Density and spatial distribution of invasive alien species in a secondary rainforest fragment

Abstract

Invasive alien species represents a risk and there are measures to prevent them from causing environmental and economical serious problems. The objective of this study was to record the species richness, abundance and spatial distribution of alien species in a small rainforest fragment in the Parque da Cidade, Pindamonhangaba (SP), southeast Brazil. Sansevieria trifasciata was the most dominant species occurring in three clusters inside the fragment. Tradescantia zebrina was only recorded in places where Sansevieria was absent or rare. The third species, Livistona chinensis, recorded low density throughout the forest fragment. In conclusion, it seems Sansevieria are aggressively competing for space not just with native species abut also with alien species and, the small forest fragment has few invasive exotic species but with large density and, a future project is urgent in the park to record more alien species and evaluate possible impacts on native species.

Key-words: Invasive alien species, forest fragmentation, Pindamonhangaba.