EFFECTS OF LITTER BULKING AND BAGGING ON DECOMPOSITION IN NORTHERN MICHIGAN HARDWOODS AND ASSOCIATED CLEARCUTS

Effects of bulking, bagging, and fragment loss on dry matter mass rete ntion were studied with fresh-fallen pine, oak, and maple leaf litter. Samples placed mid-December in 2-yr-old pine planations and hardwood stands were retrieved monthly without replacement, May through October the following year, Significant mass loss occurred June through Septe mber. Maple leaves decomposed faster than oak or pint, regardless of f ragment loss, Litterbags (3 mm aperture) retained enough leaf fragment s to provide results similar to non-bagged pine and oak leaves retriev ed without fragment loss, Litterbags did not affect moisture content. Bulking had no effect (pine and oak) or little effect (maple) on mass loss. compared with individual leaves retrieved without fragment loss, Decomposition was faster in the plantations than in the associated ha rdwoods, even after greater fragmentation in the plantations was consi dered. Initial leaf density las a measure of leaf quality did not expl ain patterns of decomposition or fragment loss. Faster decomposition i n the plantations was attributed to a moderately warmer environment. G reater fragmentation in the plantations was attributed to greater phys ical wind and solar energy inputs, compared to the more protected hard woods environment.