RETENTION OF COARSE ORGANIC PARTICLES IN STREAMS IN THE SOUTHERN APPALACHIAN MOUNTAINS

Retention of coarse particulate organic matter (CPOM) is essential to the efficient use of organic matter in streams supported by allochthon ous inputs. To measure retention and to study factors affecting retent ion, we conducted both long-term and short-term experiments using smal l dowels as indices of stick retention and pieces of paper as indices of leaf retention. These experiments were done in streams at Coweeta H ydrologic Laboratory. In general, we found that both types of CPOM wer e efficiently retained in all streams. Factors that affected CPOM tran sport and retention were storms, stream size, stream depth, and the ab undance of retention structures in the streams. After initial transpor t, woody CPOM was transported only during storms. Retention was greate r in smaller streams and in shallower stream sites. Rocks, boulders, a nd woody debris were the most important retention structures. In the s tream draining a logged catchment, lower CPOM retention was associated with lower abundance of woody debris dams.