Experimental soil metabolism responses to oxygen availability and carbon pulses

Soil metabolism rates were measured in experimental flow-through reactors (FTRs) in order to assess responses to oxygen availability (i.e., redox conditions) and pulsed inputs of bioavailable carbon. The oxygen and carbon manipulations were meant to simulate patchy conditions in the rhizosphere of Spartina alterniflora marshes. The experiment was conducted over 97 days. During the first 84 days, pulses were applied weekly and metabolic responses were measured 1 and 5 days later. After the final carbon pulse, metabolism responses were followed for another 13 days in order to assess starvation responses. We used soils from Airport marsh on Sapelo Island.