摘要：We investigated the effects of vascular plants on methane emissions from Wuliangsu Lake, a wetland in an arid region of northwestern China. Under natural conditions in early June and late July, average CH 4 fluxes were respectively 16.3±4.3 and 19.3±6.0 mg m -2 h -1 . Whereas, shading treatments, which eliminated direct sunlight to plants, resulted in lower CH 4 emission (8.2±1.9 and 10.2±2.6 mg m -2 h -1 for the two periods). When the culms were cut below the water surface, the fraction of CH 4 emissions was about 18% and 15% of that of natural control systems in early June and late July, respectively. Our findings indicated that the photosynthesis of reed had a positive influence on the process of methane emission; however, effects on production and transport outweighed oxidation. Of the carbon fixed by photosynthesis, only 4.7% was returned to the atmosphere as CH 4 .
