Japan Geoscience Union Meeting 2019

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-HW Hydrology & Water Environment

[A-HW24] Isotope Hydrology 2019

Mon. May 27, 2019 9:00 AM - 10:30 AM 105 (1F)

convener:Masaya Yasuhara(Rissho Univ.), Kohei Kazahaya(Geological Survey of Japan, AIST), Shinji Ohsawa(Institute for Geothermal Sciences, Graduate School of Science, Kyoto University), Kazuyoshi Asai(Geo Science Laboratory), Chairperson:Masaya Yasuhara(Rissho Univ.), Noritoshi Morikawa(産業技術総合研究所活断層・火山研究部門)

9:00 AM - 9:30 AM

[AHW24-01] The use of natural abundances of stable isotopes to elucidate the nitrogen dynamics in plant-soil systems

★Invited Papers

*Keisuke Koba1 (1.Center for Ecological Research, Kyoto University)

Keywords:stable isotopes, soil nitrate

Nitrogen (N) dynamics in terrestrial ecosystems are quite complex because of its high turnover due to the high biological N demand by plants and microbes. The uses of the natural abundance of stable N and oxygen (O) isotopes have been carried out in many ways to elucidate the N dynamics in intact terrestrial ecosystems. The methodological progress ("denitrifier method") can allow us to measure not only N but also O isotope ratios with samples with low N amounts. We applied this analytical method to elucidate the fate of nitrate. Among many fates of nitrate in terrestrial ecosystems, plant nitrate uptake is quite difficult to evaluate. In this talk, I will introduce our results on the uptake of the soil nitrate by tundra plants where soil net nitrification rates are quite low.