Summary data for comparisons of habitat structure data generated by volunteers and ecologists within 11 50 m × 50 m survey plots on Buton Island, Indonesia. Median numbers of trees and circumference-at-breast-height (CBH) values per subplot have values of 1 standard deviation provided in parenthesis. The Wilcoxon Signed-rank column displays Wilcoxon Signed-rank test values for comparisons of median tree count and CBH values generated by volunteers and ecologists. The Pearson’s R and Kendall’s Tau columns show correlation co-efficient values for comparisons between volunteer and ecologist-derived datasets. Test statistics denoted * are significant (P < 0.05). For Wilcoxon Signed-rank tests and Pearson’s correlations, data were aggregated by 10 m × 10 m subplots (N = 275 for tree count analysis and N = 250 for CBH measurement analysis). The same tests were applied to all individual trees in our dataset (N = 1044). As these test statistics are based on the whole tree dataset, and not median values, these are reported in a separate row. For Kendall’s Tau correlations, data were aggregated on a plot scale (N = 11) for tree count analysis and N = 10 for CBH measurement analysis)