Inflow intensity
We classified species into two groups: low abundance center group and
high
abundance center group based on the location of their abundance center
(Equation 1). Species with abundance center below the midpoint of the
elevational gradient of Lebu Valley (3,650 m a.s.l.) are defined as the
low abundance center group. Species with abundance center above the
midpoint of the elevational gradient are defined as the high abundance
center group. Inflow intensity is defined as the difference between the
mean abundance center (m) of the low abundance center group and the high
abundance center group in each 100-m elevational band (mean abundance
center high group – mean abundance centerlow group) (J.-Y. Kim et al., 2019). In elevational
bands where only species of one group (high or low abundance center
group) were found, the value of the inflow intensity was zero. If the
inflow intensity is positively correlated with species richness, the
proximity of the range margins of potentially interacting species was
considered to contribute to the richness pattern, which indicates that
the rescue effect was supported (J.-Y. Kim et al., 2019).