IMIS | Flanders Marine Institute
 

Flanders Marine Institute

Platform for marine research

IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (0): add | show Printer-friendly version

Water velocity and irradiance effects on internal transport and metabolism of methane in submerged Isoetes alpinus and Potamogeton crispus
Sorrell, B.K.; Downes, M.T. (2004). Water velocity and irradiance effects on internal transport and metabolism of methane in submerged Isoetes alpinus and Potamogeton crispus. Aquat. Bot. 79(2): 189-202. dx.doi.org/10.1016/j.aquabot.2004.02.004
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770, more
Peer reviewed article  

Available in  Authors 

Keywords
    Diffusion; Fresh water

Authors  Top 
  • Sorrell, B.K.
  • Downes, M.T.

Abstract
    Submerged aquatic macrophytes are important methane (CH4) transport pathways, but little is known about how water velocity and illumination affect plant CH4 transport. We studied CH4 transport in vitro in fully-submerged plants of two aquatic macrophytes, Isoetes alpinus and Potamogeton crispus, comparing transport between two water velocities (0.5 and 90 mm s−1) and light versus dark treatments at the shoots. In I. alpinus, CH4 taken up by the roots accumulated in the lacunar system of the leaves at concentrations >40 µmol l−1 at both flow rates, but there was no release from the shoots to the water at FLOW = 0.5 mm s−1, whereas at 90 mm s−1 release from the shoots to the water was always >0.15 µmol (CH4 g−1 dry wt. h−1). Uptake of CH4 by the roots was 1.5 times greater at the higher than the lower water velocity. In P. crispus, a gradient in lacunar [CH4] developed from the base to the apex of the shoot and was steeper at the higher than the lower water velocity. CH4 release rates from the shoots were <0.1 µmol (CH4 g−1 dry wt. h−1) at both water velocities in this species, due to CH4 consumption by epiphytic methanotrophic bacteria. Irradiance and its associated root aeration had no effect on CH4 transport in I. alpinus, but decreased root to shoot CH4 transport and release more than 10-fold in P. crispus, apparently by alleviating effects of hypoxia on the root-associated methanotrophic bacteria. Our data support the view that plant-associated methanotrophs are important CH4 sinks in freshwater habitats, and demonstrate the importance of flow velocity in the CH4 dynamics of submerged macrophytes.

All data in IMIS is subject to the VLIZ privacy policy Top | Authors