Vulnerability to biological invasion of Hovenia dulcis Thunb. in green areas of Curitiba, Paraná, Brazil

Alien invasive species alter biodiversity, landscape structure, ecosystem functions and services, and habitats of native species of flora and fauna. Multicriteria analysis in a Geographic Information Systems (GIS) environment can be used to evaluate the vulnerability of urban green areas to biological invasion by these species. The objective of this research was to investigate natural and anthropic parameters related to the vulnerability to biological invasion by the Hovenia dulcis Thunb. in Curitiba, Paraná, Brazil. A vulnerability assessment was done in the Curitiba’s urban green areas with lower degrees of anthropization. Six factors related to the presence of Hovenia dulcis were considered: nine points of species occurrence; altitude and slope (topographic metrics); and area, shape, and isolation between areas (landscape metrics). The Analytic Hierarchy Process (AHP) method was used to define weights for each factor. The vulnerability was assessed as very low (0 – 0.2); low (0.21 – 0.4); moderate (0.41 – 0.6); high (0.61 – 0.8); and very high (0.81 – 1). Spatial analyses were performed on QGIS® 3.10 software. The occurrence points of the species represented 45% of the generated model, followed by the landscape factors, mainly the shape of the fragments (17.69% of the model). Within the selected urban green areas, 995.15 ha corresponded to the high vulnerability class, and 839.54 ha to the moderate vulnerability class to invasion by the species. The western, southern, and northern parts of the city are the most vulnerable, which are also the most urbanized. Passaúna Park is the green area most susceptible to invasion by the species mainly due to its irregular shape, most susceptible to the edge effect. Curitiba has a high vulnerability to biological invasion by Hovenia dulcis in its green areas, especially in those located in more urbanized regions.