Carbon and Nutrient Dynamics of Downed Woody Debris in a Northern Hardwood Forest

• Main Author: Rudz, Philip
• Other Authors: Caspersen, John
• Language: en_ca
• Published: 2013
• Subjects: downed woody debris; modeling; carbon; wood decay; wood respiration; dissolved organic carbon; leaching; nitrogen; hardwood; forestry; 0478
• Online Access: http://hdl.handle.net/1807/43319

Downed woody debris (DWD) is a carbon-rich form of forest litter and plays a unique role in carbon and nutrient cycling. I present a novel modeling approach describing DWD decomposition and nutrient storage in a managed northern hardwood forest. The predicted half-life of DWD carbon was 7 years, less than previously observed in similar northern hardwood forests. A stage-based nutrient model indicated that harvest slash DWD was a net nitrogen and phosphorus sink for eight years following harvest and accumulated calcium during decay. Field observations of respiration and leaching supported model results with a respired C half-life of 8 years, while leached carbon export constituted 1.37% of the respired flux. DWD leachate carbon and nitrogen concentrations were 11× and 2× greater than from litter, respectively, and DWD leachate contributed disproportionately to soil C stocks. This work represents an expedient means of forecasting DWD abundance and partitioning carbon flux from DWD.