Drivers of β diversity.
Overall, models explained a relatively large amount of variance in
β-diversity: mean Rc2 = 0.71, range
0.6 - 0.87; Table 2). Also, for β-diversity, a large amount of the
variance was explained by site, as indicated by the difference in model
fit between the conditional and marginal R2 (mean
Rc2–Rm2 = 0.36, range 0.06-0.84; Table
2). This was most prominent for β-diversity of springtails, protists and
fungi, where site explained at least twice as much variation as all
other variables combined (Table 2), coinciding with patterns for
ɑ-diversity. Conversely, the effect of site was negligible for
nematodes, mites and bacteria (Table 2). Of the fixed effects, cessation
of grazing was the main factor responsible for differences in
β-diversity: grazing removal had a positive impact on β-diversity of
soil fauna groups and a negative effect on β-diversity of fungi (Table
2), in line with the results on response ratio (Figure 3B). Moreover, pH
was an explanatory variable for β-diversity of nematodes and
springtails, but not for any of the soil microbial groups.