Global warming is one of the urgent environmental issues. Increasing concentration of greenhouse gasses in the atmosphere is thought to drive an excess greenhouse effect leading to global warming. Greenhouse gasses might be produced or consumed not only at the physical surface but also at the biological one. Here, we investigated the greenhouse gas flux of living plant bodies in forest ecosystems. Twelve species of forest plants in the Sambe Forest and Matsue Campus of Shimane University were incubated in the closed chamber under field conditions. Of several naturally produced greenhouse gasses, methane and nitrous oxide content of sampled gas phase of incubation chamber was determined in the laboratory. While nine out of twelve plants had potential to emit methane, only three plants emitted nitrous oxide and their production rate remained at a lower level. Nine other plants consumed substantial amount of nitrous oxide in the chamber. Our results showed that living plant had a certain level of potential to emit methane and to consume nitrous oxide in the chamber. Thus, existence of living plants could affect the greenhouse gas flux around forest ecosystems to some extent.