Ambient and Potential Denitrification Rates in Marsh Soils of Northeast Creek and Bass Harbor Marsh Watersheds, Mount Desert Island, Maine.

摘要

This report provides estimates of in-place (in situ) rates of denitrification in marsh soils under ambient conditions and after treatment with NO3 alone, glucose alone, and combinations of NO3 and glucose in Northeast Creek and Bass Harbor Marsh watersheds, Mount Desert Island during the summers of 2008 and 2009. The data were collected by the U.S. Geological Survey (USGS), in cooperation with Acadia National Park, as part of a study to determine current in-place and maximum potential denitrification rates. Laboratory incubation experiments also are described that report the ratio of N2 to N2O produced during denitrification under ambient conditions (no treatment additions) and under treatments in which various rates of NO3 were added, with or without glucose, and with or without acetylene. The purpose of determining ratios of N2 to N2O produced in these laboratory experiments was to apply these ratios in field measurements during which no acetylene block was used and in which only N2O was measured. Ratios from the laboratory experiments also informed the design of the field experimental additions of NO3 and glucose additions to assure that appropriate rates of these additions would be applied. The more controlled conditions of the laboratory experiments, in conjunction with the field experiments assisted in the study's understanding of denitrification responses to treatments that included glucose only, acetylene only, and various rates of nitrogen additions with and without glucose.