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Today biological invasion is one of the most dangerous threats to biodiversity and there are only few tools to monitor and control. This study structure and tested the potential of niche modeling procedures from data of occurrence of Hovenia dulcis Thunberg, and Tithonia diversifolia (Hemsl.) A.Gray, using the algorithm GARP and MaxEnt, associated with sets of environmental variables, in order to develop tools not yet used to predict invasion risk in the State of Santa Catarina. The potential niche models generated with GARP and MaxEnt algorithms proved efficient to generate potential niche models for species, indicating locations with risk of biological invasion. From this study it was observed that the niche modeling for invasive species represents an important tool for the mapping of invasions established and niche prediction for invasive species. These ecological niche models generated from the GARP and MaxEnt algorithms can provide relevant information on areas with risk of invasion to Tithonia diversifolia and Hovenia dulcis and may become a tool of institutional control in anticipation of new invasions and tracking the spread of invasive species in the State of Santa Catarina. [ABSTRACT FROM AUTHOR]

The objective of this study was to infer the mechanisms of invasion (opportunism vs. competition) of Ligustrum lucidum in an Araucaria Forest fragment, in the municipallity of Lages, SC. This fragment was inventoried in 2012 and 2015, through plots, where tree individuals with dbh greater than or equal to 5.0 cm were evaluated. The plots were classified as invaded (I) or non-invaded (NI) by L. lucidum and the dynamics rates were determined for the tree community and populations. The influence of L. lucidum presence on demographic rates of community was evaluated by logistic regressions and the evaluation of species coexistence in I and NI sectors was performed by c-score index. In fragment, the recruitment rate was greater than mortality and basal area gain rate was greater than basal area loss. The community had a greater recruitment in plots with high L. lucidum abundance. While there was spatial segregation of species in NI plots, there was random pattern in I plots. We conclude that L. lucidum is increasing its relative importance in community, being associated to plots with random species co-occurrence, suggesting its opportunist nature. [ABSTRACT FROM AUTHOR]