Relationship between geographical distance, climatic distance,
habitat composition and beta diversity
At the largest scale, geographic and climatic distances did not show any
significant relationship with turnover (Fig. 5A). In the case of the
intermediate scale, all islands except São Jorge showed a positive
relationship between geographical distance and turnover
(R2=0.21, R2=0.27,
R2=0.03, R2=0.11,
R2=0.04, and R2=0.07 for Faial,
Flores, Pico, São Jorge, São Miguel, and Terceira, respectively; fig.
5B). At the smallest scale, the relationship between geographical
distance and turnover was also positive and significant in most islands
except in native forests of Flores and naturalized vegetation of Pico
(fig. 5), although all significant R2 values were
small and ranged between 0.06 and 0.1. Overall, the effect of climatic
dissimilarity on turnover was weaker than that of the geographical
distance. A positive and significant effect of climate was detected at
intermediate scale for Faial, Pico and São Jorge
(R2=0.03, 0.09 and 0.01, respectively; fig. 5B and
5C). At the smallest scale, climatic dissimilarity only had a
significant positive effect for the naturalized vegetation of São Jorge
(R2=0.45), and in the seminatural pastures in São
Jorge and São Miguel (R2=0.11 in both cases; fig. 5C).
Finally, there was no significant effect of habitat composition on
turnover at the intermediate scale (fig. 5B).