کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4533742 1325215 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Assemblages of megabenthic gastropods from Uruguayan and northern Argentinean shelf: Spatial structure and environmental controls
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Assemblages of megabenthic gastropods from Uruguayan and northern Argentinean shelf: Spatial structure and environmental controls
چکیده انگلیسی

We analyzed the structure of the megabenthic gastropod assemblages on the Uruguayan and northern Argentinean shelf and slope. Our analysis determined that there are two major biologically distinct assemblages which occurred in a 210,000 km2 area showing conspicuous environmental gradients and large frontal areas: (a) an assemblage associated with the zone under the influence of the freshwater discharge of Río de la Plata and the shallow waters of the inner shelf and (b) an assemblage associated with marine zone in the outer shelf, which includes Magellanic (Subantarctic) and subtropical faunas. A multivariate analysis demonstrated a significant correlation between the environmental and biological matrix. This evidence suggests a noticeable effect of the physical environment on the spatial structure of the assemblage. We suggest that the current distribution patterns are caused by two different processes operating together: while processes operating at ecological time scales (e.g. differential tolerances to salinity and depth) determine most of the structure observed at the inner shelf, the presence of two contrasting water masses over the outer shelf determine a biogeographic boundary for the benthic fauna, linked to shifting climatic factors influencing species niche dynamics over evolutionary time scales. Thus, at the spatial scale here considered, ecological and historical processes must be considered when attempting to understand which factors determine the current structure of benthic assemblages at regional scales.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Continental Shelf Research - Volume 28, Issue 6, April 2008, Pages 788–796
نویسندگان
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