Forest Floor Functional Group Chemistry 21-Years Following Silvicultural Prescriptions In a Northern Forested Wetland.

The forest floor is important in governing carbon and nutrient cycling in forest ecosystems. This presentation reports on changes in forest floor functional group chemistry using Fourier-Transform Infrared Spectroscopy (FTIR) 21-years after whole-tree harvesting and site preparation bedding and disc-trenching in a coniferous forested histic-mineral wetland in the Upper Peninsula of Michigan. Forest floor carbon and nitrogen concentrations were highest in the whole-tree harvested treatment than the bedded or trenched treatments. FTIR results showed that forest floor from all three treatments consisted of carbohydrates, aromatic esters, aliphatic, and alkyl carbon compounds. However, forest floor from the WTH only treatments was more complex, and presumably less easily decomposable than that from either silvicultural prescription.  The study also points to the importance of increasing carbon and nitrogen recovery following silvicultural disturbance to replenish slowly degradable forest floor carbon fractions.