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Ecologia de insetos aquáticos em córregos do Cerrado: do nicho hutchinsoniano ao distúrbio intermediário; Cerrado stream insect quatic ecology: from Hutchinsoniano to intermediary disturbance

GODOY, Bruno Spacek
Fonte: Universidade Federal de Goiás; BR; UFG; Doutorado em Ecologia e Evolucao; Ciencias Biologicas Publicador: Universidade Federal de Goiás; BR; UFG; Doutorado em Ecologia e Evolucao; Ciencias Biologicas
Tipo: Tese de Doutorado Formato: application/pdf
POR
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16.28%
The Cerrado region is the second largest biome in Brazil, covering nearly 22% of the national territory. Due to a facility provided this biome for handling and cultivating the soil, the Cerrado has been suffering an intense change in its landscape, increasing the impact in all it s natural systems. Thru a systemized sampling of 101 streams in the Rio das Almas River Basin region, center of Goias, it was observed how such change in landscape changes the community of benthonic water insects. Initially it was not observed changes in the number of genres for different river sizes. Impact raise, especially in the riparian zone leads to a reduction in the number of genres of Ephemeroptera, Plecoptera and Trichoptera. The communities in impacted streams are subsets of communities in pristine localities, showed a nestedness pattern. Despite the number of genres reduction in impacted locations, the expected richness expressed by the sum of the probability of genre occurrence in certain integrity value, is larger in preserved and degraded locations. Therefore, the genre substitution rate tends to be larger in very impacted and well preserved areas. The environmental matrix of the Cerrado is composed largely of already impacted areas, which explains this large number or genres that live in degraded locations thru simple area effect. Ultimately...

Benthic insects of the El Tala River (Catamarca, Argentina): longitudinal variation of their structure and the use of insects to assess water quality

Colla,MF; César,II; Salas,LB
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2013 EN
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The aim of this work was to determine the structure of the benthic entomofauna and its variation along the El Tala River (Catamarca, Argentina). Five sampling stations were established, considering the location of nearby housing with respect to the watercourse. The following variables were determined in situ: altitude, latitude and longitude, bedstream width, river depth, river-current speed, water and air temperatures. Benthic insects were collected with a square parcel sampler of 0.09-m2 area and 300-µm net opening and identified to the family level. Faunal density, richness, and diversity exhibited a longitudinal variation. From sampling Stations 1 (reference site) to 3, the number of orders and families decreased, whereas in sampling Station 4 those values increased and continued to do so through to Station 5 (downstream station). Station 5 showed the highest family richness (17) and the highest value for the Shannon-Wiener index (2.74) and the lowest value in Simpson's Dominance index (D = 0.22). These values could be explained because of the self-cleansing capabilities of the river downstream. The water quality of El Tala River is Class I (very clean and non-impacted), according to the results obtained from the application of the biotic Biological-Monitoring–Working-Party and Average-Store-per-Taxon indices.

Dinâmica da alimentação em Aeglidae em ambiente natural (Crustacea: Decapoda: Anomura)

Bueno, Alessandra Angelica de Padua
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
POR
Relevância na Pesquisa
16.28%
Esta pesquisa visa caracterizar a dinâmica alimentar de Aegla platensis Schmitt e A. ligulata Bond-Buckup & Buckup, especialmente, quanto ao hábito alimentar, largura do nicho trófico e preferência alimentar. Além de identificar a macrofauna bentônica dos cursos d’água estudados. As coletas foram realizadas de agosto/99 a agosto/00 no Arroio do Mineiro (29º 30' 0,2''S e 50º 46' 50''W), Taquara, e no Arroio formador do Rio Tainhas (29º 15' 30,2''S e 50º 13' 12,5'' W), São Francisco de Paula, RS. A macrofauna bentônica, coletada com amostrador Suber, foi triada em laboratório e os animais identificados e quantificados. Para análise estomacal, foram coletados juvenis e adultos de A. platensis e A. ligulata, em quatro horários. O conteúdo estomacal foi analisado utilizando-se: o Grau de Repleção (GR), a Frequência de Ocorrência (FO), o Métodos dos Pontos (MP) e o Índice Alimentar (IA). Análise de Agrupamento e Análise de Coordenadas Principais foram utilizadas para comparar as dietas de juvenis e adultos, além da variação nos itens alimentares nas classes de tamanho. Para o cálculo da largura do nicho trófico foi utilizada a medida de largura do nicho de Levins. Na identificação da preferência alimentar foram utilizados: a Taxa de Forrageamento (FR)...