Amorphous silica biomineralizations in species from Argentina: content, morphologies and tissue location, systematic and ecological relations

FERNÁNDEZ HONAINE M.; DE RITO M.; ALTAMIRANO S.M.; BENVENUTO M.L.; OSTERRIETH M.

Aix en Provence

Encuentro; 10th International Meeting on Phytolith Research; 2016

Silicification of plants is a widespread process and involves a high amount of plant families. The study of the content and distribution of amorphous silica biomineralizations in plant tissues has been approached by diverse disciplines, due to the relevance and applications that silicophytoliths have on different research areas. The knowledge of the plant production in a specific area, has multiple applications from anatomical/functional, through ecological up to palaeobotanical and palaeoenvironmental. The present study aimed to compare the content, morphologies and tissue distribution of the silicophytoliths in leaves of species from different communities of Argentina. We evaluated how silica content varied according to systematic, life cycles (perennials vs annuals), habit (herbs vs arboreals) and status (native vs exotic), and compared with results obtained by other researches. We analyzed at which level the phytolith morphologies can discriminate between plant groups, and which morphologies may be more relevant for taxonomy. Leaves from at least 3 individuals of 92 species, grouped in 26 families, representing some of the main communities of Buenos Aires, Misiones, and Tierra del Fuego provinces, were collected. Silicophytolith were extracted through a calcination technique, and silica content was measured as % dry weight. Silicophytoliths were counted and described under optical microscope following specific literature. Data of silica content was subjected to Kruskal Wallis and Mann-Whitney tests, depending on the hypothesis evaluated. Morphology data was subjected to Principal Component Analysis. Fifteen species do not produce silicophytoliths. The silica content ranged between 0.38% (Ranunculus apiifolius) and 19% (Chusquea ramossisima) and varied according to systematic. However, it was possible to observe that two species of a same genera had different behavior (producer and not producer). At family level, the highest media content was observed in Urticaceae and the lowest in Ranunculaceae. Differences were detected between Poaceae vs Asteraceae, Juncaceae, Rosaceae and Solanaceae (p