Resumo

THOMPSON B., L. Natali; MORAES R., Mónica  e  BAUDOIN W., Mario. Population structure of the endemic palm Parajubaea torallyi (Mart.) Burret in harvested zones of the Área Natural de Manejo Integrado El Palmar (Chuquisaca, Bolivia). Ecología en Bolivia [online]. 2009, vol.44, n.1, pp.17-35. ISSN 1605-2528.

Parajubaea torallyi is an endemic palm of the interandean valleys of Bolivia. It is considered “endangered” and is used locally. An exploratory study of its population was carried out in the Natural Area of Integrated Management El Palmar (Chuquisaca). Eight growth stages or categories were used on the basis of morphology, height, reproductive state and possible pressures from use. Its growth stage population structure was evaluated in five harvested communal zones, 3-4 temporary plots, each of 600 m², were located per communal zone of 600 m². Cluster analyses were carried out to see if similarities in population structure were given at the zone or plot level and an analysis of correspondence to detect categories as a function of density. In general, the population structure presented an inverted J distribution, with good presence of seeds, seedlings and juveniles (39.9%, 48.4% and 10% respectively) and an almost exponential decrease in the following stages (0.8, 0.3, 0.1, 0.4 and 0.1%). At the local level, population structure varied among zones, existing two types of distributions: a continuous one, like an inverted J and another bimodal, discontinuous, with reduced representation of juveniles and subadults (≤ 0.1%). In the cluster analyses population structures were grouped by communal zone. According to the cluster analyses, the distribution of juvenile and subadults was inversely correlated with that of palms taller than 20 m. We conclude that P. torallyi presents indications of regeneration but that at the local level it has limitations in juvenile recruitment that could be due to dense-dependent population regulation and reduced availability of habitat suitable for regeneration. The communal zonation used reflected differences in population characteristics of P. torallyi, and can be useful to plan its conservation and management.

Palavras-chave : Population structure; Parajubaea torallyi; Endemic; Bolivia.

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