Modeling terrestrial ecosystems on the global scale demands the development of simple, generalized representations of important plant processes that can be used in different biomes with minimal change. However, the sophistication and complexity of this task requires models of various domains of space and time resolution which, in turn, requires emphasis on different ecological and biophysical processes. We have developed a family of coniferous forest process models over the last several years and have used them on a variety of spatial and temporal scales to address important ecological questions. What began as a single-tree daily water-balance model run for I year is now an integrated carbon, nitrogen, and water cycle model with dual timestep resolution run for 100 years. With FOREST-BGC (biogeochemical cycles) em bedded in our Regional Ecosystem Simulation System (RESSys) with a microclimate simulator (MTCLIM) and satellite definition of the vegetation, we now map ecosystem processes such as photosynthesis, respiration, evapotranspiration, decomposition, and nitrogen mineralization over landscapes of hundreds of square kilometers (Running et al., 1989). We now use these models to calibrate simple models for global implementation using satellite data.