1,129 research outputs found
Determinants of population persistence and abundance of terrestrial and arboreal vertebrates stranded in tropical forest land-bridge islands
Megadams are among the key modern drivers of habitat and biodiversity loss in emerging economies. The Balbina Hydroelectric Dam of Central Brazilian Amazonia inundated 312,900 ha of primary forests and created approximately 3500 variable-sized islands that still harbor vertebrate populations after nearly 3 decades after isolation. We estimated the species richness, abundance, biomass, composition, and group size of medium- to large-bodied forest vertebrates in response to patch, landscape, and habitat-quality metrics across 37 islands and 3 continuous forest sites throughout the Balbina archipelago. We conducted 1168 km of diurnal censuses and had 12,420 camera-trapping days along 81 transects with 207 camera stations. We determined the number of individuals (or groups) detected per 10 km walked and the number of independent photographs per 10 camera-trapping days, respectively, for each species. We recorded 34 species, and patch area was the most significant predictor of vertebrate population relative abundance and aggregate biomass. The maximum group size of several group-living species was consistently larger on large islands and in continuous patches than on small islands. Most vertebrate populations were extirpated after inundation. Remaining populations are unlikely to survive further ecological disruptions. If all vertebrate species were once widely distributed before inundation, we estimated that approximately 75% of all individual vertebrates were lost from all 3546 islands and 7.4% of the animals in all persisting insular populations are highly likely to be extirpated. Our results demonstrate that population abundance estimates should be factored into predictions of community disassembly on small islands to robustly predict biodiversity outcomes. Given the rapidly escalating hydropower infrastructure projects in developing counties, we suggest that faunal abundance and biomass estimates be considered in environmental impact assessments and large strictly protected reserves be established to minimize detrimental effects of dams on biodiversity. Conserving large tracts of continuous forests represents the most critical conservation measure to ensure that animal populations can persist at natural densities in Amazonian forests
Widespread forest vertebrate extinctions induced by a mega hydroelectric dam in lowland Amazonia
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
Fungos associados às sementes de tento e maranhoto.
A utilização de sementes sadias é fundamental para o sucesso de um empreendimento florestal. O objetivo deste trabalho foi identificar e quantificar os fungos associados às sementes de tento (Ormosia sp.) e maranhoto (Phyllanthus nobilis (L. f.) Müll. Arg). Os experimentos foram realizados no Laboratório de Fitopatologia da Embrapa Amazônia Oriental, em Belém, Pará. As sementes testadas foram cedidas pelo Laboratório de Sementes Florestais da Embrapa Amazônia Oriental. Foram analisadas 50 sementes de tento e 50 de maranhoto, originárias de Belterra e Bonito, estado do Pará. As amostras foram divididas em sub-amostras de 25 sementes, com e sem assepsia, para realização dos testes de sanidade em meio de cultura de Batata-Dextrose-Agar (BDA). As sementes contaminadas foram analisadas e lâminas das culturas fúngicas foram avaliadas sob microscópio óptico. Aspergillus sp. foi o único fungo detectado nas duas espécies. A infestação nas sementes de maranhoto e tento, com assepsia, foi de 8% e 36%, enquanto que, nas sem assepsia, foi de 80% e 44%, respectivamente. A assepsia utilizada nos ensaios (hipoclorito de sódio a 1%, por cinco minutos) mostrou maior eficiência nas sementes de maranhoto do que de nas de tento, visto que nestas últimas o índice de infestação por Aspergillus foi considerado alto quando comparado com o tratamento sem assepsia
Recommended from our members
Health Researchers' Use of Social Media: Scoping Review.
BackgroundHealth researchers are increasingly using social media in a professional capacity, and the applications of social media for health researchers are vast. However, there is currently no published evidence synthesis of the ways in which health researchers use social media professionally, and uncertainty remains as to how best to harness its potential.ObjectiveThis scoping review aimed to explore how social media is used by health researchers professionally, as reported in the literature.MethodsThe scoping review methodology guided by Arksey and O'Malley and Levac et al was used. Comprehensive searches based on the concepts of health research and social media were conducted in MEDLINE, EMBASE, CINAHL, PsycINFO, ERIC, and Web of Science databases, with no limitations applied. Articles were screened at the title and abstract level and at full text by two reviewers. One reviewer extracted data that were analyzed descriptively to map the available evidence.ResultsA total of 8359 articles were screened at the title and abstract level, of which 719 were also assessed at full text for eligibility. The 414 articles identified for inclusion were published in 278 different journals. Studies originated from 31 different countries, with the most prevalent being the United States (52.7% [218/414]). The health discipline of the first authors varied, with medicine (33.3% [138/414]) being the most common. A third of the articles covered health generally, with 61 health-specific topics. Papers used a range of social media platforms (mean 1.33 [SD 0.7]). A quarter of the articles screened reported on social media use for participant recruitment (25.1% [104/414]), followed by practical ways to use social media (15.5% [64/414]), and use of social media for content analysis research (13.3% [55/414]). Articles were categorized as celebratory (ie, opportunities for engagement, 72.2% [299/414]), contingent (ie, opportunities and possible limitations, 22.7% [94/414]) and concerned (ie, potentially harmful, 5.1% [21/414]).ConclusionsHealth researchers are increasingly publishing on their use of social media for a range of professional purposes. Although most of the sentiment around the use of social media in health research was celebratory, the uses of social media varied widely. Future research is needed to support health researchers to optimize their social media use
A mela da soja no Estado do Pará nas safras de 2003 a 2005.
bitstream/item/18796/1/com.tec.152.pdfNa publicação: Ruth Linda Benchimo
Ocorrência da murcha de Sclerotium no feijão caupi no estado do Pará.
Edição dos resumos do 44º Congresso Brasileiro de Fitopatologia, 2011, Bento Gonçalves. Resumo 1173
Diagnóstico fitossanitário em sementes de cedro e tachi branco.
O trabalho objetivou diagnosticar fitopatógenos presentes em sementes de cedro vermelho (Cedrela odorata L.) e tachi branco (Sclerolobium paniculatum Vogel), espécies florestais nativas da Amazônia. A importância da patologia de sementes relaciona-se com a disseminação de doenças pelo fruto quando este é levado para beneficiamento e para evitar o apodrecimento das sementes, o que pode ocasionar perda pela presença de fitopatógenos nas mesmas. Os testes foram feitos com base nas Regras de Análise de Sementes (RAS) do Ministério da Agricultura, Pecuária e Abastecimento ? MAPA, pelo método de incubação em papel filtro ?Blotter Test?. Foram detectados os seguintes gêneros de fungos: Aspergillus sp., Penicillium spp. e Lasiodiplodia sp. em sementes de cedro e Penicillium spp. e Aspergillus sp. em tachi branco. As sementes de cedro apresentaram maiores níveis de incidência de fungos.PIBIC-2011
Influência do sombreamento no desenvolvimento de mudas de paricá (Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby).
O presente trabalho teve como objetivo aferir a emergência de plântulas, o crescimento e o desenvolvimento de mudas de Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby aos 20, 40, 60 e 80 dias após a semeadura, submetidas aos níveis de sombreamento de 0, 30, 50 e 70%, sendo analisados os parâmetros: altura da parte aérea e diâmetro do colo. Cada tratamento foi constituído de 100 mudas com quatro repetições, por parcela e avaliadas diariamente quanto a emergência e escolhidas 15 plantas por repetição para as mensurações. Em relação às porcentagens de emergência, os resultados se apresentaram melhores no tratamento 30% de sombreamento com 95% de emergência, porém não diferiu estatisticamente dos demais tratamentos ao nível de significância de 5% pelo teste de tukey. O diâmetro do coleto foi superior a pleno sol, respondendo satisfatoriamente a ambiente com elevada intensidade luminosa. A pleno sol, as mudas foram mais vigorosas, obtiveram maior crescimento diamétrico e um maior padrão de qualidade
Biodiversidade e suas aplicações: parcerias entre Brasil e Canadá, resultados e perspectivas futuras.
Disponível também on-line
- …