Native anurans threatened by the alien tree Ligustrum lucidum in a seasonal subtropical forest

Abstract

Amphibians and anurans in particular are declining globally from diverse and complex causes, with one of the most prevalent being alien species invasion. Alien woody invaders, such as the evergreen Ligustrum lucidum, are deeply transforming native ecosystems worldwide. Our aim was to evaluate the effect of Ligustrum lucidum invasion on native anurans in a seasonal semiarid subtropical forest. Sampling was conducted in streams dominated by L. lucidum forest and streams dominated by native forest. Amphibian species richness and diversity, and community and species abundance were recorded. We characterized invaded and non-invaded streams by measuring biotic and abiotic variables. Invaded streams support only three of the seven species present in non-invaded streams. Species richness in non-invaded streams was twice as high as in invaded streams and community abundance was almost five times greater in the former than in the latter. Invasion by L. lucidum triggers profound changes in vegetation physiognomy and composition of this xerophytic seasonal forest, resulting in dark, unsuitable habitats for several native anurans. In agreement with the few studies focused on the effect of alien woody invaders on amphibians, this study supports that woody alien invasion results in a reduction of native anuran richness and the dominance of a generalist anuran species. This is the first report on the disruptive role of L. lucidum invasion in local anurans diversity and community dynamics.