COS 31-7
Ecosystem engineering effects on species diversity across ecosystems: A meta-analysis
Ecosystem engineering is increasingly recognized as a relevant ecological driver of diversity and community composition. Although engineering impacts on the biota can vary from negative to positive, and from trivial to enormous, patterns and causes of variation in the magnitude of engineering effects across ecosystems and engineer types remain largely unknown. To elucidate the above patterns, we conducted a meta-analysis of 122 studies which explored effects of animal ecosystem engineers on species richness of other organisms in the community.
Results/Conclusions
The analysis revealed that the overall effect of ecosystem engineers on diversity is positive and corresponds to 25% increase in species richness, indicating that ecosystem engineering is a facilitative process globally. Engineering effects were stronger in tropics than at higher latitudes, likely because new or modified habitats provided by engineers in tropics may help minimize competition and predation pressures of resident species. Within aquatic environments, engineering impacts were stronger in marine ecosystems (rock shores) than in streams. In terrestrial ecosystems, engineers displayed stronger positive effects in arid environments (e.g. deserts). Within engineering functional groups, those that create new habitats or microhabitats had stronger magnitude effects than those which modified habitats or caused bioturbation. Invertebrate engineers and those with lower engineering persistence (<1 year) affected species richness more than vertebrate engineers which persisted for > 1 year. Invertebrate species richness was particularly responsive to engineering impacts. This study is the first attempt to build an integrative framework of engineering effects on species diversity; it highlights the importance of considering latitude, habitat, engineering functional group, taxon and persistence of their effects in future theoretical and empirical studies.