FERNANDEZ HONAINE mariana
Herbivore effect in the assemblages of phytoliths incorporated to soils from cow dung
PAOLICCHI, MICAELA; FERNÁNDEZ HONAINE, MARIANA; OSTERRIETH, MARGARITA L.
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
ELSEVIER SCIENCE BV
Phytoliths represent an important fraction of soil´s components and they are incorporated through differentagents. One of the sources of phytoliths to soils and sediments is dung. In particular, in agroecosystems, the incorporationof phytoliths from dung may be of importance, since pastures (grasses) belong to one of the highestproducer families. The main objective of this work was to compare the content and state of phytoliths in rumenand dung samples from cows in relation to the phytoliths produced in the forage plants eaten. Secondly, weanalyzed if phytolith assemblages differed between dung collected in different pastures in Pampean region, Argentina.Phytoliths from rumen and dung samples from five fistulated cows were compared with the main foragespecies eaten (Festuca arundinacea). Also, dung of three different pastures (two naturals and one controlled) werecompared. Phytoliths of plants and dung were extracted by a calcination technique, while rumen samples weretreated with hydrogen peroxide. In rumen and dung samples, the morphologies derived from Festuca arundinaceaplants had different stages of degradation: the acute bulbosus and the papillate were the most degraded,while the rondels remained with little wear. A high percentage of phytoliths remained unidentified, probablydue to their degradation state. Through phytolith morphometric analysis, it was possible to identify that the principalorgan eaten by cows was the inflorescence. The dung belonging from different pastures was differentiatedby their phytolith content, although the unidentified morphotypes predominated. Dung allow the incorporationof new morphologies and a high amount of degraded phytoliths to soils, modifying its permanent stock of phytoliths