Spatial And Temporal Effects Of Atmospheric Deposition Climate And Land Management On Forest Nutrient Cycling And Biodiversity

Emissions largely associated with the combustion of fossil fuels and agriculture has caused elevated atmospheric deposition of nitrogen (N) and sulfur (S) throughout much of the developed world. Increased atmospheric deposition of N and S can lead to soil and surface water acidification and affect forest soil nutrient supply. The critical load (CL) of atmospheric deposition is the level of deposition below which significant harm to ecosystems is not likely to occur. The critical load provides an understanding of the extent to which terrestrial and aquatic systems may be affected by air pollution at present or in the future. This research implements novel methods for generating CL estimates of N and S deposition and evaluates spatial and temporal trends in soil chemistry and plant biodiversity with respect to future climate and land management scenarios. Results are presented in the context of chemical thresholds known to be associated with adverse impacts to terrestrial and aquatic biota of the southern Appalachian Mountains and high elevation Colorado Rocky Mountains.