Fig. 2

Spatial patterns of American beech saplings around large American beech trees and large trees of all other species. Vertical axes indicate bivariate pair correlation function values (higher values represent increased clustering), and horizontal axes indicate distance from large trees (ranging from 1 m at the far left to 10 m at the far right of each panel). Each panel displays results for an individual plot. In the panels without confidence envelopes (left side), thick grey lines represent large American beech trees, dashed black lines represent large trees of all other species, and dotted horizontal lines indicate complete spatial randomness (clustering above, repulsion below). The panels with confidence envelopes (right side) display the difference between the two lines on the corresponding left panel (large trees of all other species minus large American beech trees). The dotted horizontal line identifies the position on the vertical axis where the difference is zero, and extensions above or below the confidence envelope indicating significant differences. As an example, in plot FS-17, American beech saplings are clustered around large trees of other species but repulsed from large American beech trees (at short distances)