In the late 1980's, the Garden of Eden Study was established to test the effects of repeated fertilizer applications (F), competing vegetation control via application of herbicide (H), and the combined effects of each type of treatment (HF) on productivity of ponderosa pine (Pinus ponderosa (Dougl. ex Laws.)) in Northern California. Treatment effects on aboveground biomass are striking. For example, At the Whitmore Garden of Eden Site, located on the western slopes of the Southern Cascades, fifteen-year standing bole volumes were 15.4, 38.9, 64.1, and 91.7 m3 ha-1 in no treatment control (O), F , H, and HF plots, respectively. The study provides a unique opportunity to investigate the effects of plantation management on belowground carbon storage and dynamics. We selected three Garden of Eden Study sites, encompassing the range in site quality found in the California Westside Ponderosa Pine Region. At these sites, we assessed total belowground C storage to one meter depth, C distribution amongst belowground pools, and indicators of surface soil organic matter quality 18 years after plantation establishment. Fertilization increased the forest floor C pool at all three sites an average of 1.5 times (p < 0.001) regardless of competing vegetation control. Competing vegetation control only affected the forest floor C pool at the poorest quality site, where herbicide application increased the pool by about 1.5 times (p = 0.03). Fine root biomass and soil C to one meter depth and surface organic matter quality will also be presented and discussed.