Traffic, air NO2, and moss d15N in Kananaskis Valley, Alberta, Canada
Description
Data used in: Donovan, M., A. L. Norman, and M. L. Reid. 2022. Local vehicles add nitrogen to moss biomonitors in a low-traffic protected wilderness area as revealed by a long-term isotope study. Journal for Nature Conservation. Hypothesis: Vehicles accessing wilderness area add nitrogen (N) to the ecosystems through vehicle emissions, particularly nitrogen enriched in the 15N isotope. Study area: Kananaskis Valley, Alberta, Canada Data: TRAFx_data_Donovan_JNC.csv Data: Number of vehicles (both directions) per day along Highway 40 in the Kananaskis Valley, collected using automated TRAFx vehicle counters. Findings: There was a gradient of declining traffic volume as distance increased from the main access point at the north end of the Kananaskis Valley. airN_data_Donovan_JNC.csv Data: nitrogen (mg/L) collected using passive samplers with triethanolamine-impregnated filters as NO2, extracted as NO3, and analyzed by ion chromatography. Findings: Air NO2 concentrations declined as distance from the main access point to the Kananaskis Valley (at north) increased, consistent with the observed decline in traffic volume. Moss_d15N_data_Donovan_JNC.csv Data: Moss collected adjacent to Highway 40, with d15N (‰) and %N determined using a continuous flow elemental analysis isotope ratio mass spectrometer (Thermo Finnigan Delta V). Findings: As distance from the main access point to the Kananaskis Valley increased, d15N values in moss decreased (less 15N), consistent with the pattern for traffic. Furthermore, annual variation in moss d15N was positively correlated with total summer traffic volume from 2004-2019, as expected if vehicle emissions added nitrogen to the ecosystem.