Plant restoration projects often either completely ignore faunal restoration or implicitly follow the ‘field of dreams’ hypothesis: if you build it, they will come. But does restoration of a plant community automatically result in re-establishment of its native faunal components? In the subtropical island of Mauritius, native plant restoration projects have been ongoing for several decades, but their effects on native invertebrate populations have never been measured. Ants are of particular interest because they play important and varied roles in the ecosystem and because of their usefulness as indicators of community health. I used three methods (pitfall traps, baiting, and direct observations) to survey 10 sites with managed plant communities and 10 paired adjacent unmanaged sites in heath habitats and upland and intermediate forests to determine whether native ants have persisted and whether they are associated with native vegetation.
Results/Conclusions
Results from all methods combined indicate that native ants were more likely to be found in unmanaged sites. Managed sites had a higher proportion of introduced ants and a greater overall abundance of ants than unmanaged sites. Native ant abundance did not correlate with managed fragment size, time since first management, or with the abundance of non-native ants but did correlate with the abundance of dead standing wood (rs=0.61). Non-native ant abundance was negatively correlated with site complexity (rs= -0.47). Although native ant and non-native ant abundance did not correlate, there may be a threshold of non-native ant abundance above which native ants cannot persist or re-establish. Disturbance created by weeding and higher levels of human foot traffic may increase the likelihood of non-native ants being introduced and persisting in managed sites.