Abstract: In order to understand the effect of climate change on Stipa krylovii grassland vegetation and its characteristics, the temperature and vegetation of Hulun Buir Stipa krylovii grassland in Argun River Basin during 2002-2006 were investigated and analyzed. Results showed that the average temperature of this area had a fluctuating decline with the advance of time. The important value of Stipa krylovii, Leymus chinensis, Suaeda glauca, Potentilla bifurca decreased with the yearly decrease of winter maximum temperature, whereas that of Cleistogenes aquarrosa increased. The plant height, cluster number, coverage and important value of Cleistogenes aquarrosa had negative correlations with winter maximum temperature significantly. The effect of precipitation on predominant species was not obvious. There was no significant relationship between winter maximum temperature and diversity indices (Simpson index and Shannon-Wiener index) and evenness index. Therefore, there was no significant impact on the structure and function of Stipa krylovii grassland community during these five years, although a few plants were sensitive to the change of winter maximum temperature.

Key words: Stipa krylovii grassland, Climate change, Important value, Characteristics of grassland

摘要： 为了解气候变化对克氏针茅(Stipa krylovii)草原植被及植被群落特征的影响,对额尔古纳河流域呼伦湖周边地区呼伦贝尔克氏针茅草原2002-2006年连续5年的温度和植被进行调查(样方法)分析。结果表明:该地区的均温随着时间的推移呈波动型递减趋势,冬季最高温逐年下降;随着冬季温度的下降,克氏针茅、羊草(Leymus chinensis)、二裂委陵菜(Potentilla bifurca)和碱蓬(Suaeda salsa)的重要值呈递减趋势,糙隐子草(Cleistogenes squarrosa)呈递增趋势,且其株高、丛数、盖度和重要值与冬季最高温显著负相关,而群落主要优势种克氏针茅和羊草对冬季最高温度的变化反应不明显;群落的多样性指数(Simpson指数和Shannon-Wiener指数)和均匀度指数与冬季最高温无显著相关性。由此可知,5年间虽有少数植物对冬季最高温度变化反应敏感,但是对群落的结构和功能没有产生明显影响。

关键词: 克氏针茅草原, 气候变化, 重要值, 草原群落特征