Contenido de sílice en gramíneas del pastizal nativo del sudeste bonaerense.

FERNÁNDEZ HONAINE M., BERNAVA LABORDE V. Y ZUCOL A.F.

Matices Interdisciplinarios en Estudios Fitolíticos y de otros Microfósiles/ Interdisciplinary Nuances in Phytolith and other Microfossil Studies

BAR Internacional Series (Oxford, Inglaterra).

Año: 2007; p. 1 - 7

Silica accumulation process in plants is influenced by edaphic, climatic and biotic conditions. Silica concentration in plants varies between .1 – 10 percent (dry matter percent). A silica content study was carried out as a complement for phytolith analysis of native species of Paspalum quadrifarium grassland. Silica contents of 18 grass species were analyzed at three levels: subfamily, species and intraespecific (between individuals collected in different locations in Buenos Aires province). Phytoliths were concentrated by a dry ashing technique and silica content was calculated as dry matter percent. Kruskal-Wallis test for species and subfamily data and a t-Student test for intraespecific data were applied. Media values for species ranged 3.91 to 13.93 percent. Significative differences were found in only three species (Sorghastrum pellitum, Dactylis glomerata and Festuca arundinacea) and two subfamilies (Pooideae and Panicoideae). The results showed a tentative accumulation patron, where subfamilies Pooideae – Stipoideae had lower values than Arundinoideae – Panicoideae subfamilies. In only one species it was found intraespecific differences (F = -2.52; df = 6; p = .04). Variations in edaphic and/or climatic conditions from the different locations where the individuals were collected can explain these results. The present study is showing the first analysis of silica content of grass species from southeastern Buenos Aires Province, Argentina.