Abstract: To explore the effects of restoration measures,such as enclosure,reseeding,and fertilization on desert grassland plant communities in both wet and dry years,a two-year manipulative experiment was conducted in desert grasslands of different degradation levels in Inner Mongolia. The results showed that in the severely degraded areas,enclosure significantly increased the density of forbs and the relative biomass of Stipa breviflora only in the wet year. Reseeding significantly increased the coverage of forbs,the density of the community and the density of grasses only in the wet year. Applying organic fertilizer significantly increased the coverage of the community and grass as well as the relative biomass of Stipa breviflora only in wet year. In the heavily desertified areas,reseeding significantly increased the density of community and grasses in wet year,and significantly decreased diversity index but increased aboveground biomass of community in dry year. In moderately degraded area,spraying foliar fertilizer significantly decreased coverage of community and forbs in wet year. Our results suggested that restoration measures had varying impacts on plant community characteristics in wet and dry years,and the same restoration measures yield different effects in grasslands with different types of degradation. The effectiveness of restoration measures can be ensured by selecting appropriate restoration measures according to local conditions,and the effects of inter-annual variations in precipitation on restoration outcomes should be fully considered.

Key words: Different rainfall years, Enclosure, Reseeding, Fertilization, Community composition, Diversity, Productivity

摘要： 为探讨干湿年份封育、补播和施肥等恢复措施对荒漠草原植物群落的影响，本研究在内蒙古不同退化程度的荒漠草原开展了两年的控制试验，发现在重度退化区，封育仅在湿润年份显著增加了杂类草密度及短花针茅相对生物量；补播仅在湿润年份显著增加了杂类草盖度、群落密度及禾草密度；撒施有机肥仅在湿润年份显著增加了群落和禾草盖度以及短花针茅相对生物量。在重度沙化区，补播在湿润年份显著增加了群落和禾草密度，在干旱年份显著降低了多样性指数，显著提高了地上生物量。在中度退化区，喷施叶面肥在湿润年份显著降低了群落和杂类草盖度。恢复措施在干湿年份对植物群落特征的影响不同，且相同恢复措施在不同退化类型的草原中的效果也不相同。因此，要因地适宜地选择恢复措施，并充分考虑降水的年际变化对恢复效果的影响，以保证恢复措施的有效性。

关键词: 不同降雨年份, 封育, 补播, 施肥, 群落组成, 多样性, 生产力