Abstract Introduction: Terrestrial isopods (Oniscidea) play important roles in the ecological processes of the soil in tropical ecosystems and are employed as indicators of environmental impact. Despite their importance, studies on the ecology of this suborder in the Neotropics are scarce. Objective: To assess spatial changes in alpha and beta diversity of Oniscidea in the supralittoral zone across Archipiélagos Coralinos (ARCO), Magdalena (MAG), and Morrosquillo (MOR) ecoregions in the Colombian Caribbean. Methods: We conducted Direct Intuitive Searches of specimens and measured soil temperature and moisture in 19 transects with logs, leaf litter, coral remains, and decomposing plant material. Results: A total of 1 970 individuals representing 17 species were collected, with Tylidae, Halophilosciidae, and Ligiidae being the most abundant families. Alpha diversity orders were higher in ARCO than MAG and MOR ecoregions. MAG and MOR differed in observed richness. The structure of the assemblage varied in dominant species and abundances. In ARCO, the indicator species were Tylos niveus, Littorophiloscia denticulata, Halophiloscia trichoniscoides, and Ligia baudiniana; in MOR, it was Tylos marcuzzii, and in MAG, it was Littorophiloscia tropicalis. High beta diversity (> 60 %), with significant differences in the assemblage structure among ecoregions, was confirmed by the NMDS, which distinctly separated each group. CCA analysis revealed a negative relationship between most species with soil temperature and moisture, with a positive relationship observed with T. marcuzzii. Conclusions: This is the first effort to describe spatial changes in the diversity of oniscideans in the supralittoral zone of the Neotropical region, providing a baseline for future studies. This information could be instrumental in identifying priority areas for conservation efforts.

Resumen Introducción: Los isópodos terrestres (Oniscidea) juegan un papel importante en los procesos ecológicos del suelo en ecosistemas tropicales y han sido empleados como indicadores de impacto ambiental. A pesar de su importancia, los estudios sobre la ecología de este suborden en el Neotrópico son escasos. Objetivo: Evaluar los cambios espaciales en la diversidad alfa y beta de Oniscidea en la zona supralitoral en las ecorregiones Archipiélagos Coralinos (ARCO), Magdalena (MAG) y Morrosquillo (MOR) en el Caribe colombiano. Métodos: Realizamos Búsquedas Intuitivas Directas de especímenes y medimos la temperatura y la humedad del suelo en 19 transectos con troncos, hojarasca, restos de coral y material vegetal en descomposición. Resultados: Recolectamos un total de 1 970 individuos representando 17 especies, siendo Tylidae, Halophilosciidae y Ligiidae las familias más abundantes. Los órdenes de diversidad alfa fueron mayores en ARCO, en comparación con las ecorregiones MAG y MOR. MAG y MOR difirieron en la riqueza observada. La estructura del ensamblaje varió en especies dominantes y sus abundancias. En ARCO las especies indicadoras fueron Tylos niveus, Littorophiloscia denticulata, Halophiloscia trichoniscoides y Ligia baudiniana; en MOR fue Tylos marcuzzii y en MAG fue Littorophiloscia tropicalis. El NMDS confirmó una alta diversidad beta (> 60%), con diferencias en la estructura del ensamblaje entre ecorregiones, que separó claramente cada grupo. El ACC reveló una relación negativa entre la mayoría de las especies con la temperatura y humedad del suelo, observándose una relación positiva con T. marcuzzii. Conclusiones: Este es el primer esfuerzo por describir los cambios espaciales en la diversidad de oniscídeos en la zona supralitoral de la región Neotropical, proporcionando una línea base para futuros estudios. Esta información podría ser fundamental para identificar áreas prioritarias para los esfuerzos de conservación.

Resumen Antecedentes: Dalea es endémico de América, posee amplia distribución en la provincia del Desierto Chihuahuense, sus especies se asocian a matorral xerófilo, bosque de encino y bosque de coníferas. Hipótesis: Las especies de Dalea funcionan como un subrogado de la flora y refuerzan las propuestas de regionalización para esta provincia. Sitio y años de estudio: Provincia del Desierto Chihuahuense, agosto 2020 a julio 2022. Métodos: Se elaboró una base de datos a partir de ejemplares de herbario. El análisis de riqueza de especies se realizó con una cuadricula de 1 × 1°. El endemismo ponderado (WE) y endemismo ponderado corregido (CWE) fueron estimados. Para regionalizar, el recambio de especies fue calculado y se aplicó el método de agrupación UPGMA. Para determinar la caracterización ambiental de los componentes bióticos, los grupos se cotejaron con ecorregiones publicadas. Resultados: Se encontraron 3,061 registros de 77 especies de Dalea, 33 son endémicas al área de estudio. La riqueza de especies se concentró al noroeste y sureste de la provincia. La riqueza de endémicos fue localizada en el centro y norte. El análisis de WE mostró tres celdas ubicadas en el centro del área de estudio; el CWE recuperó tres celdas al sur de la provincia. Se reconocen dos grupos principales (subprovincias), anidando grupos más pequeños (distritos). Los distritos corresponden en su mayoría a las ecorregiones del Desierto Chihuahuense, Matorral de la Meseta Central, Bosques secos del Bajío. Conclusiones: Dalea funcionó como subrogado de la flora y reforzó las propuestas de regionalización para esta provincia.

Abstract Background: Dalea is endemic to the Americas and has a wide in the Chihuahuan Desert province. Its species are associated with xeric scrub, oak forest, and coniferous forest. Hypothesis: Dalea species function as a surrogate of the flora and reinforce the regionalization proposals for this province. Study site and research period: Chihuahuan Desert province, August 2020 to July 2022. Methods: A database was generated from herbarium specimens. The species richness analysis was obtained using a 1 × 1° grid. Weighted endemism (WE) and corrected weighted endemism (CWE) were analyzed and estimated. For regionalization, species replacement was calculated and the UPGMA grouping method was applied. The resulting groups were checked against the published ecoregions to determine the biotic components of the environmental characterization. Results: 3,061 records were obtained, representing 77 species, of which 33 are endemics to the study area. The northwestern and southeastern parts of the province had the highest species richness. The central and northern parts had the highest endemic species richness. The WE analysis showed three cells located in the center of the study area, while the CWE recovered three cells at the south of the province. Two large main subprovinces are recognized, these nesting smaller area groups (districts). The districts mostly correspond to the ecoregions of the Chihuahuan Desert, Scrub of the Central Plateau, and Dry forests of the Bajío. Conclusions: Dalea was a surrogate for the flora and reinforced the regionalization proposals for this province.

Resumo O noroeste pacífico da Costa Rica é uma região com uma estacionalidade no regime de chuvas muito marcada. Somado a essa sazonalidade, esta área da Costa Rica é propensa a fenômenos hidroclimáticos extremos como secas e inundações, por exemplo. A distribuição limitada de pluviômetros ou a falta de disponibilidade de informações relevantes fazem com que os dados complementares obtidos de satélites e suas respectivas reanálises sejam fundamentais para obter informações cruciais e, assim, embasar as ações de gestão dos recursos hídricos e suas repercussões nos ecossistemas, tanto naturais quanto produtivos. Para analisar os padrões de precipitação, foram analisadas as séries temporais de precipitação do produto CHIRPS para cinco ecorregiões delimitadas na Área de Conservação Guanacaste, no Pacífico noroeste da Costa Rica. Estas curvas foram correlacionadas com as séries temporais das regiões de monitoramento da temperatura superficial do mar nas regiões Niño 1.2, Niño 3, Niño 3.4 e Niño 4. Todas as ecorregiões analisadas correlacionaram de forma negativa e forte com a região do Niño 1.2, com valores de R entre -0.72 e -0.74. Além disso, foi detectado um atraso na curva do Niño 4 de quatro a cinco meses, em relação à curva da região Niño 1.2. O estudo sugere que a anomalia do El Niño 4, com um desfasamento de aproximadamente 4 a 5 meses, pode ser utilizada como indicador de possíveis impactos nos padrões de precipitação nas diferentes ecorregiões estudadas. Este tempo é suficiente para planejar ações, especialmente no setor agroprodutivo. Neste trabalho, é demonstrado o potencial de previsibilidade dos efeitos do fenômeno ENOS sobre o padrão de precipitação em áreas extensas e com certa homogeneidade ecossistêmica, como as ecorregiões na Área de Conservação Guanacaste.

Abstract The Pacific Northwest of Costa Rica is a region with marked seasonality in rainfall patterns. This area of Costa Rica is prone to extreme hydroclimatic phenomena such as droughts and floods. Due to the limited distribution of rainfall gauges and the unavailability of relevant information, complementary data obtained from satellites and their respective reanalyzes become imperative for acquiring crucial information. This information can support water resource management actions and their impacts on both natural and productive ecosystems. To analyze the precipitation patterns, we utilized the CHIRPS product’s precipitation time series for five ecoregions within the Guanacaste Conservation Area, located in the northwestern Pacific region of Costa Rica. These curves were strongly and negatively correlated with time series from sea surface temperature monitoring regions, including Niño 1.2, Niño 3, Niño 3.4, and Niño 4. All analyzed ecoregions exhibited strong negative correlations with the Niño 1.2 region, with correlation coefficients (R values) ranging between -0.72 to -0.74. Additionally, a lag of four to five months was observed in the Niño 4 curve compared to the Niño 1.2 region. This study suggests that the Niño 4 anomaly, with a lag of approximately 4 to 5 months, can serve as an indicator of possible impacts on precipitation patterns in different ecoregions. This provides sufficient time to plan actions, particularly within the agricultural sector. This study demonstrates the potential predictability of the effects of ENSO phenomenon on precipitation patterns for large areas with a certain eco-systemic homogeneity, such as the ecoregions in the Guanacaste Conservation Area.

Resumen El pacífico noroeste de Costa Rica es una región con una estacionalidad en el régimen de lluvias muy marcada. Sumado a dicha estacionalidad, esta área de Costa Rica es propensa a fenómenos hidroclimáticos extremos como sequías e inundaciones, por ejemplo. La escasa distribución de pluviómetros o bien, la no disponibilidad de información pertinente, hacen que los datos complementarios obtenidos de satélites y sus respectivas reanálisis, sean fundamentales para disponer de información crucial y así poder fundamentar las acciones de gestión del recurso hídrico y sus repercusiones en los ecosistemas, tanto naturales como productivos. Para analizar los patrones de precipitación, se analizaron las series de tiempo de precipitación del producto CHIRPS para cinco ecorregiones delimitadas en el Área de Conservación Guanacaste, en el Pacífico noroeste de Costa Rica. Estas curvas se correlacionaron con las series de tiempo de las regiones de monitoreo de la temperatura superficial del mar en las regiones Niño 1.2, Niño 3, Niño 3.4 y Niño 4. Todas las ecorregiones analizadas correlacionaron de forma negativa y fuertemente con la región del Niño 1.2, con valores de R entre -0.72 y -0.74. Por otra parte, se detectó un rezago en la curva de Niño 4 de cuatro a cinco meses, con la curva de la región Niño 1.2. El estudio sugiere que la anomalía del Niño 4, con un desfase de aproximadamente 4 a 5 meses, puede ser utilizada como indicador de posibles impactos en los patrones de precipitación en las diferentes ecorregiones estudiadas. Este tiempo es suficiente para planear acciones, sobre todo en el sector agroproductivo. En este trabajo se muestra el potencial de predictibilidad de los efectos del fenómeno ENOS sobre el patrón de la precipitación para áreas extensas y con cierta homogeneidad ecosistémica, como son las ecorregiones en el Área de Conservación Guanacaste.

Abstract In Argentina, from the beginning of the 21st century onwards, it has been detected that the conservation policies deployed by the National Parks Administration have been characterized by creating numerous protected areas and extending existing ones. During these years two concurrent processes also took place. One of them, related to the adoption and consolidation of neo-extractivism as a productive model whose modalities plundered the ecosystem functions of ecoregions throughout the entire national territory. The remainder was associated with the commitments assumed by the country before the Convention on Biological Diversity through the Aichi Goals. Therefore, it is hypothesized that both processes conditioned the conservation policies of said organism during the period 2000-2022. It is concluded that these policies were reactive and compensatory when seeking to protect the relics of the ecoregions not eradicated by neo-extractivism. At the same time, they tried to comply with the international commitments assumed.

Resumen En Argentina, desde comienzos del siglo XXI, se ha detectado que las políticas de conservación desplegadas por la Administración de Parques Nacionales se han caracterizado por crear numerosas áreas protegidas y extender otras ya existentes. Durante estos años también tuvieron lugar dos procesos concurrentes. Uno de ellos, relacionado con la adopción y consolidación del neoextractivismo como modelo productivo, cuyas modalidades expoliaron las funciones ecosistémicas de las ecorregiones a lo largo de todo el territorio nacional. El restante, se asoció a los compromisos asumidos por el país ante el Convenio de la Diversidad Biológica mediante las Metas de Aichi. Por consiguiente, se plantea como hipótesis que ambos procesos condicionaron las políticas de conservación de dicho organismo durante el período 2000-2022. Se concluye que estas políticas resultaron reactivas y compensatorias al buscar proteger los relictos de las ecorregiones no erradicados por el neoextractivismo. A la vez, trataron de cumplir con los compromisos internacionales asumidos.

Abstract La Plata Basin is the second largest hydrographic system in South America but the most impacted by invasive species of molluscs in the continent. Paraguay is a land-surrounded South American country with scarce information about malacological fauna. To fill some of these gaps, a large field expedition was conducted to analyze the distribution of invasive freshwater bivalves in Paraguay. The field survey encompassed 41 sampling stations in seven Departments of Paraguay. The mussels were searched using bare hands and feet. All stations were georeferenced and some environmental parameters were measured. Results indicated the presence of three invasive species of freshwater bivalves in Paraguay: Corbicula fluminea, C. largillierti, and Limnoperna fortunei. The Asiatic clam Corbicula fluminea was the most widespread invasive species, covering main rivers and small tributaries in the four freshwater ecoregions of Paraguay. The two remaining invasive species were more restricted. Corbicula largillierti were found at the lower section of the Paraná River, and Limnoperna fortunei inhabits the main river canals of the Paraguay River and the lower section of the Paraná River. The invasive species were found in three protected areas of Paraguay and can represent a threat to the mostly unknown fauna of native mussels. The invasive bivalves are widespread in Paraguay. Mitigation measurements must be taken to avoid the spread of these species and more drawbacks over native fauna. continent landsurrounded land surrounded gaps 4 feet measured C restricted

Resumo A bacia do Plata é a segunda maior da América do Sul, mas a mais impactada pelas espécies invasoras de moluscos nesse continente. O Paraguai é uma país cercado por terra com pouca informação sobre a sua malacofauna. Com o objetivo de preencher algumas destas lacunas, uma expedição de campo foi organizada a fim de analisar a distribuição dos bivalves invasores no Paraguai. Foram realizadas 41 estações de coleta em sete departamentos do Paraguai. A busca pelos bivalves foi feita utilizando pés e mãos. Todos os pontos foram georreferenciados e algumas variáveis ambientais foram medidas. Os resultados indicam a presença de três espécies de bivalves invasores no Paraguai: Corbicula fluminea, C. largillierti e Limnoperna fortunei. O berbigão asiático Corbicula fluminea foi a espécie com a distribuição mais ampla, cobrindo os principais rios e tributários, em quatro ecoregiões de água doce do Paraguai. As outras duas espécies apresentaram uma distribuição mais restrita. Corbicula largillierti foi encontrado no Baixo rio Paraná, enquanto Limnoperna fortunei foi encontrado na calha principal do rio Paraguai e no Baixo rio Paraná. As espécies invasoras foram encontradas em três unidades de conservação e pode representar a ameaça para a pouco conhecida fauna de bivalves nativos do Paraguai. As espécies de bivalves invasores estão amplamente distribuídas no Paraguai. Medidas de mitigação são necessárias para evitar que estas espécies se dispersem ainda mais, provocando mais efeitos negativos sobre as espécies nativas. Sul continente malacofauna lacunas 4 mãos medidas C ampla tributários restrita Paraná nativas

Abstract Despite the recent increase in knowledge about Brazilian Cladoceromorpha (Cladocera and Cyclestherida), this group of fauna is poorly known in some regions of the country, including Alagoas State. Based on the literature and a few original samples, the present paper reports 35 species of Cladoceromorpha from Alagoas, 18 of which are new records for the state. The observed taxa are illustrated. In addition, distributional and taxonomic comments on selected taxa are provided. Cladocera Cyclestherida, Cyclestherida , Cyclestherida) country State samples 3 1 state illustrated addition provided

Abstract: Aim The freshwater environment is indeed diverse and complex, and it faces numerous challenges due to human activities. One approach to evaluating these human interventions is through the use of bioindicators, with fish being one of the key groups studied in the aquatic environment. However, the existent studies report that only a limited number of Brazilian ichthyofauna species have been investigated as potential bioindicators. Methods The data present here were organized through a bibliographic review that adopts an exploratory and descriptive approach, focusing on articles published between the years 2000 and 2022, utilizing terms such as “bioindicators,” “Brazilian fish,” and “aquatic ecosystem” in both Portuguese and English languages. Results Despite Brazil having the most diverse ichthyofauna on the planet, the research has focused on only 45 species thus far. Among these, Rhamdia quelen (Quoy & Gaimard, 1824) emerged as the most frequently studied species. The analysis of gill and liver tissues was found to be the most common method employed in these studies, while other tissues received relatively little attention. Moreover, the distribution of studies on bioindicator species was uneven, with the Upper Paraná ecoregion having the highest number of species investigated. This suggests that research efforts in this field have not been uniformly distributed across Brazil. Conclusions The patchy nature of studies on bioindicators of the Brazilian ichthyofauna highlights the need for greater incentives and support for research in this area. With Brazil's exceptional ichthyofauna diversity, there is ample potential to identify and utilize additional species as environmental indicators. By expanding the scope of studies and addressing the geographical imbalance, a more comprehensive understanding of the impacts of human activities on freshwater ecosystems in Brazil can be achieved. This knowledge is vital for effective conservation and management efforts to protect and sustain the country's valuable aquatic resources. Abstract complex However 200 2022 “bioindicators, fish, ecosystem languages planet 4 far Quoy Gaimard 1824 attention Moreover uneven area Brazils s diversity indicators imbalance achieved countrys country resources 20 202 “bioindicators 182 2 18 1

Resumo: Objetivo O ambiente de água doce é amplamente diverso e complexo, e devido às atividades e intervenções antrópicas, enfrenta numerosos desafios. Uma das abordagens utilizada para avaliar essas intervenções humanas é através do uso de bioindicadores, sendo os peixes um dos principais grupos estudados no ambiente aquático. Entretanto, os trabalhos disponíveis relatam que apenas um número limitado de espécies da ictiofauna brasileira foi investigado como potenciais bioindicadores. Métodos Os dados do presente trabalho foram organizados por meio de uma revisão bibliográfica que adota abordagem exploratória e descritiva, com foco em artigos publicados entre os anos de 2000 e 2022, utilizando termos como “bioindicadores”, “peixes brasileiros” e “ecossistema aquático” tanto em língua portuguesa quanto inglesa. Resultados Apesar de o Brasil ter a ictiofauna mais diversificada do planeta, a pesquisa se concentrou em apenas 45 espécies até o momento. Dentre estas, Rhamdia quelen (Quoy & Gaimard, 1824) emergiu como a espécie mais estudada. A análise dos tecidos branquiais e hepáticos foi considerada o método mais comum empregado nesses estudos, enquanto outros tecidos receberam relativamente pouca atenção. Além disso, a distribuição dos estudos sobre espécies bioindicadoras foi desigual, sendo a ecorregião do Alto Paraná a que apresentou o maior número de espécies investigadas. Conclusões Isso sugere que os esforços de pesquisa na área da ictiofauna como bioindicador não têm sido distribuídos uniformemente pelo Brasil. A natureza fragmentada dos estudos sobre bioindicadores da ictiofauna brasileira destaca a necessidade de maiores incentivos e apoio à pesquisa nesta área. Com a excepcional diversidade da ictiofauna do Brasil, há amplo potencial para identificar e utilizar espécies adicionais como indicadores ambientais. Ao ampliar o escopo dos estudos e abordar o desequilíbrio geográfico, pode-se alcançar uma compreensão mais abrangente dos impactos das atividades humanas nos ecossistemas de água doce no Brasil. Este conhecimento é vital para esforços eficazes de conservação e gestão para proteger e sustentar os valiosos recursos aquáticos do país. Resumo complexo antrópicas desafios aquático Entretanto descritiva 200 2022 , “bioindicadores” brasileiros ecossistema inglesa planeta 4 momento estas Quoy Gaimard 1824 estudada atenção disso desigual investigadas ambientais geográfico podese pode país 20 202 “bioindicadores 182 2 18 1

Resumen Austrolebias accorsii es redescrita basado en especímenes de la localidad tipo, charcos temporales cercanos y otras localidades en la misma unidad hidrológica. Además, se describe una nueva especie de Austrolebias, exclusiva de dos cuerpos de agua temporales en “Abayoy”, un tipo de vegetación único situado en la zona de transición entre las ecorregiones del Chaco Seco, Bosque Seco Chiquitano y Sabanas Inundadas del Pantanal al sureste de Bolivia, en la frontera con Paraguay, donde residen los últimos indígenas en aislamiento voluntario fuera de la Amazonía en América. Se presentan caracteres diagnósticos para ambas especies. Dentro de Austrolebias se reconocen dos grupos de especies con diferentes caracteres morfológicos, distribución geográfica y características ecológicas del hábitat. Además, sugerimos el uso de mediana y rango intercuartil en lugar de media y desviación estándar para analizar datos morfométricos y merísticos de rivúlidos, dada la distribución generalmente no gaussiana de estos datos. hidrológica Además Abayoy, Abayoy , “Abayoy” Bolivia Paraguay América morfológicos hábitat rivúlidos “Abayoy

Abstract Austrolebias accorsii is redescribed based on specimens from type-locality, nearby temporary pools, and other locations within the same hydrologic unit. Additionally, a novel Austrolebias species is described, exclusively found in two temporary waterbodies in “Abayoy”, a unique vegetation type situated in the transitional zone between the Dry Chaco, Chiquitano Dry Forest, and Pantanal Flooded Savannas ecoregions in southeastern Bolivia, bordering Paraguay, where the last voluntarily isolated indigenous people outside the Amazon in America reside. Diagnostic characters for both species are presented. Within Austrolebias two species groups are recognized with different morphological characters, geographical distribution, and ecological traits of their habitats. Furthermore, we suggest the usage of median and interquartile range rather than mean and standard deviation to analyze morphometric and meristic data of rivulids, given the typically non-Gaussian distribution of this data. typelocality, typelocality locality, locality type-locality pools unit Additionally described Abayoy, Abayoy , “Abayoy” Chaco Forest Bolivia Paraguay reside presented habitats Furthermore rivulids nonGaussian non Gaussian “Abayoy

Abstract Organisms can respond to environmental gradients from local to landscape features. Aquatic insects are particularly affected by watershed peculiarities due to their dependence on microhabitat conditions. However, these relationships are poorly understood in lotic ecosystems of subtropical grasslands, limiting water resources management and bioassessment proposals. Here, we investigated how local stream environment and variations in landscape types affect the assemblage structure of a bioindicator insect group, face to the spatial proximity of the sampled locations. We sampled immatures of Ephemeroptera, Plecoptera, and Trichoptera in streams along the Brazilian Pampa biome, recording environmental descriptors in different grassland ecosystem types. The structure of aquatic insect assemblages differed across grassland types, with specific dominant genera associated with each landscape. Spatially-structured water physicochemical descriptors explained a significant amount of variation in assemblage data. Our findings suggest that grassland ecosystem type delimitations capture ecological attributes, influencing watershed features important to EPT assemblage structuration. Moreover, we highlight the importance of niche-based process structuring EPT assemblages along grassland ecosystem types of Pampa biome. In addition, we encourage using aquatic insects in bioassessment of lotic waters to assess local and landscape environmental impacts. We strongly recommend considering the grassland ecosystem schedule for water resources management and bioassessment proposals. conditions However grasslands proposals Here group locations Ephemeroptera Plecoptera biome Spatiallystructured Spatially structured data attributes structuration Moreover nichebased niche based addition impacts

Resumo: O objetivo deste artigo é analisar os ciclos de land grabbing no Paraguai, com destaque à presença brasileira. Em termos metodológicos, além de uma revisão bibliográfica e da utilização de dados secundários, foram utilizadas informações de 215 entrevistas realizadas entre 2014 e 2023. Os resultados mostram que, no Paraguai, o processo de land grabbing por brasileiros é secular, mas cresceu substancialmente durante a ditadura militar de Alfredo Stroessner. Nos últimos anos, percebe-se que os produtores brasileiros estão alcançando novas regiões, bem como mudando seu perfil e interesses. Em suma, o atual contexto de land grabbing por brasileiros no Paraguai se apresenta mais complexo, versátil e diversificado do que em momentos pretéritos.

Abstract: The Gran Chaco has been one of the ecoregions at a global level where processes of land use change, deforestation and dispossession have been expressed with greater intensity and extension during the 21st century, which was mainly associated with the expansion of commodity frontiers. Some expressions of this in terms of agrarian change have been discussed in relation to local variants of land grabbing. This work is part of that conversation. It analyzes (a) the heterogeneity of agribusiness companies that have expanded production scales and have invigorated land grabbing processes; and (b) the diversity of their socio-productive trajectories. The study area is in northwestern Argentina. The analysis is based on primary data.

Resumen: El Gran Chaco sudamericano ha sido uno de los espacios a escala global donde se han expresado con mayor intensidad y extensión procesos de cambio de uso del suelo, deforestación y desposesión, en el transcurso del siglo XXI, lo cual estuvo principalmente asociado a la expansión de fronteras agropecuarias. Algunas expresiones de ello en términos de cambio agrario vienen siendo discutidas en relación con las variantes locales de land grabbing. Este trabajo se inscribe en esa conversación. En particular, se interroga por: a) la heterogeneidad de empresas que producen commodities, que han ampliado escalas productivas y han dinamizado procesos de acaparamiento de tierras, y b) la diversidad de sus trayectorias socioproductivas. El área de estudio se localiza en el noroeste de Argentina. El análisis se basa en datos primarios.

Abstract The Sierra Madre Occidental (SMO) is the largest mountain range in Mexico (1,400 km long), and yet one of the least studied regions. Using records from museum specimens, direct observations, photographs, and literature data, we built a database with 4,659 unique mammal records. Our aims were to generate a species list, to examine general distribution patterns, to relate these patterns to ecoregions and vegetation, and to discuss the importance of the SMO as a center of endemism and high biological diversity. We recorded 171 species (34.3% of the Mexican terrestrial mammals). Forty-seven are endemic of Mexico, including ten endemics of the SMO. The highest species richness was recorded at the Tropical ecoregion (T, 125 species), followed by Madrean South (MS, 100), and Madrean Xerophylous (MX, 95). The highest number of endemics was recorded in T (37), followed by MS (24), and Madrean tropical (MT, 22). Nine of ten species endemic to the SMO occur in the temperate highlands. Sampling efforts have been scarce or nonexistent for over half the SMO. Species turnover reflects the complexity of the biomes that occur in the Sierra, and not the expected latitudinal patterns of species richness. Only 4.8% of the SMO is within a protected area, and the areas that are protected do not include vulnerable biomes like the cloud forest. Biological research is urgent in the SMO, an area under intensive mining, forestry, cattle ranching, and more recently, tourism and environmental services.

Resumen La Sierra Madre Occidental (SMO) es la cadena montañosa más grande de México (1,400 km), y no obstante una de las regiones menos estudiadas del país. Utilizando registros de ejemplares examinados en colecciones científicas, observaciones directas, fotografías y datos bibliográficos, construimos una base de datos con 4,659 registros únicos de mamíferos. Nuestros objetivos fueron generar una lista de especies, examinar patrones generales de distribución, relacionar estos patrones con ecorregiones y vegetación, y discutir la importancia de la SMO como centro de endemismo y alta diversidad. Se documentaron 171 especies (34.3 % de los mamíferos terrestres mexicanos). Cuarenta y siete son endémicos de México, incluyendo diez endémicos de la SMO. La mayor riqueza de especies se registró en la ecorregión Tropical (125). El mayor número de endemismos se registró en esta misma ecorregión (37), seguida de Madrense Sur (24) y Madrense Tropical (22). Nueve de las diez especies endémicas de la SMO se distribuyen en áreas templadas. Poco o ningún esfuerzo de colecta ha sido llevado a cabo en más de la mitad de la SMO. El recambio de especies refleja la diversidad y complejidad de biomas, más que los gradientes latitudinales que podrían esperarse. Solo 4.8 % de la SMO se encuentra dentro de un área protegida, pero éstas no incluyen biomas vulnerables como el bosque mesófilo. Es urgente la investigación biológica en la SMO, un área donde se desarrollan extensas actividades mineras, forestales, ganaderas, y más recientemente, turísticas y provisión servicios ambientales.

Resumen Nuestro objetivo fue investigar el desarrollo larval de Argia joergenseni Ris en tres arroyos ubicados en diferentes latitudes y ecorregiones (Yungas y Chaco) en Argentina. Medimos el ancho de la cabeza y la longitud de la pteroteca del ala metatorácica de las larvas mensualmente y se las clasificó en cinco clases de tamaño. Nuestros resultados mostraron distintos patrones de crecimiento larval entre los sitios de estudio. En los sitios de Yungas (latitud 26º S) se registró una alta proporción de individuos pequeños durante todo el año, lo que sugiere un ciclo de vida multivoltino. En contraste, las larvas en la región del Chaco (latitud 32º S) mostraron una marcada estacionalidad en el crecimiento. Los hallazgos indican una correlación negativa entre el voltinismo y la latitud en A. joergenseni. La especie exhibió una época de vuelo casi continua en las Yungas, mientras que en el límite sur de su distribución (Chaco), la época de vuelo se limitó a los meses más cálidos. Este estudio proporciona información importante sobre la ecología de las larvas de A. joergenseni, contribuyendo a una mejor comprensión de la dinámica de las comunidades de caballitos del diablo y facilitando el desarrollo de medidas de conservación efectivas.

Abstract Our aim was to investigate the larval development of Argia joergenseni Ris in three streams located at different latitudes and ecoregions (Yungas and Chaco) in Argentina. We measured the head width and the metathoracic wing sheath length, and classified larvae into five size classes. Our results showed different patterns of larval growth between the three study sites. At the Yungas sites (latitude 26º S), larvae exhibited a high proportion of small individuals throughout the year, suggesting a multivoltine life cycle. In contrast, larvae in the Chaco region (latitude 32º S) showed marked seasonality in growth. The findings indicate a negative correlation between voltinism and latitude in A. joergenseni. The species exhibited an almost continuous flight season in the Yungas, while at the southern limit of its distribution (Chaco), the flight season was limited to the warmest months. This study provides important information on the larval ecology of A. joergenseni, contributing to a better understanding of the dynamics of damselfly communities and facilitating the development of effective conservation measures.

Resumen Introducción: Chironomidae (Diptera) es la familia de insectos acuáticos más extendida y abundante en los ecosistemas dulceacuícolas. Los quironómidos se consideran buenos indicadores de la calidad del agua, pero rara vez se identifican a nivel de género en estudios de amplia escala espacial. Objetivo: Identificar las condiciones ambientales asociadas a los quironómidos en un gradiente altitudinal. Métodos: Comparamos ecorregiones, tipos de ríos y estaciones para quironómidos en arroyos y ríos neotropicales (18 sitios en ríos; 2014-2018; en un bosque tropical de Yungas y un bosque seco del Chaco Occidental, Argentina). Utilizamos escalamiento no métrico multidimensional, disimilitud, análisis de envfit y curvas de rango-abundancia. Resultados: Los ''ensamblajes'' de quironómidos coincidieron tanto con las ecorregiones como con los tipos de ríos. Sin embargo, las ecorregiones presentaron un mejor ajuste con la composición de especies. Los taxones estenotérmicos de Orthocladiinae fueron dominantes en las elevaciones altas y los euritermales de Chironominae en los ríos de las tierras bajas. La altitud, la temperatura del agua y la conductividad fueron importantes. Las diferencias estacionales fueron menores que las diferencias ecorregionales. Conclusiones: las ecorregiones, la altitud, la temperatura del agua y la conductividad se correlacionaron con las comunidades de quironómidos. Orthocladiinae fue dominante en los sitios altos y Chironominae en los ríos de tierras bajas.

Abstract Introduction: Chironomidae (Diptera) is the most widespread and abundant aquatic insect family in freshwater ecosystems. Chironomids are considered good indicators of water quality but are seldom identified at the genus level in broad spatial scale studies. Objective: To identify environmental conditions associated with chironomids in an altitudinal gradient. Methods: We compared ecoregions, river types, and seasons, for chironomids in neotropical streams and rivers (18 river sites; 2014-2018; Yungas rainforest and Western Chaco dry forest, Argentina). We used non-metric multidimensional scaling, dissimilarity, envfit analysis and rank-abundance curves. Results: Chironomid ''assemblages'' matched both ecoregions and river types. However, ecoregions presented a better fit with species composition. The stenothermal taxa of Orthocladiinae were dominant at high elevations and the eurythermal Chironominae in lowland rivers. Altitude, water temperature and conductivity were important. Seasonal differences were smaller than ecoregional differences. Conclusions: Ecoregions, altitude, water temperature and conductivity correlated with chironomid communities. Orthocladiinae were dominant at high elevations and Chironominae in lowland rivers.

ABSTRACT Introduction. Giardiasis is caused by an intestinal protozoan, Giardia lamblia. Despite its high prevalence and geographical transmission variability, there is no risk stratification tool available to prioritize interventions. Objective. To estimate the prevalence of G. lamblia in Peruvian preschoolers and schoolchildren by ecoregion from 1990 to 2018. Methods. Based on a previous meta-analysis, we conducted a G. lamblia prevalence sub-analysis by ecoregions from data of 26 studies in Peruvian preschoolers and school-aged children between 1990 and 2018. The data was extracted by district, a classification by ecoregions was made through Google Earth. Heterogeneity was analyzed using Cochrane Q test and publication bias applying the Egger method with StatsDirect version 3.2.7. The absolute risk method was performed to stratify the prevalence at district level, and 4 strata were defined based on percentiles or arbitrarily. Results. Forty-three district-level prevalence data was estimated, including 7,606 participants. The highest pooled prevalences by the random effects method of G. lamblia were 47.0% (95% CI: 40.0-54.0) in the Pacific desert, 27.9% (95% CI: 22.8-33.2) in the lowland forest and 26.9% (95% CI 22.5-31.5) in the Puna. Conclusions. Of every 100 preschoolers and school-aged children living in the Pacific desert, lowland forest, and in the Puna ecoregions, 47, 28, and 27 minors are infected with G. lamblia, respectively. Likewise, 4 risk strata are proposed based on prevalence: sporadic (0 to <1%), hypoendemic (1 to <25%), mesoendemic (≥25 to <50%) and hyperendemic (≥50%).

RESUMEN Introducción. La giardiasis es ocasionada por el protozoario intestinal Giardia lamblia, su transmisión tiene variabilidad geográfica y a pesar de ser muy frecuente, no existe una herramienta de estratificación de riesgo para priorizar las intervenciones. Objetivo. Estimar la prevalencia de G. lamblia en preescolares y escolares peruanos por ecorregiones entre 1990 a 2018. Métodos. A partir de un metaanálisis previo, se realizó un subanálisis por ecorregiones de la prevalencia de G. lamblia en 26 estudios en preescolares y escolares peruanos entre 1990 a 2018. Se extrajeron los datos por distrito y utilizando Google Earth fueron clasificados en ecorregiones. La heterogeneidad fue analizada mediante la prueba de Q de Cochrane y el sesgo de publicación mediante el método de Egger con StatsDirect versión 3.2.7. Se utilizó el método de riesgo absoluto para estratificar la prevalencia a nivel de distrito y se definió 4 estratos en base a los percentiles o arbitrariamente. Resultados. Se identificaron 43 datos de prevalencia a nivel de distrito que incluyeron 7606 participantes. Las prevalencias combinadas más altas por el método de efectos aleatorios de G. lamblia fueron de 47,0% intervalo de confianza (IC) 95%: 40,0 -54,0) en el desierto del Pacífico; 27,9% (IC95%: 22,8 - 33,2) en selva baja y 26,9% (IC95%: 22,5 -31,5) en la Puna. Conclusiones. De cada 100 preescolares y escolares que viven en las ecorregiones del desierto del Pacífico, selva baja y Puna, 47, 28 y 27 menores de edad, respectivamente, están infectados con G. lamblia. Asimismo, se propone 4 estratos de riesgo en función de la prevalencia: esporádico (0 a <1%), hipoendémico (1 a <25%), mesoendémico (≥ 25 a <50%) e hiperendémico (≥50%).

Abstract Factors influencing the diversity of tenebrionid beetles in arid, high-altitude environments in the northwest of Argentina are little-known. Using pitfall traps and suction sampling in 30 sites, we collected these beetles in Altos Andes (AA) and Puna (PU) ecoregions and evaluated how local and regional factors influenced their assemblages. During each sampling date, we registered variables related to climate, vegetation, and soil in each sampling site. In total, we recorded 270 individuals from 21 species, richness of species was higher in PU than in AA, but without a statistically significant difference. Twelve species were present exclusively in PU, while two in AA. Tenebrionid assemblages in both ecoregions had different dominant species, in PU, Psectrascelis cariosicollis while Epipedonota interandina in AA. Beta diversity between ecoregions was moderate and we recorded a high beta diversity and high turnover of species in each ecoregion. The geographical distance between the sites influenced the similarity of the assemblages inside and between ecoregions, therefore, an increase in the geographical distance between sites determined a decrease in the similarity of the assemblages. The increase in elevation of the sampled sites did not produce significant changes in the abundance and richness of Tenebrionidae. There is no individual factor responsible for the darkling beetle communities structuration in these high-altitude environments. Different combinations of both local (soil and vegetation) and regional (climate and geographical distance) environmental factors together explain the ecoregional tenebrionid assemblages. We suggest including them among the focus groups in conservation studies to evaluate anthropogenic activities in this area. arid highaltitude altitude littleknown. littleknown little known. known little-known 3 AA (AA (PU date climate vegetation site total 27 2 difference ecoregion therefore Tenebrionidae area