Abstract: Grassland degradation has seriously affected the development of animal husbandry in alpine pastoral areas of Qinghai-Tibet plateau. Fertilization is a common measure to improve mildly degraded grassland. This study used the mild degraded meadow in Guinan county as the research area,in 2011,applied different amounts of nitrogen fertilizer (0,60,105,150,195 and 240 kg·hm^-2) and bacterial fertilizer (45 m³·hm^-2) to explore the effects of fertilization on the coverage,height and aboveground biomass of the degraded meadow from 2011 to 2012. The results showed that fertilization could effectively improve the community coverage,height and total aboveground biomass in the lightly degraded meadow,and the improvements were significantly (P<0.01) better in 2012 than in 2011. The effect of 45 m³·hm^-2 bacterial fertilizer treatment was better in 2011,while 195 kg·hm^-2 nitrogen fertilizer treatment was better in 2012,the total aboveground biomass was the highest from July to October 2012,which was 44.3%,97.1%,123.0% and 135.4% higher than no fertilizer treatment,respectively. Different grass species have different responses to fertilization. For 195 kg·hm^-2 nitrogen fertilizer,grass aboveground was higher than sedge in 2011,while sedge biomass was higher than grass in 2012. In summary,nitrogen application of 195 kg·hm^-2 combined with fenced enclosure can be used for vegetation restoration in Guinan county.

Key words: Fertilizer application, Degraded meadow, Vegetation characteristic, Vegetation restoration

摘要： 草地退化已严重影响青藏高原高寒牧区畜牧业的发展，施肥是改良轻度退化草地的常用措施。2011-2012年，本研究以贵南县轻度退化草地为研究对象，2011年施加不同氮肥量（0，60，105，150，195和240 kg·hm^-2）和菌肥（45 m³·hm^-2），探讨施肥在退化草地治理过程中对草地群落盖度、高度和地上生物量的影响。结果表明：施肥处理能够有效提高轻度退化草地植被群落的盖度、高度和总地上生物量，且施肥后次年轻度退化草地群落的盖度、高度和总地上生物量显著（P<0.05）优于当年。45 m³·hm^-2菌肥处理在当年的效果较好，195 kg·hm^-2氮肥处理在次年更佳，2012年7-10月地上总生物量均为最高，分别比不施肥处理分别高出44.3%，97.1%，123.0%和135.4%。不同草种对施肥的响应也不同，195 kg·hm^-2氮肥处理下，2011年禾草地上生物量较高，2012年莎草生物量高于禾草。综上，195 kg·hm^-2尿素施用量配合围栏封育的措施可用于贵南县轻度退化草地的植被恢复。

关键词: 施肥, 退化草地, 植被特征, 植被恢复