Estimation of potential forest productivity across the Oregon transect using satellite data and monthly weather records

Detailed physiological and micrometeorological studies have provided new insights that greatly simplify the prediction of gross photosynthesis ( P G ) and the fraction of production that goes into above-ground net primary production (NPPA). These simplifications have been incorporated into a process-based forest growth model called 3-PGS (Physiological Principles Predicting Growth with Satellite Data). Running the model requires only monthly weather data, an estimate of soil texture and rooting depth, quantum efficiency ( f ), and a satellitederived Normalized Difference Vegetation Index (NDVI) correlated with the fraction of visible light intercepted by foliage. The model was originally tested in Australia where seasonal variation in NDVI is extreme. In Oregon, NDVI varies much less seasonally and fully stocked coniferous stands maintain nearly constant canopy greenness throughout the year. We compared 3-PGS estimates of P G and NPPA across a steep environmental gradient in western Oregon where groundbas...