Figure 2. Distance effect from focal trees on seedling survival.

Upper panels are the results for fungicide-treated soils, whereas lower panels are for γ-radiation-treated soils, to show the distance effect from focal trees on seedling survival. (a,c) Soil samples were collected from abundant sites; (b,d) soil samples were collected from low-density sites. Boxplots for untreated soil are in blue colour (solid line) and red colour (dashed line) for fungicide-treated soil (a,b) or γ-treated soil (c,d). Each boxplot shows the median, inter-quartiles and whiskers. Dots outsides the whiskers are outliers. **indicates seedling survival rates in fungicide (or γ-radiation)-treated soils were significantly higher than that in untreated soils collected at the respective distances of 0 and 5 m away from the focal trees in the abundant sites. The P-values for the two ** in a are 6.27e−11 and 2.87e−11, respectively (Mann–Whitney test), and for the two ** in c are 6.27e−11 and 2.86e−11, respectively. Sample size for each of the Mann–Whitney tests is 90 untreated soils versus 90 treated soils.