Hacia una metodología estandarizada para el muestreo de escarabajos peloteros (Coleoptera: Scarabaeinae) en el Neotrópico: Una revisión crítica

Introducción: La estandarización de los protocolos de muestreo es imprescindible para el estudio robusto de cualquier grupo taxonómico. Los métodos replicables permiten la comparación de datos entre diferentes estudios espaciales y temporales. En el caso de los escarabajos coprófagos, uno de los grupos indicadores mejor estudiados en los análisis de perturbaciones ambientales, se utiliza una amplia gama de metodologías de recolección, desde trampas de caída básicas hasta métodos más complejos o complementarios, como el extractor mini-Winkler. Además, en los estudios de escarabajos coprófagos se utilizan diferentes tipos de cebos atractivos, esfuerzos de muestreo, duraciones y diseños. Las variaciones en los enfoques metodológicos se notan particularmente en el Neotrópico, lo que puede estar relacionado con la gran cantidad de estrategias biológicas y el comportamiento de los escarabajos coprófagos que habitan esta región. La falta de unificación metodológica para la región Neotropical imposibilita un análisis transversal de la información. Métodos: Realizamos una recopilación y revisión analítica de la literatura existente para el muestreo de escarabajos coprófagos en el Neotrópico, discutiendo las metodologías más utilizadas, sus ventajas y desventajas, y casos específicos en los que modelos particulares son más eficientes. Resultados: Las trampas Pitfall cebadas con excremento humano son el método de muestreo más común, pero existe una amplia gama de modelos y variaciones en la estructura de esta trampa. El efecto complementario generado por las trampas de interceptación de vuelos, las trampas de luz y las colecciones directas, particularmente dentro de los microhábitats, es emocionante por el potencial de encontrar nuevas especies. Algunas metodologías, como mini-Winkler extractor, fogging, o cebos muy específicos, se utilizan con poca frecuencia. Discusión: Hubo una falta de inclusión de la variación espacial y temporal entre los estudios. Por lo tanto, es necesario considerar ventanas de muestreo más amplias, que incluyan diferentes escalas espaciales, estaciones y años. Finalmente, proponemos un protocolo estándar para el muestreo de escarabajos coprófagos en el Neotrópico, dependiendo de cada objetivo, e incluyendo una metodología básica para la obtención de inventarios locales completos. Copyright © 2023 Mora-Aguilar, Arriaga-Jiménez, Correa, da Silva, Korasaki, López-Bedoya, Hernández, Pablo-Cea, Salomão, Valencia, Vulinec, Edwards, Edwards, Halffter y Noriega. Proponemos un protocolo estándar para el muestreo de escarabajos coprófagos en el Neotrópico, dependiendo de cada objetivo, e incluyendo una metodología básica para la obtención de inventarios locales completos. Copyright © 2023 Mora-Aguilar, Arriaga-Jiménez, Correa, da Silva, Korasaki, López-Bedoya, Hernández, Pablo-Cea, Salomão, Valencia, Vulinec, Edwards, Edwards, Halffter y Noriega. Proponemos un protocolo estándar para el muestreo de escarabajos coprófagos en el Neotrópico, dependiendo de cada objetivo, e incluyendo una metodología básica para la obtención de inventarios locales completos.Introduction: The standardization of sampling protocols is imperative for robustly studying any taxonomic group. Replicable methods allow the comparison of data between different spatial and temporal studies. In the case of dung beetles, one of the best-studied indicator groups in analyses of environmental disturbance, a wide range of collection methodologies are used, from basic pitfall traps to more complex or complementary methods such as mini-Winkler extractor. Also, different types of attractive baits, sampling effort, durations, and designs are used in dung beetle studies. Variations in methodological approaches are particularly noted in the Neotropics, which may be related to the vast number of biological strategies and behavior of dung beetles that inhabit this region. A lack of methodological unification for the Neotropical region makes a cross-sectional analysis of the information impossible. Methods: We performed a compilation and analytical review of the existing literature for dung beetle sampling in the Neotropics, discussing the most used methodologies, their advantages and disadvantages, and specific cases in which particular models are more efficient. Results: Pitfall traps baited with human excrement are the most common sampling method, but there is a wide range of models and variations in the structure of this trap. The complementary effect generated by flight interception traps, light traps, and direct collections, particularly within microhabitats, is exciting for the potential of finding new species. Some methodologies, such as mini-Winkler extractor, fogging, or very specific baits, are infrequently used. Discussion: There was a lack of inclusion of spatial and temporal variation among studies. Therefore, it is necessary to consider broader sampling windows, which include different spatial scales, seasons, and years. Finally, we propose a standard protocol for sampling dung beetles in the Neotropics, depending on each objective, and including a basic methodology for obtaining complete local inventories

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics

Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Daily activity of Dichotomius geminatus (Arrow, 1913) and Deltochilum verruciferum Felsche, 1911 (Coleoptera: Scarabaeinae) facing carrion: from resource perception to feeding

Dung beetles (Scarabaeinae) interact with resources in different ways and are classified according to resource relocation guilds. Dichotomius geminatus (Coprini) and Deltochilum verruciferum (Canthonini) are two of the most abundant and ecologically important species of the semi-arid region of Brazil, and understanding their behaviour may facilitate the comprehension of strategies associated to competition for resources. The aim of the present study was to investigate the behavioural repertoire of D. geminatus (tunneler) and D. verruciferum (roller), in isolation and controlled setting in the Brazilian semi-arid biome, using carrion as a food resource. Our hypothesis was that, due to the distinct food relocation strategies presented by these species, distinct behaviours would occur involving resource utilization. We also compared the behaviour of the two species and investigated the period of diel activity. Both species were more active during the night, but D. geminatus presented a shorter peak of nocturnal activity when compared to D. verruciferum. Although there was activity during the day, feeding was only observed during the night, for both species. During the periods of inactivity, D. verruciferum commonly went underneath the carrion, remaining still. As the target species of the study are very abundant, the differences in behaviour associated with the distinct relocation guilds may indicate a strategy to avoid direct competition. Keywords: Arena, Activity budget, Scarabaeidae, Semi-arid, Foragin

Daily activity of Dichotomius geminatus (Arrow, 1913) and Deltochilum verruciferum Felsche, 1911 (Coleoptera: Scarabaeinae) facing carrion: from resource perception to feeding

Abstract Dung beetles (Scarabaeinae) interact with resources in different ways and are classified according to resource relocation guilds. Dichotomius geminatus (Coprini) and Deltochilum verruciferum (Canthonini) are two of the most abundant and ecologically important species of the semi-arid region of Brazil, and understanding their behaviour may facilitate the comprehension of strategies associated to competition for resources. The aim of the present study was to investigate the behavioural repertoire of D. geminatus (tunneler) and D. verruciferum (roller), in isolation and controlled setting in the Brazilian semi-arid biome, using carrion as a food resource. Our hypothesis was that, due to the distinct food relocation strategies presented by these species, distinct behaviours would occur involving resource utilization. We also compared the behaviour of the two species and investigated the period of diel activity. Both species were more active during the night, but D. geminatus presented a shorter peak of nocturnal activity when compared to D. verruciferum. Although there was activity during the day, feeding was only observed during the night, for both species. During the periods of inactivity, D. verruciferum commonly went underneath the carrion, remaining still. As the target species of the study are very abundant, the differences in behaviour associated with the distinct relocation guilds may indicate a strategy to avoid direct competition