24 research outputs found

    Widespread forest vertebrate extinctions induced by a mega hydroelectric dam in lowland Amazonia

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    Mega hydropower projects in tropical forests pose a major emergent threat to terrestrial and freshwater biodiversity worldwide. Despite the unprecedented number of existing, underconstruction and planned hydroelectric dams in lowland tropical forests, long-term effects on biodiversity have yet to be evaluated. We examine how medium and large-bodied assemblages of terrestrial and arboreal vertebrates (including 35 mammal, bird and tortoise species) responded to the drastic 26-year post-isolation history of archipelagic alteration in landscape structure and habitat quality in a major hydroelectric reservoir of Central Amazonia. The Balbina Hydroelectric Dam inundated 3,129 km2 of primary forests, simultaneously isolating 3,546 land-bridge islands. We conducted intensive biodiversity surveys at 37 of those islands and three adjacent continuous forests using a combination of four survey techniques, and detected strong forest habitat area effects in explaining patterns of vertebrate extinction. Beyond clear area effects, edge-mediated surface fire disturbance was the most important additional driver of species loss, particularly in islands smaller than 10 ha. Based on species-area models, we predict that only 0.7% of all islands now harbor a species-rich vertebrate assemblage consisting of ≥80% of all species. We highlight the colossal erosion in vertebrate diversity driven by a man-made dam and show that the biodiversity impacts of mega dams in lowland tropical forest regions have been severely overlooked. The geopolitical strategy to deploy many more large hydropower infrastructure projects in regions like lowland Amazonia should be urgently reassessed, and we strongly advise that long-term biodiversity impacts should be explicitly included in pre-approval environmental impact assessments

    Passing the Panda Standard: A TAD Off the Mark?

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    Tilapia, a tropical freshwater fish native to Africa, is an increasingly important global food commodity. The World Wide Fund for Nature (WWF), a major environmental nongovernmental organization, has established stakeholder dialogues to formulate farm certification standards that promote ‘‘responsible’’ culture practices. As a preface to its ‘‘tilapia aquaculture dialogue,’’ the WWF for Nature commissioned a review of potential certification issues, later published as a peer-reviewed article. This article contends that both the review and the draft certification standards subsequently developed fail to adequately integrate critical factors governing the relative sustainability of tilapia production and thereby miss more significant issues related to resource-use efficiency and the appropriation of ecosystem space and services. This raises a distinct possibility that subsequent certification will promote intensive systems of tilapia production that are far less ecologically benign than existing widely practiced semiintensive alternatives. Given the likely future significance of this emergent standard, it is contended that a more holistic approach to certification is essential

    Small mammal responses to Amazonian forest islands are modulated by their forest dependence

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    Hydroelectric dams have induced widespread loss, fragmentation and degradation of terrestrial habitats in lowland tropical forests. Yet their ecological impacts have been widely neglected, particularly in developing countries, which are currently earmarked for exponential hydropower development. Here we assess small mammal assemblage responses to Amazonian forest habitat insularization induced by the 28-year-old Balbina Hydroelectric Dam. We sampled small mammals on 25 forest islands (0.83–1466 ha) and four continuous forest sites in the mainland to assess the overall community structure and species-specific responses to forest insularization. We classified all species according to their degree of forest-dependency using a multi-scale approach, considering landscape, patch and local habitat characteristics. Based on 65,520 trap-nights, we recorded 884 individuals of at least 22 small mammal species. Species richness was best predicted by island area and isolation, with small islands ( 200 ha; 10.8 ± 1.3 species) and continuous forest sites (∞ ha; 12.5 ± 2.5 species) exhibited similarly high species richness. Forest-dependent species showed higher local extinction rates and were often either absent or persisted at low abundances on small islands, where non-forest-dependent species became hyper-abundant. Species capacity to use non-forest habitat matrices appears to dictate small mammal success in small isolated islands. We suggest that ecosystem functioning may be highly disrupted on small islands, which account for 62.7% of all 3546 islands in the Balbina Reservoir

    Indicadores de sustentabilidade ambiental e de saúde na Amazônia Legal, Brasil Environmental sustainability and health indicators in the Legal Amazonia, Brazil

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    Entre os desafios atuais para a Saúde Pública está o de estruturar sistemas de indicadores que permitam monitorar as condições e tendências da sustentabilidade ambiental e de saúde. Neste artigo procuramos enfrentar esse desafio tendo como foco de análise os estados integrantes da Macrorregião Amazônia Legal, que desde a segunda metade do século XX vem sofrendo intensos processos de mudanças sócio-econômicas, ambientais, de saúde e bem-estar. Para a reunião e análise do conjunto de indicadores adotamos o modelo Forças Motrizes, Pressão, Situação, Exposição, Efeito e Ação (FMPSEEA) proposto pela Organização Mundial da Saúde. Os resultados demonstram que, ao mesmo tempo em que as forças motrizes e pressões vêm contribuindo para o crescimento econômico e populacional, resultando em melhoras de indicadores tradicionais de saúde (redução da mortalidade infantil e aumento da expectativa de vida), são grandes as desigualdades sociais e econômicas e a sobreposição dos impactos na saúde da população, em um quadro bastante heterogêneo. Além disso, a situação ambiental também aponta para um modelo de desenvolvimento insustentável para as gerações presentes e futuras, exigindo respostas dos setores ambientais e de saúde à altura dos desafios colocados na atualidade.<br>One of the challenges for public health is to build systems of indicators that allow monitoring current conditions and trends in environmental and health sustainability. This article focuses on the Legal Amazonia macro-region, which has undergone profound socioeconomic, environmental, and health changes since the mid-20th century. The conceptual framework adopted here was the model entitled Driving Forces, Pressures, State, Exposure, Effects, and Action (DPSEEA) proposed by the World Health Organization and adopted for environmental health surveillance by the Brazilian Ministry of Health. The results show that numerous motor forces and pressures have contributed to the growth of the economy and the population, as well as to improvements in some traditional health indicators (a reduction in infant mortality and an increase in life expectancy), alongside major social and economic inequalities and heterogeneity in environmental health impacts. This same process has been accompanied by environmental changes that indicate an unsustainable development model for present and future generations, demanding comprehensive action by public health and environmental institutions

    The impact of agricultural colonization and deforestation on stingless bee (Apidae: Meliponini) composition and richness in Rondônia, Brazil

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    Stingless bees were collected throughout the state of Rondônia in the southwestern Brazilian Amazon for 1 year. The impact of agricultural colonization and subsequent deforestation on species composition and richness is explored. Deforestation, around each of 187 sample sites, was characterized at the mesoscale, microscale, and local spatial scale. At the microscale, deforestation was measured using a data layer generated by satellite remote sensing and analyzed with the assistance of a geographic information system. We report perhaps the greatest richness of stingless bees ever recorded in the Tropics, collecting 9,555 individuals from 98 species of stingless bees. Ten of these are new species and 16 were first-ever records for Rondônia. Five new species were scientifically described from the study. We report statistical relationships between deforestation and species richness at all spatial scales of analysis, and we tentatively identify species that appear to be especially sensitive to deforestation. © 2013 INRA, DIB and Springer-Verlag France
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