White ash (Fraxinus americana L.) survival and growth in unmanaged upland forests

Abstract

Crown class and diameter of 704 white ash (Fraxinus americana L.) > 0.5 inches dbh have been monitored at 10-yr intervals since 1927. Nominal stand age was 25 years in 1927. Although the density of white ash in the upper canopy declined from 14/acre to 3/acre between stand ages 25 through 85, the proportion of the upper canopy comprised by white ash only fell from 5.2% to 3.6%, respectively. In contrast, both absolute and relative density of lower canopy fell precipitously between stand ages 25 to 85, from 53/acre (4.5%) to 3/acre (0.5%). White ash ingrowth has never exceeded 2.6 trees/acre/decade. Survival and growth of white ash in 25- to 85-yr-old stands were influenced by crown class and disturbance. Mortality was negatively correlated with crown class. Mortality of suppressed trees was 3-5x higher than for trees in the upper canopy. Mortality and diameter growth were independent of tree diameter when crown class effects were removed. Over the 60-yr period, diameter growth for upper canopy, intermediate, and suppressed crown classes averaged 0.8", 0.4", and 0.2"/decade, respectively. Because of low recruitment and lower canopy survival, white ash will likely decline in these forests without periodic disturbances.

Citation

Ward, Jeffery S. 1997. White ash (Fraxinus americana L.) survival and growth in unmanaged upland forests. In: Pallardy, Stephen G.; Cecich, Robert A.; Garrett, H. Gene; Johnson, Paul S., eds. Proceedings of the 11th Central Hardwood Forest Conference; Gen. Tech. Rep. NC-188. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: 220-230