Invasive alien ornamental plants in Brazil: impact, origin, preferred habitats and projections

Abstract

Ornamental horticulture is recognized as an important pathway for introducing alien plants into new habitats. Ornamental plants have been escaping from cultivated environments for centuries, and human actions are regarded as critical factors in the invasion process as they facilitate the spread of species beyond their native habitats. Understanding the diversity of invasive alien ornamental plants is essential for interpreting current trends, measuring and predicting impacts on biodiversity and economy, and guiding biosecurity programs. This paper presents a list of invasive alien ornamental plants in Brazil, addresses the Brazilian situation regarding invasive alien ornamental plants, and discusses issues related to preferred invasion habitats, origin, ecology, and management of the species. Surveys in national databases and queries to global databases were conducted to determine the invasive alien ornamental plants in Brazil. The list includes 125 ornamental plant species (53 botanical families, 40 trees, 30 shrubs, and 29 herbaceous plants). Species of Asian origin predominate. Degraded areas and forest formations are the preferred invasion habitats. The list will serve as a basis for legislation on the introduction of alien plants, biosafety programs in Brazil and neighboring nations, and will contribute to public involvement on the issue of invasive species.