El Niño impacts on human‐modified tropical forests: Consequences for dung beetle diversity and associated ecological processes

• Published in: Biotropica 2020-03, Vol.52 (2), p.252-262
• Main Authors: França, Filipe M., Ferreira, Joice, Vaz‐de‐Mello, Fernando Z., Maia, Laís F., Berenguer, Erika, Ferraz Palmeira, Alessandro, Fadini, Rodrigo, Louzada, Júlio, Braga, Rodrigo, Hugo Oliveira, Victor, Barlow, Jos
• Format: Article
• Language: English
• Subjects: Abundance; Amazonia; Anthropogenic factors; Beetles; Biodiversity; Brazil; Climate; Coleoptera; Dispersal; Dispersion; Disturbance; Drought; Dung; Ecological effects; Ecological function; ecological functions; Ecosystem disturbance; El Nino; El Nino phenomena; El Niño; fires; Forest fires; Forest management; Forests; Human influences; Removal; Seed dispersal; Species composition; Species richness; Tropical climate; Tropical forests; tropical rain forests
• ISSN: 0006-3606; 1744-7429
• DOI: 10.1111/btp.12756

Our knowledge of how tropical forest biodiversity and functioning respond to anthropogenic and climate‐associated stressors is limited. Research exploring El Niño impacts are scarce or based on single post‐disturbance assessments, and few studies assess forests previously affected by anthropogenic disturbance. Focusing on dung beetles and associated ecological functions, we assessed (a) the ecological effects of a strong El Niño, (b) if post‐El Niño beetle responses were influenced by previous forest disturbance, and (c) how these responses compare between forests impacted only by drought and those affected by both drought and fires. We sampled 30 Amazonian forest plots distributed across a gradient of human disturbance in 2010, 2016, and 2017—approximately 5 years before, and 3–6 and 15–18 months after the 2015–16 El Niño. We found 14,451 beetles from 98 species and quantified the beetle‐mediated dispersal of >8,600 seed mimics and the removal of c. 30 kg of dung. All dung beetle responses (species richness, abundance, biomass, compositional similarity to pre‐El Niño condition, and rates of dung removal and seed dispersal) declined after the 2015–16 El Niño, but the greatest immediate losses (i.e., in 2016) were observed within fire‐affected forests. Previous forest disturbance also influenced post‐El Niño dung beetle species richness, abundance, and species composition. We demonstrate that dung beetles and their ecological functions are negatively affected by climate‐associated disturbances in human‐modified Amazonian forests and suggest that the interaction between local anthropogenic and climate‐related stressors merits further investigation. in Portuguese is available with online material. Resumo Nosso conhecimento sobre os impactos de distúrbios antrópicos e climáticos na biodiversidade e funcionamento das florestas tropicais é limitado. Pesquisas sobre o El Niño são escassas ou baseadas em avaliações pós‐distúrbio sem repetições ao longo do tempo, enquanto que poucos estudos avaliam florestas previamente antropizadas. Focando nos besouros escarabeíneos e alguns processos ecológicos que eles realizam, nós avaliamos (i) as consequências ecológicas de um El Niño extremo, (ii) se as respostas dos besouros escarabeíneos após o El Niño foram influenciadas por distúrbios florestais anteriores e/ou (iii) variaram entre florestas afetadas apenas pela seca e florestas impactadas tanto pela seca quanto pelo fogo durante o El Niño de 2015–16. Em 2010, 2016 e 20