Linking DOC and DON Fluxes to Soil Properties at Watershed and Landscape Scales

University Of New Hampshire, Durham NH

Investigators

Abstract

Recent work by the PI's shows that at a global scale, soil carbon:nitrogen (C:N) is a very strong predictor of dissolved organic carbon (DOC) losses in surface runoff. If this relationship holds at the watershed and landscape scale, then soil C:N would provide a powerful tool for predicting and modeling changes in DOC flux. In this project, the PIs will examine the nature of the relationship between soil properties and DOC flux in wet tropical forests of Puerto Rico, the northern mixed forests of New Hampshire and a heath/moorland in Scotland. The proposed research examines the value of soil D:N in predicting variability in DOC flux within the three ecosystems, and also examines some of the underlying physical and biological mechanisms which may be responsible for the linkage between DOC flux and soil C:N recently documented at the global scale. The research will include empirical and modeling components and is expected to result in a better understanding of the mechanisms regulating DOC losses in tropical and temperate sites. The broader implications of this work relate to watershed management in that dissolved organic carbon and nitrogen have important effects on surface water quality. Trace metal solubility, formation of trihalomethanes in drinking water supplies, and pesticide transport are all linked to DOC levels.