Palynological analysis of a late Holocene core from Santo Antônio da Patrulha, Rio Grande do Sul, Southern Brazil

Abstract

A sedimentar core collected at Santo Antônio da Patrulha, Rio Grande do Sul State, southmost Brazil, was submitted to pollen analysis to provide the vegetational history of this region, and the paleoecological and paleoclimatic changes. A total of 98 taxa of palynomorphs was identified from 35 subsamples. Three radiocarbonic datings were obtained along a section of 115 cm depth, including the basal age of 4730 ± 50 yr BP. Pollen diagrams and cluster analysis were performed based on palynomorphs frequencies, demonstrating five distinct phases (SAP-I to SAP-V), which reflected different paleoecological conditions. The predominance of plants associated with grasslands in the phase SAP-I suggests warm and dry climate conditions. A gradual increasing of humidity conditions was observed mainly from the beginning of the phase SAP-III, when the vegetation set a mosaic of grasslands and Atlantic rainforest. Furthermore, the presence of some forest taxa (Acacia-type, Daphnopsis racemosa, Erythrina-type and Parapiptadenia rigida-type), from the phase SAP-IV, is interpreted as an influence of the seasonal semideciduous forest in the study region. From the phase SAP-V (ca. 4000 yrs BP), the vegetation became similar to the modern one (extant Atlantic rainforest Biome), especially after 2000 yrs BP (calibrated age).

Biochronostratigraphy and paleoenvironment analysis of Neogene deposits from the Pelotas Basin (well 2-TG-96-RS), Southernmost Brazil

“…Most biostratigraphic information of the Neogene deposits comes from boreholes, drilled in the onshore portion of the basin. Quaternary deposits reveal a varied fossil content, including vertebrates and microfossils, such as foraminifera, palynomorphs and diatoms (e.g., Closs 1970, Lopes et al 2010, Macedo et al 2010, Hermany et al 2013. Palynological analysis has provided paleoclimate interpretations and paleoenvironmental reconstructions for Quaternary deposits, mainly focusing on the marine influence on the coastal plain of the state of Rio Grande do Sul (Bauermann et al 2009).…”

Anthropic pollen indicators: poaceae pollen of non-native species in Southern Brazil

“…[2][3][4][5][6] However, the corn is the only crop species of grasses recorded (Figure 1) in the Quaternary samples of the region. [4][5][6][7] Many species of crops belong to Poaceae family. However, the distinction of pollen grains of native and crop species is difficult due to uniform pollen morphology of Poaceae species, except the pollen of corn that has size very large.…”

Fungos, criptógamas e outros palinomorfos holocênicos (7908±30 anos AP-atual) da Planície Costeira sul-catarinense, Brasil

“…Para o sul do Brasil, nas últimas décadas, estes regimes climáticos têm sido discutidos em diversos trabalhos de palinologia do Quaternário, tais como: Behling (1993Behling ( , 1995Behling ( , 1998Behling ( , 2002; Neves (1991Neves ( , 1998; Neves & Lorscheitter (1992, 1995a, 1995b; Behling et al ( , 2004Behling et al ( , 2007; De Oliveira et al (2005); Leal & Lorscheitter (2007) e Macedo et al (2010), dentre outros.…”