Fig. 4

Boxplots comparing pH, percent carbon and nitrogen, the natural log of phosphorus and potassium concentrations, and concentrations of calcium, magnesium, and aluminum in the top horizon of 2019 soil cores by burn treatment. The boxplot center line corresponds to the median, the box covers the interquartile range, and the whiskers extend to 1.5 times the interquartile range. Asterisk indicates marginally significant F-test (α < 0.100). Soil cores were collected at the Yale-Myers Research and Demonstration Forest, Eastford, CT, USA