Plant‐mediated methane transport in emergent and floating‐leaved species of a temperate freshwater mineral‐soil wetland

Abstract

This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Identifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales

“…Furthermore, this could be done in a spatially explicit manner to better understand site‐level heterogeneity, which is something that was not directly addressed in this study due to the integrative nature of eddy covariance measurements (although we did explore site‐level heterogeneity to some extent by including wind direction, but these variables did not come up as dominant variables in the analyses). Future research should also focus on pairing eddy covariance observations with stable isotope analyses of CH 4 , and incubation, chamber, and leaf‐level measurements to provide improved understanding of the direct mechanisms of CH 4 production, transport, and oxidation (Chanton et al, 1997; Marushchak et al, 2016; Villa et al, 2020). In particular, with respect to CH 4 transport and controls on FCH4 at the diel scale, given that the majority of the sites measured FCH4 using an open‐path sensor, it is also possible that density corrections may have influenced diel patterns in CH 4 exchange, and, in turn, the evaluation of biophysical predictors of FCH4 and associated lags (Chamberlain et al, 2017).…”

“…Physical processes such as turbulent conditions and atmospheric pressure (PA) fluctuations can influence the transport of CH 4 from the soil profile into the atmosphere, particularly in porous peat soils where ebullition is often the primary CH 4 transport mechanism during the pressure‐falling phase (Nadeau et al, 2013; Sachs et al, 2008; Ueyama, Yazaki, et al, 2020). Biological factors such as plant community type and primary production also influence CH 4 production and consumption through a variety of mechanisms, including supplying labile carbon compounds that fuel methanogenesis (Christensen et al, 2003; Tittel et al, 2019); enhancing oxygen transport into anoxic soil layers via aerenchyma, thereby supporting rhizosphere CH 4 oxidation (Laanbroek, 2010); and mediating transport of CH 4 to the atmosphere via aerenchyma, allowing CH 4 to bypass potential oxidation in surface soils (Knoblauch et al, 2015; Kwon et al, 2017; Villa et al, 2020).…”

Large Seasonal and Habitat Differences in Methane Ebullition on the Amazon Floodplain

“…Evasion via the herbaceous plants found in the study sites is unlikely to be significant because most of these plants are free‐floating and not rooted, and the few roots that reach the sediments are several meters long and not likely to be conduits for emission. Previous studies that report evasion via floating plants (e.g., Villa et al., 2020) examined quite different plants growing in shallower water.…”

Functional Representation of Biological Components in Methane‐Cycling Processes in Wetlands Improves Modeling Predictions

“…Although many biogeochemical models do represent some form of plant‐mediated transport, most approaches to simulate plant transport include coefficients or vegetation parameters that are poorly constrained and heavily biased toward some species characteristic of high‐latitude peatlands. These parameters may differ significantly for dominant species in other wetland types, such as mineral soil wetlands (Villa et al, 2020), and typically do not include functional types such as shrubs and trees, which actively transport methane as well (Pitz et al, 2018). Nonetheless, simulating the effect of individual plant species in organic matter chemistry and plant‐mediated transport is logistically impractical and hindered by a considerable paucity of field measurements and geographical coverage.…”