Frequency of grids with cryptogam species occurrence on Surprise forest block 7.5 yr after fire plotted against frequency of grids with species occurrence on London forest block fire-age mosaic. Each data point represents one species; species with the most extreme residual from a 1:1 prediction are labeled. Some data points overlap due to the limited number of grids sampled. For regression: y = 1.158x − 0.023, R2 = 0.71. For test of regression coefficients: F = 155.5, P ≤ 0.001.