Variation in nitrogen isotopic composition in the Selenga river watershed
Variation in nitrogen isotopic composition in the Selenga river watershed
复制标题
色楞格河流域氮同位素组成变化
DOI：
10.1007/s10201-011-0351-7
复制
发表时间：
2011
期刊：
影响因子：
1.6
通讯作者：
E.
中科院分区：
文献类型：
--
作者：
Hyodo;F.;Nishikawa;J.;Kohzu;A.;Fujita;N.;Saizen;I.;Tsogtbaatar;Javzan;C.;Enkhtuya;M.;Gantomor;D.;Amartuvshin;N.;Ishii;R. & Wada;E.
稳定氮 (N) 同位素比 (δ15N) 已用于检查水生生态系统的人为氮输入（即化粪池水、废水和粪便），因为人为氮通常具有与自然界中不同的 δ15N 特征。据报道，随着流域人口密度的增加，水生生物和衍生的有机物（例如沉积物）中的 15 N 变得越来越丰富。然而，人们对草原生态系统中的关系知之甚少，因为草原生态系统的牲畜数量比人类数量还要多。在这里，我们对蒙古色楞格河干流流域进行了初步研究，该流域面积约为30万平方公里。多元回归分析表明，河流沉积物的δ15N显着受人口密度影响，更显着受牲畜密度影响。人口密度，包括人类和牲畜，对大型植物眼子菜属的δ15N有显着影响。结果表明，河流有机质的δ15N可以作为人类和牲畜种群密度的指标，这可能与牲畜为主的流域的氮循环状况有关。
The stable nitrogen (N) isotope ratio (δ15N) has been used to examine the anthropogenic N input (i.e., septic water, wastewater, and manure) to aquatic ecosystems, because anthropogenic N generally has a δ15N signature distinct from that found in nature. Aquatic organisms and the derived organic matter such as sediments are reported to become increasingly enriched in15N as the human population density increases in watersheds. However, little is known about the relationship in steppe ecosystems, where the livestock population is greater than that of humans. Here, we conducted a preliminary study in the Selenga river mainstream watershed in Mongolia, which covers an area of approximately 300,000 km2. A multiple regression analysis revealed that the δ15N of the riverine sediment was significantly affected by the human population density and more significantly by livestock population density. The population density, including both humans and livestock, significantly influenced δ15N of the macrophyticPotamogetonspp. The results showed that δ15N of riverine organic matter can be an indicator of the human and livestock population density, which is likely associated with the status of N cycles in livestock-dominated watersheds.