### 2.25.7.2. CH4 and O2 Source Terms[¶](#ch4-and-o2-source-terms "Permalink to this headline")

The overall CH4 net source term consists of production, oxidation at the base of aerenchyma, transport through aerenchyma, methanotrophic oxidation, and ebullition (either to the control volume above the water table if unsaturated or directly to the atmosphere if saturated). For O2 below the top control volume, the net source term consists of O2 losses from methanotrophy, SOM decomposition, and autotrophic respiration, and an O2 source through aerenchyma.

