Heterogeneidade Espacial Do Habitat E Diversidade Específica: Implicações Ecológicas E Métodos De Mensuração

Fernandes

2010

Braz. j. oceanogr.

This study aimed to compare the density of Isognomon bicolor on four rocky shores of the State of Espírito Santo, Brazil. Further, size and weight comparisons were undertaken for the flat and creviced surfaces. Quarterly samplings were taken in 2006 and 2007, by removing organisms from 10 x 10 cm quadrants in the mid-intertidal zone, with five samples from flat surfaces and five from crevices. Although densities of I. bicolor were considered low as compared with those of other studies, this species is well established in the State. The most well-established population of I. bicolor was found in the rock crevices. The most important factor for the establishment of I. bicolor on rocky shores is substrate heterogeneity.
O objetivo deste estudo foi comparar a densidade de Isognomon bicolor em quatro costões rochosos no Espírito Santo, Brasil. Além disso, comparações do tamanho e do peso foram feitas para as superfícies lisas e com fendas. Coletas trimestrais foram realizadas entre 2006 e 2007, os organismos foram removidos utilizando um quadrado de 100 cm² na faixa do médiolitoral, sendo cinco nas superfícies lisas e cinco nas fendas. As densidades de I. bicolor foram consideradas baixas em comparação com outros estudos, mas a espécie encontra-se bem estabelecida. Foi obtido um maior número de indivíduos nas fendas. O fator mais importante para o estabelecimento de I. bicolor nos costões rochosos estudados mostrou ser a heterogeneidade do substrato

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spatial variability in the population of Isognomon bicolor (C.B. Adams, 1845) (mollusca, bivalvia) on rocky shores in Espírito Santo, Brazil

Fernandes

2010

Braz. j. oceanogr.

“…The difference between the intertidal communities of exposed and sheltered areas, as demonstrated by several authors (oLiveirA-fiLho & MAyAL, 1976;MCquAid & BrAnCh, 1984;MCquAid & LindsAy, 2000;BrAnCh & steffAni, 2004;ArAújo et al, 2005), also occurred in this study as demonstrated by the clustering analysis. The impact of waves is also an important factor influencing the intertidal benthic communities (LittLe & KitChing, 1996;BArreto, 1999;BrAnCh & steffAni, 2004;ArAújo et al, 2005). siBAjA- Cordero & Cortés (2008) concluded that the interaction between species (predation and space monopolization) was a possible cause of differences in abundance between wave-exposed and sheltered areas.…”

Section: Discussionmentioning

confidence: 99%

Temporal and spatial variation of rocky shores intertidal benthic communities in Southeast Brazil

Fernandes

2012

Iheringia, Sér. Zool.

ABSTRACT. The relationships between environmental factors and temporal and spatial variations of benthic communities of three rocky shores of the state of Espírito Santo, Southeast Brazil, were studied. Sampling was conducted every three months, from August 2006 to May 2007, using intersection points. Chthamalus bisinuatus (Pilsbry, 1916) (Crustacea) and Brachidontes spp. (Mollusca) were the most abundant taxa, occupying the upper level of the intertidal zone of the rocky shore. The species richness was higher at the lower levels. The invasive species Isognomon bicolor (C. B. Adams, 1845) (Mollusca) occurred at low densities in the studied areas. The clustering analysis dendrogram indicated a separation of communities based on exposed and sheltered areas. According to the variance analyses, the communities were significantly different among the studied areas and seasons. The extent of wave exposure and shore slope influenced the species variability. The Setibão site showed the highest diversity and richness, most likely due to greater wave exposure. The communities showed greater variation in the lower levels where environmental conditions were less severe, relative to the other levels. Pilsbry, 1916 (Crustacea) e Brachidontes spp. (Mollusca) foram os táxons mais abundantes, ocupando os níveis superiores da zona entremarés dos costões. Nas zonas inferiores ocorreu um maior número de espécies. A espécie invasora Isognomon bicolor (C.B. Adams, 1845) (Mollusca) ocorreu em baixa cobertura nas áreas estudadas. O dendrograma indicou a separação das amostras das áreas expostas e abrigadas. Segundo os resultados das análises de variância, as comunidades foram significativamente diferentes entre as áreas e as estações do ano. O grau de exposição às ondas e a inclinação do costão influenciaram a variabilidade de espécies. Setibão apresentou os maiores índices de diversidade e de riqueza, provavelmente devido à maior exposição às ondas. As comunidades apresentaram maiores variações nos níveis inferiores, onde as condições ambientais são menos estressantes em relação aos outros níveis. KEYWORDS. PALAVRAS-CHAVE.Médio litoral, exposição às ondas, bentos, Espírito Santo.

“…Substrates made of living organisms such as algae are characteristically dynamic and vary both temporally and spatially (Barreto, 1999). Variations in phytal community structure can be caused by biological parameters (such as predation, competition and recruitment) and physical parameters (such as light intensity, nutrient availability, hydrodynamics and structure of the habitat) (Chemello & Millazo, 2002).…”

Section: Introductionmentioning

confidence: 99%

Gastropod communities associated with Ulva spp. in the littoral zone in southeast Brazil

Costa

Barbiero

et al. 2013

lajar

ABSTRACT. Phytal communities are characterized by spatial and temporal variation and are influenced by fluctuating biological and physical parameters. This study aimed to describe and compare the gastropods associated with Ulva spp., at three sites of the Espirito Santo coast with ferruginous laterite substrate and different modes of wave exposure. Camburi is characterized by the presence of iron ore particles. Samples were collected bimonthly. At each site, five sampling quadrats were launched at random in the intertidal region. Individuals of Ulva spp. were collected (2964 individuals) and 53 taxa were found. In Camburi the dominant species was Amphitalamus vallei (Barleeidae), while in Capuba and Manguinhos Eulithidium affine (Phasianellidae) predominated. The analyses indicated that Camburi is distinct from the other sites. The lesser wave impacts and the more complex structure of the algae in Camburi, due to the presence of iron ore, may explain this variation.Keywords: Mollusca, phytal, ferruginous laterite, intertidal, southeast Brazil.Comunidades de gasterópodos asociados con Ulva spp. en la zona litoral del sudeste de Brasil RESUMEN. Las comunidades phytales están influenciadas espacial y temporalmente por parámetros físicos y biológicos cambiantes. Este estudio describe y compara los gasterópodos asociados con Ulva spp. entre sitios en la costa de Espírito Santo, con sustrato laterítico ferruginoso y con diferentes modos de exposición al oleaje. Camburi está caracterizado por la presencia de partículas de mineral de hierro. Las muestras fueron recolectadas bimensualmente. En cada sitio se realizaron cinco cuadrantes de muestreo al azar en la region intermareal. Se encontraron 2.964 individuos y 53 taxa. En Camburi, la espécie dominante fue Amphitalamus valley, y en Capuba y Manguinhos fue Eulithidium affine. El análisis realizado indicó que Camburi es distinto de los otros sitios. El menor impacto de las olas y la estructura más compleja de las algas en Camburi, debido a la presencia de mineral de hierro, puede explicar esta diferencia. Palabras clave: Mollusca, phytal, laterita ferruginosa, intermareal, sudeste de Brasil.