Estrutura do componente arbóreo em áreas de cerrado no município de São Tomé das Letras, MG

Abstract

The municipality of São Tomé das Letras is located in southern Minas Gerais state, in Serra da Mantiqueira, in the Rio Grande basin, in a transition zone between Cerrado and Atlantic Forest, where rupestrian fields are also found. The local economic activities are as follows: mineral extraction, agriculture and tourism. The objective of this study was to evaluate the phytosociological structure of three areas of cerrado in the municipality. Sixty quadrant-points were sampled per area by taking measures of height of the trees and trunk circumference at ground level ≥ 10 cm. The following parameters were calculated for each environment: density of individuals, dominance, frequency, basal area, Importance Value, floristic diversity (Shannon index, H'). Twenty-seven families, 36 genera and 56 species were identified. Eremanthus erythropappus (candeia, Asteraceae) was the species with the highest Importance Value (VI) in Candeias area and Vale das Borboletas area; Stryphnodendron adstringens (barbatimão, Fabaceae) and Piptocarpha rotundifolia (coração-de-negro, Asteraceae) were the species with the highest VI in Carrapatos area. The most abundant species were Eremanthus erythropappus, Miconia albicans, Stryphnodendron adstringens and Myrsine guianensis. The average height ranged from 2.0 ± 1.2 to 2.3 ± 1.3m. The average diameter ranged from 6.5 ± 4.4 to 7.3 ± 4.8cm. For the three areas, the average density was 2,315 indiv.ha-1 and median basal area was 13.4 m2.ha-1. The Shannon diversity index (H') for species ranged from 2.67 to 2.96 nats/ind. Low similarity among areas was observed. Considering anthropic pressures that natural local environments are suffering, these results can subsidize local projects of the vegetation restoration, mainly of the arboreal component.