4.2 Article

Modern diatoms from a temperate river in South America: the Colorado River (North Patagonia, Argentina)

期刊

DIATOM RESEARCH
卷 32, 期 2, 页码 133-152

出版社

TAYLOR & FRANCIS LTD
DOI: 10.1080/0269249X.2017.1321046

关键词

diatoms; rivers; estuaries; paleoecology; Patagonia; Argentina

资金

  1. Agencia Nacional de Promocion Cientifica y Tecnologica [PICT 1856/12]

向作者/读者索取更多资源

Diatom assemblage composition and distribution from surface sediment samples of the Colorado River, Patagonia were analysed in relation to environmental variables using multivariate techniques. The aim of this study was to determine the ecological preferences of the taxa and provide analogues for paleoenvironmental reconstructions in estuarine and fluvial environments of southern South America. Cluster analysis identified two main diatom assemblages, one grouping sites with a marine influence, and another group influenced by typical riverine conditions. Canonical correspondence analysis indicated that major ion concentrations contribute significantly to explain the variation in the composition of diatom assemblages. A total of 208 taxa belonging to 56 genera were recorded. In estuarine sites, the assemblages were characterized by marine-brackish tychoplankton, such as Cymatosira belgica, Rhaphoneis amphiceros, Delphineis minutissima, Paralia sulcata and Paralia sulcata var. coronota. Diatom communities in riverine sites were dominated by freshwater taxa such as Staurosira venter, Pseudostaurosira brevistriata, Punctastriata glubokoensis and Punctastriata lancettula. Two Punctastriata species that were difficult to distinguish with LM were examined in detail with SEM, and the value of detailed LM and SEM analysis for distinguishing Punctastriata spp. and other small fragilarioids is discussed. Based on their autoecological affinities, it is likely that the dominance of small fragilarioids is related to the increase in ionic concentration in the basin, as a consequence of both precipitation decrease, and an increase in urban, industrial and agricultural activities. The construction of a flood-control structure in the northern branch of the delta modified the diatom community so that marine taxa were replaced by brackish-freshwater taxa in response to changes in salinity, substrata and water depth.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.2
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据