Two sides of the same coin? Ants are ecosystem engineers and providers of ecosystem services

Ants are well-known for their roles in ecosystem engineering and for providing multiple ecosystem services. In the past, these two roles have mainly been studied independently, and the possibility that these are two interchangeable roles just studied in different ways should be considered. In this review, we outline what is known of ant populations and communities as engineers and service providers, including disservices resulting mainly from their nesting habits. Then we consider the possibility of engineering and services being similar or contrasting roles. We argue that while both are linked through the same processes, they are effectively researched as distinct because of conceptual and methodological differences; a consequence of the historical construction of both fields and of their focus. However, considering the relevance of ants within most terrestrial ecosystems and of their widespread presence and abundance, we must start combining knowledge and practices from both fields to fully acknowledge and account for the importance of ant engineering to human well-being. Thus, we provide directions and identify areas that would benefit from the incorporation of both approaches into future studies. For example, a shift of focus from ant population to ant community studies is necessary and overdue for a holistic understanding of the role of ant communities in ecosystems. Further, another direction is the potential for ant engineering to restore degraded ecosystems. Both directions would highly benefit from applying the theory and methods of functional ecology in their approaches, and the reasons are also discussed in this review. Hopefully, growing awareness on the topic will increase the demand for conservation of the ecosystems and their derived services, as well as the proper quantification of this insect contribution to human societies.