CH4 PRODUCTION IN BLANKET BOG PEAT - A PROCEDURE FOR SAMPLING, SECTIONING AND INCUBATING SAMPLES WHILE MAINTAINING ANAEROBIC CONDITIONS

A new, yet simple technique is described to obtain intact cores of bla nket bog pear whilst maintaining anaerobic conditions. Apparatus was a lso developed which allowed these cores to be sectioned (minimum slice thickness 1.0 cm) whilst excluding O-2 from the cut sections and the remaining core material. Using these procedures the vertical distribut ion of methanogenesis in peat deposits was determined on a number of o ccasions. The success of the technique was determined by (i) compariso n of CH4 production in cores sectioned anaerobically and in air and (i i) the rate of CH4 production by individual sections before and after a brief exposure to air. There was considerable between-core variabili ty in both the rate and vertical distribution of methanogenesis, such that a direct comparison between cores was difficult. However, the rat es were always lower (average 43%, range 13-74%) within the cores sect ioned in air. These effects were confirmed by sectioning peat cores un der anaerobic conditions and measuring the rate of CH4 production from individual peat slices both before and after a brief (5 min) exposure to air. The rate of methanogenesis was always lower (average 39%, ran ge 9-66%) after exposure to air. Although the careful sampling and sec tioning techniques increased the time required to prepare the samples for incubation the results showed the importance of exclusion of O-2 d uring sample manipulation.