HEIGHT STRUCTURE AND SPATIAL PATTERN OF FIVE TROPICAL TREE SPECIES IN TWO SEASONAL SEMIDECIDUOUS FOREST FRAGMENTS WITH DIFFERENT CONSERVATION HISTORIES

ABSTRACT Anthropogenic disturbances in forests modify survival conditions and development of plants, which has direct effect on the height and spatial structure of tree populations. This study aimed to compare the height structure and spatial pattern of five tree species in two distinct fragments of seasonal semideciduous forest with different histories of conservation. We studied shade-intolerant (Astronium graveolens Jacq., Gallesia integrifolia (Spreng.) Harms) and shade-tolerant species (Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl., Euterpe edulis Mart. and Holocalyx balansae Micheli). Sixty plots of 100 m2 (10 m x 10 m) were allocated, being 30 contiguous plots in each fragment. All individuals of five species were marked, assessed for total height data and mapped using Cartesian coordinates. We observed differences in height structure between fragments. All populations had a random spatial pattern, except to H. balansae in the less conserved fragment and E. edulis in the conserved fragment that showed a clumped spatial pattern. There were evidences of forest regeneration due to the establishment of shade-tolerant species in less conserved fragment and coexistence of functional groups in both fragments. The height structure and spatial pattern analyses indicating that anthropogenic exploitation changed the environment and population structure in the less conserved area when compared to conserved area. The anthropic exploitation was ceased few years ago, so it is expected that the less conserved fragment reach the stability of an old-growth forest. RESUMO Os distúrbios causados em florestas pela ação do homem alteram as condições de sobrevivência e desenvolvimento de plantas, tendo efeito direto na estrutura populacional das espécies. O presente estudo objetivou comparar as estruturas de altura e espacial de cinco espécies arbóreas em dois fragmentos de floresta estacional semidecidual, com diferentes históricos de conservação. Foram estudadas espécies intolerantes (Astronium graveolens Jacq. e Gallesia integrifolia (Spreng.) Harms) e as tolerante à sombra (Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl., Euterpe edulis Mart. e Holocalyx balansae Micheli). Foram alocadas 60 parcelas de 100 m2 (10 m x 10 m), sendo 30 parcelas contíguas em cada fragmento. Todos os indivíduos, das cinco espécies, contidos nas áreas foram marcados, medidos a altura e mapeados com o uso de coordenadas cartesianas. Foram observadas diferenças na distribu