Relationships Between Hexachloroethane Obscurant, Zinc Deposition, and Foliar Injury of Several Forest Tree Species.
Final rept. Oct 88-May 91,
GEO-CENTERS INC FORT WASHINGTON MD
Pagination or Media Count:
Open-top chambers were used to determine the relationships between a hexachloroethane HC obscurant, zinc deposition, and foliar injury of tree species indigenous to military training facilities. Eight eastern U.S. tree species were exposed four times to three exposure regimens Ox, lx, 2x of the obscurant, measured as Zn, during the 1990 growing season. Plots received ambient or charcoal-filtered air for comparison purposes. Black locust and black cherry were the most sensitive species, exhibiting significant p C 0.05 necrotic leaf spot, chlorotic mottle, and marginal necrosis of leaves at the 2x levels throughout the season. Defoliation was also greater p 0.05 in exposed versus unexposed plots. Sugar maple injury was different among exposure regimens p C 0.05 only near the end of the season. Sweet gum, eastern white pine, loblolly pine, and Virginia pine were asymptomatic. Charcoal filtration did not affect severity of symptoms. Zinc deposition was positively correlated p 0.05 with most of the symptoms on black locust and black cherry. The BC obscurant in the concentrations used in this study adversely affected these species.
- Industrial Chemistry and Chemical Processing