Regeneration of Polylepis australis Bitt. in the mountains of central Argentina

ENRICO L., FUNES G. & M. CABIDO.

FOREST ECOLOGY AND MANAGEMENT

Elsevier

Año: 2004 vol. 190 p. 301 - 309

0378-1127

In this work natural regeneration of Polylepis autralis Bitt. (“tabaquillo”) in the Córdoba Mountains, Argentina, was studied. The study was carried out in two communities dominated by P. australis: shrublands and woodlands. The main objectives of the study were: 1) to characterise shrublands and woodlands in terms of physical (e.g. soil properties) and biological (e.g. Polylepis’ growth form) characteristics, and 2) to describe P. australis` soil seed bank and compare seedling and sapling establishment among both communities. The presence of seedlings as well as saplings was quantified, and soil samples were taken so as to characterize the seed bank. Habitat characteristics of the microsite were measured in shrublands and woodlands: soil texture and organic matter content, cover by mosses and ferns and total community cover as well as canopy cover. Results show significant differences in habitat conditions between shrublands and woodlands. Seedlings’ density showed higher in the shrublands, while no differences appeared regarding the sapling numbers. A negative correlation was found between seedlings numbers and total community cover as well as mosses and ferns cover. Besides, seeds` density in the soil bank was higher in the woodlands, but seeds’ viability was less than five percent. In the shrublands, the most critical stage of the species regeneration cycle would be the transition from seedling to sapling, while in the woodlands the main “filter” would occur during seed germination. The low number of saplings observed in both units suggests a stagnation of P. australis regeneration, which could be translated into an unlikely expansion of the species throughout the Córdoba Mountains.   Key words: Polylepis australis; regeneration; seedling; sapling; seed bank