Green hydrogen has emerged as a prominent approach in an effort to mitigate global warming. Given the urgency of addressing the climate change crisis and mitigating global warming, there is an increasing emphasis on curtailing carbon dioxide emissions. This can be achieved through the production of green hydrogen. While there are various renewable power supply options capable of being utilized for producing green hydrogen, this research focuses solely on offshore wind, photovoltaics (PV), and a hybrid solution due to eThekwini's perceived abundance of solar radiation and extensive coastlines with ample wind resources, making it highly conducive to renewable energy generation. This paper initially introduces the concept of Green Hydrogen production and outlines the methodology employed to assess the viability of hydrogen production from various potential sources. Additionally, the energy requirements for a typical hydrogen plant are determined, along with a brief discussion on potential sites. In this case study, an energy yield assessment was conducted for PV, offshore wind, and a proposed hybrid model to determine the most beneficial source and identify any technical issues that may arise from the utilization of the considered power supplies. Finally, a high-level financial assessment assessing the project's financial viability is described. CC BY-NC-ND

ABSTRACT Sisal (Agave sisalana Perrine), a crucial natural fiber source, exhibits varying yields in China’s Guangdong and Guangxi regions. This groundbreaking study sampled soil and sisal leaves from these production hubs to explore the interplay among soil pH, enzyme activity, microorganisms, and sisal nutrition. Using PCR and high-throughput sequencing, results indicate Guangdong’s soil is mildly acidic, contrasting with Guangxi’s neutral to slightly alkaline soil. Both regions show a robust correlation between soil pH and nutrient availability (organic matter, P, K). Enhanced soil enzyme activity is observed at higher pH levels (6.09, 7.39). Dominant bacterial phyla Acidobacteria, Proteobacteria, and Actinobacteria peak at pH 7.39, 6.09, and 5.41, respectively. Fungal phyla Ascomycota, Basidiomycota, and Mortierellomycota thrive at pH 4.23, 7.39, and 6.48. Sisal leaves display optimal nutrient levels at specific pHs: N, P, and K at pH 6.09; Ca at pH 7.39; Mg at pH 6.48. Functional predictions reveal fungal abundance varies with pH, while bacterial functions like metabolism, disease resistance, and environmental adaptation are bolstered in Guangxi’s alkaline soils compared to Guangdong’s acidic ones. These findings provide a scientific basis for optimizing sisal cultivation management.

Abstract Wetlands worldwide face increasing challenges due to human activities such as water extraction, deforestation, and overfishing. These ecosystems are crucial for biodiversity, water retention, and purification. In Ecuador, the “Abras de Mantequilla” wetland exemplifies these pressures. It serves as a vital site for studying the interactions between soil fertility and arbuscular mycorrhizal fungi (AMF) in forest ecosystems. The study focused on the soil fertility, particularly in relation to AMF in "Noah Morán" secondary forest within the Abras de Mantequilla wetland. The key role of AMF in improving soil fertility was highlighted. Soil samples were collected from the root zone of four forest tree species i.e., Guazuma ulmifolia, Albizia guachapele, Eugenia pustulescens, Cecropia peltate. The four investigated soil samples had marginal differences in the soil physicochemical properties. Number of AMF species were found in the four soils in the range of 16 to 39; Number of por Several AMF lowest por the lowest (16) and highest (39) AMF species were found in E. pustulescens and A. guachapele soils, respectively. AMF species ‘Akent’ was the most dominant (abundance #16) AMF species found in the soils of C. peltate. The ranges of Shannon_H and Simpson_1-D values were found to be 1.78-1.9 and 0.79-0.85, respectively. These insights are important to understanding soil-plant-microorganism interactions in promoting sustainable agricultural practices in the Abras de Mantequilla wetland.

Abstract Objectives The oral cavity harbors a plethora of bacterial species. Dysbiosis of oral and gut microbiota is associated with several oral and systemic pathologies, such as cancer, obesity, diabetes, atherosclerosis and gastrointestinal diseases. Imbalance in the oral-gut microbial axis has been associated with head and neck squamous cell carcinoma (HNSCC). This study aims to analyze the bacterial profile of HNSCC across various taxonomic units, investigate molecular patterns associated with prevalent bacterial phylum in HNSCC, and compare the bacterial profile in HNSCC and gastrointestinal (GI) carcinoma using computational analysis. Methodology The microbe-host transcriptomic, proteomic, and epigenetic analyses of HNSCC and GI carcinomas were performed using The Cancer Microbiome Atlas (TCMA) database. The differential expression of the host’s mRNA transcripts and proteins associated with tumor microbiome were analyzed using The University of Alabama at Birmingham Cancer data analysis (UALCAN) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) websites. Results A decrease in Actinobacteria and an enrichment of Flavobacteria at the class level, Neisseriales, Pasteurellales, and Campylobacterales at the order level, Pasteurellaceae, Flavobacteriaceae, Campylobacteraceae, and Peptoniphilaceae at the family level, and Hemophilus, Porphyromonas, and Leptotrichia at the genus level were observed in HNSCC compared to the normal mucosa. RICTOR protein, mRNA transcripts (HIST1H2BB, SCARNA11, TBC1D21 gene), and hsa-miR-200a-5p miRNA were significantly correlated with prevalent bacterial species in HNSCC. A major increase in Actinobacteria, Fusobacteria, and Spirochaetes was observed in HNSCC compared to GI carcinoma. Conclusion The oral-gut microbial dysbiosis, as reflected by the differential abundance of bacterial species in oral and GI carcinomas, suggests the implication of tumor microbiome and their genomic interactions with the host in carcinogenesis.

Resumo Vários inventários da herpetofauna têm sido conduzidos na região Neotropical. No entanto, muitas áreas permanecem por investigar, e isto é particularmente verdade nas zonas de transição entre ecorregiões. Aqui descrevemos a riqueza, composição de espécies e abundância da herpetofauna de uma porção pouco conhecida do Cerrado brasileiro e avaliamos as semelhanças taxonômicas das assembleias entre os habitats amostrados e entre ecorregiões vizinhas. Um inventário herpetológico de médio prazo foi realizado entre maio de 2009 e janeiro de 2011 na Estação Ecológica Serra das Araras (SAES), por meio de armadilhas de interceptação e queda em cinco hábitats florestados e abertos. Nestes e em habitats adicionais, também foram utilizadas buscas visuais e acústicas e encontros ocasionais para acessar a composição da herpetofauna, juntamente com dados de literatura e exame de exemplares depositados em coleções. Também comparamos a composição de espécies do SAES em escala regional com aquelas de outras 29 localidades previamente estudadas em nove ecorregiões sul-americanas. Documentamos 123 espécies no SAES (39 anfíbios e 84 répteis), das quais 112 foram registradas durante os inventários de campo. A riqueza de espécies foi maior na mata ciliar e menor na floresta seca semidecídua e cerradão. Matas ciliares também apresentaram maior número de espécies exclusivas, enquanto apenas uma espécie exclusiva foi encontrada no cerradão. Cerrado sensu stricto e parque cerrado apresentaram 53 e 40 espécies, incluindo sete e dez espécies exclusivas, respectivamente, e mostraram maior similaridade entre si do que com os habitats florestados amostrados. Em comparação com outras localidades já inventariadas no Cerrado, a SAES abriga uma das mais diversas assembléias da herpetofauna. Isto pode ser atribuído a esforços de amostragem continuados e à acentuada heterogeneidade ambiental resultante do perfil topográfico e da confluência de diversas ecorregiões. A composição de espécies de anfíbios no SAES é mais semelhante a uma localidade próxima também estudada no Cerrado e a assembleias da Floresta Seca de Chiquitano, enquanto a composição de espécies de répteis está aninhada entre as assembleias estudadas no Cerrado. Nossos resultados indicam que a herpetofauna do SAES é rica e representativa da biodiversidade regional, com composição de espécies que evidencia seu caráter transitório.

Abstract Several herpetofaunal inventories have been conducted in the Neotropical region. However, many areas remain to be investigated, and this is particularly true of transition zones between distinct ecoregions. Herein we describe the richness, species composition, and abundance of herpetofauna from a scarcely known portion of the Brazilian Cerrado and assess the taxonomic similarities of the assemblages among the sampled habitats and between neighbouring ecoregions. A mid-term herpetological inventory was conducted from May 2009 to January 2011 at Serra das Araras Ecological Station (SAES) using pitfall traps with drift fences in five distinct forested and open habitats. In these and in additional habitats, visual and acoustic searches and occasional encounters were also used to access the local composition of the herpetofauna, together with literature data and examination of specimens deposited in collections. We also compared the species composition at SAES on a regional scale with those of other 29 localities previously studied in nine South American ecoregions. We documented 123 species at the SAES (39 amphibians and 84 reptiles), 112 of which were recorded during the field inventory. Richness was highest in riparian forests and lowest in semi-deciduous dry forest and cerrado woodland. Riparian forests also presented the highest number of exclusive species, while only one exclusive species was found in cerrado woodland. Cerrado sensu stricto and cerrado parkland contained 53 and 40 species, including seven and 10 exclusive species, respectively, and showed greater similarity than the sampled forested habitats. In comparison to other localities in the Cerrado (including transition zones), SAES is home to one of the most diverse assemblages of herpetofauna. This may be attributed to continued sampling efforts and to the marked environmental heterogeneity resulting from the topographic profile and confluence of several ecoregions. Amphibian species composition at SAES is more similar to a nearby locality also studied in the Cerrado and to Chiquitano Dry Forest assemblages, while the reptile species composition is nested among the assemblages studied in the Cerrado. Our findings indicate that the herpetofauna of SAES is rich and representative of the regional biodiversity, with species composition evidencing its transitional character.

Resumo: Objetivo Neste estudo, nós investigamos a resposta da composição, diversidade e abundância de microcrustáceos (Cladocera e Copepoda) à origem do lago (natural e artificial) e ao estado trófico (mesotrófico e eutrófico, com eutrofização natural e eutrofização artificial). Testamos as seguintes hipóteses: (I) o aumento na abundância de certas espécies de microcrustáceos pode indicar um aumento no nível trófico; (II) a riqueza e a abundância variam entre os lagos e são maiores no lago com eutrofização natural; e (III) a abundância de microcrustáceos está associada à alta produtividade primária, sendo maior no ambiente eutrófico com eutrofização artificial. Métodos O estudo foi realizado em um segmento da bacia do rio Paranapanema, no sudeste do Brasil, com foco em cinco lagos em um trecho de oito quilômetros, para entender as respostas dos diferentes organismos em condições distintas de ambientes aquáticos. A amostragem foi realizada bimestralmente ao longo de um ano. Resultados Uma análise de componentes principais (PCA) separou três tipos de lagos: eutróficos (naturais e artificiais) a mesotróficos. Adicionalmente, 25 táxons foram encontrados. A análise SIMPER filtrou seis espécies com mais de 70% de contribuição de dissimilaridade. Cinco espécies apresentaram diferenças entre os lagos, uma espécie correlacionada com variáveis naturais, como profundidade. A análise de redundância associou a abundância de Bosminopsis deitersi com lagos eutróficos artificiais e com as variáveis condutividade elétrica, fósforo, nitrogênio, clorofila-a e dureza. Altas abundâncias de B. deitersi indicaram eutrofização artificial especialmente em lagos artificiais, enquanto lagos naturais com eutrofização natural não foram ambientes favoráveis para o aumento da abundância de B. deitersi. Conclusões Este estudo destaca os lagos de meandros neotropicais, enfatizando a importância da caracterização físico-química, da amostragem temporal detalhada e da classificação dos lagos por origem e nível trófico.

Abstract: Aim In this study, we investigated the response of microcrustaceans composition, diversity and abundance (Cladocera and Copepoda) to the lake’s origin (natural and man-made) and trophic state (mesotrophic and eutrophic, with natural eutrophication and artificial eutrophication). We tested the following hypotheses: (I) the increase in the abundance of certain microcrustacean species may indicate a rise in the trophic level; (II) the richness and abundance vary amongst lakes and are higher in the lake with natural eutrophication; and (III) the microcrustaceans abundance is associate with high primary productivity, being higher in the eutrophic environment with artificial eutrophication. Methods The study was conducted in a segment of the Paranapanema River basin, in southeastern Brazil, focusing on five lakes spanning an eight-kilometer stretch, to understand the different organisms' responses to distinct conditions of aquatic environments. Sampling was carried out bimonthly over the course of a year. Results A principal component analysis (PCA) separated three types of lakes: eutrophic (natural and man-made) to mesotrophic. Additionally, 25 taxa were found. SIMPER analysis filtered six species with more than 70% dissimilarity contribution. Five species exhibited differences amongst the lakes, one species correlated with natural variables as depth. The redundancy analysis associated the Bosminopsis deitersi abundance with man-made eutrophic lakes and with the variables electrical conductivity, phosphorus, nitrogen, chlorophyll-a, and hardness. High abundances of B. deitersi indicated artificial eutrophication especially in man-made lakes, while natural lakes with natural eutrophication were not favorable environments for the increase of B. deitersi abundance. Conclusions This study highlights the neotropical oxbow lakes, emphasizing the significance of physicochemical characterization, detailed temporal sampling, and lake classification by origin and trophic level.

ABSTRACT The invasion of exotic species of natural spaces constitutes a global conservation problem. In the Siboney-Juticí Ecological Reserve, Leucaena leucocephala is considered one of the main threats to the conservation of the semideciduous microphyll forest. The objective of this study is to characterize the richness and structure of the semideciduous microphyll forest in areas with different levels of Leucaena leucocephala coverage in said reserve. For the study, 15 plots of 400 m2 were established at three levels of coverage of the invasive species: ABSM-NI (undisturbed forests), ABSM-PI (40-60 % coverage of Leucaena leucocephala) and ABSM-TI (70 % cover of Leucaena leucocephala). The number of individuals per species and their presence in each of the stratus were estimated, in addition, the height of the woody species was considered. For each of the levels studied, the specific richness, the relative abundance of the species and the floristic composition by stratus were determined; as well as the floristic similarities between each of the levels. In ABSM-NI, 55 species were recorded, in ABSM-PI 51 and in ABSM-TI 43. At the three levels of cover, the strata (tree, shrub, herbaceous) and lianas were maintained. In ABSM-TI the epiphytes were not recorded. The greatest biological similarity was between ABSM-PI and ABSM-TI; some of the shared species are ruderal and colonize areas with some type of disturbance. The main transformation was in the composition and abundance of the species as the coverage of the invasive species increased. In ABSM-TI, the specific richness and abundance/cover of secondary vegetation species increased, to the detriment of other typical forest species. In the sites with the greatest coverage of the invasive species, a decrease in the specific composition and height of the tree stratus occurs. At this site, an increase in the specific composition of the shrub and herbaceous strata was also observed. Epiphytes were only recorded in ABSM-NI and ABSM-PI.

RESUMO A invasão de espécies exóticas em espaços naturais constitui um problema de conservação global. Na Reserva Ecológica Siboney-Juticí, Leucaena leucocephala é considerada uma das principais ameaças à conservação da floresta semidecídua microfila. O objetivo deste estudo é caracterizar a riqueza e a estrutura da floresta semidecídua micrófila em áreas com diferentes níveis de cobertura de Leucaena leucocephala na referida reserva. Para o estudo foram estabelecidas 15 parcelas de 400 m2 em três níveis de cobertura das espécies invasoras: ABSM-NI (florestas intactas), ABSM-PI (40-60 % de cobertura de Leucaena leucocephala) e ABSM-TI (70% de cobertura de Leucaena leucocephala). Foi estimado o número de indivíduos por espécie e sua presença em cada um dos estratos, sendo também considerada a altura das espécies lenhosas. Para cada um dos níveis estudados foram determinadas a riqueza específica, a abundância relativa das espécies e a composição florística por estratos; bem como as semelhanças florísticas entre cada um dos níveis. Na ABSM-NI foram registradas 55 espécies, na ABSM-PI 51 e na ABSM-TI 43. Nos três níveis de cobertura foram mantidos os estratos (arbóreo, arbustivo, herbáceo) e lianas. Nenhuma epífita foi registrada no ABSM-TI. A maior similaridade biológica foi entre ABSM-PI e ABSM-TI; muitas das espécies compartilhadas são ruderais e colonizam áreas com algum tipo de perturbação. A principal transformação ocorreu na composição e abundância das espécies à medida que aumentava a cobertura das espécies invasoras. Na ABSM-TI, a riqueza específica e a abundância/cobertura de espécies de vegetação secundária aumentaram, em detrimento de outras espécies florestais típicas. Nos locais com maior cobertura das espécies invasoras ocorre diminuição da composição específica e da altura do estrato arbóreo. Neste local também foi observado aumento na composição específica dos estratos arbustivos e herbáceos. Epífitas foram registradas apenas no ABSM-NI e ABSM-PI.

RESUMEN La invasión de especies exóticas de espacios naturales constituye un problema de conservación a nivel global. En la Reserva Ecológica Siboney-Juticí, Leucaena leucocephala es considerada como una de sus principales amenazas para la conservación del bosque semideciduo micrófilo. El objetivo de este estudio es caracterizar la riqueza y estructura del bosque semideciduo micrófilo en áreas con diferentes niveles de cobertura de Leucaena leucocephala en dicha reserva. Para el estudio se establecieron 15 parcelas de 400 m2 en tres niveles de cobertura de la especie invasora: ABSM-NI (bosques sin perturbación), ABSM-PI (40-60 % de cobertura de Leucaena leucocephala) y ABSM-TI (70 % de cobertura de Leucaena leucocephala). Se estimó el número de individuos por especie y su presencia en cada uno de los estratos, además se consideró la altura de las especies leñosas. Por cada uno de los niveles estudiados se determinó la riqueza específica, la abundancia relativa de las especies y la composición florística por estratos; así como las similitudes florísticas entre cada uno de los niveles. En ABSM-NI se registraron 55 especies, en ABSM-PI 51 y en ABSM-TI 43. En los tres niveles de cobertura se mantuvieron los estratos (arbóreo, arbustivo, herbáceo) y las lianas. En ABSM-TI no se registraron epífitas. La mayor similitud biológica fue entre ABSM-PI y ABSM-TI; muchas de las especies compartidas son ruderales y colonizan áreas con algún tipo de perturbación. La principal transformación estuvo en la composición y abundancia de las especies en la medida que aumenta la cobertura de la especie invasora. En ABSM-TI incrementó la riqueza específica y la abundancia/cobertura de especies propias de vegetación secundaria, en detrimento de otras especies típicas del bosque. En los sitios de mayor cobertura de la especie invasora ocurre una disminución de la composición específica y altura del estrato arbóreo. En este sitio también se observó un aumento de la composición específica de los estratos arbustivo y herbáceo. Las epífitas solo se registraron en ABSM-NI y ABSM-PI.

Resumen (Objetivo) El objetivo fue analizar la composición de aves asociadas a cultivos orgánicos de cacao (Theobroma cacao) manejado debajo de 3 diferentes tipos de cobertura arbórea. (Metodología) Distribuimos 3 puntos de conteo en cada finca, para registrar todas las aves observadas y escuchadas, en muestreos de 5 minutos. Los conteos fueron realizados por triplicado, tanto en las primeras horas de la mañana como al atardecer. La diferencia en la composición de la avifauna entre las fincas fue analizada con la prueba ANOSIM. Las abundancias se transformaron por medio de la función decostand y el método Hellinger del paquete estadístico R-Vegan. La agrupación de las especies entre las plantaciones se efectuó mediante el escalamiento multidimensional no métrico (nMDS) y el índice de Bray-Curtis. La contribución de las especies a la disimilitud entre grupos fue analizada con el módulo SIMPER. Consideramos diferencias estadísticamente significativas cuando P ≤ 0,05. (Resultados) Observamos 428 individuos, clasificados en 49 especies y 23 familias. La finca donde las plantas de cacao crecen en condiciones más sombreadas, debido al desarrollo del dosel, mostró mayor cantidad de especies (34) y de individuos (146). La composición de aves varió significativamente entre las fincas (F(1,8) = 3,22; P < 0,02). La abundancia media de 19 especies (39,6 %) hizo notar diferencias significativas (P < 0,05), al comparar la finca con mayor sombra y menor sombra. (Conclusión) La composición de aves es más compleja en aquellas fincas de cacao orgánico que conservan un mayor desarrollo estructural de los árboles de dosel y que están cerca de bosque en regeneración.

Resumo (Objetivo) O objetivo foi analisar a composição das aves associadas às plantações de cacau orgânico (Theobroma cacao) manejadas sob três tipos diferentes de cobertura arbórea. (Metodologia) Distribuímos 3 pontos de contagem em cada fazenda, para registrar todas as aves observadas e ouvidas, em amostragens de 5 minutos. As contagens foram realizadas em triplicata, tanto nas primeiras horas da manhã quanto no final da tarde. A diferença na composição da avifauna entre as fazendas foi analisada com o teste ANOSIM. As abundâncias foram transformadas usando a função de costande o método Hellinger do pacote estatístico R-Vegan. O agrupamento de espécies entre as plantações foi feito usando o escalonamento multidimensional não métrico (nMDS) e o índice de Bray-Curtis. A contribuição das espécies para a dissimilaridade entre os grupos foi analisada com o módulo SIMPER. Consideramos as diferenças estatisticamente significativas quando P ≤ 0,05. (Resultados) Observamos 428 indivíduos, classificados em 49 espécies e 23 famílias. A fazenda onde as plantas de cacau crescem em condições mais sombreadas, devido ao desenvolvimento do dossel, apresentou um número maior de espécies (34) e indivíduos (146). A composição das aves variou significativamente entre as fazendas (F(1,8) = 3,2 apresentou diferenças significativas (P < 0,05) n; Paco< 0, mpa 02). A abundância média de 19 espécies (39,6%) ração entre a fazenda mais sombreada e a menos sombreada. (Conclusão) A composição das avesé mais complexa nas fazendas de cacau orgânico que mantêm árvores de dossel mais desenvolvidas estruturalmente e estão próximas à floresta em regeneração.

Abstract (Objective) The objective of this investigation was to analyze the composition of birds associated with organic cocoa (Theobroma cacao) crops managed under 3 different types of tree cover. (Methodology) Three census points were established in each farm to record all birds observed and heard in 5-minute sample periods. Counts were conducted in triplicate, both in the early morning and at dusk. Differences in avifauna composition between farms were analyzed using the ANOSIM test. Abundances were transformed using the Decostand function and the Hellinger method in the R-Vegan statistical package. Analysis of clustering of species among plantations was performed using non-metric multidimensional scaling (nMDS) and the Bray-Curtis index. Contribution of species to the dissimilarity between groups was analyzed with the SIMPER module. Statistically significant differences were considered when P ≤ 0.05. (Results) Four hundred and twenty-eight individuals were observed, and classified into 49 species and 23 families. The farms where cocoa plants grow in shadier conditions due to canopy development showed a higher number of species (34) and individuals (146). Bird comp P < 0.02). The mean abundance of 19 species osit (39.ion 6%) varied significantly between farms (F (1,8) = 3.22; showed significant differences (P < 0.05) when comparing the farms with the most and least shade. (Conclusion) Bird composition is more complex on organic cocoa farms, which have more developed canopies and are near regenerating forests.

Resumen Introducción: Las aves acuáticas (AA) son usualmente relacionadas a los humedales debido a que éstos funcionan como sitios de refugio, alimentación y anidación de diferentes especies residentes y migratorias. Sin embargo, el conocimiento sobre las aves acuáticas en algunos humedales es nulo. Objetivo: Investigar la composición espacio-temporal de la comunidad de AA en la laguna Juluapan, Colima, en el Pacífico Central Mexicano. Métodos: Entre junio de 2017 y mayo de 2018 se llevaron a cabo conteos mensuales en condiciones de marea baja para registrar el uso de hábitat de las AA. Se obtuvieron valores de riqueza de especies y número de individuos para realizar comparaciones entre zonas de muestreo, así como el promedio del número de especies y número de individuos para comparaciones entre temporadas. Resultados: Se registraron un total de 53 especies y 5 750 individuos. Los valores de riqueza de especies y densidad de individuos fueron más altos durante invierno, en la zona más alejada al ambiente marino, donde la actividad antropogénica es menor. La diversidad tuvo valores más altos en la zona 2 y 3, durante primavera, verano y otoño. El ambiente más explotado por las aves fueron las planicies lodosas; y el descanso fue la actividad más frecuente. Asimismo, la actividad de anidación sólo se registró en el manglar de la zona media durante primavera. Las “aves playeras” y “aves zancudas” fueron los grupos más predominantes en la comunidad de aves de la laguna Juluapan. Conclusiones: Este humedal costero es un sitio de gran importancia biológica para aves acuáticas, por lo que resulta necesario la implementación de medidas de conservación, así como el estudio de los efectos por la presión antropogénica.

Abstract Introduction: Aquatic birds (AB) are usually associated with wetlands, which provide refuge, food, and/or nesting sites for resident and migratory species. Despite their ecological importance, there is little knowledge on AB in some tropical environments, such as those found on the Colima coast. Objective: To investigate the spatial and temporal composition of the AB community in Juluapan Lagoon, Colima, Central Mexican Pacific. Methods: Monthly counts were conducted between June 2017 and May 2018 during low-tide conditions to record habitat use by AB. Species richness and bird counts were obtained to compare sampling areas; mean richness and number of individuals were compared between seasons. Results: We detected 53 species and 5 750 individuals. The highest species richness and relative abundance values were obtained in winter at the lagoon area farthest from the connection with the marine system, where anthropogenic activity is lower. Diversity was greater in zones 2 and 3 in spring, summer, and fall. Muddy flats were the most used environment, and the most frequent activity was resting. Nesting activity was only recorded in the middle of the lagoon at the mangrove during spring. “Shorebirds” and “waders” were the most dominant groups in the bird community of the Juluapan lagoon. Conclusions: This coastal wetland is a site of great biological importance for aquatic birds; thus, conservation measures should be implemented, and there should be a continuous study of the effects of anthropogenic pressure.

Resumen Introducción: El uso de artrópodos en estudios ecológicos en el bosque seco tropical (Bs-T) de Colombia se centra mayormente en arañas, mariposas, hormigas y escarabajos coprófagos; por lo tanto, es necesario comprender como es la dinámica estacional de otros grupos como Geadephaga en este ecosistema. Objetivo: Evaluar la variación espacio-temporal y el efecto de las condiciones ambientales sobre la diversidad de las comunidades de Geadephaga en dos fragmentos de Bs-T en el Caribe colombiano. Métodos: El estudio se llevó a cabo en cuatro eventos de muestreo entre febrero y junio de 2018; cada uno con una duración de cuatro días y cuatro noches. En cada localidad (Reserva Campesina La Montaña = RCM y Reserva La Flecha = RLF), se marcaron cuatro estaciones distanciadas 350 m, con parcelas de 50×50 m. En el centro de cada parcela se instaló una trampa de luz, mientras que en los cuatro vértices se instalaron trampas de caída, y se realizó captura manual, cernido de hojarasca y perturbación de follaje. Resultados: Se capturó un total de 348 ejemplares de Carabidae y 114 de Cicindelidae. La riqueza y la abundancia presentaron los valores más bajos durante el período seco, mientras que los mayores valores se observaron durante el período de lluvias, en ambos fragmentos. Tetracha affinis (Dejean, 1825) fue la especie más abundante en la RCM durante el período lluvioso. Conclusiones: La variación de la riqueza y abundancia de Geadephaga responde a un patrón estacional en ambos fragmentos. Se encontró una amplia disimilitud entre las comunidades de Geadephaga de ambos fragmentos, pese a tener condiciones ambientales parecidas.

Abstract Introduction: The use of arthropods in ecological studies in the tropical dry forest (TDF) of Colombia focused mainly on spiders, butterflies, ants, and dung beetles; therefore, it is necessary to understand the seasonal dynamics of the other groups such as Geadephaga in this ecosystem. Objective: To evaluate the spatio-temporal variations and the effect of environmental conditions on the diversity of the Geadephaga communities in two TDF fragments in the Colombian Caribbean. Methods: This study was conducted during four sampling events between February and June 2018, each lasting four days, and four nights. Four sampling stations were selected in each locality (Reserva Campesina La Montaña = RCM and Reserva La Flecha = RLF), separated 350 m one from another, with square plots of 50 × 50 m. A light trap was installed in the center of each square, while pitfall traps were installed in the four vertices, and manual capture, beating sheets and leaf litter sieve were carried out. Results: A total of 348 Carabidae and 114 of Cicindelidae were captured. In both fragments, the richness and abundance presented the lowest values in dry season, while the highest values were observed during the rainy season. Tetracha affinis (Dejean, 1825) was the most abundant species in RCM during rainy season. Conclusions: The richness variation and abundance of Geadephaga corresponds to a seasonal pattern at both locations. A high dissimilarity between the communities of Geadephaga from the two fragments was found, despite having similar environmental conditions.

Resumen Introducción: Varias presiones antrópicas sufren los ecosistemas acuáticos del piedemonte llanero en Colombia. La respuesta a estresores ambientales aún se desconoce en organismos bioindicadores como Leptohyphidae. Objetivo: Determinar la diversidad de ninfas de Leptohyphidae del río Quenane-Quenanito, en dos periodos hidrológicos contrastantes y su relación con algunas variables fisicoquímicas. Métodos: En diciembre (2014) y febrero (2015) se recolectaron organismos con red Surber en seis estaciones a lo largo del río. Se analizó la diversidad alfa y beta y se aplicó análisis de redundancia y modelos lineales generalizados con el fin de establecer la relación entre los taxones y las variables ambientales. Resultados: Se identificaron 369 organismos pertenecientes a cuatro géneros (Amanahyphes, Traverhyphes, Tricorythopsis y Tricorythodes), dos especies y ocho morfoespecies. Se reporta por primera vez para el departamento del Meta Amanahyphes saguassu. Se registró la mayor diversidad de ninfas en la transición a la sequía y la mayor abundancia en sequía. La diversidad beta señaló que la configuración del ensamblaje cambia a nivel espacial y temporal. Conclusiones: Los organismos de Leptohyphidae prefieren hábitats de corrientes, particularmente en el periodo de sequía, donde hallan alimento (hojarasca, detritos) y refugio para establecerse exitosamente; actividades antrópicas como la urbanización afectan notablemente la diversidad. La alta diversidad registrada en este pequeño río de piedemonte llanero refleja la necesidad de incrementar este tipo de trabajos y esfuerzos de recolección de material de estudio en la región.

Abstract Introduction: Various anthropic pressures affect the aquatic ecosystems of the foothills of Colombia. The response to environmental stressors is still unknown in bioindicator organisms such as Leptohyphidae. Objective: To determine the diversity of Leptohyphidae nymphs of the Quenane-Quenanito river, in two contrasting hydrological periods and its relationship with some physicochemical variables. Methods: In December (2014) and February (2015), organisms were collected with a Surber net at six stations along the current. Alpha and beta diversity was analyzed and redundancy analysis and generalized linear model were applied to establish the relationship between taxa and environmental variables. Results: Were identified 369 organisms belonging to four genera (Amanahyphes, Traverhyphes, Tricorythopsis, and Tricorythodes), two species, and eight morphospecies. Amanahyphes saguassu is reported for the first time for the Meta department. High diversity of Leptohyphidae nymphs was recorded in the transition to drought season and greater abundance in drought. Beta diversity indicated that the configuration of the assemblage changes spatially and temporally. Conclusions: Leptohyphidae organisms prefer fast habitats, particularly in the dry period where they find food (leaf litter, detritus) and shelter to establish themselves successfully; anthropic activities such as urbanization notably affect diversity. The high diversity recorded in this small river in the foothills of the plains reflects the need to increase this type of works and collection efforts of study material in the region.

Resumen Introducción: Los bosques de albardón exhiben una estratificación vertical que puede contribuir en la complejidad estructural, permitiendo que una gran diversidad de aves prospere en las islas. En ecosistemas deltaicos hay escasos datos que lo demuestren. Objetivos: Evaluar las variaciones en la composición de la comunidad de aves dentro de los bosques de albardón. Método: Se muestrearon durante tres años, dos áreas protegidas de humedales pertenecientes al Delta del Río Paraná, Argentina. Se realizó un análisis comparativo de riqueza, abundancia y diversidad de aves en tres diferentes bosques de albardón, utilizando el método de conteo por puntos. Resultados: Tres distintos tipos de bosque de albardón -abiertos, intermedios y cerrados- fueron identificados con base en la estructura de su vegetación, hospedando un total de 85 especies de aves. La variación en la estructura de la comunidad de aves entre tipos de bosque revela mayor diversidad en bosques abiertos durante el invierno (3.26 ± 0.13, P < 0.01) y la primavera (3.58 ± 0.05, P < 0.01), y mayor riqueza en otoño (35.33 ± 3.01, P < 0.01). Los bosques cerrados exhibieron mayor diversidad en el otoño (3.16 ± 0.13, P < 0.05) y en verano (3.24 ± 0.06, P < 0.05), junto con elevada abundancia en otoño (114 ± 13.70, P < 0.05) y elevada riqueza en primavera (39.17 ± 4.71, P=0.01). Debido a la historia evolutiva entre sitios, se observó variación significativa en el parque nacional de más reciente creación, influyendo en la abundancia del invierno (141 ± 22.06, P < 0.01) y de la primavera (176 ± 12.83, P < 0.01), así como en la diversidad en el invierno (3.25 ± 0.10, P < 0.01) y en la primavera (3.50 ± 0.10, P < 0.01). Conclusiones: El microhábitat en los diferentes bosques de albardón permite a las aves organizarse diferencialmente. Enfocarse en la dinámica microespacial es clave para una comprensión profunda de los procesos biológicos dentro de las islas subtropicales, planificar estrategias de conservación y evidenciar la transición de un bosque ripario en recuperación hacia su estado natural, donde el pulso del río y el efecto de la estacionalidad no dejan de operar.

Abstract Introduction: Levee forests exhibit a vertical stratification that may contribute to structural complexity allowing a great diversity of birds to thrive on the islands. In deltaic ecosystems there is scarce or no data to prove it. Objectives: To assess variations in the composition of the bird community within levee forests. Methods: Two areas of protected wetlands belonging to the Paraná River Delta in Argentina were sampled for three years. A comparative analysis of richness, abundance, and diversity was performed in different levee forests using the point count method. Results: Three distinct types of levee forests -open, intermediate, and closed- were identified based on the structure of their vegetation, hosting a total of 85 bird species. Variation in avian community structure among forest types revealed greater diversity in open forests during winter (3.26 ± 0.13, P < 0.01) and spring (3.58 ± 0.05, P < 0.01), and greater richness in autumn (35.33 ± 3.01, P < 0.01). The closed forests exhibited increased diversity during autumn (3.16 ± 0.13, P < 0.05) and summer (3.24 ± 0.06, P < 0.05), along with elevated abundance in autumn (114 ± 13.70, P < 0.05) and richness in spring (39.17 ± 4.71, P = 0.01). Due to the evolutionary history between sites, significant variation was observed in the most recently created national park, influencing abundance in winter (141 ± 22.06, P < 0.01) and spring (176 ± 12.83, P < 0.01), as well as diversity in winter (3.25 ± 0.10, P < 0.01) and spring (3.50 ± 0.10, P < 0.01). Conclusions: The microhabitat in the different levee forests allows the birds to organize differently. Focusing on microspatial dynamics is key to a deep understanding of the biological processes within subtropical islands and to plan conservation strategies and demonstrate the transition of a recovering riparian forest towards its natural state, where the pulse of the river and the effect of seasonality do not stop operating.

Resumen Introducción: Recientes investigaciones han mostrado correlaciones positivas entre la estructura del hábitat y las comunidades animales que los habitan. Generalmente, estos estudios evalúan la hipótesis de una mayor diversidad de animales en hábitats complejos y heterogéneos, ya que éstos pueden ofrecer un mayor número de nichos potenciales a diferencia de aquellos estructuralmente más simples. Objetivo: Se evaluó el efecto de la complejidad, la heterogeneidad y la estructura del hábitat sobre una comunidad de mariposas diurnas (Papilionoidea) en tres tipos de coberturas vegetales (rastrojo, bosque y páramo) ubicadas en ecosistemas de alta montaña sobre la cordillera Central, departamento de Antioquia, Colombia. Métodos: Entre enero y julio del 2012, se realizaron capturas de mariposas utilizando trampas Van Someren Rydon y se cuantificó la complejidad, la heterogeneidad y la estructura de la vegetación a partir de parcelas circulares de 0.04 ha establecidas alrededor de las trampas. Resultados: Se reportó un total de 108 especies, 48 géneros y cinco familias de mariposas. La riqueza y la abundancia de especies de mariposas fueron sensibles tanto a la complejidad y heterogeneidad de las coberturas vegetales como a los cambios en la estructura de la vegetación, mostrando fuertes correlaciones con las características del hábitat. El rastrojo presentó la mayor diversidad de mariposas (1D = 25.02; 2D = 11.97), seguido por el bosque (1D = 15.83; 2D = 9.42) y el páramo (1D = 12.36; 2D = 7.86). Adicionalmente, la riqueza y abundancia de mariposas se asoció positivamente con la cobertura de dosel y la densidad de vegetación de los estratos verticales y horizontales. Conclusión: Estos resultados subrayan la importancia de conservar la heterogeneidad de los hábitats y la estructura vegetal en los ecosistemas de alta montaña andinos, para mantener la diversidad y abundancia de las mariposas, resaltando la necesidad de políticas de conservación y manejo que consideren la complejidad y diversidad de estos ecosistemas.

Abstract Introduction: Recent ecological studies have found a positive correlation between habitat structure and animal communities that inhabit them. Generally, such studies try to test the hypotheses that animal species diversity increases in complex and heterogeneous habitats since they may provide more potential niches that structurally simpler habitats. Objective: In this research, the effect of habitat complexity and heterogeneity, and structural habitat characteristics on the butterfly community (Papilionoidea) inhabiting three vegetation covers (shrubs, highland forest and paramo) was evaluated in high-montane ecosystems of the Central Cordillera, Antioquia department, Colombia. Methods: From January to July 2012, butterflies were systematically sampled using Van Someren Rydon traps. Simultaneously, complexity, heterogeneity, and vegetation structure were quantified using 0.04 ha circular plots established around the traps. Results: We reported 108 species, 48 genus and five families of butterflies. Butterfly richness and abundance were sensible to both complexity and heterogeneity of the vegetation covers, as well as to changes in the vegetation structure, showing strong correlations with habitat characteristics. Butterfly diversity was highest in the shrub habitat (1D = 25.02; 2D = 11.97), followed by the highland forest (1D = 15.83; 2D = 9.42) and paramo (1D = 12.36; 2D = 7.86). Moreover, richness and abundance of butterfly species were positively associated with the increase in canopy cover and vegetation density in horizontal and vertical strata. Conclusion: These findings underline the importance of preserving the heterogeneity of habitats and vegetation structure in the Andean high-montane ecosystems to maintain the diversity and abundance of butterflies, highlighting the need for conservation and management policies that consider the complexity and diversity of these ecosystems.

Resumen Introducción: Las proliferaciones de cianobacterias están volviéndose cada vez más comunes, y comprender su dinámica puede ser crucial para proponer estrategias de gestión adecuadas. Si bien se han estudiado ampliamente los parámetros físicos y químicos que influyen en las proliferaciones, se ha prestado menos atención a la susceptibilidad de las comunidades biológicas. Objetivo: Analizar las redes de abundancia de fitoplancton durante las proliferaciones de cianobacterias a diferentes niveles de intensidad y cómo las mismas interactúan y/o afectan a la comunidad de fitoplancton. Métodos: Se realizaron 22 muestreos en el embalse El Limón ubicado en el norte de Argentina, conocido por las proliferaciones recurrentes de cianobacterias. Cada muestreo se clasificó en cuatro niveles basados en la abundancia de cianobacterias (células/ml): Nivel 1 (10 000-30 000); Nivel 2 (30 000-50 000); Nivel 3 (50 000-100 000) y Nivel 4 (> 100 000). Para cada nivel, se construyeron redes de correlación de abundancias considerando todas las especies. Resultados: Se observó un patrón de disminución de correlaciones de abundancia estadísticamente significativas a medida que aumentaba la intensidad de las proliferaciones: 219 correlaciones en el nivel 1; 144 en el nivel 2; 80 en el nivel 3 y solo 33 en el nivel 4. Las cianobacterias que forman proliferaciones mostraron tener poca correlación con otras especies en todos los niveles, lo que podría estar asociado a cierta independencia con respecto a la comunidad. Un aumento en la intensidad de la proliferación parece desconectar la red de correlaciones de abundancia del fitoplancton. Conclusión: El análisis de las redes de correlaciones de abundancias debería ser una herramienta valiosa para comprender la dinámica y el desarrollo de las proliferaciones de cianobacterias, así como para identificar especies clave en este proceso.

Abstract Introduction: Blooms of cyanobacteria are becoming increasingly common, and understanding their dynamics can be crucial for proposing appropriate management strategies. While physical and chemical parameters influencing blooms have been widely studied, less attention has been paid to the susceptibility of biological communities. Objective: To analyze phytoplankton abundance networks during cyanobacterial blooms at different intensity levels and how they interact and/or affect the phytoplankton community. Methods: We used 22 samplings conducted in El Limón reservoir located in Northern Argentina, known for recurrent cyanobacterial blooms. Each sampling was classified into four levels based on cyanobacteria abundance (cells/ml): Level 1 (10 000-30 000); Level 2 (30 000-50 000); Level 3 (50 000-100 000); and Level 4 (> 100 000). For each level, abundance correlation networks were constructed considering all species. Results: A pattern of decreasing statistically significant abundance correlations was observed as bloom intensity increased: 219 correlations at Level 1; 144 at Level 2; 80 at Level 3, and only 33 at Level 4. Blooming cyanobacteria showed few correlations with other species at all levels, indicating a certain independence from the community. An increase in bloom intensity appears to disconnect the phytoplankton abundance correlation network. Conclusion: The analysis of abundance correlation networks should be a valuable tool for understanding the dynamics and development of cyanobacterial blooms, as well as identifying key species in this process.

Resumen Introducción: Las arqueas metanogénicas (MA) participan en la mineralización anaerobia de la materia orgánica en sedimentos de manglar, su actividad está relacionada con el calentamiento atmosférico por la producción de metano; diversas variables ambientales pueden influir en la dinámica metanogénica y la producción de metano en estos sedimentos. Objetivo: Analizar, mediante técnicas dependientes de cultivo, la abundancia de las arqueas metanógenas viables (AMV) y la producción de metano en diferentes épocas climáticas en los sedimentos del manglar El Morro-La Mancha, Veracruz, Golfo de México. Métodos: De mayo a noviembre 2019, siguiendo un transecto de salinidad, se recolectaron sedimentos del manglar del Morro-La Mancha, en tres localidades, abarcando tres diferentes épocas climáticas, secas (mayo), lluvias (octubre) y nortes (noviembre) (N = 9), cuantificándose la abundancia de las AMV mediante la técnica del Número Más Probable (NMP) con acetato y metanol como substratos; la influencia de los sulfatos en la producción de metano a partir de acetato en microcosmos, se analizó por cromatografía de gases y se evaluaron las variables químicas de salinidad, pH, Eh, carbohidratos, contenido orgánico y carbonatos en los sedimentos. Resultados: Se determinó una abundancia de AMV de 102 a 108 NMP/g de sedimento húmedo, superior a la reportada en otros estudios, dicha abundancia se incrementó cuando se utilizó metanol (104-108 NMP/g sedimento) como sustrato, en comparación con el acetato (102-105 NMP/g sedimento); la producción de metano en los microcosmos aumentó en condiciones libres de sulfatos (29.78-929.75 nmol CH4/mes) y en los sedimentos de la temporada de lluvias. Conclusión: Se destaca la influencia de las condiciones químicas de los sedimentos del manglar sobre la dinámica metanógena, determinándose que, en la temporada de lluvias, una disminución de la salinidad, Eh más electronegativos y el incremento de las fracciones orgánicas favorecieron la metanogénesis.

Abstract Introduction: Methanogenic archaea (MA), participate in the anaerobic mineralization of organic matter in mangrove sediments, their activity is related to atmospheric warming due to the production of methane; several environmental variables can influence the presence of MA and methane production in these sediments. Objective: To analyze, through culture-dependent techniques, viable methanogenic archaea (VMA) in the sediments, and the production of methane from acetate in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (N = 9). VMA in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates. The influence of sulfate on methane production was analyzed from acetate in microcosm by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content, and carbonates in the sediments were evaluated. Results: The abundance of VMA was 102 to 108 MPN/g of wet sediment, higher than that reported in other studies, this abundance was higher when methanol (104-108 MPN/g sediment) was used as substrate, compared to acetate (102-105 MPN/g sediment); methane production in the microcosms increased in sulfate-free conditions (29.78-929.75 nmol CH4/month) and in the sediments of the rainy season. Conclusion: The influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics is highlighted, determining that in the rainy season, the decrease in salinity, more electronegative Eh, and the increase in organic fractions favored the methanogenesis.