Plant and soil phytolith analysis of a relictual community of Butia yatay in temperate-humid savannas (Entre Ríos, Argentina)

ZUCOL, ALEJANDRO F.; PATTERER, NOELIA I.; BREA, MARIANA; FERNÁNDEZ PEPI, MARIA G.

QUATERNARY INTERNATIONAL

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2019 p. 126 - 139

1040-6182

Although palms are recognized as a plant group of tropical and sub-tropical ecosystems, in SouthAmerica they can also be found in temperate savannas under certain conditions. Therefore, since theseplants have been widely used as palaeoindicators in warm and humid climates, it is important to knowwhat phytolith contribution these plants have made in temperate environments. El Palmar National Park(Argentina) protects the largest remnant of savanna palm, Butia yatay (Mart.) Becc., one of thesouthernmost palm communities in the continent. This modern analogue study assessed the variabilityof silica phytoliths in 15 selected species of plants, 20 mulch samples (organic horizon) and 60 soilsamples that were collected in all the plant communities selected for this study: dense palm trees (DPT),shrubbery with isolated tall palms (SIP), psammophile steppe (PS) and humid psammophile steppe(HPS). Our results show that grasses exhibit the most diverse forms. Palms, sedges and dicots can bedistinguished by the different proportions of several diagnostic morphotypes. Palm tree communitiescan be characterized based on a presence a high proportion of globular echinate and trapeziformsinuate/oblong phytoliths. Psammophile steppes have a high proportion of bilobate, polylobate and crossphytoliths and a low presence of globular echinate. Humid psammophile steppes show a high presenceof bilobate, cross and dicot phytoliths with a low proportion of trapeziform sinuate/oblong phytolithsand an absence of globular echinate morphotypes. The ratio of palm to grass phytoliths allowed us toobtain differences between the palm groves, psammophile steppe and humid psammophile steppeecosystems. These analyses can then be used to determine this type of ecosystem in temperate humidsavannas. Phytolith assemblages provide an important record for the characterization of the plant-soilsystem and production-incorporation system in mixed communities as a tool in the construction of palmtrees paleoenvironments.