关键词: N₂O, 全球变暖, 山地草原, 施肥, 海拔, 坡向, 坡度, 叶面积指数, 生境类型, 曲率

Abstract: Studies on N₂O emissions from grassland soils and its influence by nutrient changes resulting from global warming show that in growing season peaty gley soil has a maximtun N₂O emission varying from 1.3 to 12.2 kg N·hm^-2·yr^-1, N₂O emission in ndcropodzol soils is from 1. 5 to 2.4 kg N·hm^-2· yr^-1, and acid brown earth has the lowest ranging from 0 to 3.2 kg N·hm^-2·yr^-1.N₂O emission mainly comes from top 5cm in micropodzol soil, and from top 10cm in other two soils. Fertilizer application in growing season doesn't make any differece in different soils. However, N application greatly stimulates the N₂O emission at the end of the growing season. And in acid brown earth and in micropodzol soil, it reached respectively 44.2and 33.1 kg N·hm^-2·yr^-1 compared to 1.3 and 1.9 kg N·hm^-2·yr^-1 in the control. This implies that the influence of global warming upon decomposition of organic matters doesn't result in a significant increase in N₂O emission.

Key words: N₂O, Global warming, Mountainous grassland, Fertilizer application, slope degree, habitat type, slope aspect, leaf area index, altitude, curvature