Subaerial biofilms on outdoor stone monuments: changing the perspective towards an ecological framework

Despite the appreciation of the role played by outdoor stone heritage in societal well-being and sustainable urban development, research efforts have not been completely successful in tackling the complex issues related to its conservation. One of the main problems is that we are continuously underestimating the role and behavior of microorganisms in the form of biofilm (subaerial biofilms, SABs) in the management of stone artifacts. To this end, we discuss the necessity of approaching the topic from an ecological perspective through an overview of the characteristics of SABs that mediate different ecological interactions. Furthermore, we explore the application of functional-traits ecology to unravel the mechanisms by which SABs might respond to a changing environment. Finally, we guide and prioritize further research in order to inform policymakers and to develop management strategies for protection prior to-or following-active conservation treatment.