Understanding the effects of environmental heterogeneity on the morphofunctional structure of the phytoplankton community during the hydrological year in an Amazon floodplain lake, Brazil

Limnology ◽  
2022 ◽  
Author(s):  
Dilailson Araújo de Souza ◽  
Cleber Nunes Kraus ◽  
Ana Luiza Burliga ◽  
Sérgio de Melo ◽  
Sheyla Couceiro ◽  
...  
2017 ◽  
Vol 44 (1) ◽  
pp. 142-149 ◽  
Author(s):  
Luciana M Sanders ◽  
Kathryn H Taffs ◽  
Debra Stokes ◽  
Alex Enrich-Prast ◽  
Christian J Sanders

AbstractAnthropogenic radionuclide signatures associated with nuclear testing are increasingly utilized in environmental science to explore recent sedimentation. In this study, we assess the suitability of Pu radioisotope analysis in floodplain lake environments in the Amazon Basin to form geochronologies during the 20thcentury. The240Pu +239Pu (240+239Pu) signatures in six sediment cores indicate sediment accumulation rates in the floodplain lakes of the major rivers; Amazon (2.3 mm year-1), Tapajos (10.2 and 2.4 mm year-1) and Madeira (3.4, 4.2 and 6.2 mm year-1). The results from this study show that240+239Pu fallout activities, and the well documented (240Pu/239Pu) atomic ratios of the above ground nuclear tests which began in the 1950’s, are sufficient and well preserved in Amazon floodplain lake sediments to infer chronologies. Lead-210 dating analyses in the same sediment cores produced comparable sediment accumulation rates at three of the six sites. The differences between dating methods may be attributed to the different time scale these dating methods represent and/or in the solubility between Pb and Pu along the sediment column. The geochronologies derived from the240+239Pu and210Pb dating methods outlined in this work are of interest to identify the effects of changing sediment accumulation rates during the previous century as a result of development, including deforestation, along the Amazon Basin which increased towards the middle of the 20thcentury. This study shows that Pu dating provides a viable alternative geochronology tool for recent sediment accumulation (previous ~60 years) along the Amazon Basin.


2020 ◽  
Vol 64 (4) ◽  
pp. 389-403
Author(s):  
Luciane Silva Moreira ◽  
Patricia Moreira-Turcq ◽  
Renato Campello Cordeiro ◽  
Bruno Turcq ◽  
Keila Cristina Aniceto ◽  
...  

2019 ◽  
Vol 55 (4) ◽  
pp. 3056-3075 ◽  
Author(s):  
Xinye Ji ◽  
Lance F. W. Lesack ◽  
John M. Melack ◽  
Shilong Wang ◽  
William J. Riley ◽  
...  

1995 ◽  
Vol 40 (3) ◽  
pp. 598-609 ◽  
Author(s):  
Lance F. W. Lesack

2021 ◽  
Vol 207 ◽  
pp. 111249 ◽  
Author(s):  
Lucas Silva Azevedo ◽  
Inácio Abreu Pestana ◽  
Marcelo Gomes Almeida ◽  
Adriely Ferreira da Costa Nery ◽  
Wanderley Rodrigues Bastos ◽  
...  

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