| In this paper, the enclosed dark static chamber and float chamber technique were used and the measurements on N2O fluxes from Cyperus malaccensis var. brevifolius marsh were taken during three periods (before the flood, in the course of rising and ebbing tide, and after the ebb) and Spartina alterniflora Loisel invasion marsh, C. malaccensis marsh inputted nutrient and bare marsh treaded human (before the flood, and after the ebb) in intertidal zones, Minjing River estuary region, which intention is to show and explain fluxes change law of C. malaccensis and effect of different methods of human-caused disturbance to N2O fluxes from C. malaccensis marsh.The results of the study are as follow:①In autumn, the average nitrous oxide fluxes from C. malaccensis wetland before the flood, in the course of rising and ebbing tide and after the ebb were19.74μg·m-2·h-1、12.80μg·m-2·h-1and51.41μg·m-2·h-1, respectively. The average nitrous oxide fluxes in a tidal cycle was25.65μg·m-2·h-1. It showed C. malaccensis wetland in the day was a source of nitrous oxide in autumn. Flooding at high tide in spring, the average nitrous oxide fluxes from C. malaccensis wetland before the flood, in the course of rising and ebbing tide and after the ebb were2.39μg·m-2·h-1、2.00μg·m-2·h-1and26.05μg·m-2·h-1, respectively, and the total average fluxes of N2O were13.11μg·m-2·h-1. No flooding at high tide in spring, the average N2O fluxes were-13.19μg·m-2·h-1. The average nitrous oxide fluxes in a tidal cycle in spring was-2.67μg·m-2·h-1. It showed that C. malaccensis wetland in the day was a sink of nitrous oxide in autumn;②By observing to Spartina alterniflora Loisel invasion marsh, N2O fluxes from Spartina alterniflora Loisel invasion marsh (15.37μg·m-2·h-1) were lower those of C. malaccensis marsh (18.μg·m-2·h-1), and Spartina alterniflora Loisel invasion decreased N2O fluxes from C. malaccensis marsh;③By disturbance experiment of adding nutrient to C. malaccensis marsh, which nitrogen fertilizer and phosphatic fertilizer were added at165kg?N?hm-2and110kg?P?hm-2, respectively, the ratio of N and P was3/2, according to the agricultural fertilizer application standard, N2O fluxes from C. malaccensis marsh increased because nutrient is loaded. The average N2O flux is163.72μg·m-2·h-1after the nutrient was loaded in autumn,227.62μg·m-2·h-1and1178.64μg·m-2·h-1when C. malaccensis marsh was flooded or not at high tide in spring, respectively;④observing the N2O flux of bare marsh, it is-0.76μg·m-2·h-1to N2O fluxes from bare marsh because of human tread, which suggested that N2O fluxes from C. malaccensis marsh was decreased by tread, but the level of reducing was relevant to different growth seasons of plants or changes of environment factors resulting from flood and ebb. |
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