湖泊和水库氧化亚氮通量分析

Analysis of nitrous oxide flux from lakes and reservoirs

内陆水体中,湖泊与水库作为重要的N_2O潜在排放源,在氮循环中扮演着重要的角色.通过调研文献,在获取全球479个湖泊和83个水库N_2O通量数据的基础上,主要分析了湖泊和水库所处的纬度、面积、深度以及营养状况4个因素对N_2O通量的影响,并估算全球湖泊和水库N_2O年总通量.结果表明,湖泊和水库表现为N_2O的源,湖泊N_2O平均通量[(3.21±5.71)μmol/(m^2·d)]低于水库N_2O平均通量[(20.82±113.94)μmol/(m^2·d)].在全年尺度上,湖泊和水库N_2O通量随纬度增加呈下降的趋势;湖泊N_2O平均通量随着面积的增加而增加,水库N_2O平均通量随着面积的增加而下降;深水湖泊的N_2O通量大于浅水湖泊;富营养湖泊及水库的N_2O通量高于贫营养湖泊及水库.湖泊和水库N_2O年平均总通量分别为0.12和0.06Tg N/a,占到内陆水体N_2O排放的12%和7%.

Among inland water bodies,lakes and reservoirs are potential N2O sources and play important roles in nitrogen cycle.Based on the N2O flux data of 479 lakes and 83 reservoirs collected from published literatures,the influences of the latitude,area,depth and trophic status of the lakes and reservoirs were analyzed,and the global mean total N2O flux from lakes and reservoirs was estimated.The results indicated that most lakes and reservoirs acted as N2O sources.The mean N2O flux from lakes[(3.21±5.71)μmol/(m2·d)]was lower than that from reservoirs[(20.82±113.94)μmol/(m2·d)].At the annual temporal scale,N2O flux from lakes and reservoirs decreased with increasing latitude.The N2O flux from lakes increased with increasing area,but opposite for reservoirs.The N2O flux over deep lakes were larger than those over shallow lakes.The N2O flux over eutrophic lakes and reservoirs were higher with comparison to oligotrophic lakes and reservoirs.The annual mean total N2O flux from lakes and reservoirs were 0.12 and 0.06Tg N/a,respectively,and accounted for 12%and 7%of the total N2O emission from inland waters.