增温和施氮肥对荒漠草原植物群落的影响

Effect of plant community to warming and nitrogen fertilaztion in a desert steppe

本研究以内蒙古短花针茅(Stipa breviflora)荒漠草原为研究对象,于2015年8月,对设置在自然条件下进行增温和氮素添加交互控制模拟试验,研究了增温与氮素添加对荒漠草原植物群落结构,包括植物群落和物种盖度、高度、密度、频度和多样性。旨在为内蒙古荒漠草原植被对气候变化提供基础数据支持。主要研究结果表明:不同物种间的盖度,仅冷蒿物种的盖度在施氮肥和增温间有显著性差异;增温施氮肥交互作用显著降低短花针茅的盖度。施氮肥显著降低无芒隐子草物种平均高度,而增温和增温施氮肥交互作用对蒙古葱物种的平均高度有显著性差异。增温和施氮肥的交互作用显著降低短花针茅物种的密度。施氮肥显著降低冷蒿频度(P<0.05);增温和施氮肥的交互作用显著降低短花针茅频度(P<0.05)。

The controlled experiment on interaction between warming and nitrogen addition was conducted in August of 2015 in Stipa breviflora desert steepe in order to provide basic data about vegetation response to climate change. Plant community features, such as community and plant coverage, height, density, frequency, and spe- cies diversity were measured. The results show as follow. Among all species, only the coverage of Artemisia frigid respond differently under warming or nitrogen addition. The coverage of Stipa breviflorawas decreased greatly when these two treatment conducted meanwhile. Nitrogen addition significantly decreased the average height of Cleistogenes songorica, while both warming and nitrogen addition had great impact on average height of Allium mongolicum. Both warming and nitrogen addition significantly decreased the density of Stipa breviflora. Nitrogen addition significantly decreased the frequency of Artemisia frigid （p〈0.05）, both warming and nitro- gen addition significantly decreased the fequency of Stipa breviflora （p〈0.05）.