NO flux from soils surrounding PROPHET tower at UMBS.

Abstract

NO flux from the soils surrounding the PROPHET tower at UMBS were measured to assist in determining their significance as a source or sink in the larger N cycle of this ecosystem. A dynamic chamber method was used to measure flux from the soil, and a chemiluminescence analyzer was used to detect NO in this flux. The fluxes varied both with measurement time and site. Increasing flux measurements corresponded with increasing soil moisture (estimated by time since rainfall) until the soil reached a saturation point. No flux was observed from the soil immediately following a heavy rain event. NO flux from soil agreed well with estimates for a temperate forest published by Davidson and Klingerlee in 1997. NO flux measurements represented up to 2.5% of N wet deposition in the form of nitrate. The data can be compared to other sources and sinks of N in this ecosystem to determine whether or not to include soil flux of NO in N models.