A Uerj study shows that the jackfruit tree, an invasive species in the Atlantic Forest, reduces leaf litter depth and arthropod abundance, affecting various frog species. Areas dominated by the tree feature simpler habitats, with varied impacts on wildlife. Published in Biological Invasions, the research emphasizes the need for management to restore ecological complexity.
Invasive species pose a major threat to global biodiversity by altering habitats and reducing native diversity. In Brazil's Atlantic Forest, the jackfruit tree's effects on vegetation are known, but a recent study from the Department of Ecology at the Universidade do Estado do Rio de Janeiro (Uerj) examines its impacts on the forest floor, a critical habitat for tropical wildlife.
Conducted at the Reserva Biológica Duas Bocas in Espírito Santo, the research investigated how the jackfruit tree changes the litter layer structure. Invaded areas show shallower leaf layers and lower arthropod abundance, such as insects and invertebrates, which are vital for ecosystem function and food for small vertebrates. This simplification eliminates microhabitats, reduces moisture retention, and creates less stable conditions for sensitive species.
The scientists assessed three frog species with varying ecological requirements. Rhinella crucifer, or sapo-cururuzinho, a generalist tolerant to disturbances, was recorded more frequently in jackfruit-dominated areas. In contrast, Haddadus binotatus, known as rãzinha-do-folhiço, which relies on moist and stable microhabitats, showed a sharp decline in these zones. Proceratophrys schirchi, or sapo-de-chifres, experienced no direct impact but its presence correlated with litter depth and arthropod diversity, both diminished in invaded sites, leading to indirect effects.
These variations demonstrate how the invader acts as an ecological filter, favoring degradation-tolerant species and potentially causing biological homogenization, with communities dominated by few generalists and loss of functional diversity. The study stresses that jackfruit removal is crucial in protected areas but should involve restoring litter and native understory vegetation to prevent further issues. Funded by Faperj and Rufford Foundation, the work, with open access via Capes and Springer Nature, highlights the need to understand indirect impacts for effective conservation policies, particularly for sensitive amphibians.