N 2 Fixation Associated with Decaying Leaves of the Red Mangrove ( Rhizophora mangle )

Abstract
N2(C2H2) fixation was associated with decaying leaves of R. mangle. The process was predominantly anaerobic, with about 2/3 of the nitrogenase activity being light dependent. Average N2 fixation rates in the light were 11 .mu.g of N/g (dry weight) per h for leaves that had decayed for 2-3 wk. This N input is probably significant in the estuarine, detrital food chains linked to R. mangle.