. Species diversity measures
For quantifying tree species diversity we used the evenness
measure of the Shannon index (Shannon and Weaver, 1949, Eq.
(1)), an information theory index. The Shannon index was originally
proposed to quantify the entropy, i.e. the uncertainty of information,
in strings of text (Krebs, 1999, p. 444). By contrast, the
Simpson index (Simpson, 1949, Eq. (2)) is a dominance or concentration
measure.