Fitossociologia de remanescentes de floresta estacional decidual em Corumbá, Estado do Mato Grosso do Sul, Brasil

摘要

A survey was made on four deciduous forest remnants in the town of Corumbá, State of Mato Grosso do Sul (19o05'-19o20' S and 57o40'-57o55' W), aiming to verify the floristic and structure variation of deciduous forest remnants in different relief and types of soils. The four remnants were sampled through the point quarter method. Three areas were sampled through 20 points and the fourth area was sampled through 50 points. All trees with circumference at breast height > 9 cm were sampled. In the alluvial deciduous forest, 32 species were sampled, Attalea phalerata Mart. ex Spreng. (Arecaceae) and Aspidosperma australe Müll. Arg. (Apocynaceae) having the highest importance value indexes. In two areas of lowland deciduous forest 47 and 25 species were sampled, respectively; Sebastiania discolor (Spreng.) Müll. Arg. (Euphorbiaceae) and Phyllostylon rhamnoides (J. Poiss.) Taub. (Ulmaceae) being the most important in both. In the remnant of submontane deciduous forest 24 species were sampled, Acosmium cardenasii H.S. Irwin & Arroyo (Fabaceae) outstanding as the main species. The richest family was Fabaceae with 16 species, followed by Euphorbiaceae with six species, and Apocynaceae, Rubiaceae and Sapindaceae with five species each. Both areas of lowland forests showed to be very similar in floristic composition as well as in structure. The alluvial forest presented the most distinct structure and floristic when compared to the other areas. These remnants of deciduous forests have peculiar structure and floristic composition, containing species of the Chaco and Caatinga Provinces that require extensive botanical and ecological studies.