Fruit removal of an invasive exotic species (Ligustrum lucidum) in a fragmented landscape

摘要

We evaluated if fruit removal of an exotic and invasive species-Ligustrum lucidum (Oleaceae)-varies between fragments of different sizes in the Chaco dry forests of Cordoba, Argentina. We considered densities of both L lucidum and the other ornithochorous plant species that bear fruit simultaneously with L lucidum, as variables that could influence fruit removal of this species. We sampled three small (0.5-5 ha), two medium fragments (10-30ha), and two continuous forests (more than 1000 ha). The percentage of fruits removed per tree was higher in small fragments than in medium or large ones. We did not find significant differences in plant density between fragments of different size neither for L. lucidum nor for the other ornithochorous plant species. During the "effective" removal period of L. lucidum (i.e., when animals removed fruits), the other ornithochorous plant species did not offer fruits. This region is affected by an increasing fragmentation process, where continuous woodlands have been reduced to small fragments. Considering that the main result is higher fruit removal in small fragments, new studies on the ecology of this species are needed if Chaco dry forests are to be conserved.