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

PUECHAGUT,P. B., POLITI, N. BELLIS, L. M. AND RIVERA, L. O.

JOURNAL FOR NATURE CONSERVATION

ELSEVIER GMBH

Año: 2013 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 objective was to assess the conservation status of the five C. alba palm patches present in Northwestern Argentina: Reserve, Embarcación, Palma Sola, Vinalito, and Talar. We compared these sites to determine those patches with greatest conservation needs considering 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 3/5 sites (i.e., Embarcación, Reserve, and Talar) have palm densities >200 individuals / ha and only one site (i.e., Embarcación) showed a reverse J-shape (in DBH and height) size structure. 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 at all sites, at least two potential disperser species were found at each site, and only in the Reserve we detected the presence of all of the potential dispersers. None of the palm patches studied have an adequate conservation status. However, the palm patch that meets ¾ criteria is Embarcación, and therefore it can be considered to have the best conservation status in the Semiarid Chaco. Palma Sola and Vinalito had the greatest conservation needs. To ensure the conservation of C. alba in Northwestern Argentina its seems necessary to warrant the regeneration ensuring the establishment of seedlings to reach adequate population density and structure.