Trait–environment relationship of riverine fish assemblages across a human footprint mosaic

• Published in: Hydrobiologia 2024-03, Vol.851 (5), p.1135-1151
• Main Authors: Araújo, Francisco Gerson, de Azevedo, Marcia Cristina Costa, Guedes, Gustavo Henrique Soares, Pinto, Benjamin Carvalho Teixeira
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Biodiversity; Biological fertilization; Biomedical and Life Sciences; Climate change; Deforestation; Ecological effects; Ecological studies; Ecology; Ecosystems; Environmental conditions; Fertilization; Fish; Freshwater & Marine Ecology; Geographical distribution; Grasses; Human influences; humans; Influence; Life Sciences; Native species; Nonnative species; Phalloceros caudimaculatus; Poecilia reticulata; Poecilia vivipara; Primary Research Paper; riparian areas; Riparian land; Rivers; Species; Variables; Water shortages; Zoology
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-023-05370-9

Environmental influences on species’ functional traits are important ecological issues to assess biodiversity. Relationships among fish abundance, their functional traits, and environmental conditions across different levels of anthropogenic impacts in a tropical Brazilian river were evaluated. We combined RLQ and fourth-corner methods, utilizing local environmental variables and the Human Footprint Index (HFI) as a human activities indicator. Three HFI levels (High, Intermediate, and Low) and short-term (1993–2009) impact changes at each location were assigned. Fish with internal fertilization and small body sizes were strongly associated with high HFI scores. Grass-dominated riparian areas were common in altered locations, whereas less altered localities exhibited the riparian cover dominated by trees. Highly altered areas showed high HFI, grass-covered riparian zones, and small-sized species with internal fertilization (e.g., Cyprinodontiformes like Poecilia vivipara , Poecilia reticulata , and Phalloceros caudimaculatus ). In contrast, less altered areas had tree-lined riparian zones and medium to large-sized species with external fertilization and diverse traits. Underlying deterministic processes shape species distribution, tied to environment and traits. Filtering of traits in the most altered locations may favor small-sized species with internal fertilization. This approach, utilizing HFI and local variables to assess trait–environment relationships of riverine fish, facilitates understanding organisms’ responses to environmental constraints.