城市与草地生态系统大气氮沉降变化与特征分析

Analysis on Atmospheric Nitrogen Deposition in Cities and Grassland Ecosystems

为比较城市与草地生态系统大气氮沉降的差异,分别在内蒙古呼和浩特和锡盟赛罕塔拉两个地区采用雨量收集器收集了连续两年的降水,并测定了大气氮素沉降物中的全氮的含量,分析了不同地区大气氮素沉降与降雨量的关系,以及大气氮沉降的氮浓度、总氮量的变化规律。结果表明:呼和浩特市年降雨量集中在夏季7-8月份,占全年降雨量的一半以上。呼和浩特市大气氮沉降的浓度在4-8月份呈递减趋势。其它月份则无太明显的变化,在降雨量最大的7、8月份,沉降氮浓度降到全年的最低值;锡盟赛罕塔拉草原5-10月份的大气氮沉降浓度变化趋势与呼和浩特市基本一致,城市与草原没有显著差异;呼和浩特市氮沉降输入的总氮量2005年与2006年度间差异不显著,但是每月变化量较大。降水量对沉降总氮量影响较大。

Along with the strengthening of human activity, atmospheric nitrogen deposition increased gradually. It had a signigicant impact on the marine and terrestrial ecosystems. To compare the cities and grassland ecosystems of atmospheric nitrogen deposition differences, rainfalls in 2005 and 2006 in Hohhot and SaiHanTala were collected. The precipitation and the atmospheric nitrogen deposition in different regions were analyzed. The results showed that the rainfall concentrated in the summer months in Huhhot, accounting for over half of the total rainfall. Atmospheric deposition of nitrogen in decreased in April - August. There was no obvious change in other month; The concentration of atmospheric nitrogen deposition change Saihantala in May to October showed the same trend with Huhhot; The nitrogen deposition of nitrogen input volume in Huhhot shwoed no difference signif- icant between 2005 and 2006. Precipitation had the great impact on total nitrogen content.