The Ecology of Hydric Hammocks - USGS National Wetlands ...

locally collected litter lost 85% ofits mass in one year at a streambanksite, but only 58% annually in theterrace forest dominated by oaks(Shure et a]. 1985). The leaf decompositionrates of most floodplainspecies, including tupelo, ash, blackgum, red maple, and sweetgum, werevery rapid, but those of bald cypressand swamp laurel oak were considerablyslower (Elder and Cairns 1982; Shureet a?. 1985). Leaves that were recalcitrant to decomposition tended tohave higher carbon:nitrogen ratios andgreater concentrations of 1 ignin andcell ulose. Decomposition rates of oak1 eaves besides swamp 1 aurel were notmeasured, but they also are 1 ikely tobe slow because of similar chemicalcharacter] st~cs. Ai rnougn i i r;r;er decompositionis likely to be slow inhydric hammocks because of pl antspecies composition, low flooding frequency,and the absence of strong waterflow, probably only a small amountof 1 itter and decomposed material iswashed out by occasional floods. Theamount and form (part icul ate, dissolved)of export from a hammock dependson current velocity, the timingof floods in reiation to the seasonalpattern of litter fall, and uptakerates of dissolved nutrients by hammockplants.