Alexandre Deschamps Schmidt, Tânia Tarabini Castellani and Michele de Sá Dechoum
Programa de pós-graduação em Ecologia, Universidade Federal de Santa Catarina, Campus Universitário s/n – Córrego Grande, Florianópolis, SC 88040-900, Brazil
There are several tree species among the best known and most impacting invasive plants. Invasive non-native trees can result in changes in native plant species richness, abundance and composition, as well as in environmental characteristics and ecosystem functioning. Hovenia dulcis Thunb. (Rhamnaceae), is a tree native to East Asia and invasive in southern South America across different forest ecosystems. This study aimed at assessing the effects of H. dulcis on richness, abundance and composition of regenerating species in Seasonal Deciduous Forest (SDF) by comparing invaded and non-invaded areas. To date, studies assessing the effect of H. dulcis on the regeneration of indigenous species do not exist. This approach contributes to understanding the mechanisms involved in H. dulcis invasion and its effects on invaded plant communities. The existence of correlations between abundance and richness of regenerating species with age and density of the invasive species, as well as with characteristics of canopy openness, litter thickness, slope, and soil moisture, was investigated in areas invaded by H. dulcis. Differences observed in canopy openness and litter thickness between areas invaded by H. dulcis and control areas suggest that H. dulcis is able to change environmental conditions on a local scale, resulting in potential positive feedback for the invasive species (Table 1). Although no differences were observed in species richness between areas with and without the invasive species, the differences registered in abundance and composition of regenerating species make the impact by H. dulcis on regeneration patterns in SDF fragments evident. The impacts caused by H. dulcis on SDF confirmed by this study and the regional extent of H. dulcis invasion, highlight the need for the development of a regional management program to protect the scarce remnants of SDF in southern South America.