Resumo

BARBERIS, I. M; PIRE, E. F.  e  LEWIS, J. P.. Spatial heterogeneity and woody species distribution in a Schinopsis balansae (Anacardiaceae) forest of the Southern Chaco, Argentina. Rev. biol. trop [online]. 1998, vol.46, n.3, pp.487-492. ISSN 0034-7744.

Spatial heterogeneity of a Schinopsis balansae forest ("Quebrachal") near Vera (Santa Fe, Argentina) was studied for any correlation between woody species distribution and environmental factors. This type of forest is the most important community of the Santa Fe Forest Wedge, which is the southernmost portion of the Eastern Chaco. Thirty two 10 x 10 m plots were laid along two transects. Woody vegetation and microzones determined for microrelief, soil moisture and the presence of bromeliads were mapped; 54% of the ground is level, about half of it is muddy or frequently flooded, and little more than 11% is concave almost always flooded. Convex soils are well drained and often covered by populations of spiny bromeliads. Most woody individuals were clumped on high and well drained soils while only Geoffroea decorticans, Prosopis spp. and S. balansae were present on very humid microzones. These results strongly suggest that soil heterogeneity (microrelief and soil moisture), is the most important factor that determines the distribution of woody species.

Palavras-chave : Anacardiaceae; Argentina; Chaco; environmental heterogeneity; forests; microrelief; microsites; Schinopsis balansae.