کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4531982 | 1626142 | 2013 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Topographical and hydrographical impacts on the structure of microphytoplankton assemblages on the Abrolhos Bank region, Brazil
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
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چکیده انگلیسی
This study was conducted at the Abrolhos Bank (15°60â²-21°30â²S; 37°00â²-40°30â²W), Brazil, in July and August 2007, to evaluate the topographic and hydrographic influences on microphytoplankton composition and relative abundance. Net phytoplankton was collected from the top 200 m of the water column to assess diversity proxies (species richness, Shannon index, dominance and equitability) and compared with thermohaline, nutrient and chlorophyll profiles. A total of 326 taxa occurred in the area. Patterns in spatial distribution of microphytoplankton assemblages were two-fold: a north-south gradient linked to variations in temperature and nitrite, and a coast-offshore gradient associated with the depth of the mixed layer and the Brunt-Väisälä maximum frequency. Microphytoplankton assemblages were typical of tropical oligotrophic environments. However, the inshore community found on the Abrolhos Bank was enriched by bottom dwelling, large-sized cells ressuspended from local sediments as a result of the highly dynamic coastal circulation. Species diversity was high in oceanic sites where water column stability as measured by the Brunt-Väisälä frequency achieved its maxima, but high values of ecological indexes were also found in the southern part of the study area influenced by bottom intrusions of nutrient-rich oceanic waters, giving support to the notion that phytoplankton diversity increases at intermediate levels of environmental disturbance.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Continental Shelf Research - Volume 70, 1 November 2013, Pages 88-96
Journal: Continental Shelf Research - Volume 70, 1 November 2013, Pages 88-96
نویسندگان
Sylvia M.M. Susini-Ribeiro, Mayza Pompeu, Salvador A. Gaeta, Júlia S.D. de Souza, Laura S.D. Masuda,