Fig. 5
From: Land use change and forest management effects on soil carbon stocks in the Northeast U.S.
Organic horizon C stocks as a function of time since harvest based on meta-analysis results (filled circles) and NFI plots (open squares). Time since harvest (years) is presented as a categorical variable (age class group), due to the difficulty of precisely constraining years since harvest among the published studies used for meta-analysis. Y-axis values for NFI plot data are ln-transformed C stocks and 95% confidence intervals; for meta-analysis results, y-axis values are C stock changes (ln-transformed response ratios and bootstrapped confidence intervals). Letters denote statistical significance of pairwise comparisons (Tukey test) for NFI plot data; for meta-analysis results, the asterisk indicates the age class group with confidence intervals not overlapping 0% change (R = 1.00)