Subfossil and periphytic diatoms from the upper Paraná river, Brazil: last ~1000 years of a transition period

Abstract

Considering the lack of knowledge regarding the paleolimnology and the diatom flora from the sediment in Brazilian aquatic environments, this study aimed to provide information about diatom biodiversity and autoecology in an environment located in the upper Paraná river floodplain. Sediment and periphytic samples were collected from a swamp located in an island of the upper Paraná river floodplain. Sediment samples were obtained by collecting a core of ~2 m with a calibrated date of 726 to 903 cal yr BP near the base. The core was sliced into layers of 2.5 cm, totaling 41 samples. Periphytic diatom samples were obtained by scraping macrophytes' petioles, totaling two samples. The community was represented by 31 species belonging to 15 genera. All of the taxa were found in the sediment record, and 15 were present in the periphyton. The three new records (Eunotia longicamelus, Planothidium bagualensis and Luticola hustedtii) reinforce the importance of paleolimnological and periphytic studies to increase information about the aquatic biodiversity.

Two New Species of Achnanthidium Kützing (Achnanthidiaceae) from the Quaternary Sediments of the Colônia Basin, Southeast Brazil

“…2018), and only three have focused on its palaeoecological significance (e.g. Ruwer & Rodrigues 2018, 2021; Ruwer et al . 2021).…”

Structure and species composition of diatom community during the wet season in three floodplain lakes of Brazilian Pantanal

“…However, there is still an urgent need to expand the information to the wetland regions of the globe, where studies of diatom community are scarce [33,34]. So far, in South America, namely in Brazil, studies have focused on the planktonic and epilithic diatoms in rivers and streams, mainly related to the evaluation of water quality [35][36][37] and periphytic diatoms in floodplain [38]. Recent studies have focused on the role of eutrophication in environmental reorganization, with diatom assemblages and landuse records used as a tool to infer the trophic state history of the water body [39,40] as well as a record of biotic homogenization of diatom diversity in sedimentary samples [41].…”