Poaceae pollen grains from southern Brazilian grasslands: Pollen grain size in species from dry and humid environments

Abstract

Grãos de pólen de Poaceae dos Campos do sul do Brasil: tamanho do grão de pólen em espécies de ambientes secos e úmidos

Fire events and vegetation dynamics during the late Pleistocene-Meghalayan interval in the southernmost Brazilian coastal plain

“…The dominance of herb pollen grains (Poaceae) associated with significant pteridophyte spores (Blechnum) in the Peat 1 (35% of organic matter content) and Peat 2 facies (65% of organic matter content) implies that these plants were common in the mainly treeless peat generating community and also in the environments surrounding the peat swamp. Studies performed by Bush (2002) in modern samples from Panama, Costa Rica and Ecuador, and those by Radaeski et al (2016) and Radaeski & Bauermann (2018) in southernmost Brazil, concluded that the representation of Poaceae pollen in the neotropics is influenced by many factors, and that high Poaceae abundance does not always indicate aridity. In addition, the importance of Blechnum spores along the peatland environment testify for its moist to wet environments in "water-receiving" sites (Halverson et al, 1986;Klinka et al, 1989).…”

Holocene histories of biome stability in northern Amazonian savannas

“…In southern Brazil, such a size range was described as typical of herbaceous pollen types, while large (>45 µm) Poaceae pollen were uniquely associated with “arboreal forest” habitats in the same study (Radaeski et al, 2016). Among these grains, those > 46 µm belonged to bamboos (Radaeski and Bauermann, 2018). Salgado-Labouriau and Rinaldi (1990) studied grasses in Venezuelan mountains and found that Poaceae pollen grains that were 50–60 µm in length belonged either to Bambusoideae, for example, Chusquea , or Pooideae, for example, Bromus spp.…”

“…This approach was used in Easter Island to reveal Poaceae pollen sizes changing with deforestation (Flenley et al, 1991). Subsequently, grass pollen size spectra were used to distinguish different types of grasslands across elevational gradients (Schüler and Behling, 2011a, 2011b), precipitational gradients in southern Brazil (Radaeski and Bauermann, 2018), vegetation types (Radaeski et al, 2016) and in identifying polyploid versus diploid grasses (Jan et al, 2015). Here we will use Poaceae pollen size spectra to elicit changes in Poaceae assemblages within the savannas of Northern Brazil during Holocene.…”