Seasonal dynamics of herbaceous and microbial communities in Mediterranean urban green spaces – the role of management strategies

The management of green areas in urban ecosystems can affect their capability to support ecosystem functions and services in ways and extents still unsatisfactorily elucidated. The present research, funded by the National Recovery and Resilience Plan (NRRP), Project code CN_00000033, CUP, H43C22000530001 Project title “National Biodiversity Future Center—NBFC”, aims to shed light on the effects of management on the seasonal dynamics of the structural and functional diversity of herbaceous communities and on the activity of soil microbial communities in Mediterranean urban ecosystems. To this end, the study adopted a comparative approach between two areas differing in mowing, irrigation and fertilization. The diversity of herbaceous communities, in terms of species richness, evenness and composition, was studied by means of phytosociological surveys, with taxa identified at the species level and functional traits obtained from literature. The metabolic activity of edaphic microbial communities was evaluated through the analysis of enzyme activities (hydrolase, β-glucosidase, phenol-oxidase) as proxy for specific steps of the carbon cycle. Results highlighted that anthropogenic management pervasively affects the structure and functionality of urban ecosystems and their temporal dynamics. Management strategies reduce the structural and functional diversity of herbaceous communities via the process of biotic homogenization, fostering the dominance of generalist species with specific functional traits. Whereas management practices directly affect plant communities, the effects on microbial communities appear to be mediated by the changes in vegetation, with the promotion and inhibition of different enzyme activities through the alteration of organic matter inputs to the soil. Understanding how anthropogenic constraints in urban ecosystems affect biological communities may contribute to the planning of sustainable management approaches able to preserve biodiversity and to improve the stability of urban green spaces.