Consulta: subjectFacets:"Human impacts"
Registros recuperados: 5
Data/hora: 12/06/2024 09:44:33

Utilisation de Posidonia oceanica (L.) Delile comme bio-indicateur de la contamination métallique
Provedor de dados: 5
Autores: Lafabrie, Céline.
The coastal zone of the continental shelf contains a high ecological richness. However, this zone is very fragile towards xenobiotics ; the pollution of this environment can be damaging to the structure of the biocenoses and to the productivity of the ecosystems. Metals, contrarily to numerous contaminants, are normal constituents of the environment at a trace level, but are all toxic above a certain threshold. At the end of the 1970s, several researchers proposed the use of organisms to evaluate the quality of the marine environment ; it is in this context that the bio-indicator concept arises. The seagrass Posidonia oceanica (L.) Delile, endemic of the Mediterranean Sea, has been the subject of several works proposing to use this species to determine the...
Tipo: Text
Palavras-chave: Mediterranean Sea; Human impacts; Metal contamination; Trace metals; Bio indicator; Posidonia oceanica; Méditerranée; Impacts anthropiques; Contamination métallique; Métaux traces; Bio indicateur; Posidonia oceanica.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/these-3082.pdf

Palaeoenvironmental reconstructions during the Meso- to Neolithic transition (9.2–5.3 cal. ka BP) in Northwestern France: Palynological evidences
Provedor de dados: 5
Autores: Lambert, Clément; Vidal, Muriel; Penaud, Aurélie; Le Roy, Pascal; Goubert, Evelyne; Pailler, Yvan; Stephan, Pierre; Ehrhold, Axel.
Sedimentological, palynological, and micropalaeontological studies carried out throughout the first half of the Holocene, during the Mesolithic/Neolithic transition in the Bay of Brest (i.e. 9200–9000 and 6600–5300 cal. BP) and in the Bay of Douarnenez (i.e. 9200–8400 cal. BP), allowed characterizing coastal environmental changes under the increasing influence of the relative sea-level rise. The gradual flooding of the two studied sites implied a transition from river valleys to oceanic bays as revealed by the gradual retreat of salt marsh environments, as detected through palynological analysis. In addition, these high-resolution studies highlight the regional imprint of the North Atlantic millennial climate variability in north-western coastal...
Tipo: Text
Palavras-chave: Benthic foraminifera; Climate variability; Dinoflagellate cysts; Human impacts; Palaeoenvironments reconstructions; Pollen grains.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00472/58341/60920.pdf

Fire regimes and vegetation responses in two Mediterranean-climate regions
Provedor de dados: 97
Autores: MONTENEGRO,GLORIA; GINOCCHIO,ROSANNA; SEGURA,ALEJANDRO; KEELY,JOHN E.; GÓMEZ,MIGUEL.
Wildfires resulting from thunderstorms are common in some Mediterranean-climate regions, such as southern California, and have played an important role in the ecology and evolution of the flora. Mediterranean-climate regions are major centers for human population and thus anthropogenic impacts on fire regimes may have important consequences on these plant formations. However, changes in fire regimes may have different impacts on Mediterranean type-ecosystems depending on the capability of plants to respond to such perturbations. Therefore, we compare here fire regimes and vegetation responses of two Mediterranean-climate regions which differ in wildfire regimes and history of human occupation, the central zone of Chile (matorral) and the southern area of...
Tipo: Journal article
Palavras-chave: Human impacts; Plant regeneration; Matorral; Chaparral.
Ano: 2004
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000300005

Hydrology, plankton, and corals of the Maracajaú reefs (Northeastern Brazil): an ecosystem under severe thermal stress
Provedor de dados: 52
Autores: Mayal,Elga Miranda; Neumann-Leitão,Sigrid; Feitosa,Fernando Antônio do Nascimento; Schwamborn,Ralf; Silva,Tâmara de Almeida e; Silva-Cunha,Maria da Glória Gonçalves da.
This study provides baseline information on the hydrological conditions and on the coral and plankton communities at the Maracajaú reef ecosystem (Northeastern Brazil). Studies were performed from February to June 2000, covering the transition from dry to rainy season. In this area, there is an offshore coral reef formation, where corals were observed in loco; the water samples were collected to obtain the hydrological and plankton data. Six scleractinian species were identified. Stable isotope analysis on the carbonate fraction of Favia gravida fragments showed that these corals were under severe thermal stress. Chlorophyll-a varied from 1.1 to 9.3 mg m-3, with higher values during the rainy season. Average zooplankton wet weight biomass were 117.0...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coral reefs; Hydrology; Plankton; Thermal stress; Human impacts.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000300019

Mesozooplankton of an impacted bay in North Eastern Brazil
Provedor de dados: 52
Autores: Silva,Andréa Pinto; Neumann-Leitão,Sigrid; Schwamborn,Ralf; Gusmão,Lúcia Maria de Oliveira; Silva,Tâmara de Almeida e.
Mesozooplankton abundance and distribution at Suape Bay, Pernambuco, was studied to assess the impacts caused by the construction of an internal port to increase the capacity of the Suape Port Complex. Zooplankton sampling was done at 3 stations during the dry (November-December/1997) and rainy (April-May/1998) seasons. A plankton net with 300 µm mesh size was used. Wet weight plankton biomass ranged from 44 mg.m-3 to 3,638 mg.m-3. Forty-five macrozooplankton taxa were registered. The most abundant was Copepoda. Among copepods, Acartia lilljeborgi, Parvocalanus crassirostris, Oithona hebes, Corycaeus (C.) speciosus and Temora turbinata were most frequent. Minimum abundance was 9 ind.m-3 and maximum was 2,532 ind.m-3. Average species diversity was 2.55...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mesozooplankton; Copepoda; Human impacts; Suape Port Complex.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000300020