Effetti di un incendio boschivo sulla biodiversità degli Artropodi in un bosco vetusto di Pinus nigra Arnold subsp. laricio (“Giganti di Acatti”) in Aspromonte

Wildfires can constitute an ecological agent capable of continuously regulating and shaping ecosystems. Concern about these phenomena arises when these events are intensified (especially in terms of duration and extent) due to man. Invertebrates succumb more easily to fire, due to their reduced mobility. This study has the objective of evaluating the impact of the fire on the Arthropod community through a multi-taxa approach, in a centuries old Pinus nigra Arnold subsp. laricio forest. It is located in Serro di Acatti, in the Aspromonte National Park (municipality of San Luca in the province of Reggio Calabria) falling in integral reserve, which was destroyed during a fire in August 2021. The research compared the effects on the specific richness and abundance of Arthropods one year after the forest fire. Moreover, the seasonal variation of these communities in three Pinus stands: burned stand by a crown fire (A), transition stand burned by a grazing fire (B) both in the "old forest", and a not burned area (C) adjacent to the first two investigated. Five samplings were carried out in 2022 using pitfalls and aerial traps for the Arthropod fauna collection and three soil collections for chemical and chemical-biological analyses. The results obtained were significant and, although they exclude the results of aerial traps, for which processing is still in progress, showing that the fire profoundly affected the entire forest ecosystem. The number of Arthropods collected in the two-burned stands proved to be around 50% of that obtained in the unburnt area. Furthermore, in the burned area the soil organic matter and the enzymatic activity of the microorganisms in the soil was significantly reduced. The sampled Arthropods in the three stands (Tot N=64,450) are mostly represented in succession by the orders Diptera, Hymenoptera, Coleoptera, Araneae, Collembola and Lepidoptera. The ratio among the different groups differed in relation to the stand and the typology of the fire. The samples obtained, in each monitoring, showed overall an altered seasonal dynamics which became more evident in the stand with crown fire. The results have highlighted the clear reduction in the abundance and richness of Arthropods and evident environmental imbalances. The extensive damage caused by forest fires in the Mediterranean area, has become an ever-increasing problem, with severe ecological, economic and social consequences. They add to other unknowns that represent the fundamental environmental emergencies of recent years: desertification, climate change, decrease in water resources, disappearance of habitats and, as highlighted in this study, loss of biodiversity. The study has set further goals to be investigated in the future to obtain a holistic approach in natural environments characterized by valuable habitats and species of community interest, including the analysis of the temporal variability of the communities as a function of the temporal distance from the fire and by seasonality.