A disappearing oasis in the Semiarid Chaco: Deficient palm regeneration and establishment

PUECHAGUT PATRICIA; POLITI NATALIA; BELLIS LAURA; RIVERA LUIS OSVALDO

JOURNAL FOR NATURE CONSERVATION

ELSEVIER GMBH

Año: 2012 vol. 21 p. 31 - 36

1617-1381

Palm forests of Copernicia alba are a rare habitat in the Semiarid Chaco of Northwestern Argentina, are centers of high species diversity, and provide key resources for many species. Our goal was to assess the conservation status of five C. alba patches in Northwestern Argentina: Reserve, Embarcación, Palma Sola, Vinalito, and Talar. We compared patches to identify the sites with greatest conservation needs based on four criteria: population size structure, palm density (of individuals with height >1.30 m), probability of seedlings being browsed, and presence of potential seed dispersers. We found that three (Embarcación, Reserve, and Talar) out of five sites had palm densities greater than 200 individuals/ha and only one site (Embarcación) showed a reverse J-shaped size structure for height. Reserve and Embarcación had the greatest probability of seedlings being browsed (0.99 ± 0.01 and 0.88 ± 0.12, respectively). A total of 14 potential disperser species of mammals and birds were recorded across the five sites. Only Reserve harbored all of the potential dispersers, but at least two potential disperser species were recorded at the other sites. None of the palm patches studied had an adequate conservation status. However, Embarcación met three out of four criteria, and therefore it can be considered to have the best conservation status in the Semiarid Chaco. Palma Sola and Vinalito have the greatest conservation needs. To conserve C. alba in Northwestern Argentina, strategies are needed that ensure seedling establishment in order for future populations to reach an adequate density and structure.