Nitrogen Fixation (Acetylene Reduction) Associated with Decaying Leaves of Pond Cypress (Taxodium distichum var. nutans) in a Natural and a Sewage-Enriched Cypress Dome

摘要: Surface litter from a natural and sewage-enriched cypress dome in north-central Florida showed pronounced seasonal pattern of nitrogenase (acetylene reduction) activity associated with leaf fall deciduous trees the domes. Samples peat cores indicated negligible below surface layer. Integrating monthly rates nitrogen fixation (based on theoretical molar ratio 3:2 for C(2)H(4)/NH(3)) yielded 0.39 0.12 g N/m per year fixed domes, respectively. The first 3 months after represented about 14% increment decomposing leaves, but contributed amount (<1%) to dome.