Effect sizes
We calculated effect sizes as the Fisher’s z -transformation of Pearson’s correlation coefficients (r ) (Rosenberg et al., 2013):
\begin{equation} Z=\operatorname{}\left(\frac{1+r}{1-r}\right)\nonumber \\ \end{equation}
The corresponding variance for each Z was estimated as:
\begin{equation} Var=\frac{1}{n-3}\nonumber \\ \end{equation}
where n is the sample size. Positive values of Z indicate that increasing elevation is associated with increases in foliar fungal disease or foliar/soil pathogens, while negative values indicate decreases.