Phytolith assemblage and systematic association in grassland species of the SE Pampean Plains, Argentina

FERNÁNDEZ HONAINE, MARIANA; ZUCOL, ALEJANDRO; OSTERRIETH, MARGARITA

ANNALS OF BOTANY

OXFORD UNIV PRESS

Año: 2006 vol. 98 p. 1155 - 1165

0305-7364

Background and Aims: Phytolith descriptions of South America species are scarce. This knowledge is crucial for the interpretation of a region’s fossil phytolith record. In this study phytolith assemblages of the main grasses and Asteraceae species of Paspalum quadrifarium grassland are described. Phytolith morphotypes and systematic relationships of these South American species are analyzed. Methods: Phytoliths from leaves of Poaceae and Asteraceae species were extracted following a calcination technique. For each species, 350 – 400 phytoliths were identified and relative frequency of each morphotype was calculated. Phytolith assemblages were subject to PCA and cluster analysis (Morisita index, UPGMA). Key Results: PCA and cluster analysis showed family (Poaceae vs. Asteraceae) and subfamily (within Poaceae) differentiation. Exceptions to general trends described for other species are detected. Floristic variants of Paspalum quadrifarium grassland are separated by their phytolith assemblages.  Conclusions: The study provides a reference collection of phytolith assemblages of the main Poaceae and Asteraceae species of P. quadrifarium grassland and describes some phytolith morphotypes/systematic relationships useful for the analysis of fossil phytolith assemblages of the Pampean region.