Effect of Plant Functional Type on Methane Dynamics in a Restored Minerotrophic Peatland

This is a post-peer-review, pre-copyedit version of an article published in [insert journal title]. The final authenticated version is available online at: https://doi.org/10.1007/s11104-016-2999-6Background and Aims: Peatland methane (CH4) fluxes may vary between plant types; however, in mixed communities, the specific role of each species is difficult to distinguish. The goal of this study was to determine the individual and interacting effect of moss, graminoid and shrub plant functional types on CH4 dynamics of experimentally planted plots in a rewetted minerotrophic peatland. Methods We measured CH4 flux, pore water CH4 concentration and CH4 production and oxidation potential in pure stands of reintroduced Tomenthypnum nitens (Hedw.) Loeske, Carex aquatilis Wahlenb, or Myrica gale L., as well as mixtures of T. nitens + C. aquatilis and T. nitens + M. gale. Methane flux was also measured on bare peat plots. ResultsThe presence of both the graminoid C. aquatilis and the shrub M. gale resulted in the highest CH4 production potential in near surface peat (10 cm). The presence of moss (T. nitens) and C. aquatilis significantly increased CH4 oxidation potential. Water table position was a significant control on CH4 flux, but the presence of C. aquatilis maintained higher flux even at dry plots. Plots including C. aquatilis had significantly lower pore water CH4 concentration at 30 cm depth, likely reflecting CH4 oxidation and transport. Conclusions Management of restored sites aiming to reduce CH4 flux should focus on hydrology, i.e. water table position. The presence of graminoids enhances CH4 flux, while moss presence may result in lower CH4 emission

Carbon Dynamics in Extracted Minerotrophic Peatlands: An Analysis of the Effect of Plant Biodiversity

Recent experiments have shown that biodiversity loss can impair natural ecosystem functioning. Extraction of horticultural peat is known to alter the diversity of vegetation and convert peatlands from net sinks to persistent sources of carbon to the atmosphere. Peatland restoration has been shown to re‐establish the natural carbon sink function, however, current restoration techniques could be refined with more knowledge of the role of plant biodiversity. In a controlled field study, I tested the effect of plant biodiversity on carbon sequestration in an extracted peatland in Quebec, Canada. Closed‐chamber method was used to measure the flux of carbon between the peatland and the atmosphere in fourteen treatments planted with different numbers of species. Species richness was not found to have a significant impact on carbon sequestration and no overyielding was detected in polycultures. Species identity was important with Carex aquatilis having a significantly positive impact on carbon sequestration