Comparison of polyphenol degrading enzyme activities between forest types and soil horizons from 2003 to 2004

In the southern Appalachians Rhododendron maximum thickets suppress conifer and hardwood regeneration. While there has been research on the effects of R. maximum on physical and chemical environment, the functioning of R. maximum ericoid mycorrhizas has been unexplored. The litter of ericaceous plants tends to be rich in phenolic compounds. These compounds can form recalcitrant complexes with various forms of organic N, and may be responsible for lowering decomposition and N mineralization rates. While polyphenol-organic N complexes are highly recalcitrant, some fungi, particularly ericoid mycorrhizal fungi, have the ability to access this sequestered N. Since the litter of ericaceous plants is rich in phenolic compounds and ericoid mycorrhizal fungi are equipped to degrade phenolic compounds, polyphenol-organic N complexing may represent an N cycling strategy that prevents non-ericaceous plants from accessing sources of organic N. We propose to examine the activities of polyphenol degrading enzymes in the soil of R. maximum thickets and neighboring hardwood forests.