Feedbacks between calcium cycling and canopy tree dynamics in a north temperate forest
There has been widespread concern that acid deposition is depleting the supply of calcium (a critical nutrient for plant growth) in the soils of northeastern U.S. forests. Tree species in those forests appear to differ strikingly in both their demand for calcium, and their effects on the availability of calcium in the soil. The proposed research will (1) determine the mechanisms by which tree species regulate the availability of Ca in the soil beneath them, (2) determine the responses of tree seedlings and saplings to variation in Ca availability, and (3) develop a quantitative, predictive model of the long-term consequences of these processes for the dynamics of northeastern forests. The research will provide a bridge between two traditionally distinct fields of forest ecology: the study of population and community dynamics of forest trees, and nutrient cycling in forest ecosystems.
