Internal methane transport through Juncus effusus: experimental manipulation of morphological barriers to test above- and below-ground diffusion limitation
Article first published online: 11 SEP 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 196, Issue 3, pages 799–806, November 2012
How to Cite
Henneberg, A., Sorrell, B. K. and Brix, H. (2012), Internal methane transport through Juncus effusus: experimental manipulation of morphological barriers to test above- and below-ground diffusion limitation. New Phytologist, 196: 799–806. doi: 10.1111/j.1469-8137.2012.04303.x
- Issue published online: 9 OCT 2012
- Article first published online: 11 SEP 2012
- Manuscript Accepted: 25 JUL 2012
- Manuscript Received: 20 JUN 2012
- Danish Council for Independent Research – Natural Sciences
- Danish Ministry of Environment
- CH4 (methane) emissions;
- CH4 transport;
- diffusion limitation;
- experimental manipulation;
- greenhouse gases;
- Juncus effusus (soft rush);
- morphological barriers;
- Aerenchymatous plants can transport methane (CH4) from the root zone to the atmosphere, bypassing the surface-oxidizing layers of the soil, yet morphological and anatomical factors that govern the transport of methane have rarely been critically tested in manipulative experiments.
- Here, we investigated the methane transport capacity of hydroponically grown Juncus effusus, in experiments with roots submerged in nutrient solutions sparged with methane (1.16 mmol CH4 l−1). Through a range of manipulations of the above- and below-ground plant parts, we tested the contradictory claims in the literature regarding which sites provide the greatest resistance to gas transport.
- Root manipulations had the greatest effect on methane transport. Removing root material reduced methane transport significantly, and especially the lateral roots and the root tips were important. Cutting of the shoots, with or without subsequent sealing, did not alter methane transport significantly.
- We confirm modelling predictions that the limiting factor for methane transport in the tussock forming wetland graminoid, J. effusus, is the amount of permeable root surface, estimated using the proxy measurement of root length. The aerial tissues do not provide any significant resistance to methane transport, and the methane is emitted from the lower 50 mm of the shoots.