Abstract: By observing marsh wetlands and their surrounding dry farmlands for comparison,effect of marsh wetlands on localized micro-climate is analyzed.Results show that marsh wetlands,compared with their surrounding dryland,are lower in temperature but high in humidity in the surface layer,displaying a significant "cold-humidity island" effect,which varies with elevation.The closer to the land surface,the more significant the effect.The field observation from June to September found that the "cold-humidity island" effect was relatively more obvious in July and August.By comparing the marsh wetlands with the dryland around in diurnal variation of temperature and humidity,it was found that the effect was more significant during the time period between 12:00 and 14:00.

Key words: marsh wetlands, micro-climate, "cold-humidity island", effect