Assessment of native fauna in the expansion of the invasive species Hovenia dulcis Thunb. (Japanese grape), in an urban fragment of Atlantic Forest, Municipality of Santa Cruz do Sul, RS, Brazil

Invasive plants natural ecosystems, negatively impacting biodiversity through competition for resources such as light, water, and nutrients. Fauna plays a central role in the dispersion of native and invasive species, facilitating their expansion into new areas. When dispersed by fauna, invasive plants can rapidly colonize new habitats, competing with local flora and aggravating the problem of biological invasion, highlighting that understanding these interactions is essential to developing more effective management strategies. Thus, this research aimed to analyze the role of fauna in the dispersion of the invasive species Hovenia dulcis in an urban forest fragment of 465 hectares called Cinturão Verde, located in Santa Cruz do Sul, RS, Brazil. Five sampling points were established in the study area for 10 active sampling campaigns between March and November 2023. For passive sampling, 2,225 day-1 camera traps were used during the same period. The results indicated the occurrence of 15 mammal and 170 bird species in the Green Belt, with 40% of mammals and 8.8% of birds recorded consuming the pseudofruit of H. dulcis. These data demonstrate a significant interaction between native fauna and invasive species. Based on these results, a plan is suggested to gradually replace H. dulcis with native species that bear fruit in the same period, such as Schinus terebinthifolius (Brazilian pepper) and Psidium cattleyanum (strawberry guava), in order to meet the food needs of local fauna and protect biodiversity. Continuing research with these species is essential to preserve biodiversity and ecosystem services provided by the urban forest to the municipality's population.