. We defined 8 states, 14 negative and 5 positive transitions, factors that trigger the former (associated with grazing, fire and intensive logging) and their levels. Ñire forests with bamboo are considered the reference state, with least anthropic intervention, and the state characterized by dwarf shrub steppe with dominance of Acaena splendes was the most degraded state. Intermediate states were the most suitable for silvopastoral use (open forests with bamboo and grassland, and ñire forest with grassland). Most transitions were irreversible, even by using costly techniques (tree plantation and protection from grazing, shrub removal). In the future, we aim to improve the definition of ?critical phases? for a more precise early warning system of degradation. The development of the S&TM enabled us to gather dispersed information on long-term vegetation changes in a simple way. S&TMs are seen as an interesting tool to help maintain forest structure and composition within the boundaries of productive and environmental value.