THESIS

Trees and treelets specis in different light micro-sites in a Semideciduous Seasonal Forest in Gália - SP

Ana Claudia Costa Destefani

ABSTRACT

Tropical Forest studies elucidate the importance of understanding the light conditions preferred by species and therefore the regeneration process and community dynamics. We have described tree species distribution, with DBH > 4,8cm, by indirect light categories in a Semideciduous Seasonal Forest Forest at Gália-SP. The method used here describe ten (10) indirect light categories, corresponding to the position that each individual can occupy under the Forest (gap, understory, canopy) and to the types of covery where they can be under of under intense light incidence, under decidual trees or under evergreen trees.

To correlate obtained data for the ecological groups, every species were classified into pioneers, early successional species, late successional species and non-classified, according to available literature. We sampled 10.696 tree specimens, represented by 640 pioneers of 28 different species, 2.623 early successional species of 38 species, 7356 late successional species of 51 species and 77 non-classified specimens of 28 different species. Some pioneer species were found only under intense light incidence (Alchornea glandulosa, Anadenanthera colubrina, Heliocarpus americanus and Trema micrantha). Some early succesional species ocurred only under light incidence or lighted understory (Jacaranda micrantha, Peltophorum dubium, Seguieria floribunda e Zeyheria tuberculosa), and one late succesional species (Myroxylon peruiferum) occured only on the canopy layer or understory shadow (Jacaranda micrantha, Peltophorum dubium, Seguieria floribunda e Zeyheria tuberculosa). This method allows the understanding of tree species distribution through the distinct light micro-sites, although during the data interpretation is essential to consider the local disturbance history and the importance of the light factor on the definition of the species distribution. Repetitions of this method over the same spot during time and in different Forest formations will bring more trustful data about species ecological role and distributions patterns according to light regimes.

Key-words: light dibamics, ecological groups, permanent plot

Dissertação (Mestrado) Escola Superior de Agricultura Luiz de Queiroz, 2006.

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