Global Fiducials imagery for observing long-term forest dynamics in the North Carolina mountains under a changing climate and atmosphere

Abstract:

Mount Mitchell (2037 m) is a forested mountain ecosystem in North Carolina’s Black Mountain Range and is the highest peak in the Appalachian Mountains. It has a moderate temperate climate and a gene pool that is extraordinarily rich and unique. The region hosts a red spruce and Fraser fir forest community that has undergone significant decline in the last 25 years due to logging, pest pressures in part to the balsam woolly adelgid (BWA), climate change and air pollution. Historically, BWA induced tree mortality has been exacerbated by increased soil acidification and tropospheric ozone formation from wet and dry nitrogen deposition. Since the 1990’s there has been a significant reduction in air pollutants that cause acid rain/fog, soil acidification and ozone formation along with a decrease in BWA populations. This has led to forest regrowth with fir as the dominate species. However, the declines in BWA pressures may be cyclical and tied to fir stand maturity, which in turn may be influenced by a warming climate. These changes in atmospheric chemical composition together with a rapidly changing climate may have significant effects on forest succession and species biodiversity. The Global Fiducials Library imagery from 2004 to present was used to study forest ecosystem structure under this regime of climate and atmospheric compositional change. In addition to the imagery library, atmospheric, meteorological, and soil data from the North Carolina Environment and Climate Observing Network (ECONet) were integrated into the analysis to investigate relationships between forest regrowth, air pollutant concentrations and trends in atmospheric parameters including PAR, air temperature, rainfall, and other variables. The Mt. Mitchell site also monitors tropospheric ozone since 2017 and during a period in the late 1980s. The climate and air quality data together with the GFL imagery provides a means to map the changes in the spruce-fir composition, understand forest successional dynamics, and potentially predict ecosystem response to changes in climate and atmospheric composition.