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Detection Monitoring of Crown Condition in South Carolina: A Case Study

Informally Refereed

Abstract

This article presents a case study of how indicators of forest health can be adjusted for natural factors, standardized to a common basis, and subjected to spatial analysis for the purpose of detecting potential problems related to forest health. Two of five Forest Inventory and Analysis inventory panels in South Carolina and surrounding States were completed in 2000 and 2001. The crown volume of each sampled live tree at least 5.0 inches in diameter was estimated from field measurements associated with the Phase 3 Crown Indicator. Regression models were then used to adjust each crown volume for differences in stem diameter by species. Model residuals were subsequently rescaled to a mean of 0 and standard deviation of 1, thereby enabling direct comparisons of deviations from expected crown volumes across species and tree sizes. The occurrence of trees below the 25th percentile on these adjusted statistical distributions was then examined for spatial cohesion. A statistically significant cluster of plots containing trees with below-threshold values was identified on the South Carolina-Georgia border. Additional spatial analyses in which thresholds were lowered to the 10th and 5th percentiles yielded similar results.

Parent Publication

Citation

Bechtold, William A.; Coulston, John W. 2005. Detection Monitoring of Crown Condition in South Carolina: A Case Study. In: Proceedings of the fifth annual forest inventory and analysis symposium; 2003 November 18-20; New Orleans, LA. Gen. Tech. Rep. WO-69. Washington, DC: U.S. Department of Agriculture Forest Service. 222p.
https://www.fs.usda.gov/research/treesearch/14291