Programma della conferenza

Intense human impacts, susceptibility to species invasion, small sizes of native populations, and high levels of endemism make extinction rates on islands much higher than those observed on mainlands. Mediterranean small islands are threatened by many factors, including overexploitation, landscape degradation, tourist pressures, and climate change. These islands host unique assortments of insect species, including several endemic taxa. A review of available information on the conservation status of various insect groups on Mediterranean small islands highlights some major areas of concern: (1) Island insects are mainly threatened by habitat loss due to clearance of natural vegetation for settlement (urbanization) and agriculture; (2) Invasive plants and animals (especially other insects) may represent an important, yet overlooked, source of threats; (3) Climate change has not been directly implicated in island insect decline to date, but it will be increasingly important in the near future due to the reduction of island size from rising sea level and the direct and indirect impacts of increasing temperature on ecosystem functioning and insect biology. Preservation of areas in good conservation status (mainly through site protection), habitat management and restoration, invasive species control, and species conservation actions, are urgently needed to improve insect conservation on Mediterranean small islands.

Human activities, especially agriculture and urbanisation, are causing a significant modification of natural environments. Consequently, animals adapt their physiology to these new environments to exploit them for foraging and breeding. This study aimed to compare the physiological status of nestling common kestrels (Falco tinnunculus) sampled from nest boxes installed in natural, rural, and urban areas around Rome, Italy. A multi-biomarker approach was applied to evaluate physiological responses at multiple levels, including antioxidant concentrations, immune functions, genotoxicity, and neurotoxicity. We found lower concentrations of glutathione and GSH:GSSG ratio values and a higher number of monocytes in urban kestrels than in other areas. Additionally, we observed higher DNA damage in rural kestrels compared to urban and natural ones, and inhibition of butyrylcholinesterase activity in urban and natural area birds compared to those from rural area. Similar values emerged among the study areas for respiratory burst, complement system activity, bactericidal capacity, and plasma non-enzymatic antioxidant capacity. These results show that urban environments do not necessarily cause physiological alterations in kestrels compared to those from other habitats, and due to the different environmental pressures across habitats, the specific organisms’ responses can be detected through a multi-biomarker approach. Further studies are needed to identify which factors induce the physiological differences among natural, rural and urban. birds and to determine whether these differences are consistent over time and space.

The present study, carried out within the framework of the project code CN_00000033, Concession Decree No. 1034 of 17 June 2022 adopted by the Italian Ministry of University and Research, CUP, H43C22000530001377 Project title “National Biodiversity Future Center - NBFC”, aims to evaluate the anthropogenic constraints on the seasonal dynamics of vegetation biodiversity in urban ecosystems. The adopted approach focused on analysing, using seasonal phytosociological relevées from October 2023 to July 2024, the structural and functional diversity of the herbaceous communities colonizing two urban areas in southern Italy, subjected to different levels of management but similar climate. Taxa were identified at the species level, estimating their abundance through measures of number of individuals, dry mass and Braun-Blanquet cover, while Raunkiaer biological forms, chorology and Ellenberg indices were adopted to evaluate vegetation functional diversity.

Results show clear seasonal dynamics in vegetation composition and structure where subjected only to occasional mowing, with dominance-diversity relationships cycling through pre-emption models in winter to lognormal distributions in spring and autumn, passing through Mandelbrot models in summer. This sequence highlights the seasonal evolution of constraints due to endogenous processes (e.g. competition) and external pressures (e.g. summer drought), and is coherent with clear shifts in community composition. Where regular mowing, irrigation and fertilization occur, the seasonal signature on vegetation dynamics fades and the dominance-diversity community structure follows similar pre-emption models throughout the year, with limited variations in species richness and evenness. The relative seasonal variations in different diversity indices between the study areas further support the effects of anthropogenic constraints on vegetation seasonal dynamics.

Findings shed light on the temporal evolution of vegetation communities in complex urban ecosystems, with clear interpretations in terms of diverse anthropogenic constraints.