Shredder abundance and leaf breakdown in an Appalachian Mountain stream

SUMMARY. Breakdown rates of dogwood ( Cornus florida L.), red maple ( Acer rubrum L.) and white oak ( Quercus alba L.) leaves were investigated at two first‐order and two second‐order sites in an Appalachian Mountain stream. Leaves exposed in mesh bags were sampled on eight occasions over a 207 day period and breakdown rates were compared using an exponential decay model. There was a consistent ranking in leaf breakdown rate within each site, i.e. dogwood > red maple > white oak, and all species broke down faster at second‐than at first‐order sites. Our data suggest that differences in species‐specific leaf breakdown rates were largely a function of shredder abundance on the leaves.