Plant-mediated methane (CH<sub>4</sub>) transport and the contribution of recent photosynthates to methanogenesis were studied on two dominating vascular plant species – <i>Eriophorum vaginatum</i> and <i>Scheuchzeria palustris</i> – at three types of microrelief forms (hummocks – <i>E</i>. hummocks, lawns – <i>E.</i> lawns and hollows – <i>S.</i> hollows) of a boreal natural minerogenic, oligotrophic fen in Eastern Finland. <sup>14</sup>C-pulse labeling of mesocosms with shoots isolated from entire belowground peat under controlled conditions allowed estimation of plant-mediated CH<sub>4</sub> flux and contribution of recent (<sup>14</sup>C) photosynthates to total CH<sub>4</sub>. The results showed (i) CH<sub>4</sub> flux increased in the order <i>E.</i> hummocks ≤ <i>E.</i> lawns < <i>S.</i> hollows corresponding to the increasing water table level at the relief microforms as adjusted to field conditions. (ii) Plant-mediated CH<sub>4</sub> flux accounted for 38, 31 and 51 % of total CH<sub>4</sub> at <i>E.</i> hummocks, <i>E.</i> lawns and <i>S.</i> hollows, respectively. (iii) Contribution of recent photosynthates to methanogenesis accounted for 0.03 % for <i>E.</i> hummocks, 0.06 % for <i>E.</i> lawns and 0.13 % for <i>S.</i>hollows of assimilated <sup>14</sup>C. Thus, microsites with <i> S. palustris</i> were characterized by higher rates of transported CH<sub>4</sub> from the peat column to the atmosphere when compared to <i>E. vaginatum</i> of drier lawns and hummocks. Contribution of recent photosynthates to methanogenesis was dependent on the plant biomass within-species level (<i>E. vaginatum</i> at hummocks and lawns) but was not observed between species: smaller <i>S. palustris</i> had higher flux of <sup>14</sup>CH<sub>4</sub> as compared to larger <i>E. vaginatum</i>. Therefore, for the assessment of CH<sub>4</sub> dynamics over meso- and macroscale as well as for the implication and development of the modeling of CH<sub>4</sub> fluxes, it is necessary to account for plant species-specific differences in CH<sub>4</sub> production, consumption and transport and the attribution of those species to topographic forms of microrelief.