太湖地区湿沉降中氮磷输入量 ——以常熟生态站为例

2003年6月—2004年5月，在中国科学院常熟生态站(31°32′45″ N ，120°41′57″ E)连续定位收集降雨，分析其中颗粒态和溶解态氮磷浓度，并对期间太湖地区氮磷湿沉降动态进行研究.结果表明：湿沉降氮输入量的季节变化显著，夏、春季高，秋、冬季低；湿沉降输入氮中88.2%为溶解氮（dissolved itrogen，DN），11.8%为颗粒氮（particle nitrogen，PN）；湿沉降输入磷中溶解磷（dissolved phosphorus，DP）和颗粒磷（particle phosphorus，PP）比例分别为53.3%和46.7%；中、小雨携带的总氮（total nitrogen，TN）、总磷（total phosphorus，TP）污染物通量大于大、暴雨；太湖地区每年湿沉降输入TN、TP分别为30.2 kg·hm^-2和1.1 kg·hm^-2，且所有降雨中DN浓度均大于水体富营养化阈值，92.5%的降雨中DP大于水体富营养化阈值.

Nitrogen and phosphorus input from wet deposition in Taihu Lake region: A case study in Changshu Agro-ecological Experimental Station

From June 2003 to May 2004, the precipitation at Changshu Agro-ecological Station (31°32′45″ N, 120°41′57″ E) of Chinese Academy of Sciences was collected to monitor its particle- and dissolved nitrogen and phosphorus concentrations, with the seasonal variation of nitrogen and phosphorus in wet deposition in Taihu Lake region investigated. The nitrogen input from wet deposition had an obvious seasonal variation, being higher in summer and spring and lower in autumn and winter. The ratios of dissolved nitrogen (DN) and particle nitrogen (PN) to total nitrogen (TN) in wet deposition were 88.2% and 11.8%, and those of dissolved phosphorus (DP) and particle phosphorus (PP) to total phosphorus (TP) were 53.3% and 46.7%, respectively. The amounts of nitrogen and phosphorus deposited into Taihu Lake region by light and medium precipitation were higher than those by heavy precipitation. The annual input of TN and TP from wet deposition was 30.2 kg·hm^-2 and 1.1 kg·hm^-2, respectively, and the DN concentration in all precipitation events as well as the DP concentration in 92.5% of precipitation events was higher than the thresholds of inland water eutrophication.