『Abstract
Denitrification, the anaerobic reduction of nitrogen oxides to
nitrogenous gases, is an extremely challenging process to measure
and model. Much of this challenge arises from the fact that small
areas (hotspots) and brief periods (hot moments) frequently account
for a high percentage of the denitrification activity that occurs
in both terrestrial and aquatic ecosystems. In this paper, we
describe the prospects for incorporating hotspot and hot moment
phenomena into denitrification models in terrestrial soils, the
interface between terrestrial and aquatic ecosystems, and in aquatic
ecosystems. Our analysis suggests that while our data needs are
strongest for hot moments, the greatest modeling challenges are
for hotspots. Given the increasing availability of high temporal
frequency climate data, models are promising tools for evaluating
the importance of hot moments such as freeze-thaw cycles and drying/rewetting
events. Spatial hotspots are less tractable due to our inability
to get high resolution spatial approximations of denitrification
drivers such as carbon substrate. Investigators need to consider
the types of hotspots and hot moments that might be occurring
at small, medium, and large spatial scales in the particular ecosystem
type they are working in before starting a study or developing
a new model. New experimental design and heterogeneity quantification
tools can then be applied from the outset and will result in better
quantification and more robust and widely applicable denitrification
models.
Keywords: Denitrification; Nitrogen; Riparian; Sediment; Soil;
Stream』
Introduction
Hotspots and hot moments in soils
Temporal heterogeneity
Spatial heterogeneity
Modeling terrestrial hotspots and hot moments using existing
models
Terrestrial/aquatic boundaries as hotspots
Incorporating interface hotspots into models
Hotspots and hot moments in aquatic ecosystems
Incorporating aquatic hotspots and hot moments into models
Hotspots, hot moments and environmental decision making: a case
study from the northeastern US
Conclusions
Acknowledgments
References