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result(s) for
"Vaz-de-Mello, Fernando Z."
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Turnover and nestedness in subtropical dung beetle assemblages along an elevational gradient
by
Hensen, Maristela C.
,
da Silva, Pedro G.
,
Hernández, Malva I. M.
in
altitude
,
Atlantic Forest
,
Biodiversity
2018
Aim: We investigated changes in dung beetle β-diversity components along a subtropical elevational gradient, to test whether turnover or nestedness-related processes drive the dissimilarity of assemblages at spatial and temporal scales. Location: An elevational gradient (200-1,600 m a.s.l.) of the Atlantic Forest in southern Brazil. Methods: We investigated the extent to which β-diversity varied along the elevational gradient (six elevations) at both spatial (among sites at different elevations) and temporal (different months at the same site) scales. We compared both the turnover and nestedness-related dissimilarity of species and genera using multiple-site or multiple-month measures and tested whether these measurements were different from random expectations. Results: A mid-elevation peak in species richness along the elevational gradient was observed, and the lowest richness occurred at the highest elevations. We found two different groups of species, lowland and highland species, with a mixing of groups at intermediate elevations. The turnover component of β-diversity was significantly higher for both spatial (i.e. elevational) and temporal changes in species composition. However, when the data for genera by site were considered, the elevational turnover value decreased in relative importance. Nestedness-related processes are more important for temporal dissimilarity patterns at higher elevation sites. Main conclusions: Spatial and temporal turnover of dung beetle species is the most important component of β-diversity along the elevational gradient. High-elevation assemblages are not subsets of assemblages that inhabit lower elevations, but this relationship ceases when β-diversity is measured at the generic level. Environmental changes across elevations may be the cause of the differential establishment of distinctive species, but these species typically belong to the same higher taxonomic rank. Conservation strategies should consider elevational gradients in case-specific scenarios as they may contain distinct species assemblages in lowlands vs. highlands.
Journal Article
Effects of howler monkey reintroduction on ecological interactions and processes
by
Genes, Luísa
,
Fernandez, Fernando A. S.
,
da Rosa, Patrícia
in
Alouatta
,
Alouatta guariba
,
Beetles
2019
Rewilding has been an increasingly popular tool to restore plant–animal interactions and ecological processes impaired by defaunation. However, the reestablishment of such processes has seldom been assessed. We investigated the restoration of ecological interactions following the reintroduction of the brown howler monkey (Alouatta guariba) to a defaunated Atlantic forest site. We expected the reintroduction to restore plant–animal interactions and interactions between howlers and dung beetles, which promote secondary seed dispersal. We estimated the number of interactions expected to be restored by the reintroduction to provide the baseline interaction richness that could be restored. We followed the reintroduced howler monkeys twice a week for 24 months (337 hours total) to assess their diet. We used howler monkey dung in secondary seed dispersal experiments with 2484 seed mimics to estimate the removal rates by dung beetles and collected the beetles to assess community attributes. We compared the potential future contribution of howler monkeys and other frugivores to seed dispersal based on the seed sizes they disperse in other areas where they occur. In 2 years, howler monkeys consumed 60 animal-dispersed plant species out of the 330 estimated. Twenty-one dung beetle species were attracted to experimentally provided dung; most of them were tunnelers, nocturnal, and large-sized (>10 mm). On average 30% (range 0–100%) of the large seed mimics (14 mm) were moved by dung beetles. About 91% of the species consumed by howlers (size range 0.3–34.3 mm) overlapped in seed size with those removed by dung beetles. In our study area, howler monkeys may consume more large-seeded fruit species than most other frugivores, highlighting their potential to affect forest regeneration. Our results show reintroductions may effectively restore ecological links and enhance ecological processes.
El resalvajamiento cada vez crece más como una herramienta popular para restaurar las interacciones entre animales y plantas, así como los procesos ecológicos perjudicados por la pérdida de fauna. Sin embargo, el restablecimiento de dichos procesos ha sido poco evaluado. Investigamos la restauración de las interacciones ecológicas después de la reintroducción del mono aulladorpardo (Alouatta guariba) a un sitiode bosque atlántico con pérdida de fauna. Nuestras expectativas planteaban que la reintroducción restauraría las interacciones planta–animal y las interacciones entre los monos y los escarabajos peloteros, la cual promueve la dispersión secundaria de semillas. Estimamos que el número de interacciones que se esperaba fueran restauradas proporcionaría la línea base para la riqueza de interacciones que podría ser restaurada. Seguimos a los monos aulladores reintroducidos dos veces por semana durante 24 meses (227 horas en total) para evaluar su dieta. Usamos las excretas de los monos en experimentos de dispersión secundariade semillas con 2484 imitaciones de semilla para estimar las tasas de extracción por parte de los escarabajos peloteros y luego los colectamos para evaluar los atributos de la comunidad. Comparamos la potencial contribución futura de los monos aulladores y otros frugívoros para la dispersión de semillas con base en el tamaño de las semillas que dispersan en otras áreas en donde están presentes. En dos años los monos aulladores consumieron 60 especies de plantas dispersadas por animales de las 330 estimadas. Veintiún especies de escarabajos peloteros fueron atraídos por las excretas proporcionadas experimentalmente; la mayoría de ellas eran excavadoras de túneles, nocturnas, y grandes (>10 mm). En promedio, el 30% (rango 0 – 100%) de las imitaciones de semillas grandes (14 mm) fueron movidas por los escarabajos peloteros. Aproximadamente el 91% de las especies consumidas por los monos aulladores (rango del tamaño 0.3 – 34.3 mm) se traslaparon en cuanto a tamaño de la semilla con aquellas removidas por los escarabajos peloteros. Con base en nuestras estimaciones para el área de estudio, los monos aulladores consumieron más frutos con semillas grandes que la mayoría de los frugívoros, lo que resalta su potencial para afectar la regeneración del bosque. Nuestros resultados muestran que las reintroducciones pueden restaurar efectivamente las conexiones ecológicas y mejorar los procesos ecológicos.
Journal Article
Improving the design and management of forest strips in human-dominated tropical landscapes: a field test on Amazonian dung beetles
by
Louzada, Julio
,
Gardner, Toby A
,
Hernández, Malva I.M
in
Abundance
,
Amazonia
,
Animal, plant and microbial ecology
2010
1. The future of tropical forest species depends in part on their ability to survive in human-modified landscapes. Forest strips present a priority area for biodiversity research because they are a common feature of many managed landscapes, are often afforded a high level of legal protection, and can provide a cost-effective and politically acceptable conservation strategy. 2. Despite the potential conservation benefits that could be provided by forest strips, ecologists currently lack sufficient evidence to inform policy and guide their design and management. 3. We used a quasi-experimental landscape in the Brazilian Amazon to test the importance of four management-relevant variables (forest type, isolation distance, forest structure, and large mammal activity) on the potential biodiversity conservation value of narrow forest strips for dung beetles. 4. Information-theoretic model selection based on AICc revealed strong support for the influence of large mammal activity and forest type on dung beetle abundance; isolation distance on species richness; and forest structure on the relative abundance of matrix-tolerant species. Multi-dimensional scaling showed a strong influence of forest type and isolation on community composition and structure, with riparian and dry-land strips having complementary sets of species. 5. Synthesis and applications. To enhance the conservation value and ecological integrity of forest strips in human-modified landscapes we recommend that strip design considers both isolation distance and whether or not the strips encompass perennial streams. In addition, we identify the maintenance of forest structure and the protection of large mammal populations as being crucially important for conserving forest dung beetle communities.
Journal Article
Spatial replacement of dung beetles in edge‐affected habitats: biotic homogenization or divergence in fragmented tropical forest landscapes?
by
Peres, Carlos A.
,
Filgueiras, Bruno K. C.
,
Iannuzzi, Luciana
in
anthropogenic activities
,
Anthropogenic factors
,
Atlantic forest
2016
AIM: In this study, we investigate whether anthropogenic land use and habitat fragmentation lead to a process of either homogenization (decreasing spatial replacement and increasing nestedness) or divergence (increasing spatial replacement and decreasing nestedness) of dung beetle assemblages in edge‐affected habitats. LOCATION: A fragmented landscape of the Atlantic forest of north‐east Brazil. METHODS: We investigate the extent to which beta diversity of dung beetle assemblages varies in edge‐affected habitats at different spatial scales (i.e. traps along an interior–exterior nonlinear gradient, within and among habitats). We compare species replacement and nestedness of dung beetle assemblages using (1) multiple dissimilarity measures accounting for compositional heterogeneity across forest (i.e. forest edges, core primary forest areas and small fragments) and matrix habitats (i.e. sugar cane plantations and pastures) and (2) distance matrices accounting for the multivariate structure of dissimilarity. RESULTS: (1) Each habitat supported a distinct dung beetle assemblage; (2) there was a strong influence of anthropogenic land use and fragmentation‐related effects on dung beetle β‐diversity, with species replacements increasing in edge‐affected and matrix habitats providing support for the divergence hypothesis at all spatial scales; (3) edge effects enhanced species replacement across assemblages; (4) dung beetle assemblages were not randomly distributed, with habitat type leading to a strongly nested pattern of species composition; and (5) both dung beetle replacement and nestedness were not correlated with geographic distance, whereby neighbouring sites were not necessarily more similar in their community composition. MAIN CONCLUSIONS: Species replacement is strongly influenced by habitat configuration and β‐diversity increases in edge‐affected habitats. Accordingly, anthropogenic land use and habitat fragmentation clearly promote community‐level taxonomic divergence in human‐modified landscapes. Landscape‐scale divergence likely results from a non‐random distribution of both forest‐dependent and disturbance‐adapted species across all habitats, which are in marked contrast in terms of suitability.
Journal Article
Towards a comprehensive taxonomic revision of the Neotropical dung beetle subgenus Deltochilum (Deltohyboma) Lane, 1946 (Coleoptera: Scarabaeidae: Scarabaeinae): Division into species-groups
by
Vaz-de-Mello, Fernando Z.
,
González-Alvarado, Arturo
in
Aedeagus
,
Animal Distribution
,
Animals
2021
Deltochilum Eschscholtz, 1822 is perhaps the most speciose genus of the tribe Deltochilini sensu Tarasov & Dimitrov (2016) (Scarabaeidae: Scarabaeinae) and has been traditionally divided into eight subgenera. Among them, the subgenus Deltohyboma Lane, 1946, is the most speciose with 47 species, five of which are described here ( D . genieri sp. nov. , D . gilli sp. nov. , D . susanae sp. nov. , D . bolivariensis sp. nov. and D . inesae sp. nov. ), and at least 165 species still undescribed. Due to the large number of species, and for practical purposes, the subgenus is here divided into 19 species-groups, with D . inesae sp. nov. left as incertae sedis . This division into species-groups will help in the reliable identification of species and will aid in the completion of the revision of subgenus. This report is the first part of the taxonomic revision of the subgenus Deltohyboma ; it is based on the examination of all type specimens and almost 9,800 specimens of which approximately 1,200, mostly males, had their genitalia studied. The 19 species-groups recognized here are based mainly on characters described for the first time for Deltohyboma , namely, the state of a) the anterior margin of the clypeus (between the clypeal teeth), b) the internal margin of hypomera, c) the ventral face of the protibia, d) the posterior margin of the metafemur, and e) several new characters resulting from the first detailed study of the aedeagus and the endophallus of the group. Diagnosis, description, geographic distribution, composition and identifications keys (for males as well as males and females) for the species-groups are provided.
Journal Article
Persistence of the effect of frugivore identity on post-dispersal seed fate
by
Galetti, Mauro
,
Boutefeu, Marion
,
Huynen, Marie-Claude
in
Atlantic Forest
,
Brachyteles arachnoides
,
buried seeds
2017
Large frugivores play an important role as seed dispersers and their extinction may affect plant regeneration. The consequences of such extinctions depend on the likelihood of other species being functionally redundant and on how post-dispersal events are affected. We assess the functional redundancy of two seed dispersers of the Atlantic Forest, the muriqui (Brachyteles arachnoides) and the tapir (Tapirus terrestris) through the comparison of their seed dispersal quality, taking into account post-dispersal events. We compare tapirs and muriquis for: (1) the dung beetle community associated with their feces; (2) the seed burial probability and burial depth by dung beetles; and (3) the seed mortality due to predators or other causes according to burial depth. We determine how seed burial affects seed dispersal effectiveness (SDE) and compare the dispersal quality of four plant species dispersed by these frugivores. Muriqui feces attract 16-fold more dung beetles per gram of fecal matter and seeds experience 10.5-fold more burial than seeds in tapir feces. In both feces types, seed mortality due to predation decreases with burial depth but seed mortality due to other causes increases. Total seed mortality differ within plant species according to the primary disperser. Therefore, the effect of seed burial on SDE varies according to the plant species, burial depth, and primary disperser. As tapirs and muriquis differently affect the seed fate, they are not functionally redundant. Since the effect of the primary disperser persists into the post-dispersal events, we should consider the cascading effects of these processes when assessing functional redundancy.
Journal Article
Extinctions of interactions: quantifying a dung beetle–mammal network
by
Lewis, Owen T.
,
Riordan, Philip
,
Mikich, Sandra B.
in
anthropogenic activities
,
Anthropogenic factors
,
Biodiversity
2018
Loss of large‐bodied mammals across the globe through hunting, habitat degradation, and fragmentation is one of the most significant anthropogenic impacts on the environment. Cascading effects of these extinctions through ecosystems have been little studied, although correlative studies have revealed co‐extinctions in closely linked groups, with implications for ecosystem structure and function. Despite playing important roles in seed dispersal and hence seedling recruitment, mammals have been largely neglected in network studies. Similarly, the role of secondary seed dispersers, such as ants and dung beetles, has been largely unexplored. Most dung beetles rely on mammal feces for feeding and breeding and provide a suite of important ecosystem functions and services. While dung beetle community responses to environmental change have been widely investigated, studies quantifying the network of associations between dung beetle and mammal species are lacking. By developing the first quantitative mammal–dung beetle networks, we address several important knowledge gaps contributing to the understanding of how interactions in networks involving mammals and secondary insect seed dispersers are structured. We use the resulting quantitative interaction networks to model mammal species extinction scenarios to further explore the consequences for dung beetle populations, and the extent to which networks change the strength of interactions through resource switching. Dung beetle feeding and breeding networks did not differ significantly in structure and showed high nestedness and low levels of trophic specialization. Simulations suggested that mammal extinction scenarios based on mammal body mass and mammal dung volume will impact dung beetle populations to a greater extent than random scenarios of mammal loss. Thus, despite their generalist feeding preferences, realistic mammal extinction scenarios have the potential to negatively impact the dung beetle community, which may have consequences for ecosystem functioning.
Journal Article
El Niño impacts on human-modified tropical forests
by
Braga, Rodrigo
,
França, Filipe M.
,
Louzada, Júlio
in
Abundance
,
Amazonia
,
anthropogenic activities
2020
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 climateassociated disturbances in human-modified Amazonian forests and suggest that the interaction between local anthropogenic and climate-related stressors merits further investigation.
Journal Article
Trait-dependent response of dung beetle populations to tropical forest conversion at local and regional scales
by
Louzada, Julio
,
Spector, Sacha H.
,
Naeem, Shahid
in
Agriculture
,
Animal and plant ecology
,
Animal populations
2013
Comparative analyses that link information on species' traits, environmental change, and organism response have rarely identified unambiguous trait correlates of vulnerability. We tested if species' traits could predict local-scale changes in dung beetle population response to three levels of forest conversion intensity within and across two biogeographic regions (the Neotropics and Afro-Eurasian tropics). We combined biodiversity surveys, a global molecular phylogeny, and information on three species' traits hypothesized to influence vulnerability to forest conversion to examine (1) the consistency of beetle population response across regions, (2) if species' traits could predict this response, and (3) the cross-regional consistency of trait-response relationships. Most beetle populations declined following any degree of forest conversion; these declines were strongest for Neotropical species. The relationship between traits and population trend was greatly influenced by local and biogeographic context. We discuss the ability of species' traits to explain population trends and suggest several ways to strengthen trait-response models.
Journal Article
Effects of Climate Change on the Distribution of Key Native Dung Beetles in South American Grasslands
by
Maldaner, Maria Eduarda
,
Sobral-Souza, Thadeu
,
Prasniewski, Victor Mateus
in
agronomy
,
Algorithms
,
Amazon
2021
Climate change is a serious threat, and it is necessary to prepare for the future climate conditions of grazing areas. Dung beetle species can help mitigate global warming by contributing to intense nutrient cycling and reduction in greenhouse gas emissions caused by cattle farming. Additionally, dung beetles increase soil quality through bioturbation and reduce nematodes and hematophagous flies’ abundance in grasslands areas. There are several dung beetle species inhabiting South American pastures, however, the effects of climate change on their spatial distribution are still unknown. Here, we aimed to predict the potential effects of future climate change on the geographical spatial distribution of the four most important (“key”) pastureland dung beetle species that are native to South America. We used niche-based models and future climate simulations to predict species distribution through time. Our findings show radical reduction in the spatial range of dung beetle species, especially in recently opened areas, e.g., the Amazon region. We suggest that the consequences of these species’ spatial retraction will be correlated with ecosystem services depletion under future climate conditions, urgently necessitating pasture restoration and parasite control, as the introduction of new alien species is not encouraged.
Journal Article