Pollen and spores from surface samples in the campos region of Uruguay and their paleoecological implications

Dominique Mourelle,Aldo R Prieto

doi:10.1590/0102-33062016abb0117

Dominique Mourelle, Aldo R Prieto

Open Access

https://doi.org/10.1590/0102-33062016abb0117

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Abstract

In this study we describe and illustrate pollen and spores that have been identified as significant in modern and fossil samples from the campos region of Uruguay. We provide new information about modern pollen assemblages and their relationship to the vegetation types of this region. We discuss the taxonomic limitations of pollen and spores and their representation in both modern and fossil samples. We highlight the importance of identifying both silent and key indicator taxa for making accurate paleoecological interpretations. We also emphasize the importance of knowing the pollination strategies of parental plants because many of them are zoophilous, and so small changes in the proportions of their pollen grains in fossil assemblages could reflect important changes in vegetation. This study presents a practical approach to paleoecological research, which not only produces robust results in studies of the campos region, but can be applied to other grassland ecosystems, including those in temperate regions.

Highlights

Pollen analysis, the study of fossil pollen and spores, is the principal technique for long-term vegetation reconstructions (Seppä 2007), and it has provided fundamental advances in the understanding of the processes and mechanisms of ecological change (e.g. Jackson 2007; Rull 2010; Willis et al 2010)
There are some difficulties in studying modern pollen-vegetation relationships in Río de la Plata grasslands (RPG) (Southern South America) related to the limited pollen taxonomic resolution of their most abundant parental plants, such as Poaceae, Cyperaceae, Asteraceae subf
Even though several pollen and spores atlas (e.g. Bauermann et al 2013; Radaeski et al 2014) and catalogues (e.g. Neves & Bauermann 2004; Macedo et al 2009; Evaldt et al 2013; Masetto & Lorscheitter 2014) in the campos region of Rio Grande do Sul have been published during the last decades, there are no morphological descriptions and illustrations for the most frequent and abundant pollen and spores that appeared in surface and fossil samples from the campos region of Uruguay. For this reason we propose the following aims in this study: (1) to describe and illustrate the main pollen and spores from surface samples from the campos region of Uruguay; (2) to provide new information about modern pollen assemblages and their relationship to the vegetation types of this region; and (3) to discuss the taxonomic limitations of pollen and spores and their representation in both modern and fossil samples, and provide a practical approach to obtaining robust results for paleoecological research in the campos region

Summary

Introduction

The study of fossil pollen and spores, is the principal technique for long-term vegetation reconstructions (Seppä 2007), and it has provided fundamental advances in the understanding of the processes and mechanisms of ecological change (e.g. Jackson 2007; Rull 2010; Willis et al 2010). The study of fossil pollen and spores, is the principal technique for long-term vegetation reconstructions (Seppä 2007), and it has provided fundamental advances in the understanding of the processes and mechanisms of ecological change Pollen records do not directly reflect plant abundance due to several factors such as differences in pollen production, dispersal and preservation of taxa (Prentice 1988), which cause that taxa may be either over-represented or under-represented in pollen samples. One of the principles on which pollen analysis is based is the possibility of identifying different pollen and spores according to their morphology (Fægri & Iversen 1989). There are some difficulties in studying modern pollen-vegetation relationships in Río de la Plata grasslands (RPG) (Southern South America) related to the limited pollen taxonomic resolution of their most abundant parental plants, such as Poaceae, Cyperaceae, Asteraceae subf.

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