Precisions forestry systems are being developed for pine and eucalyptus plantations in the Southern United States and in Latin America by the Forest Nutrition Cooperative to improve the sustainability, productivity and profitability of forest management. This presentation will detail the work that has been done over the last five years to develop the fundamental links between soils, geology, climate and species needed to make precision silviculture a reality. In this approach, climatic conditions (solar radiation, temperature, rainfall) are used along with species specific ecophysiological parameters (photosynthesis, respiration, carbon allocation) to produce spatially explicit, site specific estimates of forest productivity based on detailed land classification systems that integrate geology, topography and soils data. Leaf area estimates obtained from Landsat satellite imagery are input into 3PG, an ecophysiological based process model of forest growth, to predict potential productivity, identify the climatic and soil factors that limit growth and determine the potential response to silvicultural treatments designed to ameliorate these limiting factors. The information is integrated and interpreted using GIS. This approach was developed and tested with Pinus radiata in Chile and Pinus taeda in the southern United States. The attached figure illustrates the estimates of potential productivity of Pinus radiata in Regions VII to and IX of central Chile using the approach described above. There is ongoing work with the following species: Eucalyptus grandis in Colombia, Eucalyptus nitens and Eucalyptus globulus in Chile, Pinus patula and Pinus tecunumonii in Colombia, and Pinus taeda in Argentina.