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Ecological risk assessment of a tropical metal contaminated area: the case study of Santo Amaro, Bahia, Brazil

Niemeyer, Júlia Carina
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
26.27%
O presente estudo, realizado na área abandonada de uma fundição de chumbo no Brasil, teve como principal objetivo contribuir para a aplicação, em ambientes tropicais, de um esquema de análise de risco ecológico em etapas, e avaliar a adequabilidade dos diferentes parâmetros nas etapas dentro do enfoque da Tríade. Buscou-se caracterizar o risco ecológico em vários pontos da área de estudo, uma das mais contaminadas por metais do mundo, em Santo Amaro (BA, Brasil), fornecendo informações que indiquem possíveis medidas de remediação para o local e trazendo uma importante contribuição para decisões futuras. O objetivo deste trabalho é contribuir para o uso da avaliação de risco ecológico em processos de restauração e recuperação de locais contaminados no Brasil, seguindo as atuais tendências mundiais de proteção do solo. O Capítulo 2 apresenta a investigação preliminar, incluindo a fase de formulação do problema e o levantamento de informações científicas disponíveis sobre a área de estudo, resultando na elaboração de um modelo conceitual para o local e um plano de análise para a avaliação de risco. Um esquema em fases é proposto, integrando informações de três linhas de evidência (LoE): química...

Effects of pasture implantation on the termite (Isoptera) fauna in the Central Brazilian Savanna (Cerrado)

CARRIJO, Tiago F.; BRANDAO, Divino; OLIVEIRA, Danilo E. de; COSTA, Diogo A.; SANTOS, Thiago
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.39%
The advance of agricultural frontier may cause the Cerrado (Brazilian savanna) to disappear before 2030. This work focuses on measuring the impact of pasture implantation on a cerrado`s termite fauna. Termites were sampled in a cerrado sensu stricto and a pasture, originally cerrado. All species were classified as their feeder group, accumulation curves were made and Shannon-Wiener indexes and beta diversity were calculated for both areas. Cerrado was richer than pasture and species composition differed considerably, leading beta diversity to a high value. The humivorous was the most representative species, followed by grass/litter feeders, xylophagous and, less representative, the intermediates. There were more xylophagous and intermediates species on cerrado than in pasture; the grass/litter feeders were more abundant in pasture, but didn`t differed in number or species; and humivorous didn`t differed neither in richness nor in abundance. This work shows that the simplification of the habitat is indeed causing the extinction of populations that depend on some specifics resource.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Consequences of Simulated Loss of Open Cerrado Areas to Bird Functional Diversity

BATALHA, Marco Antonio; CIANCIARUSO, Marcus Vinicius; MOTTA-JUNIOR, Jose Carlos
Fonte: ASSOC BRASILEIRA CIENCIA ECOLOGICA E CONSERVACAO Publicador: ASSOC BRASILEIRA CIENCIA ECOLOGICA E CONSERVACAO
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.18%
Over the past 35 years, more than two thirds of the Cerrado`s original expanse has been taken by agriculture. Even if some attempts have been made to conserve closed cerrado physiognomies, open cerrado physiognomies, richer in species and more fragile, have been systematically ignored. These open physiognomies are used by almost half of the Cerrado bird species, many of which being endemics. Using data from 11 surveys carried out in Cerrado landscapes, we asked what would happen to bird functional diversity if open cerrado species became extinct. Open cerrado birds would be able to keep on average 59% of the functional diversity. If they became extinct, on average 27% of the functional diversity would be lost. In this case, the remaining functional diversity would be lower than what would be expected by chance in five sites. Although many functions were shared by both open cerrado and forest species, there was some degree of complementarity between them, highlighted by the decrease in functional diversity when the former became extinct. Destruction of open cerrado physiognomies would lead to a habitat simplification, decrease in bird functional diversity, and, ultimately, to a considerable impact on community functioning. Thus, open cerrado physiognomies must receive much more conservation attention than they are currently receiving...

Variação na diversidade funcional e taxonômica de aves em plantios de Eucalyptus sp.

Jacoboski, Lucilene Inês
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
16.42%
As alterações no uso do solo decorrentes das atividades humanas modificam as condições ambientais, o que pode levar a mudanças na estrutura de comunidades locais. A expansão da silvicultura ao redor do mundo tem causado uma crescente preocupação em termos de conservação da biodiversidade. Isto por que ela resulta em uma simplificação e homogeneização do habitat originalmente nativo. Este estudo avaliou a estrutura da assembleia de aves em áreas de silvicultura e em floresta nativa, sendo que os principais objetivos foram: 1) avaliar o possível impacto da silvicultura sobre a riqueza, abundância e composição de espécies de aves, considerando diferentes idades de plantio; 2) avaliar se as espécies de aves registradas em áreas de silvicultura representam um subconjunto daquela registrada na floresta nativa; 3) analisar as respostas da diversidade funcional e dos atributos funcionais morfológicos e comportamentais das espécies de aves. Foram amostrados plantios de eucalipto de quatro idades de cultivo assim como áreas de floresta nativa num total de 150 pontos de escuta. A riqueza, a abundância de espécies de aves e a diversidade funcional foram significativamente maiores na floresta nativa. A composição de espécies também apresentou diferença significativa entre a floresta e os plantios de diferentes idades. Entretanto apesar da diferença na composição...

Habitat simplification affects nuclear-follower foraging association among stream fishes

Teresa, Fabrício Barreto; Romero, Renato de Mei; Casatti, Lilian; Sabino, José
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: 121-126
ENG
Relevância na Pesquisa
46.32%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Processo FAPESP: 08/03583-9; Processo FAPESP: 07/05400-6; A interação nuclear-seguidor é um tipo particular de associação alimentar interespecífica que envolve uma espécie nuclear, que revolve ou vasculha o substrato, e espécies seguidoras, que acessam os itens alimentares disponibilizados pela atividade do nuclear. Neste estudo investigamos o efeito da estrutura do habitat sobre essa interação em um riacho no Planalto da Bodoquena, Centro-Oeste do Brasil. Foram registradas 272 interações durante 24 sessões de observação subaquática em áreas estruturalmente inalteradas e alteradas. A espécie nuclear dominante diferiu entre as áreas. Prochilodus lineatus foi a espécie nuclear dominante das áreas alteradas, enquanto que Leporinus macrocephalus foi a espécie nuclear dominante nas áreas inalteradas. A riqueza de espécies seguidoras por interação não diferiu entre as áreas, entretanto a abundância de seguidores foi maior nas áreas inalteradas do que nas alteradas. Essas diferenças parecem ser consequência das modificações na composição da comunidade e no comportamento alimentar das espécies nucleares que são...

Grass-dominated stream sites exhibit low fish species diversity and dominance by guppies: an assessment of two tropical pasture river basins

Casatti, Lilian; Ferreira, Cristiane de Paula; Carvalho, Fernando Rogerio
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 273-283
ENG
Relevância na Pesquisa
36.6%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); This study investigates whether (1) structural configuration (considering substrate composition, wood debris, marginal and riparian vegetation) of streams suggests habitat simplification on a basin scale and (2) fish assemblage structure follows stream habitat configurations. Ninety-five sites in two pasture basins in southeastern Brazil were randomly selected. Two passes of electro-fishing were done in a 75-m reach at each site. Ten habitat descriptors related to in-stream and riparian physical structures were evaluated at each stream reach. Two groups of streams were identified by principal component analysis: a grassy and a non-grassy group. In comparison to non-grassy sites, grass-dominated streams exhibited a more homogenous fish fauna due to lower species diversity and higher dominance, especially by the guppy Poecilia reticulata, a highly generalist exotic species. The grassy group had not only the most simplified habitat but also the most simplified fish fauna, and the combination of grass-dominated, completely deforested, heavily silted conditions with recent land use conversion may cause a future habitat homogenization followed by a fish fauna homogenization on a regional scale.

A pest is a pest is a pest? The dilemma of neotropical leaf-cutting ants: Keystone taxa of natural ecosystems

Fowler, H. G.; Pagani, Maria Inez; Aulino da Silva, O.; Forti, L. C.; Pereira da Silva, V.; De Vasconcelos, H. L.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 671-675
ENG
Relevância na Pesquisa
26.18%
Leaf-cutting ants of the genera Acromyrmex and Atta are considered the principal polyphagous pests of the Neotropics. Although some members of these genera are of economic importance, have a broad geographic distribution, and are extremely good colonizers, others are endemic and closely interact with native ecosystems. Control is generally practiced against any colony, irrespective of its taxonomic status. Indiscriminate control coupled with habitat destruction threatens endemic species with extinction, and, through habitat simplification, favors other pest species. As nests of Atta are large, having several square meters of nest surface, the endemic taxa can be easily used as environmental indicators for natural ecosystems. Likewise, the pest species can be used to detect environmental disturbance. As these ants are keystone species and easily identified by nonspecialists, efforts should be made to integrate these into viable conservation programs.

Oferta de micro-hábitats artificiais em riachos degradados: respostas das comunidades de peixes e macroinvertebrados

Manzotti, Angelo Rodrigo
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 68 f. : il. color.
POR
Relevância na Pesquisa
26.47%
Pós-graduação em Biologia Animal - IBILCE; Os ambientes dulcícolas figuram entre os mais importantes para a economia humana e entre os mais ameaçados pelas atividades antrópicas. A retirada ou modificação da estrutura vegetal marginal aos ambientes aquáticos desencadeia uma série de alterações negativas que levam a simplificação de hábitat e homogeneização da fauna. Dessa forma, diversos projetos de restauração e recuperação de rios e riachos estão sendo desenvolvidos em todo o mundo, partindo do princípio de que a manipulação do canal de drenagem, associado a adição de elementos diversificadores de hábitat são capazes de recuperar a qualidade biótica dos corpos d‟água pela oferta de meso e micro-hábitats passíveis de colonização. Sendo assim, os objetivos desse trabalho foram testar se a adição de estruturas artificiais de madeira e madeira com folhas seria capaz de promover o incremento na heterogeneidade de hábitat e alterar a composição e estrutura das comunidades de peixes e macroinvertebrados, interferindo na riqueza e abundância de guildas tróficas ou de uso de hábitat. Não encontramos nenhuma evidência de que a heterogeneidade de hábitat atue como fator estruturador das comunidades de peixes e macroinvertebrados. A oferta de micro-hábitats artificiais promoveu o aumento na heterogeneidade de hábitat...

Progressive recovery of a tropical deforested stream community after a flash flood

Marques, Lucas Cerqueira; Ceneviva-bastos, Mônica; Casatti, Lilian
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: 111-123
ENG
Relevância na Pesquisa
26.39%
AIM: In this study, we evaluated and compared community attributes from a tropical deforested stream, located in a pasture area, in a period before (PRED I) and three times after (POSD I, II, and III) a flash flood, in order to investigate the existence of temporal modifications in community structure that suggests return to conditions previous to the flash flood. METHODS: Biota samples included algae, macrophytes, macroinvertebrates, and fish assemblages. Changes in stream physical structure we also evaluated. Similarity of the aquatic biota between pre and post-disturbance periods was examined by exploratory ordination, known as Non-Metric Multidimensional Scaling associated with Cluster Analysis, using quantitative and presence/absence Bray-Curtis similarity coefficients. Presence and absence data were used for multivariate correlation analysis (Relate Analysis) in order to investigate taxonomic composition similarity of biota between pre and post-disturbance periods. RESULTS: Our results evidenced channel simplification and an expressive decrease in richness and abundance of all taxa right after the flood, followed by subsequent increases of these parameters in the next three samples, indicating trends towards stream community recovery. Bray-Curtis similarity coefficients evidenced a greater community structure disparity among the period right after the flood and the subsequent ones. Multivariate correlation analysis evidenced a greater correlation between macroinvertebrates and algae/macrophytes...

Efeito da fragmentação e alteração do habitat na avifauna da região da Reserva Biologica de Una, Bahia; Effects of fragmentation and habitat change in bird community in Una Biological Reserve region, Bahia, Brazil

Rudi Ricardo Laps
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 20/12/2006 PT
Relevância na Pesquisa
36.43%
A Floresta Atlântica é um dos ecossistemas mais ameaçados no mundo e as unidades de conservação são importantes para manutenção da biodiversidade nesta paisagem altamente fragmentada. A avifauna da Floresta Atlântica do sul da Bahia é rica, com muitos endemismos e espécies ameaçadas de extinção. Nós investigamos a composição da avifauna da RBU e áreas adjacentes com o objetivo de medir a importância dessa UC para a proteção das espécies, assim como a resposta da comunidade aos diferentes hábitats (cabrucas, capoeiras e fragmentos florestais). Nós comparamos os resultados obtidos para aves, morcegos, lagartos, anuros e samambaias dentro dessa matriz predominatemente florestal com uma segunda área com paisagem oposta (fragmentos florestais imersos em matriz de cabrucas). Resultados: Nós encontramos 333 espécies de aves, incluindo 17 ameaçadas. A escassez de aves cinegéticas indica que a pressão de caça é alta na região. As cabrucas (plantações de cacau sob floresta raleada) exibem riqueza e abundância de aves maior que os demais hábitats investigados, com a presença de espécies generalistas invasoras. Frugívoros e insetívoros de copas foram abundantes e ricos nas cabrucas. Entretanto, insetívoros e frugívoros de sub-bosque são sensíveis à simplificação do hábitat deste sistema agroflorestal e muitas espécies desapareceram. O efeito de borda agiu significantemente para algumas espécies...

Habitat simplification affects nuclear-follower foraging association among stream fishes

Teresa,Fabrício Barreto; Romero,Renato de Mei; Casatti,Lilian; Sabino,José
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2011 EN
Relevância na Pesquisa
46.27%
Nuclear-follower interaction is a particular kind of interspecific foraging association that includes a nuclear species, which dig in or inspect the bottom, and follower species, which access the food items made available by the nuclear. In this study we examined the effect of habitat structure on nuclear-follower relationship in a stream of Bodoquena Plateau, Central-West Brazil. Foraging associations were registered while snorkeling in 24 observation sessions, totaling six hours in unaltered and altered sites. Overall, 272 nuclear-follower associations were registered, having four species acting as nuclear and seven as followers. The dominant nuclear species were different in each site. Prochilodus lineatus was the main nuclear species in the altered site and Leporinus macrocephalus in the unaltered site. The richness of follower species was similar between sites, however, follower species abundance per interaction were significantly higher in the unaltered site than in the altered site. These differences seem to be a consequence of the alterations in assemblage composition and feeding behavior of the nuclear species that presumably are affected by different substrate composition and food availability between the structurally distinct areas.

The role of limnological variables and habitat complexity in impacted tropical streams as regulatory factors on the flagellate protozoa community

Camargo,Janielly Carvalho; Vieira,Ludgero Cardoso Galli; Velho,Luiz Felipe Machado
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
Relevância na Pesquisa
36.39%
OBJECTIVE: To contribute to the knowledge of patterns of spatial and seasonal distribution of composition and species richness of flagellate protozoa in tropical impacted streams and to identify which variables (physical and chemical or descriptor variables of habitat complexity) control these attributes in these environments. METHODS: Samplings were performed in 10 tropical streams (5 urban and 5 rural) in two periods (summer and winter). Limnological variables were determined on the field (except for the concentration of nutrients), the habitat macrostructure was visually estimated in situ, using a quadrat and the species identification was performed in vivo, under optical microscope. RESULTS: In total, 106 taxa were identified, the order Euglenida was that contributed most to the species richness, probably due to the high tolerance to environmental changes. Multivariate analyses (ANOSIM and MDS) evidenced significant spatial and seasonal differences both for composition and species richness. The Bioenv and Mantel Test indicated that the patterns of composition and richness were controlled by physical and chemical variables indicative of water quality (pH, electrical conductivity, and concentration of nutrients). However, the species richness was also influenced by the habitat structural complexity and by its stability...

Progressive recovery of a tropical deforested stream community after a flash flood

Marques,Lucas Cerqueira; Ceneviva-Bastos,Mônica; Casatti,Lilian
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 EN
Relevância na Pesquisa
26.23%
AIM: In this study, we evaluated and compared community attributes from a tropical deforested stream, located in a pasture area, in a period before (PRED I) and three times after (POSD I, II, and III) a flash flood, in order to investigate the existence of temporal modifications in community structure that suggests return to conditions previous to the flash flood. METHODS: Biota samples included algae, macrophytes, macroinvertebrates, and fish assemblages. Changes in stream physical structure we also evaluated. Similarity of the aquatic biota between pre and post-disturbance periods was examined by exploratory ordination, known as Non-Metric Multidimensional Scaling associated with Cluster Analysis, using quantitative and presence/absence Bray-Curtis similarity coefficients. Presence and absence data were used for multivariate correlation analysis (Relate Analysis) in order to investigate taxonomic composition similarity of biota between pre and post-disturbance periods. RESULTS: Our results evidenced channel simplification and an expressive decrease in richness and abundance of all taxa right after the flood, followed by subsequent increases of these parameters in the next three samples, indicating trends towards stream community recovery. Bray-Curtis similarity coefficients evidenced a greater community structure disparity among the period right after the flood and the subsequent ones. Multivariate correlation analysis evidenced a greater correlation between macroinvertebrates and algae/macrophytes...

Agricultural landscape simplification and insecticide use in the Midwestern United States

Meehan, Timothy D.; Werling, Ben P.; Landis, Douglas A.; Gratton, Claudio
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.62%
Agronomic intensification has transformed many agricultural landscapes into expansive monocultures with little natural habitat. A pervasive concern is that such landscape simplification results in an increase in insect pest pressure, and thus an increased need for insecticides. We tested this hypothesis across a range of cropping systems in the Midwestern United States, using remotely sensed land cover data, data from a national census of farm management practices, and data from a regional crop pest monitoring network. We found that, independent of several other factors, the proportion of harvested cropland treated with insecticides increased with the proportion and patch size of cropland and decreased with the proportion of seminatural habitat in a county. We also found a positive relationship between the proportion of harvested cropland treated with insecticides and crop pest abundance, and a positive relationship between crop pest abundance and the proportion cropland in a county. These results provide broad correlative support for the hypothesized link between landscape simplification, pest pressure, and insecticide use. Using regression coefficients from our analysis, we estimate that, across the seven-state region in 2007, landscape simplification was associated with insecticide application to 1.4 million hectares and an increase in direct costs totaling between $34 and $103 million. Both the direct and indirect environmental costs of landscape simplification should be considered in design of land use policy that balances multiple ecosystem goods and services.

Complexity for Artificial Substrates (CASU): Software for Creating and Visualising Habitat Complexity

Loke, Lynette H. L.; Jachowski, Nicholas R.; Bouma, Tjeerd J.; Ladle, Richard J.; Todd, Peter A.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 14/02/2014 EN
Relevância na Pesquisa
26.18%
Physical habitat complexity regulates the structure and function of biological communities, although the mechanisms underlying this relationship remain unclear. Urbanisation, pollution, unsustainable resource exploitation and climate change have resulted in the widespread simplification (and loss) of habitats worldwide. One way to restore physical complexity to anthropogenically simplified habitats is through the use of artificial substrates, which also offer excellent opportunities to explore the effects of different components (variables) of complexity on biodiversity and community structure that would be difficult to separate in natural systems. Here, we describe a software program (CASU) that enables users to visualise static, physical complexity. CASU also provides output files that can be used to create artificial substrates for experimental and/or restoration studies. It has two different operational modes: simple and advanced. In simple mode, users can adjust the five main variables of informational complexity (i.e. the number of object types, relative abundance of object types, density of objects, variability and range in the objects’ dimensions, and their spatial arrangement) and visualise the changes as they do so. The advanced mode allows users to design artificial substrates by fine-tuning the complexity variables as well as alter object-specific parameters. We illustrate how CASU can be used to create tiles of different designs for application in a marine environment. Such an ability to systematically influence physical complexity could greatly facilitate ecological restoration by allowing conservationists to rebuild complexity in degraded and simplified habitats.

Simplification of Arboreal Marsupial Assemblages in Response to Increasing Urbanization

Isaac, Bronwyn; White, John; Ierodiaconou, Daniel; Cooke, Raylene
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 07/03/2014 EN
Relevância na Pesquisa
26.54%
Arboreal marsupials play an essential role in ecosystem function including regulating insect and plant populations, facilitating pollen and seed dispersal and acting as a prey source for higher-order carnivores in Australian environments. Primarily, research has focused on their biology, ecology and response to disturbance in forested and urban environments. We used presence-only species distribution modelling to understand the relationship between occurrences of arboreal marsupials and eco-geographical variables, and to infer habitat suitability across an urban gradient. We used post-proportional analysis to determine whether increasing urbanization affected potential habitat for arboreal marsupials. The key eco-geographical variables that influenced disturbance intolerant species and those with moderate tolerance to disturbance were natural features such as tree cover and proximity to rivers and to riparian vegetation, whereas variables for disturbance tolerant species were anthropogenic-based (e.g., road density) but also included some natural characteristics such as proximity to riparian vegetation, elevation and tree cover. Arboreal marsupial diversity was subject to substantial change along the gradient, with potential habitat for disturbance-tolerant marsupials distributed across the complete gradient and potential habitat for less tolerant species being restricted to the natural portion of the gradient. This resulted in highly-urbanized environments being inhabited by a few generalist arboreal marsupial species. Increasing urbanization therefore leads to functional simplification of arboreal marsupial assemblages...

Simplification of Caribbean Reef-Fish Assemblages over Decades of Coral Reef Degradation

Alvarez-Filip, Lorenzo; Paddack, Michelle J.; Collen, Ben; Robertson, D. Ross; Côté, Isabelle M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 14/04/2015 EN
Relevância na Pesquisa
26.41%
Caribbean coral reefs are becoming structurally simpler, largely due to human impacts. The consequences of this trend for reef-associated communities are currently unclear, but expected to be profound. Here, we assess whether changes in fish assemblages have been non-random over several decades of declining reef structure. More specifically, we predicted that species that depend exclusively on coral reef habitat (i.e., habitat specialists) should be at a disadvantage compared to those that use a broader array of habitats (i.e., habitat generalists). Analysing 3727 abundance trends of 161 Caribbean reef-fishes, surveyed between 1980 and 2006, we found that the trends of habitat-generalists and habitat-specialists differed markedly. The abundance of specialists started to decline in the mid-1980s, reaching a low of ~60% of the 1980 baseline by the mid-1990s. Both the average and the variation in abundance of specialists have increased since the early 2000s, although the average is still well below the baseline level of 1980. This modest recovery occurred despite no clear evidence of a regional recovery in coral reef habitat quality in the Caribbean during the 2000s. In contrast, the abundance of generalist fishes remained relatively stable over the same three decades. Few specialist species are fished...

Funcionalidade ecológica em cursos d'água

Rigotti, Jucimara Andreza
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Dissertação de Mestrado Formato: 146 p.| il., grafs., mapas, tabs.
POR
Relevância na Pesquisa
36.36%
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas, Programa de Pós-Graduação em Geografia, Florianópolis, 2015.; Os cursos d?água em áreas urbanas possuem alto potencial de requalificação, mesmo quando sofrem as consequências de fortes intervenções. As alterações geradas, principalmente pela poluição e canalização, intensificam-se na área costeira, onde se concentra grande parte da população do Brasil. Nesse trabalho se estudou a funcionalidade ecológica de cursos d?água em relação à urbanização, apontando algumas implicações para o gerenciamento e requalificação da paisagem fluvial. Foram avaliados os efeitos da urbanização na integridade dos cursos d?água da bacia hidrográfica do Itacorubi (Florianópolis-SC). Investigou-se a influência do revestimento do leito na funcionalidade do habitat. Além disso, foram analisados três protocolos de avaliação rápida para a caracterização da paisagem fluvial. A metodologia empregada envolveu a caracterização da urbanização pela determinação da área impermeável na bacia hidrográfica; o estudo da qualidade da água com medição de parâmetros físico-químicos e biológicos; a caracterização de parâmetros do escoamento; e...

Succession of Ground-Dwelling Beetle Assemblages After Fire in Three Habitat Types in the Andean Forest of NW Patagonia, Argentina

Sasal, Yamila; Raffaele, Estela; Farji-Brener, Alejandro G.
Fonte: University of Wisconsin Library Publicador: University of Wisconsin Library
Tipo: Artigo de Revista Científica
Publicado em 17/04/2010 EN
Relevância na Pesquisa
26.39%
Wildfires are one of the major disturbances in the dynamics of forests and shrublands. However, little is known about their effects on insect communities that contribute to faunal biodiversity and play key roles in the ecosystem's dynamics. An intense and widespread fire occurred in 1999 in the Nahuel Huapi National Park in the Andean forest in northern Patagonia, Argentina. This fire affected adjacent, but different, habitat types. After the fire, beetle abundance, species richness and assemblage composition were compared among three habitats that were structurally different before the fire. These habitats were: 1) evergreen forest dominated by Nothofagus dombeyi (Mirb.) Oerst. (Fagales: Nothofagaceae), 2) a mixed forest of the evergreen conifer Austrocedrus chilensis (D. Don) Pic. Serm. and Bizzarri (Pinales: Cupressaceae) and N. dombeyi and 3) a shrubland with a diverse community of shrub species. The relationship between beetle diversity and vegetation structure was investigated over three consecutive years. Ground beetles were collected by pitfall traps, and plant species richness, vegetation cover, and height were measured. Beetle communities varied more over years between habitats during the early regeneration after fire. There was a shift in beetle assemblage composition with time after the fire in all habitat types...

Differential effects of land use on ant and herbivore insect communities associated with Caryocar brasiliense (Caryocaraceae)

S. Neves,Frederico; F. Braga,Rodrigo; S. Araújo,Lucimar; I. Campos,Ricardo; Fagundes,Marcílio
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 EN
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Simplification of natural habitats leads to a modification of the community associated with a host plant. Pequi trees (Caryocar brasiliense) are common to find in central Brazil, especially in the middle of monocultures, such as soy, corn, pasturelands or Eucalyptus plantations. On this scenario we hypothesized that habitat modification differentially affects the diversity of ants and herbivore insects associated with this species. The aim of the work was to test if C. brasiliense trees located in human modified habitats, support a lower species richness and abundance of ants, and a greater species richness and abundance of insect herbivores, compared to preserved cerrado habitats. The study was conducted in a Cerrado area located in Northern Minas Gerais State, Brazil. Ants and herbivore insects were collected monthly during 2005 using beating technique. The results showed that ant species richness was higher in pequi trees located in preserved Cerrado, followed by trees in pastureland and Eucalyptus plantation, respectively. The ant abundance was lower in the Eucalyptus plantation but no difference in ant abundance was observed between trees in pastureland and the preserved Cerrado. Moreover, herbivore insects exhibited lower number of species and individuals in trees located in the preserved Cerrado than in the pastureland and Eucalyptus plantation. We concluded that habitats simplified by human activities may result in diversity loss and may change species interactions.