The Red Dog Mine transports concentrated zinc and lead ore in northwestern Alaska through Cape Krusenstern National monument along a haul road. High metal levels in the moss Hylocomium splendens along the haul road have been attributed to ore dust released during transport. The mine has implemented several pollution abatement measures to reduce fugitive ore dust since the original study in 2001, and a subsequent remeasure in 2006.
In 2017, we remeasured moss metal concentrations and lichen and vegetation communities with the purpose of documenting potential effects of metal deposition, and climate change to the local ecosystem from 2006 to 2017. Our results indicate significant changes in lichen and vegetation communities as seen through a loss in diversity and a gain in mean total cover. In both years lichen diversity and cover had negative relationships to metal deposition and distance from the haul road. We observed a decrease in lichen diversity and a doubling in cover over time. Vegetation diversity was nearly constant but similarly doubled in cover over time. Changes in metal content of mosses during the study period were not significant as evident from the subset of data from 60 plots available. The lichen community was correlated to metal content, which suggests a degree of sensitivity and their appropriate use as biomonitors in this system. We found no significant differences in communities between the north and south sides of the haul road. Changes observed through the study period suggest a relationship to climate change. This was observed through increases in total lichen and vegetation cover as likely mediated by regional climate, biome, temperature and drying in wetlands. Overall, pronounced changes were documented within a mere decade, indicating that continued monitoring into the future is necessary and will be an invaluable resource for future generations.