Abstract

BARCHUK, Alicia H; CAMPOS, Elena B; OVIEDO, Carolina  and  DIAZ, María Del Pilar. Survival and growth of woody species seedlings from Arid Chaco after aerial biomass removal. Ecol. austral [online]. 2006, vol.16, n.1, pp.47-61. ISSN 1667-782X.

It has been postulated that seedlings of the main woody species from the Arid Chaco exhibit differences in survival and growth when renewal buds are totally removed, and that the responses depend on their leaf life span (deciduous or evergreen plants) and phylogeny (leguminous or non-leguminous families). Seeds of 14 shrub and tree species were planted in individual pots under greenhouse conditions. The effect of the total removal of aerial biomass on 12-weeks seedlings was compared with a control situation. Variables such as post-emergence and post removal survival were considered for the study, as well as variables related to growth: total biomass, root and stem biomass, leaf area, root length and stem height. Emergence (rate) of seedlings was higher in deciduous species, especially leguminous. Seedling growth before treatment was higher in leguminous species and independent of leaf life span. Aerial part removal had a negative effect on survival chances of all species. Species were grouped according to the effect of the treatment on survival and growth: low negative effect, medium negative effect and no survival at all. Seedling resprouting occurred in 50% of the species studied, with a limited proportion of resprouting within each species. Both types of shrub species, leguminous-deciduous and sclerophyllous-evergreen, show resprouting ability at seedling stage, but respond differently in their growth and root/stem relationship. Differences determined by phylogenic effect (leguminous and non-leguminous) and leaf phenology (deciduous and evergreen) were more relevant after removal treatments. The information would indicate that the removal of the air part stimulates the length of the root in the majority of the species that resprout, so that the energy that the plant dedicates to producing root is at the cost of a minor air growth and allows the survival in environments with stress or disturbances.

Keywords : Regeneration; Resprouting; Seedling bank; Sclerophyllous evergreen; Deciduous; Fabaceae; Non-Fabaceae; Simulated Herbivory.

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