Tree Rings and Air Pollution: A Case Study on Pinus Monophylla Growing in East-Central Nevada

Five stands of Pinus monophylla (single-needle pinyon pine) from east-central Nevada were sampled and analyzed using dendrochronological methods to detect the effects of climate and copper smelter effluent on annual ring-width growth. Tree-ring chronologies were developed for two pollution sites near the smelter and for three control sites. All chronologies are highly and positively correlated before smelting began in 1908, but after that date there is a significant decrease in the correlation of the chronology from the most polluted site with the other chronologies. The results of a response function analysis suggest that trees on the most polluted site are limited by both climate and air pollution. An increase in the amount of low-frequency variance in the chronology from the most polluted site is attributed to a decrease in ring-width growth from 1910-1930 followed by and increase in growth which may have been caused by some change in the trees’ environment due to copper smelter effluent.