Resumo

BARCHUK, Alicia; IGLESIAS, María del Rosario  e  OVIEDO, Carolina. Basal resprout of Aspidosperma quebracho blanco in state of seedling: persistence mechanism in the Arid Chaco. Ecol. austral [online]. 2006, vol.16, n.2, pp.197-205. ISSN 1667-782X.

Resprouting strategy strongly contributes to survival of woody species, which can survive under stress and disturbance conditions, such as logging, herbivory and fire. The capacity of plants to resprout from adventitious buds at seedling stage, a highly vulnerable plant stage, may be determinant in the establishment success of species in arid environments. In this work, the effect of aereal biomass removal on the capacity of seedlings of A. quebracho-blanco to resprout from the hypocotyl and root neck was evaluated. Two treatments were applied in 9-month-old seedlings in greenhouse: total removal (below the cotyledon junction and without axillary buds), and partial removal of aereal biomass (above cotyledon junction, with axillary buds and presence of cotyledons). In the field, in a forest of A. quebracho blanco of the Arid Chaco, total biomas below cotyledonal junction was removed in two-year-old seedlings. In both experiments, survival and growth-estimating variables at 10 months and 1 year after removal, respectively, were evaluated. Greenhouse data were evaluated by ANCOVA for measures repeated in time; field data were analyzed using Generalized Linear Models. Results showed that seedlings can easily resprout from hypocotyl and root neck after severe disturbance. The importance of resprouting increases considerably with seedling age and is related to adventitious buds formed below the removed cotyledon junction. The data suggest that no preformed buds would occur below the cotyledon junction, but that they would be formed by the stimulus provided by the cut. Thus, this species might persist as a seedling bank in environments with water deficit because of the differentiation of adventitious buds.

Palavras-chave : Seedling bank; Persistence niche; Survival; Resprouting; Cotyledonary node.

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