918 resultados para ECOSYSTEM FUNCTIONALITY


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A study on the benthic ecosystem health was performed to assess the environmental quality of Montevideo coastal zone, in view of the construction of a new sanitation system. Data were compared to previous research undertaken 10 years ago, and biochemical composition of organic matter, heavy metals, organic matter, phytopigments, benthic diatoms, macrofauna community structure and a biotic index (AMBI) were used as proxies. Results indicate an environmental quality-gradient, with the worst conditions within the inner stations of Montevideo Bay and an improvement towards the adjacent coastal zone. Higher levels of chromium, lead, phaeopigments, organic biopolymers and poor benthic macrofauna and diatom communities, characterised the hypertrophic innermost portion of Montevideo Bay. Data indicated a clear deterioration of the adjacent coastal zone comparatively to that observed 10 years ago. The complementary use of approaches not applied before (benthic diatoms and organic biopolymers) with those formerly applied improve our assessment of the trophic status and the environmental health of the area. (C) 2010 Elsevier B.V. All rights reserved.

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This article presents data-rich findings of a comprehensive follow-up study on the patron-driven/demand-driven ebook acquisitions (DDA) plan chronicled in two prior articles from the DDA ebook plan's October 2011 inception. Into the third fiscal year, print vs. ebook usage preferences have begun to emerge, and the results broken out by discipline are presented.

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Negócios sociais, empresas autossuficientes com objetivos principalmente sociais estão a surgir e a mudar o cenário económico mundial. No Brasil, o campo de Empreendedorismo Social promete ajudar a resolver os vários problemas sociais do país, mas tal promessa depende do desenvolvimento de um ecossistema de suporte. No entanto, a pesquisa desenvolvida no tópico ainda é limitada, especialmente quando considerando pesquisa em contextos macro como estruturas de suporte ao negócio. O presente estudo explora o ecossistema de suporte aos negócios sociais no Brasil, oferecendo uma análise qualitativa preliminar da eficácia da rede de suporte existente para os negócios sociais, de acordo com as perceções de empreendedores sociais e prestadores de suporte. O estudo é desenvolvido baseando-se no modelo conceptual de Turrini et al. (2010) sobre os determinantes de eficácia de redes a fim de facilitar a captura de padrões. Desta forma, cada variável de eficácia de redes é desenvolvida no contexto da presente investigação e as principais conclusões relativas ao ecossistema de suporte para negócios sociais no Brasil são destacadas. Os resultados sugerem um rápido crescimento da disponibilidade de suporte para negócios sociais, mas indicam que estes serviços ainda são em número limitado e concentrados no Sudeste do país. Adicionalmente, os serviços de suporte são percecionados pelos empreendedores sociais como serviços de alta qualidade e embora se observe um sentimento generalizado de que a colaboração entre organizações de suporte tem sido importante para a construção do campo, os resultados indicam que um maior nível de interação e formalização entre prestadores de suporte levaria a maiores níveis de criação de sinergias e potenciaria a construção do ecossistema. Por último, é observado um sentimento generalizado de que o crescente nível de recursos financeiros, consciência pública e apoio do governo ao campo impactarão positivamente o desenvolvimento do ecossistema.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This study aimed to compare the development of crab and tree communities of two restored mangrove areas, one planted with Rhizophora mangle and the other naturally recovered, and also to compare the predation of Grapsid crab Goniopsis cruentata and the Ocypodid Ucides cordatus over the propagules of three mangrove trees: Rhizophora mangle, Avicennia schaueriana e Laguncularia racemosa. Specifically, we tested the hypothesis that Goniopsis predation is more important that Ucides predation, and that these consumers have antagonist effects over propagule consumption. In each area, 10 quadrates were selected at random to analyze tree richness, diameter, height, tree biomass and crab richness and density five years after restoration experiment start. Results show that tree height, biomass and crab density were significantly higher in artificially restored area. No significant differences were observed in crab species richness between areas, but higher tree richness was observed in self-recovered area. Results suggest that planting propagules of Rhizophora can significantly increase tree recovering if the aim was increase tree biomass and crab density, which can accelerate return of ecological functionality. Goniopsis is a more important propagule predator than Ucides both in natural and restored areas. The effects of Goniopis were higher in absence of Ucides, due to negative interactions among these two predator species. The preference of Goniopsis by Avicennia and Laguncularia can favor the dominance of Rhizophora observed in Neotropical mangroves. This study suggests that propagule predation by Goniopsis should be controlled in restoration programs, if dominance of Rhizophora is undesirable respect to more rich tree communities

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A strategy to measure bacterial functional redundancy was developed and tested with soils collected along a soil reclamation gradient by determining the richness and diversity of bacterial groups capable of in situ growth on selected carbon substrates. Soil cores were collected from four sites along a transect from the Jamari tin mine site in the Jamari National Forest, Rondonia, RO, Brazil: denuded mine spoil, soil from below the canopy of invading pioneer trees, revegetated soil under new growth on the forest edge, and the forest floor of an adjacent preserved forest. Bacterial population responses were analyzed by amending these soil samples with individual carbon substrates in the presence of bromodeoxyuridine (BrdU), BrdU-labeled DNA was then subjected to a 16S-23S rRNA intergenic analysis to depict the actively growing bacteria from each site, the number and diversity of bacterial groups responding to four carbon substrates (L-serine, L-threonine, sodium citrate, and or-lactose hydrate) increased along the reclamation-vegetation gradient such that the preserved forest soil samples contained the highest functional redundancy for each substrate. These data suggest that bacterial functional redundancy increases in relation to the regrowth of plant communities and may therefore represent an important aspect of the restoration of soil biological functionality to reclaimed mine spoils. They also suggest that bacterial functional redundancy may be a useful indicator of soil quality and ecosystem functioning.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This study provides information concerning the feeding behaviour of Goniopsis cruentata (Latreille, 1803), through analysis of stomach contents according to demographic categories. Collections were carried out monthly from May 2005 through April 2006 in a subtropical estuary on the southeastern Brazilian coast (23 degrees 29'24 '' S 45 degrees 10'12 '' W). The crabs were collected by hand, with a 2-hour sampling effort by three people. In the laboratory, the crabs were sexed and measured for greatest carapace width, and grouped into demographic categories: adult males, juvenile males, adult females, juvenile females, and ovigerous females. For the fullness analysis, the stomachs were grouped into two categories: (1) E = Empty, with no food; and (2) F = Full, whether partially filled or totally. The frequency-of-occurrence method was used to characterize feeding behaviour, and the demographic categories recognired were compared. We obtained stomachs from 171 adult males, 69 juvenile males, 136 adult females, 72 juvenile females, and 41 ovigerous females, of which 85.6% were full. of the eight food items recorded, sediment was the most frequent, and unidentified material was the least. Goniopsis cruentata can be characterized as a generalist feeder, exploiting most of the food items available in the mangrove swamps. In spite of this generalist behaviour, the dominant presence of sediment suggests that G. cruentata is primarily a detritivore that exploits particulate organic matter from microbial biodegradation, one of the most important mangrove functions. The trophic role of this crab in the ecosystem showed no significant differences among the demographic categories, and seems to be wider than those observed for sesarmid and ocypodid mangrove crabs. These ecosystem engineers may occupy different positions in the trophic chains of estuarine environments.

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Ainda que aranhas Thomisidae sejam comumente encontradas em flores, as associações desses aracnídeos a espécies de plantas e às suas características florais foram pouco registradas na região neotropical. Observações do hábito das plantas, visitantes florais, e também das características florais, tais como antese, odor, forma, cor e recursos da flor, foram assinaladas para espécies floridas de uma área de cerrado presentes em uma trilha de 2 km de extensão. Misumenops argenteus e Misumenops pallens representaram 62,86% das aranhas habitantes de 22 espécies de plantas floridas. As plantas Senna rugosa (Fabaceae), Styrax ferrugineus (Styracaceae) e Banisteriopsis campestris (Malpighiaceae) abrigaram, individualmente, cerca de 10 a 17% do total das aranhas e, nestas plantas, a antese diurna; flores de coloração atrativa a abelhas, como amarela (S. rugosa), branca (S. ferrugineus) e rosa (B. campestris) e as anteras poricidas, bem como a visita das flores por abelhas reforçou a evidência de síndrome de polinização para melitofilia. Este é o primeiro levantamento de espécies de aranhas Thomisidae associadas a plantas do cerrado brasileiro.

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This study investigated the structure and properties of a tropical stream food web in a small spatial scale, characterizing its planktonic, epiphytic and benthic compartments. The study was carried out in the Potreirinho Creek, a second-order stream located in the south-east of Brazil. Some attributes of the three subwebs and of the conglomerate food web, composed by the trophic links of the three compartments plus the fish species, were determined. Among compartments, the food webs showed considerable variation in structure. The epiphytic food web was consistently more complex than the planktonic and benthic webs. The values of number of species, number of links and maximum food chain length were significantly higher in the epiphytic compartment than in the other two. Otherwise, the connectance was significantly lower in epiphyton. The significant differences of most food web parameters were determined by the increase in the number of trophic species, represented mainly by basal and intermediate species. High species richness, detritus-based system and high degree of omnivory characterized the stream food web studied. The aquatic macrophytes probably provide a substratum more stable and structurally complex than the sediment. We suggest that the greater species richness and trophic complexity in the epiphytic subweb might be due to the higher degree of habitat complexity supported by macrophyte substrate. Despite differences observed in the structure of the three subwebs, they are highly connected by trophic interactions, mainly by fishes. The high degree of fish omnivory associated with their movements at different spatial scales suggests that these animals have a significant role in the food web dynamic of Potreirinho Creek. This interface between macrophytes and the interconnections resultant from fish foraging, diluted the compartmentalization of the Potreirinho food web.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)