Fish mortality in the Amazonian drought of 2023: the role of experimental biology in our response to climate change.

Higher temperatures exacerbate drought conditions by increasing evaporation rates, reducing soil moisture and altering precipitation patterns. As global temperatures rise as a result of climate change, these effects intensify, leading to more frequent and severe droughts. This link between higher temperatures and drought is particularly evident in sensitive ecosystems like the Amazon rainforest, where reduced rainfall and higher evaporation rates result in significantly lower water levels, threatening biodiversity and human livelihoods. As an example, the serious drought experienced in the Amazon basin in 2023 resulted in a significant decline in fish populations. Elevated water temperatures, reaching up to 38°C, led to mass mortality events, because these temperatures surpass the thermal tolerance of many Amazonian fish species. We know this because our group has collected data on critical thermal maxima (CTmax) for various fish species over multiple years. Additionally, warmer waters can cause hypoxia, further exacerbating fish mortality. Thus, even Amazon fish species, which have relatively high thermal tolerance, are being impacted by climate change. The Amazon drought experienced in 2023 underscores the urgent need for climate action to mitigate the devastating effects on Amazonian biodiversity. The fact that we have been able to link fish mortality events to data on the thermal tolerance of fishes emphasizes the important role of experimental biology in elucidating the mechanisms behind these events, a link that we aim to highlight in this Perspective.

A global map of species at risk of extinction due to natural hazards.

An often-overlooked question of the biodiversity crisis is how natural hazards contribute to species extinction risk. To address this issue, we explored how four natural hazards, earthquakes, hurricanes, tsunamis, and volcanoes, overlapped with the distribution ranges of amphibians, birds, mammals, and reptiles that have either narrow distributions or populations with few mature individuals. To assess which species are at risk from these natural hazards, we combined the frequency and magnitude of each natural hazard to estimate their impact. We considered species at risk if they overlapped with regions where any of the four natural hazards historically occurred (n = 3,722). Those species with at least a quarter of their range subjected to a high relative impact were considered at high risk (n = 2,001) of extinction due to natural hazards. In total, 834 reptiles, 617 amphibians, 302 birds, and 248 mammals were at high risk and they were mainly distributed on islands and in the tropics. Hurricanes (n = 983) and earthquakes (n = 868) affected most species, while tsunamis (n = 272), and volcanoes (n = 171) affected considerably fewer. The region with the highest number of species at high risk was the Pacific Ring of Fire, especially due to volcanoes, earthquakes, and tsunamis, while hurricane-related high-risk species were concentrated in the Caribbean Sea, Gulf of Mexico, and northwestern Pacific Ocean. Our study provides important information regarding the species at risk due to natural hazards and can help guide conservation attention and efforts to safeguard their survival.

Age and sex effects on histological features and in vitro culturing of Antillean manatee (Trichechus manatus manatus, Linnaeus 1758) dermis.

The biobanks from dermal biopsies represent an interesting strategy for biodiversity conservation. Nevertheless, the morphological and cellular patterns of the dermis can be influenced by the age and sex of the individual. Therefore, evaluating these factors is interesting for forming biobanks of Antillean manatees. These animals, representatives of marine fauna, have had their population reduced, and biobanks are essential for their conservation. Then, we evaluated the effects of age (3.5 years vs. 3.6-16 years vs. 23.6 years) and sex (males vs. females) on morphological and cellular parameters using histological and in vitro culture techniques. Regardless of age, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery. Nonetheless, fibroblast reduction was observed in groups aged 23.6 years compared to other animals (p < 0.05). Additionally, cells from animals aged 3.6-16 years showed more significant mitochondrial damage than the other groups (p < 0.05). Regardless of sex, no differences were observed for dermal thickness, collagen fibres, tissue proliferative activity and viable cell recovery; however, females had fewer fibroblasts than males (p < 0.05). Cells from females showed lower mitochondrial damage when compared to cells from males. In summary, although age and sex do not influence dermal thickness and cell recovery, variations in the number of fibroblasts and mitochondrial characteristics were observed among the groups. These differences may be significant for understanding the dermis aspects to be correlated to biobank systems.

Serum starvation is as efficient as roscovitine on the cycle synchronization in G0/G1 of red-rumped agouti fibroblasts.

Fibroblast cycle synchronization in G0/G1 is an essential step for nuclear reprogramming by cloning or induced cells to pluripotency. Considering the diversity among rodents and the ecological and scientific importance of these animals, we compared the contact inhibition, serum starvation, and 10 µM of roscovitine as methods of synchronization of red-rumped agouti fibroblasts. The effects of each protocol were evaluated on the percentage of cycle phase, morphology, viability, and apoptosis levels. The results showed that culturing the cells to serum starvation for 24 h (75.9%), 48 h (81.6%), 72 h (86.2%), 96 h (84.0%), and 120 h (83.7%) yielded a significantly higher percentage of cells arrested in the G0/G1 (P < 0.05) phase than cells not subjected to any cell cycle synchronization method (31.4%). Also, this effect was not different between the times of 48 and 120 h (P > 0.05). A similar response was observed for cells cultured with roscovitine for 12 h (86.9%), 24 h (74.8%), and 48 h (81.7%), with a higher percentage of synchronized cells in G0/G1 compared to cells not submitted to any synchronization treatment (52.2%). Nevertheless, this effect was best evidenced at 12 h (P < 0.05). Also, the contact inhibition for 24-120 h could not synchronize cells in G0/G1, with values ranging from 70.9 to 77.9% (P > 0.05). Moreover, no difference was observed for morphology, viability, and apoptosis levels in any synchronization method (P > 0.05). Therefore, serum starvation is as efficient as roscovitine on cycle synchronization in G0/G1 of red-rumped agouti fibroblasts.

Impact of El Niño 2015-2016 on the coral reefs of the Pacific of Costa Rica: the potential role of marine protection / Impacto del fenómeno El Niño 2015-2016 en arrecifes coralinos del Pacífico de Costa Rica

Introduction: El Niño 2015-2016 was considered one of the most severe worldwide, causing the third global event of coral bleaching. Previous high-intensity El Niño events (1982-83 and 1997-98) caused high coral mortalities and deterioration of coral reef structures along the Eastern Tropical Pacific, affecting both ecosystem and associated economical activities. Objective: The aim of this study was to determine the impact of the most recent El Niño event on coral reefs from Cocos Island and the Pacific coast of southern Costa Rica. Methods: Coral reefs were surveyed before (2013-2014) and after (2016) the disturbance, using underwater visual censuses within belt transects, to quantify the bottom coverage at different depths. Results: In general, average live coral cover decreased 50% after the 2015-2016 El Niño event, with Golfo Dulce being the most affected area with 75% of live coral cover decline. However, in certain localities such as Isla del Coco and Isla del Caño, the effects of El Niño were apparently minimal, since no substantial loss of live coral cover was detected. Differences in the level of deterioration found between coral reefs could be related to several factors, including the age of the protected area, the distance to centers of human population, and the effectiveness in the application of management strategies. Conclusions: The synergistic impact of the 2015-16 El Niño event and other stressors (e.g. illegal fishing and unregulated coastal human development) increased the levels of disturbance on coral reefs, threatening their structure and functioning. It is necessary to strengthen conservation strategies in order to improve the resilience of coral reefs to the impact of natural and anthropogenic disturbances. Concrete actions such as coral reef restoration, marine environmental education, and marine spatial planning must become important tools to maintain the good health of coral reefs and ensure the sustainability of the goods and services provided by these ecosystems.

Introducción: El fenómeno El Niño del 2015-2016 fue considerado como uno de los más severos a nivel mundial, causando el tercer evento global de blanqueamiento coralino. Eventos previos de alta intensidad (1982-83 y 1997-98), causaron altas mortalidades coralinas y el deterioro de estructuras arrecifales a lo largo de Pacífico Tropical Oriental, afectando tanto al ecosistema como las actividades económicas asociadas. Objetivo: El objetivo de este estudio, fue determinar el impacto del evento El Niño 2015-2016 en la salud de los arrecifes coralinos de la Isla del Coco y la costa Pacífico Sur de Costa Rica. Métodos: La evaluación de los arrecifes de coral se realizó antes (2013-2014) y después (2016) de la perturbación, utilizando censos visuales subacuáticos en transectos de banda, con el fin de cuantificar la cobertura del fondo a distintas profundidades. Resultados: En general, la cobertura coralina viva promedio disminuyó 50% después del evento El Niño 2015-2016, siendo Golfo Dulce la zona más afectada con una reducción del 75%. Sin embargo, en ciertas localidades como las islas Coco y Caño, los efectos de El Niño fueron aparentemente mínimos, ya que no se detectó una pérdida sustancial de la cobertura coralina viva. Las diferencias en el nivel de deterioro encontradas entre los arrecifes podrían estar relacionadas con varios factores, incluyendo el tiempo transcurrido desde que se estableció el área protegida, la distancia a los centros de la población humana y la efectividad en la aplicación de estrategias de manejo. Conclusiones: El impacto sinérgico del evento El Niño 2015-2016 y otros factores de estrés (por ejemplo, la pesca ilegal y el desarrollo costero no regulado) incrementó los niveles de perturbación en los arrecifes coralinos, amenazando su estructura y funcionamiento. Es necesario fortalecer las estrategias de conservación para mejorar la resiliencia de los arrecifes coralinos ante el impacto de perturbaciones naturales y antropogénicas. Acciones concretas como la jardinería de corales, la educación ambiental marina y el ordenamiento espacial marino, deben convertirse en herramientas importantes para mantener la buena salud de los arrecifes coralinos y asegurar la sostenibilidad de los bienes y servicios proporcionados por estos ecosistemas.

Quantitative and descriptive histological aspects of jaguar (Panthera onca Linnaeus, 1758) ear skin as a step towards formation of biobanks.

Skin of mammals vulnerable to extinction, such as the jaguar, is used as a source of material in conservation strategies. The composition of skin is not uniform among species, and the ability to distinguish similarities in skin morphology in animal groups is fundamental in the application of skin tissue for use in biobanks. The aim of our study was to evaluate the structure, composition and capacity for culture of ear skin from the yellow and black jaguars. Both qualitative and quantitative methods were used, focusing on skin thickness, cell quantification and distribution, collagen density, proliferative activity and viability. Histomorphometrical study of the skin showed a total thickness of 273.2 and 274.6 µm for the yellow and black jaguars, respectively. Melanocytes and fibroblasts were, respectively, 9.7 and 23.0 for the yellow jaguar and 11.3 and 26.8 for the black jaguar. A collagen density of 67.0% and 49.0% was observed for yellow and black jaguars, respectively. Both animals presented a proliferative activity varying between 1.20 and 1.30. All tissues could promote cellular detachment, reaching subconfluence in 10-15 days. This kind of information from histomorphometrical features and cell cultures can be essential for a more targeted application of ear skin cryopreservation in this species, as such information will enable understanding the action of substances on tissues during the conservation process.

Small-sized fish: the largest and most threatened portion of the megadiverse neotropical freshwater fish fauna / Peixes de pequeno porte: a porção maior e mais ameaçada da fauna megadiversa de peixes de água doce neotropicais

Abstract: We introduce the work providing a synthetic description of the diversity and phyletic structure of freshwater fish in the Neotropical Region, especially emphasizing that of Brazil. This is accompanied by a discussion about environments of fish from small to medium sized to large, taking into account how it shaped their respective biologies/ecologies, as well as what they imply for their use by humans. We present, as figures, the results of our exploratory analysis of Brazilian Red Book of Threatened Species of Fauna (2018), focusing on the small-sized ones, with up to 15 cm of standard length. We continue to present the main human impacts in small fish environments, along with those suffered by medium to large fish environments, and then follow by their respective deleterious effects. Finally, we present a general synthesis, reinforcing the enormous importance of small fish conservation and their respective preferred environments, followed by our main conclusions, and possible conservation strategies.

Resumo: Iniciamos o trabalho fornecendo uma descrição sintética da diversidade e estrutura filética dos peixes de água doce da Região Neotropical, com ênfase naquela do Brasil, acompanhada de uma exposição sobre onde vivem os peixes de pequeno porte e os de porte médio a grande, levando em conta como isso moldou suas respectivas biologias/ecologias, e o que as mesmas implicam para seu uso pelos seres humanos. São apresentados, sob a forma de figuras, os resultados de uma análise exploratória dos dados sobre as 311 espécies de peixes ósseos de água doce contidos no Livro Vermelho da Fauna Brasileira Ameaçada de Extinção (2018), com ênfase naquelas de pequeno porte, com até 15 cm de comprimento padrão. Continuamos apresentando os principais impactos antrópicos nos ambientes de peixes de pequeno porte, juntamente com aqueles sofridos pelos ambientes de peixes de portes médio a grande, seguidos dos seus respectivos efeitos deletérios. Finalmente, concluímos com uma síntese geral, reforçando a enorme importância da conservação dos peixes de pequeno porte e seus ambientes preferenciais, e estratégias possíveis para conservação dos mesmos.

An overview of the applicability of functional diversity in Biological Conservation / Uma visão geral sobre a aplicabilidade da diversidade funcional na Conservação Biológica

Abstract Functional diversity is increasingly pointed as a useful approach to reach Biological Conservation goals. Here, we provide an overview of the functional diversity approach status in the Biological Conservation field. We sought for peer-reviewed papers published over a period of twenty years (from 1994 to 2014). First we used the general topic "functional diversity" and then refined our search using the key-word "conservation". We have identified the conservation strategies addressed, the organism studied, and the continent of study site in each paper. Thirteen classes of conservation strategies were identified. Plants were the most commonly studied organism group and most study-sites were located in Europe. The functional diversity approach was introduced in the Biological Conservation field in the early 2000's and its inclusion in conservation strategies is broadly advised. However, the number of papers that operationalise such inclusion by developing models and systems is still low. Functional diversity responds differently and eventually better than other measures to changes in land use and management, which suggests that this approach can potentially better predict the impacts. More studies are needed to corroborate this hypothesis. We pointed out knowledge gaps regarding identification of the responses for functional diversity about urban impacts and in research on the level of management intensity of land needed to maintain functional diversity. We recommend the use of functional diversity measures to find ecological indicators. Future studies should focus on the development of functional diversity measures of other taxa beyond plants as well as test hypothesis in tropical ecosystems.

Resumo A diversidade funcional é crescentemente apontada como uma abordagem útil para alcançar os objetivos da Conservação Biológica. Neste artigo, nós mostramos uma visão geral do status desta abordagem no campo da Conservação Biológica. Nós buscamos por artigos revisados por pares publicados ao longo de vinte anos (desde 1994 até 2014) usando, primeiramente, o tópico geral "functional diversity" e em seguida, refinamos a pesquisa com a palavra-chave "conservation". Identificamos a estratégia de conservação abordada, o organismo estudado e o continente da área de estudo de cada artigo. Treze classes de estratégias de conservação foram identificadas. As plantas foram o grupo de organismos mais amplamente estudado e a maior parte das áreas de estudo estavam localizadas no continente europeu. A abordagem da diversidade funcional entrou no campo da Conservação Biológica no início dos anos 2000 e sua inclusão nas estratégias de conservação é amplamente recomendada. Entretanto, o número de artigos que operacionalizam tal inclusão ainda é pequeno. A diversidade funcional responde diferentemente e, eventualmente, melhor do que as outras medidas às mudanças no uso da terra e no manejo, sugerindo que essa abordagem pode potencialmente prever melhor os impactos. Mais estudos são necessários para corroborar esta hipótese. Destacamos lacunas de conhecimento sobre a identificação das respostas da diversidade funcional aos impactos urbanos e sobre a busca pelo nível de intensidade de manejo da terra necessária para manter a diversidade funcional. Recomendamos o uso de medidas de diversidade funcional para encontrar indicadores ecológicos. Estudos futuros devem focar no desenvolvimento de medidas de diversidade funcional de outros taxa, além das plantas bem como testar hipóteses em ecossistemas tropicais.

An overview of the applicability of functional diversity in Biological Conservation / Uma visão geral sobre a aplicabilidade da diversidade funcional na Conservação Biológica

Functional diversity is increasingly pointed as a useful approach to reach Biological Conservation goals. Here, we provide an overview of the functional diversity approach status in the Biological Conservation field. We sought for peer-reviewed papers published over a period of twenty years (from 1994 to 2014). First we used the general topic functional diversity and then refined our search using the key-word conservation. We have identified the conservation strategies addressed, the organism studied, and the continent of study site in each paper. Thirteen classes of conservation strategies were identified. Plants were the most commonly studied organism group and most study-sites were located in Europe. The functional diversity approach was introduced in the Biological Conservation field in the early 2000s and its inclusion in conservation strategies is broadly advised. However, the number of papers that operationalise such inclusion by developing models and systems is still low. Functional diversity responds differently and eventually better than other measures to changes in land use and management, which suggests that this approach can potentially better predict the impacts. More studies are needed to corroborate this hypothesis. We pointed out knowledge gaps regarding identification of the responses for functional diversity about urban impacts and in research on the level of management intensity of land needed to maintain functional diversity. We recommend the use of functional diversity measures to find ecological indicators. Future studies should focus on the development of functional diversity measures of other taxa beyond plants as well as test hypothesis in tropical ecosystems.(AU)

A diversidade funcional é crescentemente apontada como uma abordagem útil para alcançar os objetivos da Conservação Biológica. Neste artigo, nós mostramos uma visão geral do status desta abordagem no campo da Conservação Biológica. Nós buscamos por artigos revisados por pares publicados ao longo de vinte anos (desde 1994 até 2014) usando, primeiramente, o tópico geral functional diversity e em seguida, refinamos a pesquisa com a palavra-chave conservation. Identificamos a estratégia de conservação abordada, o organismo estudado e o continente da área de estudo de cada artigo. Treze classes de estratégias de conservação foram identificadas. As plantas foram o grupo de organismos mais amplamente estudado e a maior parte das áreas de estudo estavam localizadas no continente europeu. A abordagem da diversidade funcional entrou no campo da Conservação Biológica no início dos anos 2000 e sua inclusão nas estratégias de conservação é amplamente recomendada. Entretanto, o número de artigos que operacionalizam tal inclusão ainda é pequeno. A diversidade funcional responde diferentemente e, eventualmente, melhor do que as outras medidas às mudanças no uso da terra e no manejo, sugerindo que essa abordagem pode potencialmente prever melhor os impactos. Mais estudos são necessários para corroborar esta hipótese. Destacamos lacunas de conhecimento sobre a identificação das respostas da diversidade funcional aos impactos urbanos e sobre a busca pelo nível de intensidade de manejo da terra necessária para manter a diversidade funcional. Recomendamos o uso de medidas de diversidade funcional para encontrar indicadores ecológicos. Estudos futuros devem focar no desenvolvimento de medidas de diversidade funcional de outros taxa, além das plantas bem como testar hipóteses em ecossistemas tropicais.(AU)

An overview of the applicability of functional diversity in Biological Conservation

Abstract Functional diversity is increasingly pointed as a useful approach to reach Biological Conservation goals. Here, we provide an overview of the functional diversity approach status in the Biological Conservation field. We sought for peer-reviewed papers published over a period of twenty years (from 1994 to 2014). First we used the general topic functional diversity and then refined our search using the key-word conservation. We have identified the conservation strategies addressed, the organism studied, and the continent of study site in each paper. Thirteen classes of conservation strategies were identified. Plants were the most commonly studied organism group and most study-sites were located in Europe. The functional diversity approach was introduced in the Biological Conservation field in the early 2000s and its inclusion in conservation strategies is broadly advised. However, the number of papers that operationalise such inclusion by developing models and systems is still low. Functional diversity responds differently and eventually better than other measures to changes in land use and management, which suggests that this approach can potentially better predict the impacts. More studies are needed to corroborate this hypothesis. We pointed out knowledge gaps regarding identification of the responses for functional diversity about urban impacts and in research on the level of management intensity of land needed to maintain functional diversity. We recommend the use of functional diversity measures to find ecological indicators. Future studies should focus on the development of functional diversity measures of other taxa beyond plants as well as test hypothesis in tropical ecosystems.

Resumo A diversidade funcional é crescentemente apontada como uma abordagem útil para alcançar os objetivos da Conservação Biológica. Neste artigo, nós mostramos uma visão geral do status desta abordagem no campo da Conservação Biológica. Nós buscamos por artigos revisados por pares publicados ao longo de vinte anos (desde 1994 até 2014) usando, primeiramente, o tópico geral functional diversity e em seguida, refinamos a pesquisa com a palavra-chave conservation. Identificamos a estratégia de conservação abordada, o organismo estudado e o continente da área de estudo de cada artigo. Treze classes de estratégias de conservação foram identificadas. As plantas foram o grupo de organismos mais amplamente estudado e a maior parte das áreas de estudo estavam localizadas no continente europeu. A abordagem da diversidade funcional entrou no campo da Conservação Biológica no início dos anos 2000 e sua inclusão nas estratégias de conservação é amplamente recomendada. Entretanto, o número de artigos que operacionalizam tal inclusão ainda é pequeno. A diversidade funcional responde diferentemente e, eventualmente, melhor do que as outras medidas às mudanças no uso da terra e no manejo, sugerindo que essa abordagem pode potencialmente prever melhor os impactos. Mais estudos são necessários para corroborar esta hipótese. Destacamos lacunas de conhecimento sobre a identificação das respostas da diversidade funcional aos impactos urbanos e sobre a busca pelo nível de intensidade de manejo da terra necessária para manter a diversidade funcional. Recomendamos o uso de medidas de diversidade funcional para encontrar indicadores ecológicos. Estudos futuros devem focar no desenvolvimento de medidas de diversidade funcional de outros taxa, além das plantas bem como testar hipóteses em ecossistemas tropicais.

An overview of the applicability of functional diversity in Biological Conservation

Abstract Functional diversity is increasingly pointed as a useful approach to reach Biological Conservation goals. Here, we provide an overview of the functional diversity approach status in the Biological Conservation field. We sought for peer-reviewed papers published over a period of twenty years (from 1994 to 2014). First we used the general topic functional diversity and then refined our search using the key-word conservation. We have identified the conservation strategies addressed, the organism studied, and the continent of study site in each paper. Thirteen classes of conservation strategies were identified. Plants were the most commonly studied organism group and most study-sites were located in Europe. The functional diversity approach was introduced in the Biological Conservation field in the early 2000s and its inclusion in conservation strategies is broadly advised. However, the number of papers that operationalise such inclusion by developing models and systems is still low. Functional diversity responds differently and eventually better than other measures to changes in land use and management, which suggests that this approach can potentially better predict the impacts. More studies are needed to corroborate this hypothesis. We pointed out knowledge gaps regarding identification of the responses for functional diversity about urban impacts and in research on the level of management intensity of land needed to maintain functional diversity. We recommend the use of functional diversity measures to find ecological indicators. Future studies should focus on the development of functional diversity measures of other taxa beyond plants as well as test hypothesis in tropical ecosystems.

Resumo A diversidade funcional é crescentemente apontada como uma abordagem útil para alcançar os objetivos da Conservação Biológica. Neste artigo, nós mostramos uma visão geral do status desta abordagem no campo da Conservação Biológica. Nós buscamos por artigos revisados por pares publicados ao longo de vinte anos (desde 1994 até 2014) usando, primeiramente, o tópico geral functional diversity e em seguida, refinamos a pesquisa com a palavra-chave conservation. Identificamos a estratégia de conservação abordada, o organismo estudado e o continente da área de estudo de cada artigo. Treze classes de estratégias de conservação foram identificadas. As plantas foram o grupo de organismos mais amplamente estudado e a maior parte das áreas de estudo estavam localizadas no continente europeu. A abordagem da diversidade funcional entrou no campo da Conservação Biológica no início dos anos 2000 e sua inclusão nas estratégias de conservação é amplamente recomendada. Entretanto, o número de artigos que operacionalizam tal inclusão ainda é pequeno. A diversidade funcional responde diferentemente e, eventualmente, melhor do que as outras medidas às mudanças no uso da terra e no manejo, sugerindo que essa abordagem pode potencialmente prever melhor os impactos. Mais estudos são necessários para corroborar esta hipótese. Destacamos lacunas de conhecimento sobre a identificação das respostas da diversidade funcional aos impactos urbanos e sobre a busca pelo nível de intensidade de manejo da terra necessária para manter a diversidade funcional. Recomendamos o uso de medidas de diversidade funcional para encontrar indicadores ecológicos. Estudos futuros devem focar no desenvolvimento de medidas de diversidade funcional de outros taxa, além das plantas bem como testar hipóteses em ecossistemas tropicais.

Understanding patterns of land-cover change in the Brazilian Cerrado from 2000 to 2015.

Clearing tropical vegetation impacts biodiversity, the provision of ecosystem services, and thus ultimately human welfare. We quantified changes in land cover from 2000 to 2015 across the Cerrado biome of northern Minas Gerais state, Brazil. We assessed the potential biophysical and socio-economic drivers of the loss of Cerrado, natural regeneration and net cover change at the municipality level. Further, we evaluated correlations between these land change variables and indicators of human welfare. We detected extensive land-cover changes in the study area, with the conversion of 23 446 km(2) and the natural regeneration of 13 926 km(2), resulting in a net loss of 9520 km(2) The annual net loss (-1.2% per year) of the cover of Cerrado is higher than that reported for the whole biome in similar periods. We argue that environmental and economic variables interact to underpin rates of conversion of Cerrado, most severely affecting more humid Cerrado lowlands. While rates of Cerrado regeneration are important for conservation strategies of the remaining biome, their integrity must be investigated given the likelihood of encroachment. Given the high frequency of land abandonment in tropical regions, secondary vegetation is fundamental to maintain biodiversity and ecosystem services. Finally, the impacts of Cerrado conversion on human welfare likely vary from local to regional scales, making it difficult to elaborate land-use policies based solely on socio-economic indicators.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.

Pilares del ahorro transfusional / Pillars in the blood conservation

Las transfusiones sanguíneas alogénicas han tenido un rol central en el desarrollo de la medicina, principalmente como terapia de soporte en pacientes críticos, cirugía mayor, trauma y trastornos hematopoyéticos. Sin embargo, su utilización no está exenta de importantes efectos adversos y de altos costos asociados. Además, los productos sanguíneos son un recurso limitado que no debe ser desperdiciado. Por otro lado, la cirugía en pacientes que rehúsan la utilización de hemoderivados ha mostrado igual o mejores resultados que los pacientes que aceptan transfusiones. Esto ha llevado a buscar un manejo apropiado de la sangre en todos nuestros pacientes, evitando los riesgos y costos innecesarios de las transfusiones, pero permitiéndolos cuando se cree que los beneficios serán mayores que los riesgos. En este trabajo se presentan 3 pilares esenciales. El primero es el diagnóstico y manejo apropiado de la anemia preoperatoria, disminuyendo los riesgos perioperatorios, ya que la anemia por sí sola es un factor de morbimortalidad. El segundo pilar está constituido por diversas técnicas, que están disponibles en la actualidad, para minimizar el sangrado perioperatorio. Finalmente, el tercer pilar es mejorar la tolerancia a la anemia. El uso en conjunto de diversas técnicas descritas en este trabajo ha mostrado ser efectivo en disminuir el sangrado perioperatorio, la necesidad de transfusiones alogénicas y las unidades de sangre utilizadas, lo cual podría permitir mejores resultados clínicos en nuestros pacientes.

Allogeneic blood transfusions have played a central role in the development of medicine, mainly as a support therapy in critically ill patients, major surgery, trauma and hematopoietic disorders. However, their use is not without significant adverse effects and associated high costs. Moreover, blood products are a limited resource that should not be wasted. Furthermore, surgery in patients who refuse the use of blood products has shown equal or better results than patients who accept transfusions. This has led to seek an appropriate blood management in all our patients, avoiding unnecessary costs and risks of transfusions, but allowing them when they believe the benefits outweigh the risks. In this paper three essential pillars are presented. The first is the appropriate diagnosis and management of pre-operative anaemia decreasing perioperative risk, since anaemia itself is a factor of morbidity and mortality. The second pillar is formed by various techniques that are available today to minimize bleeding perioperative. Finally, the third pillar is to improve tolerance to anaemia. The joint use of various techniques described in this paper has proven effective in decreasing perioperative bleeding, the need for allogeneic transfusions and blood units used, which may allow better clinical outcomes in our patients.