Acidic atmospheric deposition is an ongoing occurrence throughout the United States.  Recently, it has been suggested that this deposition may be accelerating calcium depletion in base-poor ecosystems. The response of these forests to calcium depletion is not clear. Different tree species have been found to dominate sites according to Ca status. Along with the influence of geology on soil chemistry, it has been suggested that the trees themselves may alter soil chemistry. It appears that sugar maple may elevate the amount of exchangeable calcium in the soil under certain conditions. 

Calcium depletion has been noted as a predisposing factor for decline disease of sugar maple in eastern forests and also as a possible limiting factor for seedling establishment.  Yet sugar maple can be found in the Yellow Creek watershed with soil base saturation levels of less than 2%. With its low base saturation, Yellow Creek may be considered an end member for the effects of acidic deposition on forest soils in the Northeast. I am interested in describing how sugar maple exists in this base poor system as compared to systems with higher base status.  Investigating the influence of geology and tree species on soil chemistry and the implications this may have for seedling mortality may ultimately lead to clues as to how forest composition could be affected by calcium depletion.