Resumo

GALLARDO, Anabella; MONTTINI, Lía  e  BRAVO, Susana Patricia. Effects of tacuarembó (Chusquea ramosissima, Poaceae) on seed dispersal process in Misiones Forest. Ecol. austral [online]. 2008, vol.18, n.3, pp.347-356. ISSN 1667-782X.

Seed dispersal by mammals results spatially heterogeneous since some areas of mammals' territories that are avoided by them. Therefore, seed arrival is high in areas frequently used by the animals and negligible in the avoided areas. Besides, seeds in mammals' scats can suffer high levels of removal and predation by rodents. Disturbed areas of semi-deciduous Atlantic forest (Province of Misiones) are invaded by the native bamboo Chusquea ramosissima (tacuarembó), which precludes forest regeneration. Several areas invaded by tacuarembó flowered during 2001-2003 and, as individuals died after flowering events, piperaceas and ferns replaced them. Our objective was to determine whether the presence of tacuarembó disrupts the seed dispersal process during dispersal and post-dispersal phases, and if tacuarembó flowering reverts this situation in the Iguazú National Park. We evaluated removal and predation of seeds by rodents with and without scats, and in environments with and without tacuarembó. We also evaluated the abundance of big and medium mammals' signals (tracks, scats, caves) in both environments. Tacuarembó did not affect rodents' activity, and they might use mammals' scats as a signal to find seeds. Big mammals did not use areas invaded by tacuarembó, thus big seeds arrival of species dispersed by them would be restricted to areas free of invasion. Flowering of tacuarembó might revert this situation.

Palavras-chave : Bamboo flowering; Seed predation; Seed removal; Habitat use.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )