Influence of methane concentration on methanotrophic activity of Mollic Gleysol and Haplic Podzol

A b s t r a c t. The influence of methane concentration on the methanotrophic and respiration activity of two soils (Mollic Gleysol and Haplic Podzol), characterized by similar granulometric composition and pH values but different organic matter content, was studied in a model experiment. The two investigated soils showed significant differences in the daily methane consumption - 48.2 mg CH 4 -C kg -1 d -1 for Mollic Gleysol and 5.95 mg CH 4 -C kg -1 d -1 for Haplic Podzol, as well as in the daily oxygen consumption - 0.88% and 0.33% O 2 d -1 for Mollic Gleysol and Haplic Podzol, respectively. The soils studied exhibited high (Mollic Gleysol) and low (Haplic Podzol) affinity methane oxidation. Daily CO 2 production increased with increasing methane amendment and ranged from 10.6 to 87.7 ml CO 2 kg -1 d -1 and was about 2.5 fold higher in the Mollic Gleysol than in the Haplic Podzol. The investigated soils showed different values of the CH 4 :O 2 :CO 2 ratio.