Figure 2. K-function envelopes and Diggle-Cressie-Loosmore-Ford
(DCLF) test p-values weighted by tree diameter for select sites in the
Midwestern point-pattern dataset. Dashed red lines represent the
theoretical Poisson distribution. Grey shaded sections are 95%
acceptance envelopes. The black line illustrates the empirical
K-function. Departure of the black line from the envelope signify a
non-random distribution where points above indicate clustering and below
indicate overdispersion.
Examination of Dixon contingency tables of points marked either by
species (redcedar vs deciduous trees) or by size of trees (DBH
< 2.5 cm vs DBH > 2.5 cm) revealed segregation in
many of study sites in the Midwest all trees dataset andMidwest living trees datasets (Table S3). When considering Dixon
contingency tests of only two classes (e.g. small vs large), significant
findings indicate the nearest neighbor is likely to be of adifferent type. At Lakeside 1 in the Midwest all trees andMidwest living trees datasets the nearest neighbor of deciduous
species was more likely to be a redcedar tree than another deciduous
tree. In both datasets, the redcedars at Edge 5 were segregated from
other redcedar trees. Instances of segregation according to size in theMidwest all trees dataset was mixed. In Edge 4 and Gettysburg 1,
large trees were segregated from each other.