2:00 PM - 2:15 PM
[HTT21-08] Tracing Atmospherically Deposited Nitrate in Forest Ecosystem Using Triple Nitrate Isotopes
Keywords:forest ecosystem, nitrate isotopes, oxygen isotope anomaly
We measured δ15N-NO3-, δ18O-NO3-, Δ17O-NO3-, and NO3- concentration along with forest hydrological pathways, through fall, soil water, ground water and stream water at Kiryu Experimental Watersheds (KEW) in central Japan.
We calculated the value of fatm of four stream water, and mean value was about 10% except for one of the stream water which flows steep slope catchment. These results are consistent with the reports for stream. In soil, the concentration of NO3- and the values of fatm were decreased along with the soil depth suggesting that NO3-atm was consumed immediately at surface soil. In contrast, the values of fatm were not fluctuated in ground water which suggests that the value of fatm in stream water is almost determined at soil.