A mesocosm study of the role of the sedge Eriophorum angustifolium in the efflux of methane-including that due to episodic ebullition-from peatlands

作者：Green Sophie M^*; Baird Andy J

来源：Plant and Soil, 2012, 351(1-2): 207-218.

DOI：10.1007/s11104-011-0945-1

• Peatlands
• Methane flux
• Ebullition
• Vascular plants
• Eriophorum angustifolium

Vascular plants may reduce episodic ebullition losses of methane (CH4) from peatlands. They transport CH4 to the atmosphere, which may lead to a reduction in pore-water [CH4], bubble formation and release. This effect may be compounded by rhizospheric oxidation and associated methanotrophy. However, any reduction in pore-water [CH4] may be countered by root exudation (substrate for methanogens). The aim of this study was to determine how the presence of sedges affects CH4 emissions from peatlands. %26lt;br%26gt;Five pairs of peat cores were collected from a raised bog. One of each pair contained Sphagnum cuspidatum and Eriophorum angustifolium (%26apos;sedge%26apos; cores); the other was dominated by S. cuspidatum (%26apos;no-sedge%26apos;). From these the total CH4 efflux-including that due to episodic ebullition-were measured. A partial-shading treatment helped isolate the potential effect of root exudation. %26lt;br%26gt;Sedge samples had significantly higher CH4 fluxes than no-sedge samples, but episodic-ebullition fluxes were not significantly different. Between full-light and partially-shaded conditions, there was a significant increase in the difference in CH4 fluxes between the sedge and no-sedge cores. %26lt;br%26gt;The higher rates of CH4 flux from the sedge cores cannot be explained simply by higher rates of CH4 production due to rapid utilisation of exudates.

• 出版日期2012-2