Silvopastoral Systems Based on Natural Grassland and Ponderosa Pine in Northwestern Patagonia, Argentina

This chapter summarizes the results of research conducted over the past 15 years and provides management guidelines for the development of silvopastoral systems based on ponderosa pine plantations established on natural grasslands in northwestern Patagonia, Argentina. The goals of the studies were to generate knowledge for improving environmental and production efficiency in that region. Ecological interactions among the different life forms which make up a silvopastoral system (grasses, trees and animals) were studied to determine what management system would optimize environmental resource sharing. In addition, aspects affecting environmental sustainability of the systems were analyzed, such as resource use (mainly water use) by silvopastoral components and biodiversity patterns. The results suggest that applying silvicultural practices leading to a tree canopy cover level equal to or below 50 % is compatible with proper production of natural grassland species, particularly the palatable Festuca pallescens. Animal rearing should include rotation between different areas in this type of system, where partial shade may limit grass re-growth compared to open grasslands. However, microclimatic benefits of the trees on the animals may be particularly significant, and deserve specific future research. Currently available information indicates that the studied silvopastoral systems constitute a biologically and environmentally sustainable activity in the fragile ecosystem of semiarid Patagonia.