Jennifer Kitchel Long-term studies of the movement and storage of nutrients in forests, soils and streams at the Hubbard Brook Experimental Forest indicate that calcium has been depleted from soils over the last 50 years. Loss of base cations reduces percent base saturation and diminishes soil fertility. Calcium is the predominant base cation in soils and stream water. In New England ecosystems, calcium is primarily derived from the weathering of calcium-silicate minerals present in glacial till or bedrock. Calcium is an essential plant nutrient required for the formation of cell walls and membranes, the synthesis of important compounds and the regulation of cell permeability.
Trees require calcium to form wood.
Calcium also acts as a buffer, neutralizing inputs of acid from precipitation. The calcium was added in the form of Wolastonite, a calcium silicate mineral, to match natural sources of calcium at the site as closely as possible. The Wollastonite was applied by helicopter in one ton increments. Prior to the application it was pelletized with a biodegradable binder to minimize wind dispersal. Over the next 50 years, researchers at HBEF will investigate the response of soil, water and forest organisms to the addition of calcium.