Late Quaternary vegetation dynamics from central parts of the Madeira River in Brazil

Abstract

The present study reconstructs the paleovegetation of a varzea (seasonally flooded) forest in the central parts of the Madeira River floodplain in Brazil using palynological data. Forty-nine cut-bank sediment samples from the Madeira River were processed in the study; from these, ten samples contained pollen: two contained pollen from the Middle Pleniglacial age, one contained pollen from the Tardiglacial age, six contained pollen from the Holocene, and one contained more recently deposited pollen. The Middle Pleniglacial pollen belonged to a primary succession varzea forest, while the Tardiglacial pollen represented a late succession varzea forest. On the other hand, the three Holocene samples showed the characteristic composition of chavascal (water-logged forest) or lacustrine varzea forest, and three samples belonged to a late succession varzea forest. The most recent pollen deposit represented a secondary succession varzea forest. This paleovegetation showed a typical mosaic distribution, which may be explained by the fluvial dynamics, high species richness and diversity in the varzea forest, and the presence of dominant species.

Lagoa do Quari (São Raimundo Nonato, Piauí): Palaeoenvironment and wetland archaeology in Northeastern Brazil

“…This situation persisted till the Middle Holocene, when a drier climate settled in, according to a wide array of proxy data (Figure 9 and references therein). On the contrary, in the Amazon basin, a dryer Late Pleistocene climate favoured the expansion of open vegetation forming biogeographic corridors between the Amazon lowlands and the northeastern Brazilian plateaux (Behling & Hooghiemstra, 2000; Carneiro Filho et al, 2002; Feitosa et al, 2015; Haffer & Prance, 2002; Rossetti et al, 2010). We guess that such climate modification was of great importance for human adaptation, leading to a radical change of the settlement system established in the Late Pleistocene.…”

Sporepolinic morphology of fluvial terrace sediments in the Western Amazon

“…However, the palynological record of the Quaternary sediments of Acre is still unknown. Advances have been made in the palynological study of lacustrine and fluvial Quaternary deposits and, although the morphological description of palynomorphs preserved in sediment serves as an important tool for paleoenvironmental analyses, there are still few studies about Quaternary research carried out in the Brazilian Amazonia such as Absy (1979); Hammen & Absy (1994); Colinvaux et al (1999);D'Apolito et al (2013;2017;2018); Feitosa et al (2015). Thus, the objective of this study was to provide morphological descriptions of pollen grains and spores of the samples of three sedimentary profiles of fluvial terraces of the Chandless and Purus rivers in the state of Acre, aiming to contribute to Quaternary paleoecological and paleoenviromental research in the Western Amazon region.…”

Sponges as a complement of sedimentary facies analysis in island deposits of Upper Paraná River

“…Frenzel and Boomer, 2005). Although not frequent in fluvial studies, biological indicators have been used in the last decade in the Upper Paran a, Ivaí, Madeira and Pantanal rivers and have included pollen (Feitosa et al, 2015), sponges (Gonçalves, 2014), seeds (Ramírez, 2014), diatom frustules (Brassac et al, 1999) and, more recently, phytoliths (Rasbold, 2016).…”