Correlating the Spatial Distribution of Atmospheric Ammonia with ?15N Values at an Ammonia Release Site

Abstract

A field ammonia (NH 3 ) release experiment and open top chambers containing moorland monoliths continuously fumigated with NH 3 or sprayed with NH 4 Cl were used to assess the potential for using δ 15 N values in determining the area of influence around a point NH 3 emission source. δ 15 N values are being increasingly used as environmental tracers and we tested the hypothesis that the δ 15 N signal from an NH 3 emission source is observable in nearby vegetation. Using modified monitoring devices, atmospheric NH 3 concentrations were found to decrease with distance from source, with δ 15 N values also reflecting this trend, producing a signal shift with changing concentration. Open top chamber studies of δ 15 N values of Calluna vulgaris (L.) Hull indicated a correlation with deposition treatments in current year shoots. Analysis of Calluna shoots from the NH 3 release showed a similar trend of δ 15 N enrichment. Significant linear correlations between δ 15 N and percent N in plant material were found, both in the controlled conditions of the open top chambers and at the NH 3 release site, illustrating the possible use of this technique in N deposition biomonitoring.

Characterizing the isotopic composition of atmospheric ammonia emission sources using passive samplers and a combined oxidation‐bacterial denitrifier approach

“…While quantification of isotope fractionation during NH 3 collection by the ALPHA sampler was beyond the scope of this study, prior studies have addressed potential fractionations during passive collection associated with meteorological conditions or the collection mechanism itself . These studies reported that passive samplers have minimal fractionation associated with variability in wind speed and NH 3 concentrations .…”

“…These advantages allow for multiple deployments of passive samplers at a single site. Passive samplers, either Ogawa (Ogawa & Co., USA, Inc., Pompano Beach, FL, USA) or Adapted Low‐Cost Passive High Absorption (ALPHA) (Centre for Ecology and Hydrology, Edinburg, UK), have been used in previous studies to collect NH 3 emissions and monitor NH 3 concentrations . The Ogawa is a double‐sided passive diffusion sampler equipped with a diffusive end cap, followed by a stainless steel screen, and a 14 mm quartz filter impregnated with phosphorous acid.…”

The effects of short-term rainfall variability on leaf isotopic traits of desert plants in sand-binding ecosystems

“…Similar observations are reported for southern African ecosystems where foliar δ 15 N values of some leguminous Acacia trees reach 8‰ (Wang et al, 2010b), indicating minimum nitrogen fixing activities in normal years (vs. wet years). Because atmospheric nitrogen tends to have more negative δ 15 N values, more negative δ 15 N values in A. ordosica suggest that this shrub may obtain a large amount of its nitrogen from precipitation and deposition (Skinner et al, 2004).…”