Figure Captions
Figure 1 . Potential changes in ɑ and β-diversity of soil organisms resulting from the cessation of grazing. ɑ-diversity can potentially increase or decrease independently of changes in β-diversity, which can also increase or decrease, from a starting position (indicated in red).
Figure 2. Locations of the 12 sites. Numbers correspond to the different sites: 1) Glen Saugh; 2) Ben Lawers; 3) Glen Finglas; 4) Glen Shee; 5) Lake District; 6) Moor House; 7) North Pennines; 8) Yorkshire Dales; 9) Peak District; 10) Snowdonia; 11) Exmoor; 12) Dartmoor. Background map depicts soil organic matter concentrations (Joneset al, 2016): darker colors indicate high carbon stocks. Picture of Glen Shee (inset) shows a typical pattern as a result of grazing: higher grass cover at the grazed side of the fence with dominance ofNardus stricta and dominance of ericaceous shrubs, such asCalluna vulgaris on the side of the fence where grazers were excluded. Photo: M. Schrama.
Figure 3. Response ratios of different species groups to cessation of grazing (±SD). Light brown bars indicate soil microbes, dark brown bars indicate soil fauna, green bars indicate plants. A) Effects on ɑ-diversity (species richness); B) Effects on β-diversity (homogenization). Positive values indicate an increase in diversity as a result of grazer removal and a negative value indicates a decrease in diversity. Stars indicate significant differences: *** p< 0.001; ** 0.001 < p < 0.01; *0.01 < P < 0.05; ns: not significant
Figure 4. Response ratios of ɑ diversity (±SD) of relatively rare, common and widespread microbes, plant species and soil fauna to abandonment. Light brown bars indicate soil microbes, dark brown bars indicate soil fauna, green bars indicate plants. A positive value indicates an increase in species richness in response to removal of grazing; a negative value indicates a decrease in species richness as a result of abandonment. Stars indicate significant differences: *** p< 0.001; ** 0.001 < p < 0.01; *0.01 < P < 0.05; ns: not significant.
Figure 5 . Long term effects of cessation of grazing on local (ɑ) and compositional (β) diversity. For all groups except mites, collembolans and bacteria we found a significant decrease in species richness when grazers were excluded. There was a more varied response for β-diversity: some groups, such as nematodes, exhibited a strong community divergence, indicating that grazing removal results in increased β-diversity. Other groups, such as, fungi and protozoa exhibited a community convergence, indicating that cessation of grazing led to a decreased β-diversity, while the β-diversity of bacteria was not affected.