Variation in nitrogen isotopic composition in the Selenga river watershed, Mongolia

The stable nitrogen (N) isotope ratio (δ 15 N) 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 δ 15 N signature distinct from that found in nature. Aquatic organisms and the derived organic...

Full description

Saved in:

Bibliographic Details
Published in:	Limnology Vol. 13; no. 1; pp. 155 - 161
Main Authors:	Hyodo, Fujio, Nishikawa, Junko, Kohzu, Ayato, Fujita, Noboru, Saizen, Izuru, Tsogtbaatar, Jamsran, Javzan, Choijilsuren, Enkhtuya, Mangaa, Gantomor, Davaadorj, Amartuvshin, Narantsetsegiin, Ishii, Reiichiro, Wada, Eitaro
Format:	Journal Article
Language:	English
Published:	Japan Springer Japan 01-04-2012 Springer Nature B.V
Subjects:	Anthropogenic factors Aquatic ecosystems Aquatic organisms Biomedical and Life Sciences Ecology Environment Freshwater & Marine Ecology Human population density Human populations Isotopes Life Sciences Livestock Nitrogen Organic matter Population density Rivers Steppes Watersheds Mongolia Population Mongolia Livestock Stable N isotope ratio Watershed
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The stable nitrogen (N) isotope ratio (δ 15 N) 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 δ 15 N signature distinct from that found in nature. Aquatic organisms and the derived organic matter such as sediments are reported to become increasingly enriched in 15 N 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 km 2 . A multiple regression analysis revealed that the δ 15 N 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 δ 15 N of the macrophytic Potamogeton spp. The results showed that δ 15 N 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.
ISSN:	1439-8621 1439-863X
DOI:	10.1007/s10201-011-0351-7