Influence of ecoregion-scale variables
We found assemblage position relative to the ecotone —either as an
isolated effect or interacting with habitat type— among the main
predictors of aTR, aST, and aLT. Position had the largest coefficient in
the model of aTR (Table 2). Position x habitat type interaction had the
largest coefficient in the model of aST, and the third largest
coefficient in the model of aLT (Table 2).
Position, habitat type, and the position x habitat type interaction were
the variables causing the largest deviation in aTR from the expected aTR
mean (Table 2). Although there was substantial phylogenetic uncertainty
on parameter estimates, as observed by the range of values along the
x-axis of the density plot, we found that ecotone assemblages generally
had lower aTR than the expected aTR mean (intercept, Fig. 2).
Assemblages at the ecotone of forested ecoregions had higher aTR than
the expected aTR mean (Fig. 2). Assemblages at forested ecoregions had
lower aTR than the expected aTR mean (Fig. 2). Density plots of least
important coefficients —the ones with small regression coefficients
(Table 2) and generally tight overlap of intercept and coefficient
estimates— can be found in the Supplementary Results (Figs. S2-S4).
Position x habitat type interaction, location at Atlantic Rainforest,
and position were the variables causing the largest deviation in aST
from aST mean (Table 2). Although there was substantial phylogenetic
uncertainty, with different groups of phylogenies leading to two
different peaks of aST estimates, we found that assemblages at the
ecotone of forested ecoregions generally had higher aST than the
expected aST mean (Fig. 3). Assemblages in Atlantic Forest had higher
aST than the expected aST mean. Points at ecotones had lower aST than
the expected aST mean (Fig. 3).
Habitat type, location in Atlantic Rainforest, and position x habitat
type interaction were the variables causing the largest deviation in aLT
from aLT mean (Table 2). Although phylogenetic uncertainty again
affected parameter estimates, we found that assemblages at forested
ecoregions generally had longer last transition time than the expected
aLT mean (Fig. 4). Assemblages in Atlantic Forest had lower aLT than the
expected aLT mean, and assemblages at the ecotone of forested ecoregions
had lightly higher aLT than the expected aLT mean (Fig. 4).