Fig. 3

Schematic representation of how community diversity may change between environments differing in stress and productivity (i.e. integrating the “predation” “intermediate disturbance” ⇔ “compensatory mortality” hypotheses; after Bertness and Callaway 1994; Hacker and Gaines 1997). The dashed lines indicate how ecosystem engineers in stress dominated habitats can both enhance community diversity by facilitation processes (after Hacker and Gaines 1997) or reduce local diversity by causing negative species interactions (EE-exclusion = ecosystem engineering-exclusion) via their modification of the environment (after van Wesenbeeck et al. 2007). These potential effects are also indicated below the x axis