Ligustrum lucidum as an opportunist invasive species in an Araucaria Forest in South Brazil

Abstract

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.

Key words:
exotic species; Atlantic Forest; biological invasion; demographic patterns; Santa Catarina