Estrutura populacional de Euterpe edulis Mart. no Sul da Bahia, Brasil

Abstract

-(Population structure of Euterpe edulis Mart. in the Southern Bahia, Brazil). The objective of this study was to better understand the populational structure of juçara palm (Euterpe edulis Mart.) in the Southern Bahia Atlantic Forest, in the Ecoparque de Una, Una, BA, Brazil. The plants in the population were classified into one of six size classes: Seedlings, Juvenile I, Juvenile II, Immature I, Immature II, and Adult. For each size class, the following data were gathered: density and distributions of frequency class of height at leaf insertion, number of leaves, diameter at breast height (DAP), and diameter at soil level (DAS). Comparisons were made among these values through Pearson correlation. The population revealed a demographic structure similar to that found in studies of E. edulis in South and Southeast Brazil, except seedlings density, with a large number of immature individuals and few individuals in the largest size classes. The population density was found to be relatively low, leaving open the possibility that these populations should be treated as an ecotype different from other already studied. The variables showed positive correlations with the exception of number of leaves and DAS in the adult size class.

Demographic structure of a threatened palm (Euterpe edulis Mart.) in a fragmented landscape of Atlantic Forest in northeastern Brazil

“…These patterns corroborate our assumption that the F1 fragment has the E. edulis population in a better conservation status in Una region. As expected, the fragment with most restrictive protection status and longer history of protection (F1) had densities similar to those of populations sampled in other long-protected areas in the Una region (Martini, unpublished data;Silva et al 2009), in contrast with F2, F3, and F4, which had lower densities. The Una region is a mosaic of forest fragments and secondary effects of disturbance gradients have been observed within this landscape (Faria et al 2009).…”

“…All Euterpe edulis populations in the Una region showed densities that were lower than those reported for E. edulis populations in other states: by Reis et al (2000) for São Paulo (n = 17,914/ha); by Reis et al (1996; for Santa Catarina (n = 17,200/ha and 17,966/ha, respectively); and by Raupp et al (2009) for Rio Grande do Sul (n = 5,343/ha). Densities for F2, F3, and F4 were also lower than the 3,780 individuals/ha reported for the state of São Paulo by Silva-Matos (2000), as well as being lower than the 4,232 individuals/ha and 4,559 individuals/ ha previously reported for other areas sampled in the Una region by Silva et al (2009) and A. M .Z. Martini (unpublished data), respectively.…”

“…We evaluated the following morphometric characteristics: number of leaves; type of leaves (palmate or pinnate); height at leaf insertion; and DGL above the root cone, a measurement shared by all individuals (Silva Matos et al 1999). The individuals were then classified into development stages that were based on biological criteriasigns of reproduction and plant size (adapted from Silva et al 2009): seedling-one palmate leave and an endosperm reserve; sapling-pinnate leaves, although palmate leaves might still be present, height ≤ 0.15 m; juvenile-pinnate leaves only, height ≤ 1 m; immature-stem > 1 m with no sign of reproductive events; and adult-stems with signs of reproductive events. The survey was undertaken near the end of the fruiting season, from August to October 2010.…”

“…Although E. edulis is widely distributed, studies focusing on its demographic structure have largely been concentrated on southern and southe astern Brazil (Reis et al 1996, Silva Matos et al 1999, Portela 2008. In northeastern Brazil, the population structures of E. edulis have been analyzed only in the Una region (Silva et al 2009), which is in the southern portion of the state of Bahia.…”

“…This "Bahia" ecotype (Bovi et al 1987) is principally characterized by its reddish crownshaft and the reduced numbers of rachillae-which implies lower seed production (Silva et al 2009). Low seed production can lead to reduced recruitment of seedlings into the population, ultimately resulting in a population with fewer individuals.…”