留茬高度对典型草原大针茅种群特征影响的研究

Effects of Stubble Height on Characteristics of Stipagrandis Populations in Typical Steppe

本研究选在锡林郭勒盟毛登牧场,通过设置3个留茬高度与不刈割对照处理,3次重复进行随机区组试验。对大针茅(Stipagrandis)的高度、盖度、密度、分枝数、每枝叶片数及地上生物量等种群特征进行研究。结果表明:大针茅种群的高度、盖度、密度及地上生物量在4种处理下均表现出显著的差异性(P<0.05),且都在留茬5cm处理时达到最大;大针茅种群的地上生物量与植株的高度和分枝数之间具有极显著的正相关关系(r^2=0.3605、P<0.0001;r2=0.6325、P<0.0001);大针茅种群的密度与盖度之间具有极显著的正相关关系(r^2=0.5445、P<0.0001),与每枝的叶片数之间具有显著的负相关关系(r^2=0.3801、P<0.05)。

This study was conducted in Maodeng rangeland,Xilingol League,Inner Mongolia. The experi-ment was designed as a randomized block with three replicates. The treatments included heights,2 cm,5 cm, 8 cm and the un-mowed （control CK）. The population characteristics of Stipa gran-dis ,such as the height , coverage , density , number of branches , each branch leaf number and aboveground biomass were analyzed. The results showed that,the height,coverage and density of S . grandss were sig- niiicantly different in four treatments（P 〈0. 0 5）,and all reached the maximum with the treatment of 5 cm- stubbed height. The S . grandis＇ aboveground biomass showed positively correlation withand the number of branches （r2 =0. 3605、P〈0. 0001 ;r2 = 0 . 6325、P〈0. 0001）. The density was positively related to coverage（r2 = 0. 5445、P〈0. 0001）,while negatively correlated with each branch leaf number（r2 =0.3801、P〈0.05）.