Urban green areas retain just a small fraction of tree reproductive diversity of the Atlantic forest

• Published in: Urban forestry & urban greening Vol. 54; p. 126779
• Main Authors: Oliveira, Marcela T.P., Silva, Jéssica L.S., Cruz-Neto, Oswaldo, Borges, Laís A., Girão, Luciana C., Tabarelli, Marcelo, Lopes, Ariadna V.
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.10.2020
• Subjects: Brazil; ecosystem services; Exotic plants; Floral traits; forest stands; Functional diversity; green infrastructure; hermaphroditism; indigenous species; insects; introduced plants; Native plants; old-growth forests; Pollination; reproductive traits; social welfare; trees; Tropical urban ecosystem; urban areas; urban parks; Brazil; Native plants; Exotic plants; Tropical urban ecosystem; Functional diversity; Floral traits; Pollination
• ISSN: 1618-8667
• DOI: 10.1016/j.ufug.2020.126779

•Tropical urban green areas are dominated by generalist-pollinated trees.•Squares and parks in tropical city have similar functional plant reproductive traits.•Tropical urban ecosystems have less trees pollinated by bats compared to natural.•Native plants can contribute for the maintenance of pollinators in tropical urban ecosystems.•Exotic plants distort the reproductive profile of tropical green spaces. Urban green spaces have gained notoriety in recent years, as they have been argued to play an important role in supporting native biodiversity, ecosystem services and human well-being. However, such a promising perspective is poorly investigated in the tropical context. Here we examine the role played by urban green areas in a major city (Recife-Brazil) as a repository for Atlantic forest biodiversity relative to pollination systems. Plant assemblages were examined across 17 urban green areas and compared to those from ten old-growth forest stands in the largest Atlantic forest remnant in northeastern Brazil (natural areas). Just a small portion of tree species inhabiting urban green areas is native to the northeastern Brazilian Atlantic forest (29.8 %). At plant community-level, squares and parks were impoverished in terms of number of species and individuals with specialized pollination systems (e.g. bats, Sphingids), as compared to forest remnants. Moreover, urban green areas were dominated by generalist-pollinated trees with reproductive traits associated with easily accessible floral resources and an increase of hermaphrodites. Finally, squares and parks had similarly low functional diversity of reproductive traits. Our results suggest that urban green areas support largely distorted and impoverished tree assemblages in terms of floral rewards and pollination, while services are restricted to those offered by generalist small insects. This pattern emerges mainly from the contribution of exotic plants. This largely limits the tropical urban green areas as biodiversity repositories and potential source for specialized pollination services, what calls for a better use of tropical urban areas as conservation tool.