Biotic Control of Calcium Supply: Distinguishing Sources to Regrowing Forests

Suny College Of Environmental Science And Forestry, Syracuse NY

Investigators

Abstract

ABSTRACT: The effects of forest management, and the changes associated with stand development, have not been given sufficient emphasis in studies of environmental stress in forested ecosystems. Calcium budgets indicate that young northern hardwood stands (<30 yrs old) transfer Ca from mineral soil into aboveground vegetation, forest floor, and drainage water, whereas older stands are in approximate steady state. This difference is important to understanding the relative importance of acid rain in Ca depletion in the northeastern United States. Futhermore, if young stands tap a pool of soil Ca unavailable to older stands, then repeated harvest will not result in rapid Ca depletion, as has been predicted based on rates of export and weathering in older stands. If, on the other hand, rapid Ca uptake by young stands hastens the depletion of readily available pools, sustainable forestry may be threatened. Our objectives are to determine the importance of non-silicate sources of weatherable Ca in the mineral soil, and the effect of stand age on the source and magnitude of Ca mobilized from the mineral soil. We will use Sr isotopes and element ratios to identify the relative importance of different soil Ca pools to meeting the Ca needs of regenerating forests. BROADER IMPACTS: Multiple Universities will be involved in this research through subcontracts, and at least 3 graduate students and 2 undergraduates will be trained. This work will provide information that will enable forest managers and policy makers to maker better decisions about silviculture.