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White ash (Fraxinus americana) health in the Allegheny plateau region, Pennsylvania: Evaluating the relationship between FIA phase 3 crown variables and a categorical rating system

Informally Refereed

Abstract

Following the detection of white ash (Fraxinus americana) decline in the Allegheny National Forest (ANF) of Pennsylvania, we established an intensified white ash monitoring network throughout the ANF. We rated crowns using both a categorical system as well as Forest Inventory and Analyses (FIA) Phase 3 measures of uncompacted live crown ratio, density, dieback, and transparency. Across our plots, ash averaged 17.33 trees/acre and made up 19 percent of the total stand basal area. We found that trees on lower slopes were healthier than those on upper slopes. Categorical ratings correlated well with density and dieback and allowed us to develop and test conversion formulas to predict dieback and density using categorical scores. Our formulas proved robust in predicting density and dieback on an independent ash tree dataset. Erroneous predictions were generally linked to differences in what either measure defined as dieback. We suggest categorical assessments may provide a suitable alternative for rapid crown evaluations.

Parent Publication

Citation

Royo, Alejandro A.; Knight, Kathleen S.; Himes, Jamie M.; Will, Ashley N. 2012. White ash (Fraxinus americana) health in the Allegheny plateau region, Pennsylvania: Evaluating the relationship between FIA phase 3 crown variables and a categorical rating system. In: McWilliams, Will; Roesch, Francis A. eds. 2012. Monitoring Across Borders: 2010 Joint Meeting of the Forest Inventory and Analysis (FIA) Symposium and the Southern Mensurationists. e-Gen. Tech. Rep. SRS-157. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 123-129.
https://www.fs.usda.gov/research/treesearch/40982