Diversidad taxonómica y funcional de aves: Diferencias entre hábitats antrópicos en un bosque subtropical

Abstract

RESUMEN.Una de las amenazas principales para la biodiversidad es el avance de las actividades humanas que implican usos extensivos de la tierra. En este estudio buscamos identificar los usos de la tierra que mejor preservan el ensamble de especies de aves y sus rasgos funcionales en un bosque subtropical. Para ello comparamos simultáneamente la diversidad taxonómica (riqueza específica y similitud en la composición de especies) y la funcional (diversidad de rasgos funcionales y similitud en la composición de rasgos) de aves entre el bosque nativo y los hábitats antrópicos que resultan de actividades como las forestaciones, la urbanización, la ganadería y la agricultura, en uno de los bosques subtropicales más diversos y amenazados del mundo: el Bosque Atlántico del Alto Paraná. Relevamos aves y variables ambientales en los cinco tipos de hábitat, y seleccionamos 11 rasgos para estimar la diversidad funcional. Estimamos el "1-índice de disimilitud de Gower" para explorar las similitudes entre el bosque nativo y los hábitats antrópicos. Pusimos a prueba modelos de cuadrados mínimos generalizados para comparar la similitud ambiental y las diversidades taxonómica y funcional entre los tipos de hábitat. Estudiamos la asociación de los rasgos funcionales en cada tipo de hábitat mediante un fourth corner analysis. Como esperábamos, las forestaciones fueron el hábitat que mejor preservó el ensamble de aves y de rasgos funcionales del bosque nativo, y los usos de la tierra que resultan en hábitats abiertos fueron los más diferentes al bosque nativo en diversidad taxonómica y funcional. La similitud ambiental entre los hábitats antrópicos y el hábitat nativo es clave para conservar las aves y sus rasgos funcionales. Estudiar la diversidad taxonómica y funcional en estos hábitats es esencial para predecir las respuestas de las comunidades a los usos de la tierra y permite tomar decisiones de manejo adecuadas.[Palabras clave: agricultura, conservación, filtrado ambiental, forestaciones, ganadería, rasgos funcionales, riqueza específica, diversidad beta, urbanización] ABSTRACT. Taxonomic and functional bird diversity: Differences between anthropogenic habitats in a subtropical forest. The extensive land use for human activities is one of the main threats to biodiversity. In this study, we investigate what anthropogenic habitat that best preserves the native assemblage of birds and their functional traits in a subtropical forest. We compared simultaneously the taxonomic (species richness and composition similarity) and functional (functional traits diversity and traits composition similarity) bird diversity between native forest and different anthropogenic habitats (tree plantations, urban centers, cattle pastures and crop fields) in one of the most diverse and threatened forest in the world, the Upper Parana Atlantic Forest. We surveyed birds and measured environmental variables in five anthropogenic habitat types, and selected 11 traits to estimate functional diversity. We estimated "1-Gower dissimilarity index" to explore s...

Taxonomic and functional avian diversity vary with cattle management practices in humid Chaco forests of Argentina

“…Furthermore, the forest with cattle exclusion was negatively associated with generalist species in nesting habitat selection (De la Peña, 2016). These results partially agree with what was reported by Vaccaro and Bellocq (2019) for the interior Atlantic Forest where it was observed that forest with cattle exclusion was associated with forest specialist birds, sensitive to anthropogenic disturbance, insectivorous, frugivorous, and granivorous birds. Similarly, Dardanelli et al.…”

Factors underlying bird community assembly in anthropogenic habitats depend on the biome

“…Surprisingly, bird assemblages in the native forests (i.e., natural habitats of the Forest) were characterized by functional redundancy. These results are in accordance with those of Vaccaro and Bellocq 11 , who, for these same sites, found lower and higher functional diversity in natural habitats and tree plantations, respectively, than in other habitat types. Tree plantations exhibited functional divergence probably because they harbored not only species with traits similar to those inhabiting the native forest 57 , but also generalist species that forage and nest in a variety of environments 11 .…”

“…These results are in accordance with those of Vaccaro and Bellocq 11 , who, for these same sites, found lower and higher functional diversity in natural habitats and tree plantations, respectively, than in other habitat types. Tree plantations exhibited functional divergence probably because they harbored not only species with traits similar to those inhabiting the native forest 57 , but also generalist species that forage and nest in a variety of environments 11 . Tree plantations are generally unsuitable for native forest birds 58,59 , while extra-regional species possess traits that enable them to take advantage of the resources available not only in these habitat types but also in open habitats.…”

“…Finally, urban settlements revealed a random functional pattern but a clustering phylogenetic structure. If we assume that phylogeny represents functional differences in species assemblage composition 60 and urbanization leads to the loss of traits 11,61 , then phylogenetic clustering results from environmental filtering selection of closely related species that share similar niches 62,63 . The study of Sol et al 64 reported that exotic species did not compensate for the loss of phylogenetic diversity related to urbanization.…”

Flowering phenology and reproductive success of native shrub Berberis darwinii Hook. along different light environments

“…Since B. darwinii pollen presents high self‐incompatibility, the reproduction of this species strongly depends on pollinators (Vázquez & Simberloff, 2004). As occurs in other species of the genus Berberis , its fruits are consumed by birds, such as Elaenia albiceps and Turdus falcklandii (Amico & Aizen, 2005; Garcia et al, 2010), which disperse their seeds. Remarkably, its fleshy fruits are a high‐value non‐timber forest product due to its nutraceutical properties associated with a noticeable antioxidant capacity (Chamorro et al, 2019).…”