In June 2008, 303,000 L of hydrofracturing fl uid from a natural gas well were applied to a 0.20-ha area of mixed hardwood forest on the Fernow Experimental Forest, West Virginia. During application, severe damage and mortality of ground vegetation was observed, followed about 10 d later by premature leaf drop by the overstory trees. Two years after fl uid application, 56% of the trees within the fl uid application area were dead. Fagus grandifolia Ehrh. was the tree species with the highest mortality, and Acer rubrum L. was the least aff ected, although all tree species present on the site showed damage symptoms and mortality. Surface soils (0–10 cm) were sampled in July and October 2008, June and October 2009, and May 2010 on the [...]