Vegetation and soil gradient in the restinga forest in Espirito Santo, Brazil / Gradiente vegetacional e pedológico em floresta de restinga no Espírito Santo, Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The Restingas are ecosystems that occur in sandy soils deposited during the Quaternary. These are known to have a high diversity of vegetation, but few studies provide information on abiotic factors determining this diversity. This study aimed to: (i) assess the influence of the chemical aspects, physical soil and flooding in phytophysionomic determination, (ii) assess the possible influences of flooding and soil characteristics in richness, abundance and composition of species, (iii) analyze the possible structural variations and diversity in terms of flooding and soil gradient of forest formations. To answer the first objective were opened four representative soil profiles with different depths, where samples were collected in each horizon exists. To analyze the fluctuation of groundwater piezometer were installed to depth of 2 m in each phytophysionomic. To characterize the vegetation, four diagrams were made from profile to 50 m long by 3 m deep, and included individuals with circumference at breast height (CAP) ≥ 10 cm at 1.30 m above the ground. To answer the second and third goal were performed quantitative analysis of species shrub / tree with 80 plots of 5x25 m, distributed equally between the forests studied, totaling 1.0 ha of sampling, which were included individuals with circumference at breast height ≥ 10 cm at 1.30 m above the ground. For both parameters were calculated phytosociological usual, basal area, density and height of individuals sampled, and the values of diversity, richness and equability. We realized analysis of canonical correlation and indicator species. We used for analysis of the floristic similarity, with the Jaccard index and the soil variables was used Euclidean distance. Samples were collected from topsoil (0-10 cm) in each plot for chemical analysis and physical. Four different classes of soils were recognized under the four studied vegetation, and dystrophic in all configurations. The class of Organossolos Tiomorficos Sapricos Solodicos very poorly drained is present in the flooded forest. Under the flooded forest were Gleissolos Tiomorficos Humicos sodicos poorly and drained. The class of Espodossolos Humiluvicos Hidromorficos Duricos it is moderately to imperfectly drained, occurring on the Forest not flood Transition. The Neossolo Quartizarênicos Órticos Espódicos excessively drained under the Forest are not flooded. These formations were raised 132 species, distributed in 49 families, where the greatest wealth were Myrtaceae (23), Lauraceae (12), Fabaceae (9), Clusiaceae (8), Sapotaceae (6), Melastomataceae and Euphorbiaceae (5) and Rubiaceae, Apocynaceae and Annonaceae with four species each. The training showed significant differences in species richness, except for not swamp forest on Forest Transition not flooded. The analysis of canonical correlation (CCA) showed that the species have their distribution along the gradient under the influence of drainage, the concentrations of nutrients and the physical characteristics of the soil, these results are corroborated by analysis of indicator species. 3804 individuals were sampled in forests, were significant differences in the values of basal area, density and height of individuals of forest formations. The increase in diversity was so gradual, following the slope of the flooded forest to the forest not flooded. Changes in structure and diversity of four forest communities are related to the variables of flooding, soil chemistry and physics. Given the above we can see that the vegetation characteristics (density, basal area and height) and richness, composition, abundance and diversity of species found in forest formations are in part conditioned by edaphic variables.

ASSUNTO(S)

riparian forest fitossociologia florística florestas não inundáveis floresta inundáveis floresta ciliar phytosociology floristic botanica flooded forest forest not flooded

ACESSO AO ARTIGO

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