First report of modern pollen deposition in moss polsters in a semiarid area of Bahia, Brazil

Abstract

Recent studies have shown that pollen analyses of natural substrates can produce data valuable for understanding the local pollen productivity and dispersal, deposition, and preservation potential of pollen grains. In this study, we aimed to acquire novel information about the dynamics and preservation of pollen in Caatinga environment through the palynological study of moss polsters. Samples of moss polsters in soil (MPS) and on rock (MPR) were collected from the Canudos Biological Station in the Bahia State (Brazil) and subjected to standard chemical treatments for the extraction of pollen residues. In total, 372 pollen types were recorded from the samples of which the taxonomical affinity of 140 was determined. The most represented families were Fabaceae (23 pollen types/16.42%) and Asteraceae (12 pollen types/8.57%). The MPS samples had a higher pollen concentration (21,042.04 pollen grains/cm²) than the MPR samples (7,829.35 pollen grains/cm²). On the other hand, the MPR samples had a greater diversity (68.26% of the identified pollen types). Qualitative analysis showed that the plants of shrub and subshrub habits had the greatest representation among the pollen types (35.0%). Overall, moss polsters proved to be excellent natural air pollen collectors in Caatinga environment, provided they had moist microhabitats for their development.

Pollen-based characterization of montane forest types in north-eastern Brazil

“…Their associated pollen assemblages are characterized by a decrease of Myrtaceae at the expense of Fabaceae-Mimosideae and by high frequencies of herbaceous pollen taxa (Mitracarpus or Alternanthera). This change in pollen signature highlights an opening of the forest canopy, as shown in other semi-arid regions in north-eastern Brazil (dos Santos et al, 2015;Gomes et al, 2014). Most of the surface soil samples of the semi-deciduous montane forest were collected at Pacatuba.…”

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“…Their low representation could possibly be due to their low pollen productivity owing to insect pollination [28,29,30], low dispersal efficiency as well as poor preservation in the sediments [31]. Another possible factor could be their sampling period, which could give a better representation in the case of anemophilous species [32]. Non-cereal Poaceae has the highest representation, contributing 8.6% to the total palynoflora which could be due to the transferring many palynomorphs into the Lake basin and the marshy area due to rainwater runoffs.…”

First Quaternary Brazilian cave pollen record: morphological descriptions, taxonomic and ecological data

“…Pollen types are related with phytosociological and floristic data for distinct topographical areas in North-Central and Northeastern Brazil (Colinvaux et al, 1999;Alcoforado-Filho et al, 2003;Rodal & Nascimento, 2006) and modern pollen rain to Cerrado, Caatinga and Amazon Forest biomes (Gosling et al, 2005(Gosling et al, , 2009Chaves, 2013Santos et al, 2015) (Figure 5; Table 2).…”